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First experiences with a 2.0-μm near infrared laser system for neuroendoscopy
Abstract
Nd:YAG, argon and diode lasers have been used in neurosurgical procedures including neuroendoscopy. However, many neurosurgeons are reluctant to use these lasers because of their inappropriate wavelength and uncontrollable tissue interaction, which has the potential to cause serious complications. Recently, a 2.0-microm near infrared laser with adequate wavelength and minimal tissue penetration became available. This laser was developed for endoscopic neurosurgical procedures. It is the aim of the study to report the initial experiences with this laser in neuroendoscopic procedures. We have performed 43 laser-assisted neuroendoscopic procedures [multicompartmental congenital, posthaemorrhagic or postinfectious hydrocephalus (n = 17), tumour biopsies (n = 6), rescue of fixed and allocated ventricular catheters (n = 2), endoscopic third ventriculostomy (ETV, n = 17) and aqueductoplasty (n = 1)] in 41 patients aged between 3 months and 80 years. The laser beam was delivered through a 365-microm bare silica fibre introduced through the working channel of a rigid endoscope. It was used for the opening of cysts, perforating the third ventricular floor, and for coagulation prior to and after biopsy. The therapeutic goals [creating unhindered cerebrospinal fluid (CSF) flow between cysts, ventricles and cisterns, sufficient tissue samples for histopathological diagnosis and catheter rescue] were achieved in 40 patients by the first and in 2 patients by a second neuroendoscopic operation. In one child, a CSF shunt was later required despite patency of the created stoma proven by magnetic resonance imaging (MRI). In another patient ETV was abandoned due to a tiny third ventricle. There was neither mortality nor transient or permanent morbidity. The authors conclude that the use of the 2.0-microm near infrared laser enables safe and effective procedures in neuroendoscopy.
... Keywords: Neuroendoscopy; Thulium; Laser; Coagulation; Ablation; Microsurgery Insights in Neurosurgery ISSN 2471-9633 [2]. It can work in air or water solutions with the same result like in urology. ...
... In our experience, the use of Tu laser in microsurgery or in assisted endoscopy was a skill learning curve. In 2007 the first experience in neuroendoscopy to perform ETV was reported [2]. The Tu laser efficacy both in coagulation both in tissue ablation makes itself an elective tool in neuroendoscopy, especially for ventricular tumors. ...
In the last years, neuroendoscopy has gained consensus as a minimally invasive surgical approach to ventricular lesions. The magnification of the endoscope has become wonderful, but the bleeding control and tumor ablation continue to be harmful by standard tools only through the working channel. Specially, in vascularized tumors and near vital structures the traditional electrosurgery can be ineffective and dangerous. Since 2009, we are using the Tu diode pumped solid state (DPSS) laser (Revolix, LISA laser products) to improve neuroendoscopic procedures. In the Tu DPSS laser the active material is thulium (Tu), emitting light at wavelength of 2,0 μ, through one microfiber large 0,2 mm in diameter introduced in the endoscope working channel. The Tu DPSS laser works very well in water solution, as in the CSF of the ventricles. This laser can hit the tumor by touching or targeting from short distance with low penetration. Tumor cutting and ablation is possible, too. We report our experience in 26 ventricular tumors, 16 in 3rd ventricle and 10 in the lateral ventricle. The histology was: 13 high grade glioma, 5 craniopharyngiomas, 2 PNET, 2 metastasis, 4 colloid cysts. A flexible or rigid scope was used. In 18 neuroendoscopic biopsies the Tu DPSS laser microfiber was used for hemostasis and partial ablation. In 5 craniopharyngiomas wall ablation was performed. In 4 colloid cysts complete removal was possible in one case 3rd ventricular nodule was totally removed by Tu laser ablation. The ETV or tumors cyst fenestration or septostomy through infiltrated septum was successfully performed. The Tu laser showed precise coagulation at low temperature without tissue sticking. In all surgical procedures bleeding control was easy and successful. During Tu laser activation endoscopic vision was always clear. No side effects due to this device were observed. We consider Tu DPSS laser extremely handle and safe. The Tu laser is very efficient for coagulation and ablation of vascularized tumors.
... It has been mainly used in urological surgery for vaporesection of prostate and bladder neck incisions [9,10]. In neurosurgery, it has been used mainly for third ventriculostomy [14]. Its wavelength is absorbed selectively by water, which is ubiquitous in the human body. ...
... In neurosurgical practice, 2-m thulium laser was used in third ventriculostomy procedures [14]. Set in a continuous modality, it cuts and vaporizes tissue with a limited penetration and diffusion. ...
Background and objective:
Since the 1960s, lasers have been used in neurosurgery for surgical removal of intracranial tumors. Because of its limited penetration (2 mm) through tissues and its wavelength, which is useful in water medium, the 2-µ thulium laser has been applied primarily in urology. Its features are attractive for application under microscope magnification during neurosurgical procedures. The aim of this study was to evaluate the usefulness of the 2-µ thulium laser during microsurgical removal of intracranial meningiomas.
Materials and methods:
Twenty patients with a diagnosis of intracranial meningiomas were treated with surgical intervention using a 2-µ thulium laser together with bipolar forceps, cavitron ultrasonic surgical aspirator (CUSA) and traditional microdissection instruments. Surgical removal was divided in four phases: (1) dissection from the external structures; (2) coagulation and debulking; (3) dissection from the deep structures; and (4) coagulation and removal of the basal implant. During all these steps, we evaluated the percentage of usage of the 2-µ thulium laser comparing them with bipolar forceps and ultrasonic aspirator and blunt dissection.
Results:
Thulium laser was used mainly during phases 2 and 4 for 43% and 48.7% of the total removal, respectively. Although also useful during phases 1 and 3, it was only used for 2.2% and 31.3%, respectively: traditional dissection with scissors and forceps was preferred.
Conclusions:
Thulium laser seems to be a useful aid in the surgery of intracranial meningiomas, especially to debulk, shrink, and coagulate the mass and the basal implant.
... [14][15][16][17][18][19] In neurosurgery, it was used mainly for third ventriculostomy. 20 Its wavelength is selectively absorbed by water, which is present everywhere in the human body; this feature allows it to vaporize and coagulate small vessels. 18 In an aqueous medium, the laser's effect is limited to tissues located < 2 mm before the tip of the fiber; any tissue further than 2 mm from the tip is shielded by the water medium. ...
... 17 In neurosurgical practice, the 2-lm thulium laser was used in third ventriculostomy procedures. 20 Used in continuous modality, the laser cuts and vaporizes tissue with a limited degree of penetration and diffusion. Water, despite increasing heat, maintains its absorption properties more than hemoglobin during laser incision. ...
The authors evaluated the histological effects of the 2-μm thulium laser on meningioma tissue, comparing them to the results obtained using bipolar forceps and an ultrasonic aspirator.
The authors analyzed nine samples of intracranial meningiomas. Four slices were obtained for every sample, and one incision was performed on each slice. Two incisions were made with a 2-μm thulium laser (one set to a 6 W and another set to a 12 W power level). One incision was made using a bipolar forceps and the other using an ultrasonic aspirator. Tissue was addressed and analyzed. Upon microscope analysis, three zones of laser action were identified: (A) a central crater; (B) a vaporized zone; and (C) a shrunken layer. These three layers were measured and compared.
When addressed with the laser, all nine meningiomas presented a crater having an average depth of 1 mm. Three layers were clearly distinguished and measured: A (average depth: 0.8 mm at 6 W and 1.24 mm at 12 W); B (average depth: 0.32 mm at 6 W and 0.72 mm at 12 W); and C (average depth: 0.39 mm at 6 W and 0.44 mm at 12 W). On slices treated with bipolar forceps incisions, only zones B and C were identified. Ultrasonic aspirator incisions showed a deeper A zone (average depth: 2.93 mm), no B zone, and a tiny C zone (average depth: 0.16 mm).
Thulium laser can be safely used for the surgical removal of intracranial meningiomas; beyond 2 mm under the surface of action, no tissue alterations were found. The lesions produced on meningiomas were characterized by vaporization and shrinking. When compared with bipolar forceps, the thulium laser offers cutting precision and vaporization of the tissue. When compared to the cavitron ultrasonic surgical aspirator (CUSA), the laser offers shrinking and coagulation of small vessels.
... In addition, the cw thulium laser was used in the enucleation of the prostate with no collateral damage to adjacent tissue [11] . Neuroendoscopy study with a 2.0-μm near-infrared (NIR) laser system was also performed [12]. Lasers in neurosurgery provided precise tumor ablation by making spherical lesions without carbonizing. ...
... Lasers in neurosurgery provided precise tumor ablation by making spherical lesions without carbonizing. Brain tissue ablation has been investigated with different laser sources, such as 2.0-μm NIR laser [12], CO 2 , KTP, argon lasers, Nd: YAG lasers, 980-nm diode lasers [13], and 2.94-μm Er:YAG [14] lasers, as alternative tools to conventional electrosurgical units. The CO 2 laser was not found to be suitable for coagulating blood vessels but they were reported to be good tools for cutting brain tissue [13]. ...
In this study, a thulium (Tm:YAP) laser system was developed for brain surgery applications. As the Tm:YAP laser is a continuous-wave laser delivered via silica fibers, it would have great potential for stereotaxic neurosurgery with highest local absorption in the IR region. The laser system developed in this study allowed the user to set the power level, exposure time, and modulation parameters (pulse width and on-off cycles). The Tm:YAP laser beam (200-600 mW, 69-208 W/cm(2)) was delivered from a distance of 2 mm to cortical and subcortical regions of ex-vivo Wistar rat brain tissue samples via a 200-μm-core optical fiber. The system performance, dosimetry study, and ablation characteristics of the Tm:YAP laser were tested at different power levels by maximizing the therapeutic effects and minimizing unwanted thermal side-effects. The coagulation and ablation diameters were measured under microscope. The maximum ablation efficiency (100 × ablation diameter/coagulation diameter) was obtained when the Tm:YAP laser system was operated at 200 mW for 10 s. At this laser dose, the ablation efficiency was found to be 71.4% and 58.7% for cortical and subcortical regions, respectively. The fiber-coupled Tm:YAP laser system in hence proposed for the delivery of photothermal therapies in medical applications.
... Our survey of the English literature (Pubmed) showed just one report about the use of thulium lasers in neurosurgery. 22 Our group recently initiated occasional use of a thulium laser (Revolix JrÒ), along with the cavitron ultrasonic surgical aspirator (CUSA) and bipolar forceps, for the resection of benign intracranial masses, such as meningiomas and neurinomas. The laser has mainly been applied for debulking and shrinking of the lesions, coagulation and vaporization of the margins and the basal implant. ...
... As other authors have noted, the thulium laser works at a wavelength of 2013 nm, which is close to the absorption peak of water. 7,22 The depth of tissue penetration is 0.8 mm, halfway between a Nd:YAG laser (20 mm), which can produce deep lesions in tissue free of hemoglobin, and a CO 2 laser (0.05 mm), which only superficially penetrates tissue. This feature of the thulium laser permits safe surgical resection. ...
Since the early 1980s, CO(2), neodymium-doped yttrium aluminum garnet (Nd:YAG), and other laser prototypes have been widely used in neurosurgery as an intraoperative aid along with the cavitron ultrasonic surgical aspirator (CUSA), bipolar forceps, and microdissection. However, the English literature contains almost no reports on the use of thulium lasers during neurosurgical procedures.
We report our experience with a thulium laser during the surgical removal of a tentorial meningioma. The intraoperative technique utilized, as well as the clinical and radiological results of the procedure, are described.
