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Brachial Plexus
Abstract
Several interventions remain almost inaccessible to endoscopic surgery, such as brachial plexus injuries. Development of minimally invasive and robot-assisted surgical approaches has the potential to greatly improve the surgical outcome.
Our clinical experience is based on 12 cases of brachial plexus tele-endomicrosurgery operated using a da Vinci robot.
Considering the microsurgical gesture, all nerve repairs were achieved under excellent conditions. Considering the minimally invasive approach, results are yet inconclusive, with a need to convert to open surgery in 9 cases. The reasons for conversion were numerous: difficulties to maintain the resection cavity, unsuited instrumentation, blurring of the stereoscopic vision and major difficulties in visual identification of anatomical landmarks.
In brachial plexus surgery, tele-endomicrosurgery is feasible but faces major constraints regarding the creation, maintenance and navigation inside the working chamber. Adaptation of the endoscopic equipment and use of advanced techniques of augmented reality should address most of these problems.
The size of the incisions for free muscle flaps is often very large, and a source of deep adhesions and unaesthetic scars. But it is justified by performing the microsurgical step comfortably. In the hopes of shortening the size of incisions, the goal of this work was to study the feasibility of vascular microanastomoses through an endoscopic approach. The material consisted of two cadavers, a telemanipulator, and a vascular clamp. The antebrachial skin was detached then distended by gas insufflation. Four incisions, 1cm each, allowed the insertion of four trocarts connected to the telemanipulator. The artery was dissected (radial or ulnar) and the vascular clamp was introduced under the skin through one of the trocarts, and then installed on the dissected artery. The vascular anastomosis was performed with the use of a 10/0 nylon suture. The anastomosis lasted 2hours under insufflation without any leak. The two arteries were identified then dissected without difficulty. The anastomosis was performed in good conditions. The assembling and disassembling of the clamp were time consuming. The main difficulties were caused by a long suture and a very fragile needle. Our results demonstrate the feasibility of vascular microanastomosis through an endoscopic approach. The next step is to perform the first clinical case for example on a latissimus dorsi free muscle flap.
Objective:
The purpose of this article is to provide a practical review of the spectrum of MRI findings in inflammatory muscle diseases and their noninflammatory mimics.
Conclusion:
MRI is a highly sensitive tool for the diagnosis of muscle diseases. Although it has low specificity, awareness of the potential imaging findings in the various, sometimes rare, muscular disorders is helpful for accurate diagnosis.
The purpose of our study was to determine whether a three-dimensional (3D) isotropic resolution fast spin echo sequence (FSE-cube) has similar image quality and diagnostic performance to a routine MRI protocol for brachial plexus evaluation in volunteers and symptomatic patients at 3.0 T. Institutional review board approval and written informed consent were guaranteed.
In this prospective study FSE-cube was added to the standard brachial plexus examination protocol in eight patients (mean age, 50.2 years) with brachial plexus pathologies and in six volunteers (mean age, 54 years). Nerve visibility, tissue contrast, edge sharpness, image blurring, motion artefact and acquisition time were calculated for FSE-cube sequences and for the standard protocol on a standardised five-point scale. The visibility of brachial plexus nerve and surrounding tissues at four levels (roots, interscalene area, costoclavicular space and axillary level) was assessed.
Image quality and nerve visibility did not significantly differ between FSE-cube and the standard protocol (p>0.05). Acquisition time was statistically and clinically significantly shorter with FSE-cube (p<0.05). Pathological findings were seen equally well with FSE-cube and the standard protocol.
3D FSE-cube provided similar image quality in a shorter acquisition time and enabled excellent visualisation of brachial plexus anatomy and pathology in any orientation, regardless of the original scanning plane.
The objective was to demonstrate the feasibility of MRI/CT fusion in demonstrating lumbar nerve root compromise.
We combined 3-dimensional (3-D) computed tomography (CT) imaging of bone with 3-D magnetic resonance imaging (MRI) of neural architecture (cauda equina and nerve roots) for two patients using VirtualPlace software.
