Tetsuya Nagatani

Kyoto Daini Red Cross Hospital, Kioto, Kyoto, Japan

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Publications (52)64.53 Total impact

  • Kazuhito Takeuchi · Tetsuya Nagatani · Toshihiko Wakabayashi
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    ABSTRACT: Background: Skull base reconstruction after extended transsphenoidal surgery is essential to prevent postoperative cerebrospinal fluid leakage. Methods: A novel and simple technique for skull base reconstruction termed "shoelace dural closure" was devised. The dura mater was closed with a fat graft using a continuous running suture with both ends of a double-armed suture. Conclusions: The shoelace dural closure is an effective method for achieving watertight closure of the anterior skull base without the use of lumbar drains, fascia lata grafts, or nasoseptal flaps.
    No preview · Article · Oct 2015 · Acta Neurochirurgica
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    ABSTRACT: Case report: Bilateral occlusion of the foramina of Monro is an extremely rare clinical condition. We present the case of a 10-year-old girl who complained of frequent headaches. Methods: Magnetic resonance imaging showed triventricular hydrocephalus due to aqueductal stenosis, so endoscopic third ventriculostomy was performed successfully. The headaches subsequently disappeared, but the patient presented with exacerbation of headaches 32 months postoperatively. Magnetic resonance imaging demonstrated bilateral hydrocephalus of the lateral ventricles, implying bilateral occlusion of the foramina of Monro. We again performed endoscopic surgery, confirming bilateral occlusion of the foramina of Monro. Results: The foramina of Monro were apparently obstructed by normal ependyma, and no tumor masses or other structures were detected around the foramina, so we diagnosed the occlusion of the foramina as secondary after endoscopic third ventriculostomy. We fenestrated the septum pellucidum using a monopolar micro endoscopic electrode, and a ventriculoperitoneal shunt was placed for the management of hydrocephalus. The postoperative course was uneventful, and the headaches were completely resolved.
    No preview · Article · Oct 2015 · Child s Nervous System
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    ABSTRACT: Introduction: Biopsy procedures of intra-parenchymal lesions are divided into needle biopsy (stereotactic or frameless) or navigation-guided endoscopic biopsy. Methods: We retrospectively reviewed 36 consecutive patients with intra-parenchymal lesions who underwent biopsy at our institution. Fourteen patients underwent navigation-guided endoscopic biopsy (endoscopic group) and 22 patients underwent needle biopsy (needle group). Rates of pathological diagnosis and postoperative hemorrhage were compared between groups and analyzed using Fisher's exact test. Probability values of <0.05 were considered statistically significant. Results: Pathological diagnostic rates were 100% (14/14) for the endoscopic group and 96% (21/22) for the needle group, showing no significant difference. The postoperative hemorrhage rate was 7.1% (1/14) in the endoscopic group and 27.3% (6/22) in the needle group (p=0.21). Symptomatic postoperative hemorrhage was seen in 0% (0/14) of the endoscopic group and 18.2% (4/22) in the needle group (p=0.14). Conclusion: Both needle and endoscopic biopsies are accurate procedures with high rates of pathological diagnosis. Postoperative hemorrhage tended to be less frequent with endoscopic biopsy than with needle biopsy. Here, we described procedure selection and ingenuity of accurate and safe biopsy at our institution.
    No preview · Article · Sep 2014 · No shinkei geka. Neurological surgery
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    ABSTRACT: We describe a new endoscopic technique, the dual-endoscopic method, in which two independent endoscopic systems are simultaneously used in the subtemporal space and intraparenchymal field for patients with pontine cystic tumours. Tumours were successfully removed through a sheath placed in the brainstem via the subtemporal keyhole approach, with safety ensured by the second subtemporal endoscope. A purely endoscopic subtemporal approach was performed in three cases of pontine cystic tumour, including two low-grade gliomas and a recurrent chordoma. The gliomas showed nodules. Recurrent chordoma consisted of a mucinous component. Using a keyhole subtemporal approach and a 4.0-mm rigid endoscope with a high-definition camera, a transparent puncture needle containing a 2.7-mm rigid endoscope was inserted into the cyst. The tumour was removed using suction, biopsy forceps, and scissors simultaneously placed with the 2.7-mm endoscope in a transparent sheath. Since the 4.0-mm endoscope placed in the subtemporal space monitored all procedures of the 2.7-mm endoscope, tumour removal was performed safely without damaging the pons, cranial nerves, or vessels. We safely and successfully removed a cystic pontine tumour using a dual-endoscopic method. This new method ensures the safety of deep-seated endoscopic procedures via a minimally invasive transcranial approach.