The thulium laser proved to be a useful tool during coagulation, shrinking, and resection of the basal implant of the tumor. Use of the laser made the surgical procedure faster and easier, and no intraoperative bleeding was noted. No side effects were observed.
Our experience indicates that thulium lasers are a valid aid during resection of benign intracranial tumors under microscope magnification. Additional studies are required to define fully the role of these lasers in neurosurgical procedures.
... neuroendoscopy without mechanical irritation, and proved to be time-saving, due to fewer instrument changes [13][14][15]. The photothermal effect differs in cortical and subcortical tissue since the water percentage is different and pulsed modulation caused lower ablation efficiencies [16,17]. ...
Due to wavelength-specific water absorption, infrared lasers like the thulium laser emitting at 1940 nm wavelength proved to be suitable for coagulation in neurosurgery. Commonly bipolar forceps used for intraoperative haemostasis can cause mechanical and thermal tissue damage, whilst thulium laser can provide a tissue-gentle haemostasis through non-contact coagulation. The aim of this work is a less-damaging blood vessel coagulation by pulsed thulium laser radiation in comparison to standard bipolar forceps haemostasis. Ex vivo porcine blood vessels in brain tissue (0.34 ± 0.20 mm diameter) were irradiated in non-contact with a thulium laser in pulsed mode (1940 nm wavelength, 15 W power, 100–500 ms pulse duration), with a CO2 gas flow provided simultaneously at the distal fibre tip (5 L/min). In comparison, a bipolar forceps was used at various power levels (20–60 W). Tissue coagulation and ablation were evaluated by white light images and vessel occlusion was visualised by optical coherence tomography (OCT) B-scans at a wavelength of 1060 nm. Coagulation efficiency was calculated by means of the quotient of the difference between the coagulation and ablation radius to the coagulation radius. Pulsed laser application achieved blood vessel occlusion rate of 92% at low pulse duration of 200 ms with no occurrence of ablation (coagulation efficiency 100%). Bipolar forceps showed an occlusion rate of 100%, however resulted in tissue ablation. Tissue ablation depth with laser application is limited to 40 μm and by a factor of 10 less traumatising than with bipolar forceps. Pulsed thulium laser radiation achieved blood vessel haemostasis up to 0.3 mm in diameter without tissue ablation and has proven to be a tissue-gentle method compared to bipolar forceps.
... As mentioned, lasers have been used in neurosurgery for different purposes. Third ventriculostomy has been performed by some groups in big series with optimal results and no damage to the basilar and related arteries (7,9). However, for this purpose, the power should be limited to 4 W. The use of a 2-µm thulium laser has also been developed in vestibular neurinoma surgery by our group, being especially suitable for capsule opening ("V cut"), central debulking, and internal auditory canal opening. ...
Aims
We performed a retrospective nonrandomized study to analyze the results of a microsurgery of intracranial meningiomas using 2-μm thulium flexible handheld laser fiber (Revolix jr).
Methods
From February 2014 to December 2021, 75 nonconsecutive patients suffering from intracranial meningiomas, admitted in our department, have been operated on with microsurgical technique assisted by 2-μm thulium flexible handheld laser. We have reviewed demographic and clinical data to evaluate safety and efficacy of the technique.
Results
There were no complications related to the use of the 2-μm thulium laser. We operated on a high percentage of cranial base and tentorial and posterior fossa meningioma in our series. The neurological outcome and degree of resection did not differ from previous series. The neurosurgical team found the laser easy to use and practical for avoiding bleeding and traction.
Conclusion
The use of 2-μm thulium fiber handheld flexible laser in microsurgery of intracranial meningiomas seems to be safe and to facilitate tumor resection, especially in “difficult” conditions (e.g., deep seated, highly vascularized, and hard tumors). Even if in this limited retrospective trial the good functional outcome following conventional microsurgery had not further improved, nor the surgical time was reduced by laser, focusing its use on “difficult” (large and vascularized) cases may lead to different results in the future.
... Coagulation of regions of vasculature adjacent to the tumor were done as a means to reduce perfusion to the tumor area prior to ablation. Additionally, tumor coagulation treatments are commonly performed clinically in association with tumor biopsies to prevent bleeding [44]. The process consisted of a pre-treatment OCT imaging step to visualize tumor and associated vasculature, delivery of Tm laser energy for coagulation, followed by OCT angiography to verify blood flow stoppage. ...
Higher precision surgical devices are needed for tumor resections near critical brain structures. The goal of this study is to demonstrate feasibility of a system capable of precise and bloodless tumor ablation. An image-guided laser surgical system is presented for excision of brain tumors in vivo in a murine xenograft model. The system combines optical coherence tomography (OCT) guidance with surgical lasers for high-precision tumor ablation (Er:YAG) and microcirculation coagulation (Thulium (Tm) fiber laser).
Methods: A fluorescent human glioblastoma cell line was injected into mice and allowed to grow four weeks. Craniotomies were performed and tumors were imaged with confocal fluorescence microscopy. The mice were subsequently OCT imaged prior, during and after laser coagulation and/or ablation. The prior OCT images were used to compute three-dimensional tumor margin and angiography images, which guided the coagulation and ablation steps. Histology of the treated regions was then compared to post-treatment OCT images.
Results: Tumor sizing based on OCT margin detection matched histology to within experimental error. Although fluorescence microscopy imaging showed the tumors were collocated with OCT imaging, margin assessment using confocal microscopy failed to see the extent of the tumor beyond ~ 250 µm in depth, as verified by OCT and histology. The two-laser approach to surgery utilizing Tm wavelength for coagulation and Er:YAG for ablation yielded bloodless resection of tumor regions with minimal residual damage as seen in histology.
Conclusion: Precise and bloodless tumor resection under OCT image guidance is demonstrated in the murine xenograft brain cancer model. Tumor margins and vasculature are accurately made visible without need for exogenous contrast agents.
... Fenestrations of separating membranes during SP, CF, and ETV were conducted using a fiber-guided near-infrared Thulium-laser (Revolix®, Lisa laser products, Katlenburg, Germany) [24,33] inserted into rigid endoscopes (Storz LittleLotta® and Pediscope® Aesculap). All cases were assisted by neuronavigation (Brainlab®, Heimstetten, Germany). ...
Purpose
The specific pathophysiological processes in many forms of obstructive hydrocephalus (HC) are still unclear. Current concepts of cerebrospinal fluid (CSF) dynamics presume a constant downward flow from the lateral ventricles towards subarachnoid spaces, which are in contrast to neurosurgical observations and findings of MRI flow studies. The aim of our study was to analyze CSF movements in patients with obstructive HC by neuroendoscopic video recordings, X-ray studies, and MRI.
Methods
One hundred seventeen pediatric patients with obstructive HC who underwent neuroendoscopy in our center were included. Video recordings were analyzed in 85 patients. Contrast-enhanced X-rays were conducted during surgery prior to intervention in 75 patients, and flow void signals on pre-operative MRI could be evaluated in 110 patients.
Results
In 83.5% of the video recordings, CSF moved upwards synchronous to inspiration superimposed by cardiac pulsation. Application of contrast medium revealed a flow delay in 52% of the X-ray studies prior to neurosurgery, indicating hindered CSF circulation. The appearances and shapes of flow void signals in 88.2% of the pre-operative MRI studies suggested valve-like mechanisms and entrapment of CSF.
Conclusions
Neuroendoscopic observations in patients with obstructive HC revealed upward CSF movements and the corresponding MRI signs of trapped CSF in brain cavities. These observations are in contrast to the current pathophysiological concept of obstructive HC. However, recent real-time flow MRI studies demonstrated upward movement of CSF, hence support our clinical findings. The knowledge of cranial-directed CSF flow expands our understanding of pathophysiological mechanisms in HC and is the key to effective treatment.
... Almanya Göttingen Üniversitesi'nden Ludwig ve ark. tarafından 2007 yılında yayınlanan 41 hastalık nöroendoskopik seride hiçbir mortalite ve morbidite görülmemiş olması bu laser tipinin giderek yaygınlaşmasına neden oldu (48). Bu laser tipinin kullanıldığı diğer serilerden Ebner ve ark.na ait olanında 44 hastada 1 asemptomatik sisternal kanama ve 1 kötüleşen okülomotor palsi haricinde komplikasyon görülmedi (24). ...
Laser teknolojileri elli yılı aşkın bir süredir nöroşirürji pratiğinde kullanılmaktadır. Günümüzde bu alandaki gelişmelere paralel olarak laser temelli birçok yeni cihaz üretilmekte ve var olan cihazlar geliştirilmektedir. Söz konusu aygıtlar nöroşirürji uygulamalarında, gerek tanı gerekse de tedavi alanında, oldukça geniş bir yelpazede kendilerine yer bulabilmektedir. Bu derlemede laser ve laserin nöroşirürjideki kullanım alanlarının ortaya konulması amaçlanmıştır. Bu bağlamda, ilk bölümde laserin tanımı yapılarak, laserin tarihi, fiziği ve doku üzerindeki etkileri hakkında bilgi verilmiş, ikinci bölümünde ise laserin nöroşirürji pratiğinde tanı ve tedavideki kullanım alanları irdelenmiştir. Ek olarak, laser kullanılarak uygulanan tedavilerin başarı oranları ve komplikasyonları da güncel literatür eşliğinde tartışılmıştır.
Laser technologies have been used in neurosurgery practice for more than fifty years. With the improvement of laser technologies over the years, novel devices have been produced and upgraded. These devices have widespread application in the diagnosis and treatment of neurosurgical pathologies. In this article, we aim to review the laser technology and its use in neurosurgical practice. Thus, we give information regarding the history, physics and tissue interactions of the lasers in the first part, and we review the neurosurgical applications of the lasers in the second part. Additionally, we evaluate the relevant clinical studies on laser use in the literature regarding their success and complication rates.
... [10][11][12] It has also been used in the areas of ophthalmology, 13,14 and neurology. 15 These studies characterized the device as a precise cutting tool causing well-defined thermal damage to ensure hemostasis. In otorhinolaryngology, several studies have shown the efficacy of a 1940 nm laser in various procedures specific to this field: [16][17][18] Guney et al. reported on the ablation efficacy of a 1940 nm laser in intraoral surgery. ...
... These include the pulsed holmium:YAG laser for fiber optic based clearance of occluded shunts, 10,11 as well as continuous-wave neodymium:YAG, thulium:YAG, and diode lasers for endoscopic third ventriculostomy, using either bare optical fibers or carbon ball tip optical fibers for precise tissue ablation. [14][15][16][17][18][19][20][21] The primary advantage of the TFL is its near single mode spatial beam profile, which enables coupling of high laser power into ultrasmall (50 and 100 μm core) optical fibers. This property frees up valuable cross-sectional space within the typical 1.2-mm ID lumen of the ventricular catheter for simultaneous use of a miniature endoscope for image guidance and saline irrigation tube for visibility and safety during the procedure. ...
