Endoscopic transoral surgery for craniovertebral junction anomalies

Indian Neurosurgeons at the Forefront: A Comprehensive Exploration of their Pioneering Contributions to Neuroendoscopy

This article delves into the profound impact of Indian neurosurgeons on the expansive canvas of neuroendoscopy. By scrutinizing their trailblazing research, innovations, new surgical techniques, and relentless dedication to education and training, we aim to unravel the intricacies of their influence on a global scale. The review, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, conducts a comprehensive analysis of the literature related to neuroendoscopy contributed by Indian neurosurgeons. The exploration covers a spectrum of achievements, ranging from pioneering research and innovations to complication avoidance, neuroendoscopic training, and global recognition. Despite challenges, Indian neurosurgeons continue to lead the way in shaping the future of neuroendoscopy, ensuring better patient outcomes and improved quality of life. Many Indian neurosurgeons have contributed significantly to the development of neuroendoscopy in India. Prof. YR Yadav's contributions stand significant in the form of research articles and publications on almost all subjects on neuroendoscopy, the textbook on neuroendoscopy, popularizing neuroendoscopy by starting the first university-certified neuroendoscopy fellowship training program in India, describing many innovative techniques/first report of endoscopic techniques and conducting regular endoscopic workshops in his institutions and other major cities of India.

Transtubular Transoral Approach for Irreducible Ventral Craniovertebral Junction Compressive Pathologies: Surgical Technique and Outcome

Introduction

To investigate the use of a tubular retractor to provide access to the craniovertebral junction (CVJ) sparing the soft palate with the aim of reducing complications associated with traditional transoral approach but yet allowing adequate decompression of the CVJ.

Materials and methods

Twelve consecutive patients with severe myelopathy (JOA-score less than 11) from ventral CVJ compression were operated between 2014-2020 using a tubular retractor assisted transoral decompression.

Results

All patients improved neurologically statistically (p=0.02). There were no posterior pharynx wound infections or rhinolalia. There was one case with incomplete removal of the lateral wall of odontoid and one incidental durotomy.

Conclusions

A Tubular retractor provides adequate access for decompression of the ventral compression of CVJ. As the tubular retractor pushed away the uvula, soft palate and pillars of the tonsils as it docked on the posterior pharyngeal wall, the traditional complications associated with traditional transoral procedures is completely avoided.

Transdural Approach for Resection of Craniovertebral Junction Cysts: Case Series

BACKGROUND

Craniovertebral junction (CVJ) cysts, including retro-odontoid pseudotumors, are challenging pathologies to treat and manage effectively. Surgical intervention is indicated when these lesions result in progressive myelopathy, intractable pain, or instability.

OBJECTIVE

To present a case series of older patients who underwent successful resection retro-odontoid lesions using transdural approach.

METHODS

A single-center, retrospective observation study of older patients who underwent transdural resection of CVJ cysts at a single institution was performed. Summary demographic information, clinical presentation, perioperative and intraoperative imaging, and Nurick scores were collected and analyzed.

RESULTS

Eight patients were included (mean age [±SD] 75.88 ± 9.09 years). All patients presented with retro-odontoid lesions resulting in severe cervical stenosis, cord compression, and myelopathy. The mean duration of surgery was 226 ± 83.7 minutes. The average intraoperative blood loss was 181.2 cc. The average hospital stay was 4.5 days ± 1.3 (range, 3-7 days). The average follow-up time was 12.5 ± 9.5 months. No intraoperative complications were encountered. The Nurick classification score for myelopathy improved at the final postoperative examination (2.38 ± 1.06 vs 1 ± 1.07). Three patients demonstrated a pre-existing deformity prompting an instrumented fusion. Both computed tomography and MRI evidence of complete regression of retro-odontoid cyst were noted in all patients on the final follow-up.

CONCLUSION

Posterior cervical transdural approach for ventral lesions at the CVJ is a safe and effective means of treating older patients with progressive myelopathy. This technique provides immediate spinal cord decompression while limiting neurological complications commonly associated with open or endoscopic anterior transpharyngeal approaches.