Although the pathological condition of nerve roots could not be assessed using MRI, myelography or CT myelography, 3-D MRI/CT fusion imaging enabled unambiguous, 3-D confirmation of the pathological state and courses of nerve roots, both inside and outside the foraminal arch, as well as thickening of the ligamentum flavum and the locations, forms and numbers of dorsal root ganglia. Positional relationships between intervertebral discs or bony spurs and nerve roots could also be depicted.
Use of 3-D MRI/CT fusion imaging for the lumbar vertebral region successfully revealed the relationship between bone construction (bones, intervertebral joints, and intervertebral disks) and neural architecture (cauda equina and nerve roots) on a single film, three-dimensionally and in color. Such images may be useful in elucidating complex neurological conditions such as degenerative lumbar scoliosis(DLS), as well as in diagnosis and the planning of minimally invasive surgery.
This technical note demonstrates the relevance of the isotropic 3D T2 turbo-spin-echo (TSE) sequence with short-term inversion recovery (STIR) and variable flip angle RF excitations (SPACE: Sampling Perfection with Application optimized Contrasts using different flip angle Evolutions) for high-resolution brachial plexus imaging. The sequence was used in 11 patients in the diagnosis of brachial plexus pathologies involving primary and secondary tumors, and in six volunteers. We show that 3D STIR imaging is not only a reliable alternative to 2D STIR imaging, but it also better evaluates the anatomy, nerve site compression and pathology of the plexus, especially to depict space-occupying tumors along its course. Finally, due to its appropriate contrast we describe how 3D-STIR can be used as a high-resolution mask to be fused with fraction of anisotropy (FA) maps calculated from diffusion tensor imaging (DTI) data of the plexus.
A synopsis of the assessment and treatment of injuries to the brachial plexus is given. There are two principal types of injury to the brachial plexus: one is due to violent trauma in the adult and the other is sustained during birth. Diagnosis is by anatomical knowledge plus imaging and laboratory investigations. Clinical signs and history-taking direct treatment. Referrals should be to an established Nerve Repair Centre once diagnosis has been confirmed. The best outcome follows early intervention.
In the endoscopic surgical fields, more information which could be used intraoperatively is strongly demanded. Three-dimensional reconstructed images are useful imaging modalities to assist the surgeon in endoscopic surgery. We expected a new magneto-optic hybrid 3-D sensor configuration, and have developed an augmented reality navigation system using an accurate three-dimensional sensory system that can be utilized in endoscopic surgery. The system has accommodated oblique endoscope, real-time distortion correction of magnetic fields. We have preliminary established ‘combined’ navigation system. The complete system consists of a laparoscope, two (magnetic and optic) 3D digitizers, ultrasonographic device, a laparoscopic US probe, and a workstation with a volume rendering accelerator. Augmented reality (AR) visualization, which superimposed the visualized 3D-US images and segmented and rendered CT-based images on captured laparoscopic live images, was achieved. We applied our system to various clinical cases. The system provides us real-time anatomical information which cannot be visualized without navigation system. 3D-US as an imaging modality has the advantage that real-time imaging is acquirable, regardless of organ shift or distortion.
Recent advances in magnetic resonance imaging (MRI) technology has improved vizualization of the peripheral nerve system, enabling further explorations of plexopathy beyond the physical examination and electrodiagnostic studies. High-resolution MRI is a method of choice, showing diffuse or focal enlargement, hyperintensity on T2-weighted images, altered fascicular patterns, enhancement after gadolinium injection or masses causing infiltration or compression, and signs of muscle denervation. Other techniques are complementary. Ultrasonography can depict a spectrum of lesions and can be coupled with dynamic manoeuvres to explore entrapment syndromes. Positron emission tomography (PET) can be helpful to differentiate between tumor recurrence and postradiation plexopathy. In posttraumatic brachial plexopathy, postmyelographic tomography and MRI are complementary. Traumatic injury, tumor formation, entrapment syndrome, and other conditions illustrate the different techniques available for imaging. Adequate imaging of the brachial and lombosacral plexuses is a useful aid for diagnosis, preoperative assessment and therapeutic planning and follow-up.