Hydrocephalus is a chronic medical condition that occurs in individuals who are unable to reabsorb cerebrospinal fluid (CSF) created within the ventricles of the brain. Treatment requires excess CSF to be diverted from the ventricles to another part of the body, where it can be returned to the vascular system via a shunt system beginning with a catheter within the ventricle. Catheter failures due to occlusion by brain tissues commonly occur and require surgical replacement of the catheter. In this preliminary study, minimally invasive clearance of occlusions is explored using an experimental thulium fiber laser (TFL), with comparison to a conventional holmium: yttrium aluminium garnet (YAG) laser. The TFL utilizes smaller optical fibers ( < 200 - ? m OD) compared with holmium laser ( > 450 - ? m OD), providing critical extra cross-sectional space within the 1.2-mm-inner-diameter ventricular catheter for simultaneous application of an endoscope for image guidance and a saline irrigation tube for visibility and safety. TFL ablation rates using 100 - ? m core fiber, 33-mJ pulse energy, 500 - ? s pulse duration, and 20- to 200-Hz pulse rates were compared to holmium laser using a 270 - ? m core fiber, 325-mJ, 300 - ? s , and 10 Hz. A tissue occluded catheter model was prepared using coagulated egg white within clear silicone tubing. An optimal TFL pulse rate of 50 Hz was determined, with an ablation rate of 150 ?? ? m / s and temperature rise outside the catheter of ? 10 ° C . High-speed camera images were used to explore the
... Near infrared 2-µm lasers including Nd:YAG, diode, fiber and argon laser have been reported in medical research such as neuroendoscopy [8], pulmonary endoscopy [9], dermatology [10,11], and urology [12,13]. The 1942nm wavelength is located in the vicinity of water vibrational absorption peaks between 1.88 μm and 1.91 μm [14][15][16]. ...
A surgical laser soft tissue ablation system based on an adjustable 1942 nm single-mode all-fiber Tm-doped fiber laser operating in pulsed or CW mode with nitrogen assistance is demonstrated. Ex vivo ablation on soft tissue targets such as muscle (chicken breast) and spinal cord (porcine) with intact dura are performed at different ablation conditions to examine the relationship between the system parameters and ablation outcomes. The maximum laser average power is 14.4 W, and its maximum peak power is 133.1 W with 21.3 μJ pulse energy. The maximum CW power density is 2.33 × 10<sup>6</sup> W/cm<sup>2</sup> and the maximum pulsed peak power density is 2.16 × 10<sup>7</sup> W/cm<sup>2</sup>. The system parameters examined include the average laser power in CW or pulsed operation mode, gain-switching frequency, total ablation exposure time, and the input gas flow rate. The ablation effects were measured by microscopy and optical coherence tomography (OCT) to evaluate the ablation depth, superficial heat-affected zone diameter (HAZD) and charring diameter (CD). Our results conclude that the system parameters can be tailored to meet different clinical requirements such as ablation for soft tissue cutting or thermal coagulation for future applications of hemostasis.
... 12,13 Furthermore, it was also used in neurosurgery during third-ventriculostomy procedures. 8 At our institution, we started to apply it during microsurgical removal of intracranial meningiomas, in addition to using traditional microsurgical instrumentation [Cavitron UltraSonic Aspirator (CUSA) and bipolar cautery]. ...
The purpose of this study was to assess the feasibility of the use of the 2μ-thulium laser in harvesting nasal septal flaps.
Nasal septal flaps are routinely performed in almost every trans-sphenoidal surgery. The preservation of the arterial vasculature is a mainstay of the procedure. However, the margins of the flap should be sufficiently healthy to regenerate faster, reducing the risk of possible complications.
Eight patients underwent trans-sphenoidal surgery and removal of pituitary adenomas. Reparation of the defect was performed with the positioning of a rotational vascularized nasal-septal flap. The flaps were harvested with the aid of the 2μ-thulium laser. Every patient was then monitored for 6 months through seriated endoscopic endonasal controls.
There were no complications related to the use of the laser, either intraoperatively, or postoperatively. The operative timing did not significantly differ from that of traditional techniques.
The use of the 2μ-thulium laser for the harvesting of nasal septal vascularized flaps can be considered safe and feasible. The limited number of treated patients could be considered as the only restriction to the study. A larger study might have uncovered possible instrumentation-related complications, which were not observed in the present study.
... 5 Tm 3+ (,Ho 3+ )-doped dielectric lasers have emerged as a very promising technology to meet these requirements. [1][2][3][4][5][6] For efficient operation, these devices generally exploit beneficial selfquenching or/and cross-relaxation effects occurring between neighbouring Tm 3+ ions under ~785nm excitation. Recently, an alternative pumping scheme using an ~1215nm laser was nevertheless demonstrated to offer valuable design flexibility. ...
We report the first use of a Semiconductor Disk Laser (SDL) as a pump source for ~2mum-emitting Tm3+ (,Ho3+)-doped dielectric lasers. The ~1213nm GaInNAs/GaAs SDL produces >1W of CW output power, a maximum power transfer net slope efficiency of 18.5%, and a full width half maximum wavelength tuning range of ~24nm. Free-running operation of a Tm3+-doped tellurite glass laser under 1213nm SDL pumping generated up to 60mW output power with 22.4% slope efficiency. Wavelength tunable output is also obtained from 1845 to 2043nm. Improved performance with output powers of ~200mW and a slope efficiency of ~35% are achieved by replacing the Tm3+-doped glass with a Tm3+-doped KYW active medium. Emission of a Tm3+,Ho3+-codoped tellurite glass laser is also reported with maximum output power of ~12mW and a ~7% slope efficiency. Finally, preliminary investigations of 1213nm-pumping of a Tm3+,Ho3+-codoped silica fibre laser lead to 36mW output power with ~19.3% slope efficiency.
... With advances in the delivery system, the Holmium:YAG replaced the Nd:YAG due to the fact that it produced less charring and more shallow tissue penetration due to its higher absorption rate (Vorwerk et al., 1989). Recently, the Thulium:YAG laser was intro-duced, and has been shown to have even more favorable tissue effects than the Ho:YAG Laser (Ludwig et al., 2007). The use of lasers for treating discogenic pathology is increasing, and the potential medical and economic benefits likely justify continued research and exploration (Rothstein, 2003(Rothstein, , 2004(Rothstein, , 2005Schenk et al., 2006). ...
In recent years, technical advances have allowed more significant structural spine surgery through small access portals. Minimally invasive spinal surgery (MISS) is commonly thought of as posterior approaches using muscle dilating tubular retraction systems, but these approaches are best suited to a single spinal level and require bony disruption at each level treated. Access through the sacral hiatus with a flexible endoscope allows an alternative, longitudinal approach to the entire lumbar epidural space. Surgical instruments can be introduced through the endoscope, including laser waveguide fibers. In this article, we expand upon previous reports and describe the combined clinical results of endoscopic laser decompression in 154 patients from 8 centers. All cases of anterior endoscopic neural decompression via sacral laminotomy between December 2009 and May 2011 were reviewed at participating centers and sent a follow-up questionnaire. One hundred and fifty-four cases were identified. There was a significant improvement in disability caused by low-back and/or leg pain as measured by the RMQ. The postoperative level of pain improved from 7.5 to 3.4. By the MacNab scale, success was achieved in 82%. Overall, the patients demonstrated significant clinical recovery and improvement in both quality of life and overall pain levels.
... The method to open the floor depends on the individual surgeon's preference: leucotome, puncturing needle, the scope tip itself, saline torch, monopolar electrode, Fogarty balloon, yttrium aluminum garnet (YAG) laser, forceps, YAG diode laser, flexible or rigid bipolar electrodes, sharp perforation, and unipolar wire electrodes. [4,11,14,18] SRS has become a well-accepted modality for the treatment of various neurological indications, from primary and metastatic malignancies to benign tumors, arteriovenous malformations and some functional procedures such as thalamotomies, pallidotomies, etc. [7,27] This technique was conceived to be more analogous to conventional surgery than to conventional radiotherapy. Similar to other neurosurgical procedures, it is one ablative, precisely localized and limited to a well-defined volume. ...
... The method to open the floor depends on the individual surgeon's preference: leucotome, puncturing needle, the scope tip itself, saline torch, monopolar electrode, Fogarty balloon, yttrium aluminum garnet (YAG) laser, forceps, YAG diode laser, flexible or rigid bipolar electrodes, sharp perforation, and unipolar wire electrodes. [4,11,14,18] SRS has become a well-accepted modality for the treatment of various neurological indications, from primary and metastatic malignancies to benign tumors, arteriovenous malformations and some functional procedures such as thalamotomies, pallidotomies, etc. [7,27] This technique was conceived to be more analogous to conventional surgery than to conventional radiotherapy. Similar to other neurosurgical procedures, it is one ablative, precisely localized and limited to a well-defined volume. ...
We describe a minimally invasive technique to perform a radiosurgical third ventriculostomy in a patient with mild obstructive hydrocephalus secondary to malignant pathology.
A 42 years old woman with diagnosis of clear cells renal carcinoma and with right nefrectomy performed last year. Cranial Magnetic Resonance Imaging showed two brain metastasis: one right temporal, and other in the pons with Sylvian aqueduct partial obliteration and mild ventricular enlargement. The patient received radiosurgical treatment for brain metastasis; after this procedure a new target was defined on the floor of the third ventricle, in the midpoint between the mamillary bodies and the infundibular recess where we delivered 100 Gy delivered by an isocentric multiple noncoplanar arcs technique, with a 6 MV Novalis(®) dedicated LINAC. A series of 21 arcs was arranged with a radiation field generated by a 4 mm circular collimator.
One week pos-irradiation in the head CT we did not find significant changes in the metastatic lesions; however the VSI diminished 4%, despite of persistent aqueduct obliteration. At three months we perform 3.0 T MRI where we confirmed the presence of the third ventriculostomy (2.63 mm diameter).
This report demonstrates, for the first time, the ability of a dedicated LINAC to perform a precise third ventriculostomy without associate morbility in short term.
... Until today, the thulium 2010 nm-wavelength laser has been used only in urologic (prostatic) surgery and in neurosurgery, with overall good clinical results 6,7 . The absorption length of this type of laser (0.18 mm, 180 µm) could be theoretically useful also in pulmonary surgery, and this microscopic and ultrastructural study seems to support the use of the device (the depth of zone 1 alteration was about 0.2 mm, 200 µm; zone 1 + 2 about 0.6 mm, 600 µm). ...
There are few papers on the cytostructural effects of surgical instruments used during pulmonary resections. The aim of the present study was to evaluate the parenchymal damage caused by different surgical instruments: a new generation electrosurgical scalpel and two different-wavelength lasers.
Six surgical procedures of pulmonary resection for nodules were performed using a new generation electrosurgical scalpel, a 1318 nm neodymium (Nd:YAG) laser or a 2010 nm thulium laser (two procedures for each instrument). Specimens were analyzed using optical microscopy and scansion electronic microscopy.
Severe cytostructural damage was found to be present in an average of 1.25 mm in depth from the cutting surface in the patients treated using electrosurgical cautery. The depth of this zone dropped to less than 1 mm in patients treated by laser, being as small as 0.2 mm using the laser with a 2010 nm-wavelength and 0.6 mm with the 1318 nm-wavelength laser.
These preliminary findings support the use of laser to perform conservative pulmonary resections (i.e., metastasectomies), since it is more likely to avoid damage to surrounding structures. Controlled randomized trials are needed to support the clinical usefulness and feasibility of new types of lasers for pulmonary resections.
... In recent years, laser technology has also been introduced in the neurosurgical armamentarium [15], becoming a unique and sometimes invaluable tool for many procedures including neuroendoscopy [16]. ...
In the history of medicine, the understanding of the nervous system, both from an anatomical and a functional point of view, has always required new and more sophisticated tools. It has been widely demonstrated that engineering has helped towards this end. Incorporation of improved technical tools has expanded the available armamentarium to perform neurological surgery. Neurosurgery probably presents the most major challenges and always benefits from the introduction of sophisticated tools, from cranial trephination to the most modern robotics. This review examines the role of engineering to assist in neurosurgery.