    No preview · Article · Apr 2014 · Acta Neurochirurgica
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    ABSTRACT: Hyponatremia is a common and potentially serious complication of transsphenoidal surgery (TSS). Since September 2009, we have implemented moderate water intake restriction (< 2500 mL/day) after TSS in an attempt to prevent this complication. The aim of this study was to investigate the efficacy of a combination of moderate restriction of water intake plus antidiuretic hormone (arginine vasopressin [AVP]) replacement therapy in patients with diabetes insipidus (DI) for reducing the incidence of delayed hyponatremia after TSS. Patients treated from September 2005 to August 2009 were allowed to drink water freely after surgery (the control group), while patients treated from September 2009 to June 2012 were restricted to less than 2500 mL water per day (the water restriction group). To reduce the occurrence of hypernatremia, AVP replacement therapy was provided immediately after the development of DI. We retrospectively analyzed the incidence of hyponatremia, DI, and hypernatremia in patients following TSS. Hyponatremia incidence was significantly lower in the water restriction group (P = 0.017); however, there were no significant differences in DI incidence and hypernatremia incidence between the 2 groups. Under DI control with AVP replacement therapy, the water restriction group showed no significant difference in the daily self-rated thirst level for the patients with and without DI. Moderate water intake restriction in addition to AVP replacement therapy significantly decreases the incidence of hyponatremia without patient discomfort (extreme thirst) and other complications. However, further studies are required to determine the most effective amount of water and the optimal duration of postoperative water restriction.
    Preview · Article · Feb 2014 · Nagoya journal of medical science
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    ABSTRACT: A combined transsphenoidal-transcranial approach for the resection of pituitary adenomas has previously been reported. While this approach is useful for specific types of pituitary adenomas, it is an invasive technique. To reduce the invasiveness of this approach, we adopted the keyhole concept for pituitary adenoma resection. A 23-year-old man presented at a local hospital with a 6-month history of bilateral hemianopia. Magnetic resonance imaging revealed a large pituitary adenoma extending from the sella turcica toward the right frontal lobe. Endoscopic transsphenoidal surgery was planned at a local hospital; however, the operation was abandoned at the start of the resection because of the firm and fibrous nature of the tumor. The patient was subsequently referred to our hospital for additional surgery. The tumor was removed purely endoscopically via a transsphenoidal and transcranial route. Keyhole craniotomy, 3 cm in diameter, was performed, and a tubular retractor was used to achieve a wider surgical corridor; this enabled better visualization and dissection from the surrounding brain and provided enough room for the use of surgical instruments under endoscopic view. The tumor was successfully removed without complication. This is the first case report to describe the resection of a giant pituitary adenoma using a purely endoscopic and simultaneous transsphenoidal and transcranial keyhole approach.
    Preview · Article · Jan 2014
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    ABSTRACT: Central diabetes insipidus (CDI) is caused by deficiency of arginine vasopressin, an antidiuretic hormone. Patients with CDI manifest polyuria which is usually compensated for by increases in water intake. However, some patients are not able to sense thirst due to the destruction of osmoreceptors in the hypothalamus. These adipsic CDI patients are easily dehydrated and the consequent dehydration could be life-threatening. The objective of this study was to investigate the prognosis of adipsic CDI patients. We have reviewed 149 patients with CDI in three hospitals using databases of the electronic medical recording systems, and examined whether adipsia could affect the morbidity and mortality in CDI patients with multivariable analyses. Twenty-three patients with CDI were adipsic while the remaining 126 patients were non-adipsic. The multivariate analyses showed that the incidence of serious infections which required hospitalization was significantly higher in the adipsic CDI patients compared to that in non-adipsic CDI patients (p <0.001). A total of 6 patients with CDI died during the follow-up (median duration; 60 months, range 1 to 132 months). Four of them were adipsic, three of whom died of infection. The statistical analyses revealed that the risk of death in adipsic CDI patients was significantly higher than in non-adipsic patients (p =0.007). It is thus suggested that adipsic CDI patients were susceptible to serious infections which could be the causes of death.