Tele-operating robots, that have been developing for 10 years, are a revolution in the field of minimally invasive gynaecology. Indeed, by restoring three-dimensional view and the surgeon's hand freedom, the robot diminishes the technical difficulties of laparoscopy. The robot brings the surgeon back to open-air movements while preserving the minimally invasive aspect of the procedure and should, therefore, allow an easier transition for laparotomic surgeons to minimally invasive techniques. However, some inconvenients remain: the robot's size, its time-consuming installation, the lack of force feedback and the cost of robotic surgery. To this day, the robot was used in gynaecology for tubal reversal, myomectomies, hysterectomies, promontofixations and the treatment of gynaecological cancers, but the benefits compared to laparoscopic techniques have not yet been demonstrated and will require large scale prospective studies. These benefits will also have to be weighed up to the cost and organizational constraints.
The management of peripheral nerve injuries is nowhere so complex as in the brachial plexus, and in this article we use this absorbing structure to exemplify important principles of diagnosis and treatment of these significant injuries.
Brachial plexus injuries have increased in numbers since the turn of the twentieth century in line with the increased use of motorcycles. Advances in microsurgical and tissue transfer techniques have seen the management of such injuries change dramatically during this time period. As a result, surgery for plexus injuries is now considered a legitimate option. Such injuries require extensive medical input in a multidisciplinary environment. All patients should be thoroughly investigated to establish the exact extent of the injury and managed on an individual basis. The options available are conservative or surgical. Conservative options include physiotherapy, orthotics and pain control. Surgical reconstruction of the plexus may involve neurolysis, nerve grafting, nerve transfer and late peripheral reconstruction including arthrodesis, tendon transfers, free muscle transfers and amputation. Despite many advances in the field, injuries still result in considerable disability and loss of working days.
Anatomy is the key of success for all regional anesthesia techniques. Knowledge of the relevant brachial plexus anatomy and its relations, as well as the distribution of its sensory and motor innervation to the upper extremity, is crucial for understanding the resulting distribution of sensory anesthesia and motor blockade. Correct identification of superficial bony, muscular and vascular landmarks and profound structures are fundamental to achieving consistent success and minimizing complications with brachial plexus anesthesia. The different approaches to the plexus determine the characteristics of the resulting anesthesia that only occurs if a high local anesthetic volume is delivered sufficiently near the desired neural structures and into the brachial plexus sheath.
Unlabelled:
Robotics allows up to 40× visual magnification and 10× magnification of the surgeon's movements, and eliminates physiologic tremors. These properties should allow the development of mini-invasive limb surgery, especially of the brachial plexus. The purpose of this work was to test the feasibility of the restoration of elbow flexion according to the technique of Oberlin using a da Vinci robot. The authors' series included four patients (average age, 31 years) presenting with elbow flexion paralysis. They were operated on 8 months after injury using a da Vinci S robot. In three patients, the open technique (technique 1) was used, and the mini-invasive approach (technique 2) was used for the last one. Strength of elbow flexion was measured. After 1-year follow-up, all of the patients had recovered elbow flexion. No sensory or motor deficit was found in the ulnar nerve territory. There was no difficulty with technique 1; technique 2, however, required a conversion to technique 1 because of difficulty visualizing the operative field. The results of the authors' series show the feasibility of the robot-assisted technique for the Oberlin procedure. The lack of sensory feedback was not an issue. The development of specific retractors and instruments should improve the mini-invasive technique.
Clinical question/level of evidence:
Therapeutic, V.
The EU Research Training Network on Augmented Reality in Surgery (ARIS*ER) was established with two aims: (1) to develop next-generation novel image guidance (augmented reality based on medical images) and cross-linked robotic systems (automatic control loops guided by information sensed from the patient) and (2) to educate young researchers in the user-centred, multidisciplinary design of emerging technologies for minimally invasive surgery (MIS) and intervention radiology. Collaborations between engineers, Human Factors specialists, industrial designers and medical end users were foreseen, but actual methodologies had to be developed. Three applications were used as development vehicles and as demonstrators. The resulting teamwork and process of identifying requirements, finding solutions (in technology and workflow), and shifting between these to optimize and speed development towards quality of care were studied. The ARIS*ER approach solves current problems in collaborative teams, taking a systems approach, and manages the overview of requirements and solutions, which is too complex to manage centrally.
In patients with a peripheral nerve injury, a simple conceptualization assumes that pain disability is determined by pain intensity. This study evaluated the relationships among pain intensity, illness intrusiveness, and pain disability.