While there have been great strides in endoscopic and endoscope-assisted neurosurgical approaches, particularly in the treatment of deep-sited brain and skull base tumours, the greatest technical barrier to their adoption has been the availability of suitable surgical instruments. This systematic review seeks to identify specialised instruments for these approaches and evaluate their safety, efficacy and usability. Conducted in accordance with the PRISMA guidelines, Medline, Embase, CENTRAL, SCOPUS and Web of Science were searched. Original research studies that reported the use of specialised mechanical instruments that manipulate tissue in human patients, cadavers or surgical models were included. The results identified 50 specialised instruments over 62 studies. Objective measures of safety were reported in 32 out of 62 studies, and 20 reported objective measures of efficacy. Instruments were broadly safe and effective with one instrument malfunction noted. Measures of usability were reported in 15 studies, with seven reporting on ergonomics and eight on the instruments learning curve. Instruments with reports on usability were generally considered to be ergonomic, though learning curve was often considered a disadvantage. Comparisons to standard instruments were made in eight studies and were generally favourable. While there are many specialised instruments for endoscopic and endoscope-assisted neurosurgery available, the evidence for their safety, efficacy and usability is limited with non-standardised reporting and few comparative studies to standard instruments. Future innovation should be tailored to unmet clinical needs, and evaluation guided by structured development processes.
It was Albert Einstein, who described the quantum theory of radiation in 1916 and published it in 1917, AL Schawlow described the fundaments of LASER 1940 and TH Maiman constructed the first LASER in 1960. But it needed until 1989 that “LASER in Neurosurgery”, Springer, was published by EF Downing, PW Ascher et al. presenting of the start-up of LASER use in neurosurgery during the 1970th and 1980th. However, while LASER played a major role in other disciplines in medicine, neurosurgery did never accept it widely.
Background
Quality of life is essential for oncologic patients. Several tools are available to improve microsurgery and reduce morbidity. Diode laser is a precise and useful technology for microsurgery. The goal of this pioneer case series is to describe the oncologic use of the 980nm diode laser and the qualitative variables analyzed. Besides, review the current literature about lasers in neurosurgery.
Methods
A longitudinal prospective study described patients with meningioma or glioma submitted to neurosurgical laser-assisted procedures. Also, we performed a review in medical databases using the terms “diode laser” and “neurosurgery.”
Results
No paper described the use of a diode laser in neurooncology. The 980nm diode laser was used in 15 patients. The device is thin, silent, and easy to handle. Excellent hemostasis was observed, especially in skull base meningiomas. Also, it was easy and fast to delimit tumor from normal brain tissue without damage to surrounding parenchyma. No postoperative complications occurred.
Conclusions
The diode laser is a useful tool for brain tumor surgery, particularly concerning hemostasis. Surgical site coagulation is effective without damage to adjacent structures, especially in gliomas near eloquent regions. We consider this technique a suitable adjuvant resource for brain tumor surgeries to provide an excellent hemostasis and help cut and vaporize a lesion.
Introduction:
Treatment or multilevel hydrocephalus is a complex problem. Neuroendoscopic interventions, make it possible to combine minimal invasiveness with the possibility of fenestration of several cysts during one procedure and thereby eliminate multi-level occlusion. We present our the experience of using a neodymium YAG laser (Nd-YAG laser) as an additional tool to improve the treatment results of patients with non-communicating hydrocephalus.
Material and methods:
This study included 10 patients aged from 5 months to 8 years who underwent endoscopic interventions with the use of rigid endoscope with frameless navigation. A surgical laser with a radiation wavelength of 1.064 μm was used as the main tool for fenestrating the walls of the cysts.
Results:
13 endoscopic laser interventions were performed in 10 patients with multilevel hydrocephalus. In 3 children, the two-stage treatment was chosen in due to the impossibility of simultaneous fenestration of all cysts. The interval between procedures was 1 month in two cases and 11 months in one case. We managed to compensate for cerebrospinal fluid disturbances in each patient, positive dynamics in the condition was noted. The duration of postoperative stay averaged 8 days (from 4 to 13 days). There were no deaths in the study group. All patients were discharged in good condition. Average follow-up duration was 14 months (from 8 to 25 months). During the observation, the condition of the patients remained stable; there was no need for repeated operations.
Conclusion:
Combined use of bypass operations, endoscopic techniques and neural navigation may improve the results of treatment of patients with multilevel hydrocephalus. Data presented in this article demonstrates the safety and effectiveness of the clinical use of laser radiation as an additional tool for interventions in patients with this condition.
Thulium:YAG (Tm:YAG) lasers use a 90 W energy source and the laser energy is delivered through a 550 μm optical‐core bare‐ended, reusable laser fiber. The procedure is performed using a 26 Fr continuous‐flow laser resectoscope combined with a mechanical tissue morcellator (0.9% saline as irrigation fluid). Theoretically, the prostate can be enucleated in a one‐, two‐, or three‐lobe technique, depending on its size and anatomical configuration. The three‐lobe technique starts with puncture of a little dimple (Herrmann's arc) lateral to the verumontanum. Then a Turner–Warwick‐like incision is made at 5 and 7 o'clock from the bladder neck to the Herrmann's arcs. A U‐shaped incision connects both lines just in front of the verumontanum. The laser fiber is pulled back into the scope until invisible. Then, a blunt enucleation of the middle lobe is performed using the beak of the resectoscope in a retrograde fashion towards the bladder neck. The laser is used for coagulation of bleeders only. Blunt enucleation of the lateral lobes starts at either side of the Herrmann's arcs and the instrument is rotated in the layer between prostatic pseudocapsule and adenoma. Typically, a little strip of mucosa remains at the 12 o'clock position. This strip is resected a safe distance from the sphincter. The following enucleation is performed bluntly with the beak of the resectoscope until the bladder neck is reached. For coagulation of vessels, the laser fiber is advanced. It is important to activate the laser at the bladder neck to coagulate bleeders from the mucosa at the bladder neck. The contralateral lobe is treated in the same fashion. The two‐lobe technique follows the same rules in principle. The only difference is that the middle lobe remains attached to one of the lateral lobes. The one‐lobe technique is self‐explanatory. The next step after vaporization of bleeding vessels is morcellation of the enucleated adenoma. A nephroscope is inserted over the same shaft of the resectoscope. At the end of surgery a 22 Fr three‐way Foley catheter is inserted for continous bladder irrigation.
Objective:
The aim of this study is to present the clinical experience of two neurosurgical centers with the use of a 2-micron continuous wave laser (2μ-cwL) system as standard tool in neuroendoscopic procedures and to discuss the safety and efficacy of this system.
Methods:
469 patients underwent neuroendoscopic procedures using 2μ-cwL between September 2009 and January 2015. All patient data were retrospectively reviewed. 241 (51%) patients were children and 228 (49%) adults. Mean age was 27.5 years (range:3 days - 83 years). Intraoperative ultrasound or neuronavigation iwere used to guide ventricular or cyst puncture and for intraventricular or intracystic orientation if necessary.
Results:
A total of 524 neuroendoscopic procedures using 2μ-cwL were performed. Laser-assisted endoscopic third ventriculostomy (LA-ETV) was the most common procedure in 302 (64%) patients. Cyst fenestration was performed in 124 (26%), septostomy in 45, tumor biopsy in 41, tumor resection in 8 and choroid plexus coagulation in 3 patients. There was no intra-operative complication directly attributable to the use of laser and an overall procedural complication rate of 4.8%.
Conclusion:
This large series of 2μ-cwL as a routine tool in neuroendoscopic procedures demonstrates, that this 2μ-cwL is safe for ETV, septostomy, cyst fenestration and intraventricular tumor biopsy or resection. As a cutting and coagulation tool it combines the action of mechanical tools like forceps, balloons and scissors plus those of electric tools. It therefore renders neuroendoscopic procedures more straightforward with a minimum need to change tools.
Aims and Background
There are few papers on the cytostructural effects of surgical instruments used during pulmonary resections. The aim of the present study was to evaluate the parenchymal damage caused by different surgical instruments: a new generation electrosurgical scalpel and two different-wavelength lasers.
Methods
Six surgical procedures of pulmonary resection for nodules were performed using a new generation electrosurgical scalpel, a 1318 nm neodymium (Nd:YAG) laser or a 2010 nm thulium laser (two procedures for each instrument). Specimens were analyzed using optical microscopy and scansion electronic microscopy.
Results
Severe cytostructural damage was found to be present in an average of 1.25 mm in depth from the cutting surface in the patients treated using electrosurgical cautery. The depth of this zone dropped to less than 1 mm in patients treated by laser, being as small as 0.2 mm using the laser with a 2010 nm-wavelength and 0.6 mm with the 1318 nm-wavelength laser.
Discussion
These preliminary findings support the use of laser to perform conservative pulmonary resections (i.e., metastasectomies), since it is more likely to avoid damage to surrounding structures. Controlled randomized trials are needed to support the clinical usefulness and feasibility of new types of lasers for pulmonary resections.
Esophageal achalasia is a type of motility disorder characterized by incomplete relaxation of lower esophageal sphincter (LES) and absence of esophageal peristalsis. Peroral endoscopic myotomy (POEM) is a new treatment option for achalasia that is less invasive, more effective, and safe as compared to surgery. High-frequency electrotome is commonly used in POEM, but takes longer time to make the tunnel in the esophagus and causes many complications. The thulium laser decreases the risk of bleeding and perforation in endoscopy but has not been reported in digestive diseases, especially in POEM. Therefore, the aim of this study is to evaluate the feasibility of the 1940 nm thulium laser in POEM. From March 2015 to August 2015, five patients with achalasia at the Digestive department, Beijing Friendship Hospital, Capital Medical University, Beijing, China were included. Before the procedure, the patients’ gender, age, and duration of symptoms were recorded. Eckardt symptom score and LES thickness, which measured by endoscopic ultrasonography, were recorded. While the subtypes of achalasia (according to the Chicago classification), lower esophagus sphincter resting pressure (LESRP) and integrated relaxation pressure (IRP) were measured by HRM for all patients. Barium esophagram was also used to rule out anatomical lesions, esophageal varices, or neoplasia, which may cause similar symptoms. All examinations were performed one week before POEM. POEM was performed with the 1940 nm thulium laser under general anesthesia. Eckardt score, procedure duration, myotomy length, and complications were recorded one week after POEM. All the patients were followed-up at two weeks and four weeks after POEM. POEM was successfully performed in all five patients. The mean age of the patients was 38.8 years (24–54 years). Achalasia subtypes were type I (n = 1), II (n = 2), and III (n = 2). The operation duration was 186, 180, 111, 75, and 126 minutes for the five cases. Pre/postprocedure Eckardt scores were 3/0, 7/0, 5/1, 6/0, and 9/0. Pre/postprocedure LESRP (mmHg) were 45.3/26.4, 18.0/1.1, 25.8/10.4, 16.5/11.2, and 24.2/20.8. Pre/postprocedure IRP (mmHg) were 27.3/15.5, 15.4/4.2, 5.7/6.8, 15.5/10.1, and 13.1/14, respectively. No adverse events occurred during the procedure. After POEM, subcutaneous emphysema occurred in case 1 on the first day, which relieved spontaneously after two days without special intervention. Infection occurred in case 5 on the day of POEM was healed with antibiotics three days later. The 1940 nm thulium laser is feasible for POEM procedure. Further studies are needed to determine whether the 1940 nm thulium laser is better than high-frequency electrotome.
Background and Objective
Endoscopic third ventriculostomy is used to treat hydrocephalus. Different laser wavelengths have been proposed for laser‐assisted endoscopic third ventriculostomies over the last decades. The aim of this study was to evaluate Thulium laser endoscopic third ventriculostomy heat penetration in the surrounding environment of the floor of the third ventricle in an in vitro setting with visualization of thermal distribution. Subsequently 106 Thulium laser endoscopic third ventriculostomy procedures were retrospectively analyzed to demonstrate safety.