    Full-text · Article · Nov 2013 · Endocrine Journal
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    ABSTRACT: The usefulness of 1.5-T high-field intraoperative magnetic resonance (iMR) imaging during transsphenoidal surgery for functioning pituitary adenomas was retrospectively evaluated based on long-term endocrine remission from the records of 14 patients who underwent transsphenoidal surgery with iMR imaging for functioning pituitary microadenomas and small adenomas located in the intrasellar region. The maximum tumor diameter was 9.3 ± 2.6 mm. Patients were diagnosed with acromegaly (n = 7), prolactinoma (n = 4), and Cushing's disease (n = 3). If iMR imaging detected tumor remnants after resection, the resection cavity was reexamined and further resection was performed. Postoperative endocrine follow-up period was mean 33.7 ± 13.3 months. Tumor remnants were detected after the first resection in seven patients. Further resection was performed in five of these patients, and three achieved long-term endocrine remission. As a result, the overall long-term endocrine remission rate was 78.5% (11/14), instead of the 57.1% (8/14) that would be expected if iMR imaging had not been performed. Long-term endocrine remission had a tendency to be associated with the absence of tumor remnants on the final iMR images, but this was not significant (p = 0.09). Long-term endocrine remission was associated with presence of tumor remnants in the cavernous sinus on the final iMR images (p = 0.03). High-field iMR imaging is useful for depicting tumor remnants after resection, and increased the long-term endocrine remission rate for patients with functioning pituitary microadenomas and small adenomas.
    No preview · Article · Jul 2013 · Neurologia medico-chirurgica
  • Tadashi Watanabe · Tetsuya Nagatani · Kiyoshi Saito
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    ABSTRACT: Endoscopic approaches to intraventriclar lesions and the endoscopic anatomy of the cerebral ventricles are described. A wide visual field, close observation for deep seated lesions and exploration in the wet field are the benefits of endoscopic surgery. In addition, changes in view point help to foster a better understanding of the three-demensional anatomy of the cerebral ventricles. Endoscopic tumor removal is performed via various types of transparent sheathes with specially designed instruments. The ventricles are surrounded by essential structures, which should be kept intact during the surgery. Distortion of the paraventricular structures is often seen in patients with paraventricular tumors. The foramen of Monro, choroid plexus, and thalamostriate vein are the clear landmarks to follow even in distorted anatomy. Understanding the endoscopic anatomy of the cerebral ventricles based on these landmarks assures a correct orientation and safety during the surgical treatment. © 2013, Japanese Congress of Neurological Surgeons. All rights reserved.
    No preview · Article · Jan 2013 · Japanese Journal of Neurosurgery
  • Tetsuya Nagatani · Toshihiko Wakabayashi
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    ABSTRACT: Although the recent progress in neruoendoscopy including image-guidance techniques has enhanced pituitary surgery via the transsphenoidal route, it still requires the surgeon possess sophisticated skills to overcome conflicts between the lens rod-scope and surgical tools in the narrow surgical corridor. To achieve a safe and reliable technique, a systematic understanding of the anatomical structures of the nasal cavity, sphenoid and ethmoid sinuses, and sellar region are mandatory. The nasal phase is the first step of the procedure, which includes the inferior and middle turbinates, bony septum of the vomer, perpendicular plate of the ethmoid bone and sphenopa-latine artery as important landmarks. For the sphenoid phase, the superior turbinate, posterior ethmoid sinus, sphenoid septum, optic prominence, carotid prominence, and opticocarotid recess should be cared for before approaching the sellar floor. Finally, after making an incision into the sellar floor dura matter and medial cavernous sinus wall, such structures as diaphragm sellae, and arachnoid recess should be mentioned. In this article, the authors describe the basis of microsurgical anatomy in a step-by-step way in relation to pure endoscopic endonasal removal of pituitary tumors. © 2013, Japanese Congress of Neurological Surgeons. All rights reserved.