After we obtained ethics board approval, we enrolled English-speaking adult patients who had experienced an upper extremity peripheral nerve injury 0.5 to 15 years previously. Patients completed the Disabilities of the Arm, Shoulder, and Hand (DASH), Illness Intrusiveness Scale, Pain Disability Index, and McGill Pain questionnaires. We used multivariate linear regression to evaluate the variables that predicted pain disability.
There were 124 patients (41 women, 83 men; mean ± SD, 41 ± 16 y of age). The median time since injury was 14 months (range, 6-145 months), and there were 43 brachial plexus nerve injuries. Mean ± SD scores were: pain disability, 29 ± 18; illness intrusiveness, 40 ± 18; DASH, 45 ± 22; and pain intensity, 4.6 ± 3.0. The pain disability, DASH, and illness intrusiveness scores were significantly higher in patients with brachial plexus injuries than in those with distal nerve injuries (p<.05). There was strong correlation between pain disability and DASH (r = 0.764, p<.001) and illness intrusiveness (r = 0.738, p<.001) and a weaker correlation with pain intensity (r = 0.549, p<.001). The final regression model predicting pain disability scores explained 70% of the variance with these predictors: DASH (β = 0.452, p<.001), illness intrusiveness (β = 0.372, p<.001), and pain intensity (β = 0.143, p=.018).
Pain disability was substantial after nerve injury, and pain intensity explained the least variance among the model variables. Pain intensity should be considered only one component of pain, and the impact of pain in the context of disability should be considered in patients with chronic nerve injury.
Prognostic IV.
The objective of this article was to review the literature regarding brachial plexus injury (BPI) in laparoscopic and robotic surgery. BPI complicates gynecologic laparoscopic surgery with an estimated incidence of 0.16%. Nevertheless, as the numbers of advanced laparoscopic and robotic procedures increase, the anticipated risk of this complication may rise as well. Robotic surgery often requires steeper Trendelenburg positioning and longer operative times when compared with traditional laparoscopic surgery. In this article we review the anatomy, pathophysiology, diagnosis, and treatment of position-related BPI in the context of laparoscopic and robotic gynecologic surgery. We suggest a multidisciplinary approach to the diagnosis and treatment of BPI. Recommendations for prevention of this complication are also provided.
The present report describes four cases of brachial nerve injury caused by percutaneous radiofrequency (RF) ablation of lung cancer. All the tumors were located in the lung apex. The patients developed symptoms indicative of a low brachial plexus injury during RF ablation or as long as 7 days afterward. These symptoms partially receded over time. The indications of RF ablation in patients with apical lung cancer should be carefully determined because of the risk of brachial nerve injury associated with the procedure.
As the number of survivors of motor vehicle accidents and extreme sporting accidents increases, the number of people having to live with brachial plexus injuries increases. Although the injured limb will never return to normal, an improved understanding of the pathophysiology of nerve injury and repair, as well as advances in microsurgical techniques, have enabled the upper extremity reconstructive surgeon an opportunity to improve function in these life-altering injuries. The purpose of this review is to detail some of the current concepts of the treatment of adult brachial plexus injuries and give the reader an understanding of the nuances of the timing, available treatment options, and outcomes of treatment.
Injury to the brachial plexus is a rare complication of neck dissection. We present a case of a 65-year-old man who developed a lesion of the nerve root of C5 and C6 as a result of radical neck dissection.
Minimally invasive surgery has been established as an important way forward in surgery for reducing patient trauma and hospitalization with improved prognosis. The introduction of robotic assistance enhances the manual dexterity and accuracy of instrument manipulation. Further development of the field in using pre- and intra-operative imaging guidance requires the integration of the general anatomy of the patient with clear pathologic indications and geometrical information for preoperative planning and intra-operative manipulation. It also requires effective visualization and the recreation of haptic and tactile sensing with dynamic active constraints to improve consistency and safety of the surgical procedures. This paper describes key technical considerations of tissue deformation tracking, 3D reconstruction, subject-specific modeling, image guidance and augmented reality for robotic assisted minimally invasive surgery. It highlights the importance of adapting preoperative surgical planning according to intra-operative data and illustrates how dynamic information such as tissue deformation can be incorporated into the surgical navigation framework. Some of the recent trends are discussed in terms of instrument design and the usage of dynamic active constraints and human-robot perceptual docking for robotic assisted minimally invasive surgery.