Methods
The in vitro visualization was based on the color Schlieren method. The heat penetration was measured beneath a tissue phantom of the floor of the third ventricle with a fiber of 365 μm in diameter at different energy settings; 1.0W (956 J/cm²), 2.0W (1,912 J/cm²), 4.0W (3,824 J/cm²), and 7.0W (6,692 J/cm²), with a pulse duration of 1.0 second. All experiments were repeated five times. In addition, 106 Thulium laser endoscopic third ventriculostomy procedures between 2005 and 2015 were retrospectively analysed for etiology, sex, complications, and laser parameters.
Results
In the energy settings from 1.0 to 4.0 W, heat penetration depth beneath the phantom of the third ventricle did not exceed 1.5 mm. The heat penetration depth at 7 W, exceeded 6 mm. The clinical overall success rate was 80% at the 2‐year follow‐up study. Complications occurred in 5% of the procedures. In none of the 106 investigated clinical patients bleeding or damage to the basilar artery was encountered due to Thulium laser ablation.
Conclusions
The in vitro experiments show that under 4.0W the situation is considered safe, due to low penetration of heat, thus the chance of accidentally damaging critical structures like the basilar artery is very small. The clinical results show that the Thulium laser did not cause any bleeding of the basilar artery, and is a safe technique for laser endoscopic third ventriculostomy. Lasers Surg. Med. © 2017 Wiley Periodicals, Inc.
Neuroendoscopy is now considered to be a minimally invasive surgical approach for expanding lesions bulging into the ventricle, and it is also considered to be a relevant tool for performing biopsy procedures, fenestration of cystic walls, or for performing tumor removal in selected cases. Furthermore, the use of neuroimaging and the accurate follow-up of brain tumor patients have allowed the documentation of tumoral and pseudotumoral cystic areas that cause the obstruction of cerebrospinal fluid (CSF) pathways. Neuroendoscopic procedures enable the fenestration of cystic lesions, in addition to enabling third ventriculostomy or septostomy to restore CSF pathways. We analyze our experience regarding 77 patients affected by brain tumors arising from the wall of the third or lateral ventricle. In all cases hydrocephalus or obstruction of CSF flow was present. With an endoscopic technique, septostomy, cystostomy, endoscopic third ventriculostomy (ETV), and tumor resection were performed to control intracranial hypertension.
ETV was performed in 53 patients with noncommunicating hydrocephalus. In 4 patients with low-grade astrocytoma ETV was definitely the only surgical treatment. In 12 cystic tumors, cystostomy and marsupialization into the ventricle solved a relevant mass effect with clinical intracranial hypertension syndrome. In 10 patients, neuroendoscopic relief of CSF pathways was possible by performing septostomy with the implantation of an Ommaya reservoir or one-catheter shunt. In 5 colloid cysts and 2 cystic craniopharyngiomas, removal was possible by restoring CSF flow without other procedures. After intracranial hypertension control, in 13 malignant gliomas and 5 leptomeningeal metastases, the patients’ quality of life improved sufficiently to provide for tumor adjuvant therapy.
In this series, endoscopy, due to its minimally invasive characteristics and reduced complications, was found to be safe and effective, without any relevant postoperative morbidity, gained by avoiding major surgical approaches.
Based on these results and on the increasing number of series described in the literature, we believe that endoscopic techniques should be considered a selected approach for treating CSF obstructions caused by para-intraventricular tumors. The result of using neuroendoscopy is the reconstruction of CSF pathways that bypass the tumor occlusion. This surgical procedure is not only limited to the relief of noncommunicating hydrocephalus, but it is also useful for tumor removal or biopsies and the evacuation of cystic lesions. In patients affected by malignant tumors, neuroendoscopy can be performed to control intracranial hypertension before the patients start adjuvant chemotherapy or radiotherapy.
The evolution of endoscopic techniques and the development of useful endoscopes as well as supplementary working instruments have improved surgical results and expanded indications for neuroendoscopy. The design of modern microprocessor-controlled solid-state coagulating and cutting devices has been another milestone to establish this technique in daily operative routine. Furthermore, intraoperative fluoroscopy, three-dimensional approach planning using digital fluoroscopy, CCT or MRI stereotactic guidance and neuronavigation and intraoperative MRI offer a high grade of safety and precision. Thin laser probes and ultrathin bare laser fibres and intraluminal ultrasonic probes can be used either for different purposes in endoscopic neurosurgery. For the future ultrasound-navigated neuroendoscopy through a burr hole could also be an option in diagnosis and treatment of hydrocephalus. All these components have contributed to make neuroendoscopic interventions acceptable as an alternative treatment option in well-defined indications. A new and very sophisticated technique, which will become available in the future, will integrate the third dimension into neuroendoscopes. These endoscopes will give a high quality of field of depth and will provide a higher level of accuracy for neuroendoscopic interventions.
Today, after a long developmental period, endoscopy is well integrated in the environment of the modern neurosurgical operating room. However, these technologies are cost-intensive and very sensitive and tend to break. Knowledge of the endoscopic topographical anatomy and the availability of basic and useful instruments are therefore indispensable prerequisites.
In order to investigate the feasibility of fiber-guided 2.013 μm Q-switched thulium:YAG lasers as one microsurgical scalpel, dissection performance of 200 μm core diameter fiber-guided thulium:YAG lasers operating at 1 kHz repetition rate and 400~1400 ns pulse duration on fresh pig kidney tissues, is researched under different pulse energies and dissection velocities. One professional camera and one optical microscope are used to capture the macro-histological tissue surfaces and the micro-histological craters, respectively. A scientific standard software is used to analyze the experimental data. The experimental results show that the dissection effect is not obvious for higher dissection velocity under the same low energy level. However, it is obvious for higher energy under the same dissection velocity. The fiber-guided high repetition rate Q-switched thulium:YAG lasers will be expected to be used in clinical operation as a microsurgical scalpel.
Background:
Endoscopic third ventriculostomy (ETV) has been used predominantly in the pediatric population in the past. Application in the adult population has been less extensive, even in large neurosurgical centers. To our knowledge, this report is one of the largest adult ETV series reported and has the consistency of being performed at 1 center.
Objective:
To determine the efficacy, safety, and outcome of ETV in a large adult hydrocephalus patient series at a single neurosurgical center. In addition, to analyze patient selection criteria and clinical subgroups (including those with ventriculoperitoneal shunt [VPS] malfunction or obstruction and neurointensive care unit patients with extended ventricular drainage before ETV) to optimize surgical results in the future.
Methods:
We conducted a retrospective review of adult ETV procedures performed at our center between 2000 and 2014.
Results:
The overall rate of success (no further cerebrospinal fluid diversion procedure performed plus clinical improvement) of 243 completed ETVs was 72.8%. Following is the number of procedures with the success rate in parentheses: aqueduct stenosis, 56 (91%); communicating hydrocephalus including normal pressure hydrocephalus, nonnormal pressure hydrocephalus, and remote head trauma, 57 (43.8%); communicating hydrocephalus in postoperative posterior fossa tumor without residual tumor, 14 (85.7%); communicating hydrocephalus in subarachnoid hemorrhage without intraventricular hemorrhage, 23 (69.6%); obstruction from tumor/cyst, 42 (85.7%); VPS obstruction (diagnosis unknown), 23 (65.2%); intraventricular hemorrhage, 20 (90%); and miscellaneous (obstructive), 8 (50%). There were 9 complications in 250 intended procedures (3.6%); 5 (2%) were serious.
Conclusion:
Use of ETV in adult hydrocephalus has broad application with a low complication rate and reasonably good efficacy in selected patients.
The thulium:YAG laser (Tm:YAG), at a wavelength of 2 m, has recently emerged in endourology. Physical characteristics and biologic effects of this new laser differ from those of earlier lasers, such as Nd:YAG, Ho:YAG, KTP, and diode. In contrast to other vaporizing lasers, the surgical effect is entirely independent of vascularization or tissue coloration. Whereas other lasers are suitable for one or two surgical benign prostatic hyperplasia protocols only, with the Tm:YAG laser all surgical soft tissue procedures are possible: resection, vaporization, vaporesection, enucleation, and blunt dissection. The Tm:YAG laser has a power capacity that exceeds 200 W and it is compatible with standard bare-ended and side-firing fibers.
Object:
Hypothalamic hamartomas (HH) may induce drug-resistant epilepsy (DRE), thereby requiring surgical treatment. Conventionally, treatment is aimed at removing the lesion, but a disconnection procedure has been shown to be safer and at least as effective. The thulium laser (Revolix) has been recently introduced in urological endoscopy because of its ability to deliver a smooth cut with good control of the extent of tissue damage. The authors sought to analyze the safety and efficacy of the thulium 2-μm laser applied through navigated, robot-assisted endoscopy in disconnection surgery for HHs.
Methods:
Twenty patients with HH who were drug resistant were treated during a 12-month period. Conventional disconnection by monopolar coagulation (endoscopic electrode) was performed in 13 patients, and thulium laser disconnection was performed in the remaining 7 patients. The endoscope was inserted into the ventricle contralateral to the attachment of the HH on the third ventricular wall. Results in terms of safety, efficacy, and ease of use of the instrument were analyzed.
Results:
All 20 patients achieved a satisfactory postoperative Engel score (Classes I-III). At 12 months, the Engel class was I or II in 8 of 13 patients (61.5%) who underwent monopolar coagulation and in 6 of 7 patients (85.7%) who underwent laser disconnection (p = 0.04). Seven of 13 patients (53.8%) who underwent monopolar coagulator disconnection and 2 of 7 patients (28.6%) who underwent laser disconnection had immediate postoperative complications. At the 3-month follow-up, only 2 patients (15.4%) treated by coagulation still experienced mild surgery-related recent memory deficits. No complications persisted at the 12-month follow-up.
Conclusions:
The disconnection procedure is a safe and effective treatment strategy to treat drug-resistant epilepsy in patients with HHs. With the limitations of initial experience and a short-term follow-up, it appears that the thulium 2-μm laser has the technical features to replace the standard coagulation in this procedure.
Durable pain remission using radiofrequency thermal neurotomy (RTN) requires thoughtful patient selection and a lesion of optimal size and position. Success necessitates complete ablation of approximately 8-10 mm of the targeted neural pathway. Technical failure may result if anatomical variations in the targeted pathway are not incorporated into the lesion and if the electrode is not positioned optimally relative to the target nerve. This paper
presents an improvement in RF electrode design intended to improve RTN outcomes.
Keywords: radiofrequency thermal neurotomy, pain management
Aims:
This randomized trial evaluated the feasibility and safety of thulium 2010-nm laser to perform anatomic lung resections in patients with incomplete fissures, as compared to mechanical staplers with or without sealants.
Study design:
Seventy-two patients scheduled for segmentectomy or lobectomy were enrolled. After intraoperative confirmation of the extent of resection and incomplete fissures (Craig type 2, 3 or 4), they were randomized and allocated to one of the following arms: laser resection by thulium (group A) or standard resection with mechanical staplers with or without sealants (group B). The primary endpoints of the study included analysis of intraoperative and postoperative course, and costs.
Results:
Thirty-eight patients were assigned to group A (32 lobectomies, 6 segmentectomies) and 34 to group B (31 lobectomies, 3 segmentectomies). No 30-day mortality was observed. Median operative times were 145.0 minutes (group A) and 142.5 minutes (group B, P = 0.83). The median time to drainage removal was 5 days (group A) and 4 days (group B), while the median length of hospital stay was the same (7 days). Prolonged air leaks >7 days were observed in 12 patients of group A (32%) and 10 patients of group B (29%, P = 0.46). Unpredictable late pneumothorax occurred in 3 patients of group A (2 readmissions, need for 1 repeat thoracotomy). Cost analysis demonstrated an intraoperative advantage for group A (mean 807 ± 212 euro) versus group B (mean 1,047+/-276 euro, P <0.0001), but the differences in total costs could be due to chance (P = 0.83).