    No preview · Article · Jan 2013 · Japanese Journal of Neurosurgery
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    ABSTRACT: Endoscope biopsy guided navigation for intra-parenchymal lesions is safe and effective, but determination of the entry point and trajectory of the endoscopic biopsy is less clear. We describe preoperative planning based on stereotactic methods, and achieving the plan using several techniques. The preoperative planning was based on stereotactic methods such as determining target, entry point, and trajectory. A transparent sheath was advanced under guidance of the navigation system and specimens collected under visual endoscopic monitoring. After collecting specimens, intraoperative magnetic resonance imaging was performed for confirming accurate sampling. Correct specimens were obtained in 6 cases as confirmed by intraoperative magnetic resonance imaging. The histological diagnoses were diffuse large B-cell type malignant lymphoma (n = 3), astrocytoma (n = 1), glioblastoma (n = 1), and inflammatory changes without neoplastic cells (n = 1). No postoperative intracranial hemorrhage or other operative complications occurred. Preoperative planning based on stereotactic methods and procedures guided by navigation systems can achieve endoscopic biopsy for intraparenchymal lesions safely and accurately.
    No preview · Article · Sep 2012 · Neurologia medico-chirurgica
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    ABSTRACT: Nonfunctioning pituitary macroadenoma (NFMA) is a benign neoplasm that causes visual function disturbances and headaches and can be treated by transsphenoidal surgery (TSS). It is unclear how quality of life (QOL) changes with surgery and which QOL factors are affected by treatment. The aim is to assess the temporal transition of QOL in NFMA patients undergoing TSS and to identify influential factors. The QOL of NFMA patients who underwent endoscopic TSS was investigated with the short-form 36 (SF-36) health survey questionnaire, general health questionnaire 30 (GHQ30), and numerical rating scale (NRS) of pain at the following three time points: immediately before, 1 month after, and 6 months after surgery. Twenty-four of 30 patients had visual deterioration. The SF-36 baseline value of visual function-impaired NFMA patients was lower than that of the normal population. SF-36 results showed that physical summary scores decreased at 1 month after the operation, but recovered up to the normal population level by 6 months. Mental summary scores generally increased at 1 month after surgery and remained stable until 6 months later. The GHQ30 results were similar to the SF-36 mental summary scores. The strongest factor related to the QOL was visual function. The amount of pain and the necessity of hormonal replacement were also influencing factors. The QOL of NFMA patients is affected both physically and mentally by surgical treatment and symptoms. This QOL assessment is important for planning treatment strategies.
    No preview · Article · Aug 2012 · Acta Neurochirurgica
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    ABSTRACT: Mouse models have been widely used in developing therapies for human brain tumors. However, surgical techniques such as bone drilling and skin suturing to create brain tumors in adult mice are still complicated. The aim of this study was to establish a simple and accurate method for intracranial injection of cells or other materials into mice. The authors performed micro CT scans and skull dissection to assess the anatomical characteristics of the mouse postglenoid foramen. They then used xenograft and genetically engineered mouse models to evaluate a novel technique of percutaneous intracranial injection via the postglenoid foramen. They injected green fluorescent protein-labeled U87MG cells or virus-producing cells into adult mouse brains via the postglenoid foramen and identified the location of the created tumors by using bioluminescence imaging and histological analysis. The postglenoid foramen was found to be a well-conserved anatomical structure that allows percutaneous injection into the cerebrum, cerebellum, brainstem, and basal cistern in mice. The mean (± SD) time for the postglenoid foramen injection technique was 88 ± 15 seconds. The incidence of in-target tumor formation in the xenograft model ranged from 80% to 100%, depending on the target site. High-grade gliomas were successfully developed by postglenoid foramen injection in the adult genetically engineered mouse using virus-mediated platelet-derived growth factor B gene transfer. There were no procedure-related complications. The postglenoid foramen can be used as a needle entry site into the brain of the adult mouse. Postglenoid foramen injection is a less invasive, safe, precise, and rapid method of implanting cells into the adult mouse brain. This method can be applied to both orthotopic xenograft and genetically engineered mouse models and may have further applications in mice for the development of therapies for human brain tumors.