Brachial plexus injury is an underestimated complication from anterior dislocation of the shoulder. To our knowledge, there is limited information available about the factors that influence neurological recovery of this injury. We reviewed 15 upper extremities in 14 patients with brachial plexus injuries caused by anterior shoulder dislocation. Two-thirds of the cases had total brachial plexus palsy. With the conservative treatment, the motor recoveries of all cases are full or nearly full within 20 months except intrinsic muscle of the hand. Intrinsic muscle recovery may be better in a younger age group (less than 50 years). Nerve exploration is usually unnecessary. However, reconstructive surgery for the residual neurological deficit can provide improvement of hand function.
There are few reports of brachial plexopathy following the onset of a herpes zoster skin rash. Moreover, the MRI findings of zoster-induced brachial plexopathy have rarely been described. In the present study, we describe two cases of zoster brachial plexopathy and their MRI findings. MRI of the brachial plexus demonstrated T2 hyperintensity and contrast enhancement in the part of the brachial plexus that was compatible with both the clinical symptoms and the electrophysiological findings. Especially, MR imaging reflected the functional impairments more accurately than electrophysiological studies in the acute phase, during which MRI showed more extensive inflammatory involvement of the brachial plexus. MRI findings in the present cases suggest that, in addition to electrophysiological studies, MRI of the brachial plexus could provide valuable information for evaluating the location and extent of lesions and for understanding the pathophysiological mechanisms of zoster brachial plexopathy.
Use of an augmented reality (AR)-based soft tissue navigation system in urologic laparoscopic surgery is an evolving technique.
To evaluate a novel soft tissue navigation system developed to enhance the surgeon's perception and to provide decision-making guidance directly before initiation of kidney resection for laparoscopic partial nephrectomy (LPN).
Custom-designed navigation aids, a mobile C-arm capable of cone-beam imaging, and a standard personal computer were used. The feasibility and reproducibility of inside-out tracking principles were evaluated in a porcine model with an artificially created intraparenchymal tumor in vitro. The same algorithm was then incorporated into clinical practice during LPN.
Evaluation of a fully automated inside-out tracking system was repeated in exactly the same way for 10 different porcine renal units. Additionally, 10 patients underwent retroperitoneal LPNs under manual AR guidance by one surgeon.
The navigation errors and image-acquisition times were determined in vitro. The mean operative time, time to locate the tumor, and positive surgical margin were assessed in vivo.
The system was able to navigate and superpose the virtually created images and real-time images with an error margin of only 0.5 mm, and fully automated initial image acquisition took 40 ms. The mean operative time was 165 min (range: 135-195 min), and mean time to locate the tumor was 20 min (range: 13-27 min). None of the cases required conversion to open surgery. Definitive histology revealed tumor-free margins in all 10 cases.
This novel AR tracking system proved to be functional with a reasonable margin of error and image-to-image registration time. Mounting the pre- or intraoperative imaging properties on real-time videoendoscopic images in a real-time manner will simplify and increase the precision of laparoscopic procedures.
In this article, the authors describe the evolution of urologic robotic systems and the current state-of-the-art features and existing limitations of the da Vinci S HD System (Intuitive Surgical, Inc.). They then review promising innovations in scaling down the footprint of robotic platforms, the early experience with mobile miniaturized in vivo robots, advances in endoscopic navigation systems using augmented reality technologies and tracking devices, the emergence of technologies for robotic natural orifice transluminal endoscopic surgery and single-port surgery, advances in flexible robotics and haptics, the development of new virtual reality simulator training platforms compatible with the existing da Vinci system, and recent experiences with remote robotic surgery and telestration.
Computer-aided surgical navigation systems with fusion or overlaying capability, coupled with newer position tracking systems, can provide new opportunities to improve the precision of minimally invasive urology. Three-dimensional feedback of spatial position of surgical targets, and the predictive ability to guide laparoscopic dissection along the ideal surgical plane, with built-in safety checks and balances may help to lay the foundation for automated surgery in the future.