Conclusions:
The use of laser to complete fissures can lead to late pneumothorax, even in the absence of postoperative air leaks. Moreover, the use of laser to complete fissures did not prove to reduce overall costs. Trial Registration Identification Number: 41/10 (IRB00001457 - FWA00001798 - IORG0001063).
Adult Idiopathic Occlusion of the Foramen of Monro (AIOFM) is a rare condition, with only few cases described in the modern literature. We propose that AIOFM may result from unilateral or bilateral occlusion of Monro foramina, as well as from progression of a monolateral hydrocephalus. Different surgical strategies may be required for effective treatment according to the type of occlusion. To date, only 12 cases of AIOFM have been reported in the literature. We report the cases of two patients, aged 20 and 47 years respectively, who presented with intracranial hypertension secondary to bilateral ventricular dilatation due to obstruction at the level of the foramen of Monro. Both patients were successfully treated with endoscopic fenestration of the primarily obstructed foramen of Monro and, in one patient, fenestration of the septum. We propose that septum pellucidum displacement could play a role in the occlusion of the second foramen of Monro. AIOFM can, therefore, result also from unilateral stenosis of Monro. The difference in AIOFM (i.e. unilateral vs bilateral) will be useful in guiding the most suitable surgical approach in this rare condition.
Nd:YAG laser (1064 nm) is standard in bronchology. The thulium fiber laser (1940 nm) has a nearly 1000-fold increased absorption in water, enabling precise tissue ablation with a small margin of coagulation, whereas 1064-nm laser light penetrates deeper into tissue with less controllable effects.
To assess the safety, feasibility, and versatility of endobronchial thulium laser therapy in an observational cohort study.
Endobronchial treatment with the thulium fiber laser was performed in a cohort study of 187 bronchoscopies on 132 consecutive patients with 135 endobronchial lesions amenable to laser resection.
The thulium fiber laser produced superficial, precise, and rapid tissue ablation. Eighty-one lesions were completely vaporized; 82 lesions were treated by deep tissue destruction by inserting the fiber into tissue followed by mechanical resection. Tumor bleeding was coagulated with rapid and sustained hemostasis (n = 28). Nitinol stents were removed after resection of severe granulation tissue overgrowth (n = 10). Intact stents were maintained after ablation of in-stent tissue (n = 47). In 11 cases, bleeding occurred during laser treatment (n = 11 of 187). Power settings between 5 and 20 W were found to be safe.
Endobronchial therapy with the thulium laser at 1940 nm seems to be safe, feasible, and highly versatile for treatment of airway stenosis and stent obstruction caused by tissue ingrowth. Further studies are warranted.
BACKGROUND: Post lumbar surgery syndrome refers to pain occurring or present after lumbar surgery. While the causes of pain after lumbar surgery are multi-factorial, scarring is a significant source of that pain. Low back and/or leg pain after lumbar surgery can persist despite appropriate conservative therapy. Spinal endoscopy allows direct visual evaluation of the epidural space, along with mechanical lysis of any adhesions present.
STUDY DESIGN: A systematic review of the effectiveness of spinal endoscopic adhesiolysis in post lumbar surgery syndrome.
OBJECTIVE: To evaluate and update the effectiveness of spinal endoscopic adhesiolysis in treating post lumbar surgery syndrome.
METHODS: The available literature on spinal endoscopic adhesiolysis in treating post lumbar surgery syndrome was reviewed. The quality assessment and clinical relevance criteria utilized were the Cochrane Musculoskeletal Review Group criteria as utilized for interventional techniques for randomized trials and the criteria developed by the Newcastle-Ottawa Scale criteria for observational studies.The level of evidence was classified as good, fair, and limited or poor based on the quality of evidence developed by the U.S. Preventive Services Task Force (USPSTF). Data sources included relevant literature identified through searches of PubMed and EMBASE from 1966 to September 2012, and manual searches of the bibliographies of known primary and review articles.
OUTCOME MEASURES: Pain relief and functional improvement were the primary outcome measures. Other outcome measures were improvement of psychological status, opioid intake, and return to work. Short-term effectiveness was defined as improvement of 12 months or less; whereas, long-term effectiveness was defined 12 months or longer.
RESULTS: For this systematic review, 21 studies were identified. Of these, one randomized controlled trial (RCT) and 5 observational studies met the inclusion criteria. Two of the observational studies were excluded because of other methodological issues, despite showing positive outcomes.Using current criteria for successful outcomes, these studies indicate that there is fair evidence for the effectiveness of spinal endoscopy in the treatment of persistent low back and/or leg pain in post lumbar surgery syndrome.
LIMITATIONS: The limitations of this systematic review include the paucity of literature.
CONCLUSIONS: The evidence is fair that spinal endoscopy is effective in the treatment of post lumbar surgery syndrome.
Background:
Endoscopic third ventriculostomy (ETV) has become a well-established method for the treatment of noncommunicating hydrocephalus with a high success rate and a relatively low morbidity rate. However, vessel injury has been repeatedly reported, often with a fatal outcome. Vessel injury is considered to be the most threatening complication. The use of indocyanine green (ICG) angiography has become an established tool in vascular microneurosurgery.
Objective:
We report our initial experience with endoscopic ICG angiography in ETV for intraoperative visualization of the basilar artery and its perforators to reduce the risk of vascular injury.
Methods:
Eleven patients with noncommunicating hydrocephalus underwent ETV. Before opening of the third ventricular floor, ICG angiography was performed using a prototype neuroendoscope for intraoperative visualization of ICG fluorescence.
Results:
In 10 patients, ETV and ICG angiography were successfully performed. In 1 case, ICG angiography failed. Even in the presence of an opaque floor of the third ventricle (n = 5), ICG angiography clearly demonstrated the course of the basilar artery and its major branches and was considered useful.
Conclusion:
ICG angiography has the potential to become a useful adjunct in ETV for better visualization of vessel structures, especially in the presence of aberrant vasculature, a nontranslucent floor of the third ventricle, or in case of reoperations.
Laser-assisted techniques offer a huge potential in neurosurgery, but have achieved little acceptance to date. One reason is the concern regarding heat production, uncontrollable and distant penetration, and tissue interaction.
We describe our experience with a 2-micron continuous wave laser (RevoLix jr.; LISA Laser Products OHG, Katlenburg-Lindau, Germany) for neuroendoscopic intraventricular procedures.
The laser beam is delivered through flexible fibers. In an aqueous medium, the effect is restricted to <2 mm in front of the tip with tissue penetration depth of 500 μm.
Forty-four patients (25 adults, 19 children) were operated on using the endoscopic, laser-assisted technique for treatment of obstructive hydrocephalus (n = 39), pure cyst fenestration (n = 4), or pure tumor biopsy (n = 1). All 53 procedures were successfully performed in those 44 operations, with the laser being the main effective instrument used (except for biopsy). Besides one clinically silent small intracisternal hemorrhage and one worsening of a preexisting oculomotor palsy (following fenestration of multiple midbrain cysts), no procedure-related complications occurred.
The 2-micron continuous wave laser is a most valuable and useful tool, in our experience with safe applicability for endoscopic intracranial procedures in patients of all ages.
We report spectroscopic and bulk laser performance characteristics for Tm(3+)-doped tellurite glasses when used as gain media operating around 1.9 microm. Two glass hosts studied are TZN and TZNG and their performances have been compared. In each case, well-characterized cw laser performance was obtained and this has been related to detailed spectroscopic measurements of the important lasing parameters of the laser transitions around 1900 nm when pumped at 793 nm. The maximum output power achieved was 124 mW from the TZNG sample with an associated slope efficiency of 28 % with a tuning range of 135 nm. Efficiency and loss analyses yielded a calculated maximum attainable efficiency of 48 % in Tm(3+):TZN compared to 28 % for the TZNG host.
We read with interest the recent paper by Benabarre et al 1 of the first reported case of endoscopic third ventriculostomy followed by severe psychiatric complications.
In our department, we also had a patient who developed severe psychiatric symptoms after an endoscopic third ventriculostomy (ETV).
A 45 year old woman with an aqueductal stenosis underwent an EVT because of progressive gait and visual disturbances. In November 1997 she underwent an ETV through a right side precoronal burr hole using a rigid neuroendoscope. The third ventricular floor was perforated with a 4 French Fogarty catheter, the perforation being enlarged with the inflatable balloon. No problems were encountered during the procedure, although we noted an incomplete septum pellucidum. After ETV her gait and visual disturbances gradually resolved. However, after the procedure the patient was nervous and agonised, and she complained of a crepitating sound in her head and behaved aggressively towards her spouse. Because her complaints and behaviour worsened a psychiatric evaluation was performed. Psychotic depression was diagnosed and three weeks after the EVT she was admitted to the department of psychiatry. For several months she was treated …
Lasers have been used in neurosurgery for the past 25 years, undergoing modifications to suit the specific needs of this medical discipline. The present report reviews the current use of lasers in neurosurgical practice and examines the pros and cons of lasers in specific neurosurgical applications. In spite of their advantages, laser use is still not widespread in neurosurgery. One reason is the continued lack of complete control over real-time laser interactions with neural tissue. A greater acceptance and use of lasers by neurosurgeons will depend upon automated control over defined specific parameters for laser applications based upon the type of tissue, the desired effect on tissue, and application to the clinical situation without loss of precision and a lot of expense. This will require the integration of newer lasers, computers, robotics, stereotaxy, and concepts of minimally invasive surgery into the routine management of neurosurgical problems. © 1994 Wiley-Liss, Inc.
Multiloculated hydrocephalus with multiple intraventricular septae due to meningitis associated with ventriculitis and other CSF containing intraventricular cysts can be treated by endoscopic fenestration. Seven patients with various CSF containing intraventricular cysts were treated using a flexible steerable endoscope and the argon laser. The experience using several currently available steerable endoscopes for treatment of this neurosurgical problem is reviewed. Emphasis is placed on the use of the laser for cyst fenestration. Successful decompression of the ventricular cyst(s) was accomplished in five cases with the endoscope alone. Craniotomy was required in two patients in order to complete cyst fenestration. It is the author's impression that laser assisted ventriculoscopy with steerable flexible endoscopes is an alternative and oftentimes superior method of treating CSF containing cysts within the lateral ventricles of hydrocephalic patients. Steerable flexible endoscopes designed specifically for neurosurgical use are needed.
In recent years neurosurgeons have shown an increasing interest in lasers. An understanding of the basic laser mechanism and tissue effects is important. CO2 laser is an excellent no-touch tool for excising and evaporating brain tumors. It has several other uses in neurosurgery both with free hand technique and with microscope attachment and micromanipulator. Nd: YAG and Argon lasers are more effective for coagulation of blood vessels and dealing with vascular neoplasms. Advantages and disadvantages of this technique are discussed and compared with other methods like bipolar coagulation and CUSA. Indications for the use of the different laser types in neurosurgery are summarized and a prospect of laser in neurosurgery is given.