    Preview · Article · Dec 2011 · Journal of Neurosurgery

  • No preview · Article · Sep 2011 · No shinkei geka. Neurological surgery
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    ABSTRACT: Visualization of endolymphatic hydrops has been performed using magnetic resonance imaging (MRI) after intratympanic or intravenous gadolinium (Gd) injection. Our recent findings indicate that just as the prevalence of asymptomatic glaucoma is greater than that of symptomatic glaucoma, there are also many cases of asymptomatic endolymphatic hydrops. It is assumed that the asymptomatic endolymphatic hydrops that precedes Ménière's disease is found more frequently using MRI than with other techniques. Gd in the inner ear moves into the cerebrospinal fluid (CSF) via the internal auditory meatus. Gd enhancement is also recognized in the ocular fluid after the intravenous Gd administration. In this paper, the relationships between CSF, ocular fluid and inner ear fluid are reviewed. The central nervous system, eye and inner ear contain specialized extracellular fluids that are essential for maintaining their function: CSF, ocular fluid consisting of vitreous humor and aqueous humor, and inner ear fluid consisting of perilymph and endolymph. Abnormal accumulation of or pressure elevation in these fluids is associated with hydrocephalus, glaucoma and Ménière's disease, respectively. The dura mater and the arachnoid membrane of the optic nerve canal and inner ear meatus are very close to the eye and the inner ear, respectively. It has been reported that low CSF pressure is associated with glaucoma and endolymphatic hydrops. In glaucoma and Ménière's disease, nerve damage to ganglion cells rather than damage of the sensory cells is directly associated with progression of the disease. Retinal ganglion cells in glaucoma and spiral ganglion cells in Ménière's disease are targets of the abnormal accumulation of, or increased pressure in, the extracellular fluid, just as neurons are damaged in hydrocephalus. Studies on hydrocephalus, glaucoma and Ménière's disease as a group may deepen our understanding of each disease.
    No preview · Article · Aug 2011 · Auris, nasus, larynx
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    ABSTRACT: A 51-year-old man was referred to the Department of Cardiology in our hospital due to severe congestive heart failure and ventricular arrhythmias in March 2008. He had repeated ventricular tachycardia for years and the left ventricular ejection fraction (EF) was 11% on admission. A myocardial biopsy revealed that over 50% cardiomyocytes were replaced by fibrosis. Due to the typical acromegalic features, he was referred to the endocrinology department and diagnosed as acromegaly. He was treated with octreotide for 8 months followed by trans-sphenoidal surgery. The plasma levels of growth hormone (GH) and insulin-like growth factor-1 (IGF-1) decreased by octreotide and normalised by surgery after which the cardiac function improved drastically. The current case demonstrates that cardiac dysfunction in acromegaly could be recovered by normalisation of GH and IGF-1 even in the presence of severe fibrosis in the myocardium.
    Full-text · Article · Oct 2010 · Case Reports
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    ABSTRACT: The authors have developed a novel intraoperative neuronavigation with 3-dimensional (3D) virtual images, a 3D virtual navigation system, for neuroendoscopic surgery. The present study describes this technique and clinical experience with the system. Preoperative imaging data sets were transferred to a personal computer to construct virtual endoscopic views with image segmentation software. An electromagnetic tracker was used to acquire the position and orientation of the tip of the neuroendo-scope. Virtual endoscopic images were interlinked to an electromagnetic tracking system and demonstrated on the navigation display in real time. Accuracy and efficacy of the 3D virtual navigation system were evaluated in a phantom test and on 5 consecutive patients undergoing neuroendoscopic surgery. Virtual navigation views were consistent with actual endoscopic views and trajectory in both phantom testing and clinical neuroendoscopic surgery. Anatomic structures that can affect surgical approaches were adequately predicted with the virtual navigation system. The virtual semitransparent view contributed to a clear understanding of spatial relationships between surgical targets and surrounding structures. Surgical procedures in all patients were performed while confirming with virtual navigation. In neurosurgery with a flexible neuroscope, virtual navigation also demonstrated anatomic structures in real time. The interactive method of intraoperative visualization influenced the decision-making process during surgery and provided useful assistance in identifying safe approaches for neuroendoscopic surgery. The magnetically guided navigation system enabled navigation of surgical targets in both rigid and flexible endoscopic surgeries.