We present in this paper an augmented reality guidance system for liver thermal ablation in interventional radiology. To show the relevance of our methodology, the system is incrementally evaluated on an abdominal phantom and then on patients in the operating room. The system registers in a common coordinate system a preoperative image of the patient and the position of the needle that the practitioner manipulates. The breathing motion uncertainty is taken into account with a respiratory gating technique: the preoperative image and the guidance step are synchronized on expiratory phases. In order to fulfil the real-time constraints, we have developed and validated algorithms that automatically process and extract feature points. Since the guidance interface is also a major component of the system effectiveness, we validate the overall targeting accuracy on an abdominal phantom. This experiment showed that a practitioner can reach a predefined target with an accuracy of 2mm with an insertion time below one minute. Finally, we propose a passive evaluation protocol of the overall system in the operating room during five interventions on patients. These experiments show that the system can provide a guidance information during expiratory phases with an error below 5mm.
Since the development of microsurgery in the 1960s, the prognosis of peripheral nerve lesions has greatly improved. However this new technique's evolution has remained limited by human factors, in particular by physiological tremor. Telesurgery, a technique used in other surgical fields, was developed in the 1990s. This study assesses the feasibility of peripheral nerve repair using telemicrosurgery. Anatomical material from three subjects of different species (rat, pig, and human) was used. The telesurgical step of the procedure was performed with a Da Vinci S robot (Intuitive Surgical, Inc., Sunnyvale, CA). Four anatomical epiperineural repairs were performed. Another neurotrophic repair was performed with a nerve regrowth guide. Regardless of the type of repair performed, the telemanipulator removed the physiological tremor factor. The suture needle was distorted when held by two clamps at a time. Repairs were all performed without any damaging twisting movements of both nerve ends. Our results demonstrated that telesurgery allows very safe and precise peripheral nerve repairs by counteracting physiological tremor and by improving the overview of the surgical field, either with an anatomical or a neurotrophic technique.
New developments in clinical peripheral nerve imaging with MRI over the past few years, primarily those related to nerve entrapment syndromes, are reviewed. The basic principles of peripheral nerve imaging are described briefly. Relevant current or forthcoming technical innovations are described, and then recent work describing novel findings, organized by anatomic location (brachial plexus, upper extremity, and lower extremity), is reviewed. The review concludes with a summary and suggestions of areas in which future clinical research would be particularly helpful.
Robotic technology has recently been introduced to gastrointestinal laparoscopic surgery. We prospectively evaluated early results of robotic surgery using the Da Vinci system in our department. Data were prospectively collected in 40 patients who underwent robotic surgery during a 1-year period. We performed 3 cholecystectomies, 10 anterior fundoplications for gastroesophageal reflux disease, 17 transperitoneal adrenalectomies, 2 Heller myotomies, 5 procedures for rectal prolapse, and 3 colpohysteropexies for genital prolapse. The results for robotic adrenalectomies and anterior fundoplications were compared with the results from patients who underwent these procedures laparoscopically without robotic assistance at our department during the same period. We encountered two conversions to laparotomy (5%) and one conversion to standard laparoscopy (2.5%). There was no morbidity imputable to the robotic approach and no deaths. The mean operative times were significantly longer in robotic groups compared with laparoscopic groups for adrenalectomies and fundoplications. The Da Vinci robotic system enables surgeons to perform advanced laparoscopic procedures with ease, safety, and precision. We believe that preferable indications for using this system are to perform surgery in narrow spaces (pelvic surgery) or when precise dissection is mandatory (Heller myotomy).
In 1965 Gordon Moore, cofounder of Intel Corporation, made his famous observation now known as Moore's law. He predicted that computing capacity will double every 18 to 24 months. Since then, Moore's law has held true; the number of transistors per integrated computer circuit has doubled every couple of years. This relentless advance in computer technology ensures future advances in robotic technology. The ultimate goal of robotics is to allow surgeons to perform difficult procedures with a level of precision and improved clinical outcomes not possible by conventional methods. Robotics has the potential to enable surgeons with various levels of surgical skill to achieve a uniform outcome. As long as urologists continue to embrace technological advances and incorporate beneficial technology into their practice, the outlook for patients remains bright.