A flexible therapeutic ventriculoscope allowing for the use of a variety of different instruments has been developed. Endoneurosurgical instruments are composed of an endoscopic contact YAG laser endoprobe, grasping forceps and a punctured needle. Endoneurosurgical procedures include biopsies, III ventriculostomy, fenestration of the septum pellucidum, aspirations of cysts and excisions of tumors in the cerebrospinal fluid pathways. Our ventriculoscope allows the initial treatment for progressive hydrocephalus caused by intraventricular tumors to take the form of reducing ventricular size and decreasing intracranial pressure, and it can also be used to perform biopsy examinations, so that acceptable neurological outcomes and an accurate histological diagnosis can be obtained with fewer side effects. The subsequent therapies for hydrocephalus caused by intraventricular tumors include radical surgery for benign tumors, irradiation for radiosensitive tumors, and irradiation and/or chemotherapy for either malignant or disseminated tumors. We have tried to avoid the sequelae of shunt surgery and have achieved maximum effects with the minimum of procedures by using our ventriculoscope.
Because no data are available concerning the histopathological effects of the potassium titanyl phosphate (KTP) laser on central nervous tissue, a study was performed using a canine model to compare the histopathological effects of a commonly used laser (CO2) and the KTP laser on brain and spinal cord tissue. Exposed brain and spinal cord tissue were irradiated with 0.1-s pulses (x10), with spot sizes of 1 mm (in focus) over a range of 1 to 10 W. Wedge-shaped lesions were produced with the CO2 laser, while more blunt, semilunar-shaped lesions were produced by the KTP laser. The depth and width of the lesions were proportional to the energy applied. The lesions ranged in surface diameter from 0.6 to 1.3 mm for CO2 and 0.8 to 1.6 mm for KTP lasers, respectively. The depth of the lesions varied from 0.4 to 2.0 mm for CO2 and 0.3 to 1.1 mm for KTP lesions. Histopathologically, a central zone of tissue destruction and vaporization was surrounded by a zone of coagulative necrosis, in turn surrounded peripherally by a zone of pallor. CO2-induced lesions were histologically more hemorrhagic than KTP-induced lesions. In view of the histopathological findings, the KTP laser appears as safe as the CO2 laser in terms of tissue lateral thermal change (penetration) and tissue absorption. The additional hemostatic advantage observed clinically for the KTP laser is demonstrated histologically as well. Although the wavelength of the KTP and argon laser light are similar, the histopathological effects seem to be less pigment dependent. The KTP laser seems well suited for neurosurgery and has the versatility provided by a fiberoptic delivery system.
Figure 1. Endoscopic Laser Third Ventriculostomy. A 37-year-old woman was admitted to the hospital because she had had headaches for two years. A neurologic examination was remarkable for the absence of retinal venous pulsations. Magnetic resonance imaging of the brain (Panel A) showed noncommunicating hydrocephalus due to stenosis of the caudal aqueduct of Sylvius (open arrow), with enlargement of the third ventricle and attenuation of its floor (solid arrow). Endoscopic laser third ventriculostomy (Panel B) was performed in an effort to control hydrocephalus without the use of a ventricular shunt. The right lateral ventricle was cannulated through a coronal burr . . .
The authors demonstrate an experimental use of the newly developed high power aluminium-gallium-arsenide (AlGaAr) diode laser (DIOMED 25, Olympus Optical Company, Tokyo, Japan). The unit consists of a compact body and fiberoptic probes with small accessories. There are two types (contact and non-contact) of probes. Tissue effects on rat liver, femoral artery, and brain tissue were examined. Adding that, we measured the thermal changes on the liver surface produced by the laser beam with a thermography system. For coagulation with the contact probe, 5 or 7 W was adequate but 10 W was too excess because of tissue adhesion. For cutting, low absorption of the laser in less vascularized tissue like brain white matter provided a deeper tissue damage compared with more vascularized tissue. The temperature at the center reached over 100 degrees C during 10 seconds after laser treatment with the cutting probe. These findings suggest that this system proved to be a good candidate for endoscopic hemostasis and cutting with meticulous maneuver.
This case illustrates that although endoscopic third ventriculostomy for patients with aqueductal stenosis is successful and minimally invasive, it can have severe, life-threatening complications.
A 3-year-old girl presented with hydrocephalus and aqueductal stenosis. She underwent endoscopic third ventriculostomy with laser fenestration of the third ventricular floor. During the procedure, she developed a severe intraventricular hemorrhage that required prolonged external ventricular drainage and ultimately ventriculoperitoneal shunting. Despite having a negative angiogram after the procedure, she presented 1 month later with a subarachnoid hemorrhage and a traumatic basilar tip aneurysm.
The patient underwent a right subtemporal approach with clip ligation of the aneurysm and subsequently had a good recovery.
Hemorrhagic complications after endoscopic third ventriculostomy are rare. The formation of a traumatic basilar tip aneurysm after this procedure has not been reported in the literature. Laser fenestration of the third ventricular floor may increase the risk of this event.
Although lasers have proved to be valuable in neuroendoscopy, surgeons are still not comfortable using high-energy laser endoscopic probes in proximity to vital structures such as the basilar artery in third ventriculostomy. The authors have developed a special laser catheter for use in neuroendoscopy; the object of this paper is to present their experimental and clinical experiences using the catheter.
This laser catheter is fitted with an atraumatic ball-shaped fiber tip that is pretreated with a layer of carbon particles. These carbon particles absorb approximately 90% of the energy emitted, which is very effectively converted into heat. As the heat is generated in this very thin layer of carbon coating, the temperature at the surface of the ball-shaped tip reaches ablative temperatures instantly at powers of only a few watts per second, which has enabled the authors to limit drastically the amount of laser light used and the length of exposure needed, thereby increasing safety even around critical structures.
The authors present experimental data and their clinical experience using these pretreated fiber tips with a neodymium-yttrium aluminum garnet contact laser or a diode contact laser in 49 patients (22 males and 27 females) and a variety of procedures: third ventriculocistemostomy (33 patients), cyst fenestration (nine patients), colloid cyst resection (six patients), and fenestration of the septum pellucidum (one patient). There was no instance of mortality or increased morbidity. To date, the procedure success rate is 100% and the overall outcome success rate is 86%. The authors conclude that pretreated atraumatic ball-shaped fiber tips now make laser application safe and effective in a variety of neuroendoscopic procedures. Because of their low power range (only several watts), compact diode lasers will be the energy source of first choice.
High-power semiconductor diode lasers were recently introduced and have been tested in ophthalmology and general surgery. These lasers are attractive from the practical and economical standpoint, and have enough power to perform most surgical procedures. They could replace other surgical lasers such as CO2, argon, 1.06 microm, and 1.32 microm Nd-YAG lasers for many applications in neurosurgery. We report our initial experience with the first available 0.805-microm surgical diode laser, the Diomed 25 (Diomed, Ltd, Cambridge, U.K.) in a series of 30 patients.
The diode laser was evaluated during surgical resection of various types of central nervous system tumors in 30 patients. It was used free-hand in 27 patients in contact and non-contact, continuous wave (cw) and pulsed modes, and during ventricular endoscopy in three patients. Average time of laser use during a procedure was 248 seconds. Output power ranged from 1 to 25 watts, with an average power per patient of 2.64 to 15.5 watts (mean, 8.78 watts). Total energy delivered ranged from 65 to 11,051 joules per patient.
Using 600- or 400-microm non-contact optic fiber, well pigmented tumor tissue hemostasis was obtained at cw 3 to 10 watts with a defocused beam, whereas vaporization required 10-25 cw or pulsed watts with a focused beam. Soft and tough tissue section could be obtained using a sculpted cone-shaped (600-300 microm tip) contact fiber at 7-10 cw watts after fiber tip charring. Because of the deeper penetration of 0.805-microm light in non-pigmented tissues, non-contact mode is not recommended for white matter or poorly vascularized tumors. The contact mode was not efficient on very soft tissues such as edematous brain parenchyma. The contact fibers proved to be very fragile because of heat generation.
The high power diode laser proved to be efficient for hemostasis, section and vaporization, using contact and non-contact modes, at different output powers. Economical and ergonomical advantages of this new generation of surgical lasers may cause them to replace other surgical lasers such as argon, CO2, and Nd-YAG lasers, mostly for tumor surgery.
Since more than 20 years CO2 and Nd:YAG lasers are established in the microsurgery of the nervous system. CO2 lasers can be used handheld, but may be focused on the target area by mirror optics and sideports of the operating microscope's micromanipulator. Nd:YAG lasers have the disadvantage of deep penetration into the brain and provocation of a large collateral damage. The need is for a fibre conducted solid system for surgery in delicate areas as for brain stem surgery. Fibre conduction of near infrared lasers allows better exposure of the target area compared to hollow wave guides or mirror equipment. Fibres can be tapered and modified according to the purpose. The holmium:YAG (Ho:YAG) laser has acquired interest by introducing the system into microsurgery of parenchymal tissue. They have not been proven yet sufficiently for neurosurgical tasks. The effort to minimalize the collateral tissue damage has to be maximalized in the surgery of nervous tissue and functional low redundant brain stem or spinal cord tissue. Volumetric data may be more precise in comparison to depth and width data of the laser lesion even when the different levels of the tissue interaction have to be analyzed for estimation of the real side effects in nervous tissue. We have used 50-800 ml delivered Ho:YAG single pulses in cortical areas of Sprague-Dawley rats and investigated the different lesion zones by volumetric data. The functional lesion zone was detected and measured by immunohistological staining of the heat shock protein HSP 72. For further reduction of the focus area, we have used tapered 400 to 200 microns fibres.
Third ventriculostomy for acquired non-communicating hydrocephalus is an excellent alternative to shunting procedures. Nevertheless, complications can be severe and even fatal (e.g., lesion of the basilar artery), especially if the floor of the 3rd ventricle is very tough and/or opaque. The authors describe a safe method of sharp perforation of the floor, which should be applied if blunt fenestration cannot be achieved easily.
The objective of the study was to report the initial experiences with the combined use of an infrared-based frameless stereotactic navigation device and neuroendoscopy. Ten hydrocephalic patients underwent endoscopic third ventriculostomy and two patients with intracranial cysts underwent cystoventriculostomy. The trajectory of the rigid endoscope and target point were planned by frameless stereotaxy. An articulated arm served to maintain the predetermined trajectory during the surgery and to guide the endoscope. Endoscopic surgery was successfully performed in 11 of the 12 patients. In one patient with a small third ventricle the ventriculostomy had to be abandoned. We observed no surgical morbidity. In none of the cases was it necessary to correct the predetermined trajectory of the endoscope to reach the planned target area. The planning of the trajectory and the target area, as well as the maintenance of the trajectory during endoscopy reduce the risk of inadvertent damage to vital structures. The combined use of frameless stereotaxy and neuroendoscopy might contribute to a decrease of procedure-related morbidity.
Endoscopic third ventriculostomy (ETV) has been shown to be a sufficient alternative in the surgical treatment of occlusive hydrocephalus. To elucidate the ongoing discussion of timing, indication, and surgical technique, a retrospective analysis of 100 consecutive ETVs was conducted.
One hundred ETVs were performed in 95 patients (43 female and 52 male patients). Their age ranged from 3 weeks to 77 years (mean age, 36 yr). Hydrocephalus was caused by aqueductal stenosis in 40 patients, space-occupying lesions in 42, and intraventricular or subarachnoid hemorrhage in 8. One patient had postinflammatory hydrocephalus, and four patients had occlusive hydrocephalus of unknown origin. In 33 cases, surgery was performed using stereotactic guidance.
ETV was accomplished in 98 of 100 cases. The overall success rate was 76%. Patients with benign space-occupying lesions and nontumorous aqueductal stenosis had the highest success rates, which were 95 and 83%, respectively. Complications were arterial bleeding in one case, venous bleeding in three cases, intracerebral bleeding in one case, and infection in one case. There were no permanent morbidities or mortalities.