    No preview · Article · Jun 2010 · Neurosurgery
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    ABSTRACT: Intradural chordomas are rare and have been considered benign owing to the feasibility of complete resection and the display of lesser aggressive biologic behavior than typical chordomas. We herein reported 2 cases of intradural cranial chordoma with aggressive biologic behavior. A tumor (anti-Ki-67 monoclonal antibody [MIB-1], 13.9%) in a 59-year-old woman was strongly adherent to the brainstem and involved the basilar artery and its branches. After subtotal removal, the remnant tumor was treated with stereotactic radiotherapy. A tumor (MIB-1, 6.2%) in a 75-year-old woman repeatedly recurred even after initial gross total removal. The recurrent chordomas were treated with γ-knife radiosurgery. The cases presented in this study indicate that intradural chordomas can also be aggressive such as typical chordomas. Long-term follow-ups with a large number of patients with this condition are essential for elucidating the prognosis of intradural chordomas.
    No preview · Article · Mar 2010 · World Neurosurgery
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    ABSTRACT: This paper proposes a rapid method for compensating registration error between the tracker and the endoscope in a flexible neuroendoscopic surgery navigation system, as well as evaluates the accuracy of the proposed method. Recently, flexible neuroendoscopic surgery navigation systems have been developed utilizing an electromagnetic tracker (EMT). In such systems, an electromagnetic tracker sensor is fixed at the tip of a flexible endoscope to get the position and the orientation of the endoscope camera by using the relationship between the camera and the sensor. Usually, the relationship is estimated by a registration method using a calibration chart. Then, virtual images corresponding to real endoscopic views are generated by using the position and orientation of the camera. However, in the clinical application, the sensor has to be re-fixed before or during the surgery due to its disinfection or breakage. Although the sensor can be re-fixed at the same position as the registered position, it is difficult to ensure the roll of sensor in the same because the senor is a cylinder. Furthermore, the sensor can also be rotated by the operation of tools during surgery. As a result, the virtual images will be rotated and become greatly different from the real endoscopic views. In this case, the relationship between camera and sensor has to be re-estimated by a registration method or manually, which makes the operation of endoscope complicated and nonfeasible. In order to overcome this problem, we proposed a rapid method for compensating the rotational error between real and virtual cameras using the epipolar geometry. In this study, various experiments of the method are performed in order to evaluate and to improve its accuracy. Experimental results suggested estimation accuracy can be improved by reducing the relative error of EMT outputs, and it is necessary to ensure the quality of images which are used in the estimation.
    No preview · Article · Mar 2010 · Proceedings of SPIE - The International Society for Optical Engineering
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    ABSTRACT: This paper presents a method for compensating the rotation error between the virtual and real endscopic images in a flexible neuroendoscopic surgery navigation system. Recently, electromagnetic tracker sensor is used in the flexible neuroen-doscopic surgery navigation system to track the tip of the endoscope camera in order to generate the navigation information such as virtual endoscope images corresponding to the endoscope views. However, due to the operation of surgery tools, the sensor will be rotated frequently during the surgery. Therefore, the virtual images become greatly different from the real endoscopic views. In this paper, we propose a method to overcome this problem using epipolar geometry. The epipoles of real (virtual) endoscope image pairs which are captured (generated) at different positions are estimated, and the rotation error between real endoscope and virtual endoscope is estimated by comparing the epipoles on the real image and corresponding virtual image. We implemented the proposed method in a navigation system for flexible neuroendoscopic surgery and performed a phantom test. The result showed the proposed method was efficient for compensating the rotation error between the virtual and real endscopic images in a flexible neuroendoscopic surgery system.
    No preview · Article · Jan 2010