Brachial plexus injuries are devastating and usually result from high-energy trauma in young patients. Clinicians treating brachial plexus injuries need to recognize the pattern of injury presenting in each patient. Most injuries can be described as either supraclavicular or infraclavicular. The specific injury is determined by means ofa precise workup, including careful physical examination, electrodiagnostic studies, and imaging studies; a thorough workup is essential for successful preoperative planning. Priorities need to be identified and matched with available resources in each patient. A growing number of good treatment alternatives are available. Finally,counseling patients toward realistic expectations isa critical component of preparation for surgery.
Objective:
The educational objectives of this continuing medical education activity are to describe the normal anatomy of the brachial plexus, to name the most common symptoms associated with a brachial plexopathy, to describe the most common imaging findings resulting from trauma to the brachial plexus, to describe the imaging manifestations of common neoplasias affecting the brachial plexus, and to also describe the imaging findings and symptoms related to irradiation-induced brachial plexopathies.
Conclusion:
In this article, I have illustrated and described the normal anatomy of the brachial plexus; the most common symptoms related to brachial plexopathy; and imaging findings related to trauma, tumors, and irradiation affecting the brachial plexus.
Restoration of elbow flexion is the main objective in the treatment of brachial plexus palsies affecting the upper roots. Transfer of the ulnar nerve to the nerve of the biceps has given satisfactory results, but the restored biceps is often weak in cases with avulsions of the C5-C6-C7 roots, in elderly patients, and after long preoperative delays. The authors decided to investigate a double nerve transfer: one or more fascicles of the ulnar nerve to the nerve to the biceps and a fascicle of the median nerve to the motor branch to the brachialis muscle.
The authors operated on 15 patients using this technique. The authors have follow-up of more than 6 months in 10 of them. Six had C5-C6 injuries, three had C5-C6-C7 palsies, and one had sustained an infraclavicular injury. The average age was 27.2 years. The average delay before surgery was 6.6 months. The average follow-up was 12.1 months.
Grade 4 elbow flexion was restored in each of the 10 patients. In 10 cases, the patients were able to lift 1 to 5 kg. There was no secondary deficit in grip strength or sensation.
The results of this technique compare favorably with those of other methods. The percentage of success and the strength of elbow flexion restored were increased without any morbidity. This technique will probably reduce the need for secondary procedures to augment elbow flexion. The authors propose double nerve transfer as a standard procedure in C5-C6 and C5-C6-C7 injuries.
Objective:
The usefulness of neurosurgical navigation with current visualizations is seriously compromised by brain shift, which inevitably occurs during the course of the operation, significantly degrading the precise alignment between the pre-operative MR data and the intra-operative shape of the brain. Our objectives were (i) to evaluate the feasibility of non-rigid registration that compensates for the brain deformations within the time constraints imposed by neurosurgery, and (ii) to create augmented reality visualizations of critical structural and functional brain regions during neurosurgery using pre-operatively acquired fMRI and DT-MRI.
Materials and methods:
Eleven consecutive patients with supratentorial gliomas were included in our study. All underwent surgery at our intra-operative MR imaging-guided therapy facility and have tumors in eloquent brain areas (e.g. precentral gyrus and cortico-spinal tract). Functional MRI and DT-MRI, together with MPRAGE and T2w structural MRI were acquired at 3 T prior to surgery. SPGR and T2w images were acquired with a 0.5 T magnet during each procedure. Quantitative assessment of the alignment accuracy was carried out and compared with current state-of-the-art systems based only on rigid registration.
Results:
Alignment between pre-operative and intra-operative datasets was successfully carried out during surgery for all patients. Overall, the mean residual displacement remaining after non-rigid registration was 1.82 mm. There is a statistically significant improvement in alignment accuracy utilizing our non-rigid registration in comparison to the currently used technology (p<0.001).
Conclusions:
We were able to achieve intra-operative rigid and non-rigid registration of (1) pre-operative structural MRI with intra-operative T1w MRI; (2) pre-operative fMRI with intra-operative T1w MRI, and (3) pre-operative DT-MRI with intra-operative T1w MRI. The registration algorithms as implemented were sufficiently robust and rapid to meet the hard real-time constraints of intra-operative surgical decision making. The validation experiments demonstrate that we can accurately compensate for the deformation of the brain and thus can construct an augmented reality visualization to aid the surgeon.