ETV is most effective in treating uncomplicated occlusive hydrocephalus caused by aqueductal stenosis and space-occupying lesions. ETV is still effective in two-thirds of the patients with previous infections or intraventricular bleeding. Patients who have previously undergone shunting and who have occlusive hydrocephalus should undergo ETV at the time of shunt failure, with immediate ligation or removal of the shunt device. In selected cases of distorted anatomy or impaired visual conditions, stereotactic guidance is helpful.
Various biophysical features of the laser beam have already been utilized in clinical neurosurgery. However, the application of this therapeutic modality has by no means been overexploited. The history of laser application in neurosurgery has shown that there is no universal laser system capable of performing all surgical tasks in a suitable manner. The best results in traditional neurosurgery were achieved with instruments combining various wavelengths, such as the CO2 and neodymium-YAG lasers. A pulsed holmium-YAG and neodymium-YAG (Ho:YAG and Nd:YAG) combined laser have been recently developed to meet the special requirements of minimally invasive neurosurgery. The system consists of a compact double-crystal single-head solid-state laser system generating 2 different wavelengths (Ho:YAG 2.08 microns and Nd:YAG 1.05 microns), selected for their capabilities of efficient coagulation and ablation. The two wavelengths are coupled into a common flexible optical fiber, which allows endoscopic application. The wavelengths can act simultaneously or separately without any interchange of the instruments. The system was employed first for experimental and subsequently for clinical purposes, primarily for endoscopic operations. In this work the initial clinical experience is reported. The excellent haemostatic properties of the Nd:YAG laser and the ablative properties of the Ho:YAG laser were confirmed. It was concluded that simultaneous application of the two laser modalities within one flexible fiber offers new perspectives in tissue handling in endoscopic neurosurgery and as in open microsurgery.
Endoscopically "working around the corner" is presently restricted to the use of flexible endoscopes or an endoscope-assisted microneurosurgical (EAM) technique. In order to overcome the limitations of these solutions, endoscopic equipment and techniques were developed for "working around the corner" with rigid endoscopes. A steering insert with a 5 French working channel is capable of steering instruments around the corner by actively bending the guiding track and consecutively the instrument. A special fixation device enables strict axial rotation of the endoscope in the operating field. Endoscopic procedures "around the corner", including aqueductal stenting, pellucidotomy, third ventriculostomy and biopsy were performed in human cadavers. Special features of the used pediatric neuroendoscope system, i.e., reliable fixation, axial rotation, and controlled steering of instruments, increase the safety and reduce the surgical traumatization in selected cases, such as obstructive hydrocephalus due to a mass lesion in the posterior third ventricle, since endoscopic third ventriculostomy and biopsy can be performed through the same burr hole trephination. Limitations of this technique are given by the size of the foramen of Monro and the height of the third ventricle as well as by the bending angle of the instruments (40-50 degrees).
We retrospectively analyzed the indications, surgical techniques, and applicability of frameless neuronavigation to endoscopic procedures in a heterogeneous group of 15 patients.
In 8 patients indications for surgery were cystic lesions, in 3 patients intraventricular tumors, and in 4 patients occlusive hydrocephalus. The mean age was 39 years (range 9-76 years). The follow-up period ranged from 5-24 months (mean 10 months). Frameless neuronavigation was accomplished with the "operating arm system" in 10 cases and with the "optical tracking system" in 5 cases (RADIONICS, Burlington, USA).
In all 15 cases, neuronavigation sufficiently provided anatomical orientation, preoperative planning, and intraoperative realization of the approach. The calculated mean calibration error was 2.1 mm. There have been no permanent morbidities and no mortalities related to the use of endoscopes and neuronavigation.
In endoscopic neurosurgery, frameless neuronavigation is a useful tool in planning and realizing the approach and improving intraoperative orientation in selected cases. Indications are small or hidden lesions, impaired visual conditions, abnormal anatomy, and narrow ventricles. Endoscopic procedures include fenestration and resection of intraventricular or intraparenchymal cysts, biopsy of intraventricular tumors, and third ventriculostomy in selected cases.
Endoscopic third ventriculostomy (ETV) is an alternative to shunt placement in occlusive hydrocephalus. The negative impact of anatomic anomalies and variants on ETV have been sporadically reported but not yet investigated systematically. Therefore, the objectives of the present study are 1) to evaluate the frequency of endoscopic anatomic anomalies of the ventricular system, 2) to define their potential to complicate the procedure and to compromise the surgical results, and 3) to investigate the value of preoperative magnetic resonance (MR) imaging for their detection.
The video recordings, the operative reports, and the preoperative MR images of 25 hydrocephalic patients who underwent ETV were reviewed. The surgical results were classified into completed and successful, completed, but failed, and unsuccessfully attempted ETV and were correlated with the absence or presence of anatomic variants.
In 9 of the 25 patients, 10 anatomic anomalies or variants, respectively, were identified, accounting for an incidence rate of 36%. The single most common anatomic anomaly was a thickened third ventricular floor in 4 patients. Anatomic variants extended the operation time (n = 6), increased the stretching of floor and walls of the third ventricle during perforation (n = 4), were related to minor arterial bleeding (n = 3), and obscured the visual control of the basilar artery (n = 2). In 5 of the 9 patients, ETV was completed and successful, but in 2 patients, ETV was finally abandoned, and in an additional 2 patients, ETV was completed, but failed to cure the symptoms of hydrocephalus. In contrast, ETV was completed and successful in all 16 patients with normal anatomy. All anatomic anomalies had been detectable on preoperative MR imaging, with the exception of the thickened floor of the third ventricle.
Anatomic anomalies are a frequent finding during ETV. Successful perforation and control of the hydrocephalus correlates with the absence of anatomic anomalies. Most anatomic variants have the potential to increase the operative risk. With the exception of the thickened third ventricular floor, MR imaging allows us to identify all anatomic anomalies preoperatively, and enables the neurosurgeon to weigh the operative risk in a patient with an anatomic anomaly against the chance to perform ETV successfully.
Laser-assisted endoscopic neurosurgery by using conventional fibres requires the use of high-power laser light. Because this is potentially hazardous, we developed a pretreated fibre tip and evaluated tissue effects in vitro and in vivo.
By applying a highly absorbing coating to the front of the ball tip, almost all laser light is transformed into thermal energy, instantly producing ablative temperatures at the tip itself. The temperature distribution was examined by using an in vitro thermal imaging technique. The in vivo effect on rabbit cerebral tissue was examined macroscopically and histologically.
By using a conventional fibre tip, ablation was not observed, despite the use of high energy and power (20 W for 10 seconds), whereas histology and thermal imaging demonstrated deleterious effects deeply into the cerebral tissue. By using the coated fibre tip, ablation was observed at low energy and power (1 W for 1 second) with thermal effects restricted to superficial structures.
We show that laser-assisted neuroendoscopy can only be considered to be safe when pretreated "black" fibre tips are used, as laser light damages deep structures.
Today, endoscopic third ventriculostomy is an established operative modality in occlusive hydrocephalus. The elemental step in third ventriculostomy is the perforation of the floor of the third ventricle. Especially with a thickened third ventricular floor, anatomical orientation can be disturbed and perforation of third ventricular floor technically difficult. The combination of a neuronavigation system with an endoscope provides interactive image-guided neuroendoscopy. Exact planning of the approach is thus possible and the ideal trajectory to the target area can be determined. We have combined interactive neuronavigation and intraoperative fluoroscopy for incorporating real-time feedback to optimize endoscopy in patients with a thickened third ventricular floor selected for third ventriculostomy.
Hemorrhage control in endoscopic neurosurgery is critical because of the lack of suitable instruments for coagulation. One reason for this problem is that miniaturization of the instruments is still a technical problem. In this article, we present a solution: the use of bipolar microforceps with a small diameter of 1.5 mm.
With the use of modern synthetic and metallic materials, the construction of the bipolar microforceps was designed without the use of mechanical joints. All movable elements are integrated within the instrument shaft. This design provides optimal visibility of the operating field because the sheath has a diameter of only 1.5 mm along its entire length. Therefore, this instrument is compatible with most working channels of neuroendoscopes.
The new, joint-free design of the forceps and the electric insulation of the branches were the technical innovations that led to the development of this novel, multipurpose instrument.
This new instrument may enhance endoscopic resection and shrinkage of cystic lesions and may offer new possibilities in endoscopic tumor resection and the treatment of hemorrhage.
To report a case series of endoscopic third ventriculostomy (ETV) using laser in 40 consecutive patients with obstructive hydrocephalus.
Under stereotactic and endoscopic guidance, multiple perforations in the ventricular floor using a 1.32 microm neodymium-yttrium/aluminum/garnet (Nd-YAG) or a 0.805 microm diode laser unit and removal of intervening coagulated tissue ensued with a 4-6 mm opening between third ventricle and basilar cisterns.
The procedure could be completed in all cases. A transient complication occurred in five cases. In 39 patients (mean follow-up 28 months), 31 (79%) had a favorable outcome. Failure occurred in six patients, requiring permanent shunting leading to complete recovery, and two patients remained in a poor clinical status despite ETV.
Laser-assisted ETV is a safe and efficient procedure for the treatment of obstructive hydrocephalus. Laser is advantageous in cases of distorted anatomy and may reduce technical failures.
Endoscopic third-ventriculostomy (ETV) became the treatment of choice for non-communicating hydrocephalus and its effectiveness is largely reported. On the contrary, specific articles on complications and failures of this technique are very rare and this review aims at supplying further information about it. Therefore, an analysis of the main and up-to-date series is made and exhaustive data about complications and failures of ETV and about their incidence are obtained. The overall frequency rate of complications is 6-20%. Their severity may vary either because of the length of the damage (transient or permanent) or the value of the involved structures (basilar artery, areas of the CNS, hypothalamus) or the importance of the injury (from subclinical sequelae to fatal complications). Moreover, this study showed both the risk that the endoscopic procedure must be suspended (intra-operative failure) and the risk of an early (before 1 month) or delayed (even some years after the intervention) narrowing of the ventriculostomy. The rate of and the reasons for failure have been analysed and the success of a second ETV has been estimated. The results of this analysis suggest that the children proposed for ETV are carefully selected and meticulously studied during the follow-up.
The indications for neuroendoscopy are not only constantly increasing, but even the currently accepted indications are constantly being adjusted and tailored. This is also true for one of the most frequently used neuroendoscopic procedures, the endoscopic 3rd ventriculostomy (ETV) for obstructive hydrocephalus. ETV has gained popularity and widespread acceptance during the past few years, but little attention has been paid to the techniques of the procedure. After a short introduction describing the history of ETV, an overview is given of all the different techniques that have been and still are employed to open the floor of the 3rd ventricle. The spectrum of indications for ETV has been widely enlarged over the last years. Initially, the use of this procedure was restricted to patients older than 2 years, to patients with an obvious triventricular hydrocephalus, and to those with a bulging, translucent floor of the 3rd ventricle. Nowadays, indications include all kinds of obstructive hydrocephalus but also communicating forms of hydrocephalus. The results of endoscopic procedures in treating these pathologies are given under special consideration of shunt technologies. In summary, from the review of the publications since the first ETV performed by Mixter in 1923, this technique is the treatment of choice for obstructive hydrocephalus caused by different etiologies and is an alternative to cerebrospinal fluid shunt application.
How to avoid complications of endoscopic third ventriculostomy In: Ferrer E (ed) Minimally invasive neurosurgery
- Grotenhuis
How to avoid complications of endoscopic third ventriculostomy
- J A Grotenhuis
- JA Grotenhuis
The histopathological effects of the CO2 versus the KTP laser on the brain and spinal cord: a canine model
- F W Gamache
- S Morgello
- FW Gamache Jr