This study was designed to evaluate the impact of 3-dimensional vision on the performance of resident and experienced surgeons using the da Vinci Robot System (Intuitive Surgical, Sunnyvale, CA).
Four tasks were performed by 12 surgeons with varying experience. Performance times and errors were recorded using both 2-dimensional and 3-dimensional vision for each task.
Performance time and error rates for all 4 skills confirm a significant advantage using 3-dimensional vision. Performance times were reduced by 34% to 46% using 3-dimensional imaging for all participants with statistical significance. Error rates were reduced by 44% and 66%.
Independent of the biomechanical advantages of the da Vinci Robot System, 3-dimensional vision allows for significant improvement in performance times and error rates for both inexperienced residents and advanced laparoscopic surgeons.
To establish the clinical characteristics, aetiology, neuro-physiological characteristics, imaging findings and other investigations in a cohort of patients with non-traumatic brachial plexopathy (BP).
A 3-year retrospective study of patients with non-traumatic BP identified by electromyography (EMG) and nerve conduction studies (NCS). Clinical information was retrieved from patients' medical charts.
Twenty-five patients were identified. Causes of BP included neuralgic amyotrophy (NA) (48%), neoplastic (16%), radiation (8%), post infectious (12%), obstetric (4%), rucksack injury (4%), thoracic outlet syndrome (4%) and iatrogenic (4%). Patients with NA presented acutely in 50%. The onset was subacute in all others. Outcome was better for patients with NA. All patients with neoplastic disease had a previous history of cancer. MRI was abnormal in 3/16 patients (18.8%). PET scanning diagnosed metastatic plexopathy in two cases.
NA was the most common cause of BP in our cohort and was associated with a more favourable outcome. The authors note potentially discriminating clinical characteristics in our population that aid in the assessment of patients with brachial plexopathies. We advise NCS and EMG be performed in all patients with suspected plexopathy. Imaging studies are useful in selected patients.
To evaluate the spatial accuracy of electromagnetic needle tracking and demonstrate the feasibility of ultrasonography (US)-computed tomography (CT) fusion during CT- and US-guided biopsy and radiofrequency ablation procedures.
The authors performed a 20-patient clinical trial to investigate electromagnetic needle tracking during interventional procedures. The study was approved by the institutional investigational review board, and written informed consent was obtained from all patients. Needles were positioned by using CT and US guidance. A commercial electromagnetic tracking device was used in combination with prototype internally tracked needles and custom software to record needle positions relative to previously obtained CT scans. Position tracking data were acquired to evaluate the tracking error, defined as the difference between tracked needle position and reference standard needle position on verification CT scans. Registration between tracking space and image space was obtained by using reference markers attached to the skin ("fiducials"), and different registration methods were compared. The US transducer was tracked to demonstrate the potential use of real-time US-CT fusion for imaging guidance.
One patient was excluded from analysis because he was unable to follow breathing instructions during the acquisition of CT scans. Nineteen of the 20 patients were evaluable, demonstrating a basic tracking error of 5.8 mm +/- 2.6, which improved to 3.5 mm +/- 1.9 with use of nonrigid registrations that used previous internal needle positions as additional fiducials. Fusion of tracked US with CT was successful. Patient motion and distortion of the tracking system by the CT table and gantry were identified as sources of error.
The demonstrated spatial tracking accuracy is sufficient to display clinically relevant preprocedural imaging information during needle-based procedures. Virtual needles displayed within preprocedural images may be helpful for clandestine targets such as arterial phase enhancing liver lesions or during thermal ablations when obscuring gas is released. Electromagnetic tracking may help improve imaging guidance for interventional procedures and warrants further investigation, especially for procedures in which the outcomes are dependent on accuracy.
Brachial plexus injuries. In: Current therapy in plastic surgery
- S M Shenaq
- Jys Kim
- J Bullocks
- G M Joseph
- D G Robert
- G B Sean
- SM Shenaq
Apport de la sequence T2-STIR dans l’exploration des plexopathies brachiales demyelinisantes chroniques
- Ben Salem
- D Couvreur
- G Soichot
- P Giroud
- M Krausé
- D Ricolfi
- D Ben Salem