History of Endoscopic Spine Surgery in India

Endoscopic spine surgeries provide distinct advantages and is therefore a viable alternative to open or microscopic techniques. Indian surgeons have shown their expertise from craniovertebral junction to lumbosacral spine with these techniques. Many novel approaches like endoscopic transcervical, partial corpectomy, and others have been designed, and many technological innovations for these surgeries have been made. With different training programs attracting both native and international surgeons, the future of endoscopic spine surgery is bright.

Surgical outcomes of posterior occipito-cervical decompression and fusion for basilar invagination: A prospective study

STUDY DESIGN

A Prospective Study.

OBJECTIVE

To assess results of posterior occipito-cervical decompression and fusion operated with intra-operative traction/manipulation and instrumented reduction in cases of Basilar Invagination(BI).

METHODS

Total 22 patients of 8-65 years with diagnosed BI were operated for posterior occipito-cervical fusion by intra-operative traction/manipulation and instrumented reduction. Fusion was done using autologous bone graft taken from iliac crest. Immediate post-operative, first month and then every 3 months' follow-up examination were done for minimum period of 2 years.

RESULTS

22 patients (10 males,12 females) with mean age of 23.9 years having BI were included. 11 patients had C1 occipitalization, 4 had platybasia and 9 had atlanto-axial dislocation (AAD). 1 patient with os odontoideum with kyphotic deformity expired on 4th postoperative day due to respiratory insufficiency (mortality rate 4.54%). Neurological improvement by at least by one grade according to RANAWAT's and/or NURICK'S scale was observed in 17/21 patients (80.95%). 3 patients remained static and 1 had neuro-worsening. Mean mJOA score of 13.14 improved to 16.24. All had reduction of dens below foramen magnum according to McRae, chamberlain line and Ranawat index. Bone graft fused in all patients as confirmed with CT scan and dynamic X-rays. 1 wound dehiscence and 1 asymptomatic implant loosening were seen on follow-up.

CONCLUSION

Surgical treatment of BI with intra-operative traction/manipulation, instrumented reduction and posterior occipito-cervical fusion can achieve good correction of radiology, functional performance and clinical neurology as well as excellent fusion rates without adverse effects of trans-oral surgery.

Can Posterior Reduction Replace Odontoidectomy as Treatment for Patients With Congenital Posterior Atlantoaxial Dislocation and Basilar Invagination?

BACKGROUND

For patients with odontoid process protrusion and basilar invagination, posterior screw–rod fixation can usually achieve satisfactory horizontal reduction, but in some cases satisfactory reduction in the vertical direction cannot be achieved at the same time.

OBJECTIVE

To propose a method for calculation of the theoretical maximum vertical reduction possible in individual patients.

METHODS

The computed tomography imaging data of patients with occipitalization and basilar invagination who were treated at our institute between January 2013 and June 2016 were retrospectively analyzed. The direction of odontoid reduction was decided by the inclination of the lateral joint. The atlanto-dental distance was assumed to be the maximum possible reduction in the horizontal direction. The maximum vertical reduction possible was calculated based on these values.

RESULTS

A total of 82 patients (34 males and 48 females) were included. The theoretical vertical reduction value was 4.2 ± 3.0 mm, which was significantly smaller than that of the dental protrusion (14.5 ± 3.8 mm, P = .000). Analysis of follow-up data (29 cases) showed that, the difference between the theoretical vertical reduction value H (4.7 ± 3.5 mm) and the actual vertical reduction value Ha (5.6 ± 3.5 mm) was not significant (P = .139).

CONCLUSION

The theoretical calculation method we proposed can well predict the actual degree of vertical reduction. The theoretical vertical reduction value is significantly lower than the odontoid protrusion value, indicating that satisfactory reduction in the vertical direction is difficult with a posterior approach alone.

Refinement of the Transoral Approach to Craniovertebral Junction Malformations

BACKGROUND

The transoral approach provides the most direct surgical corridor for treatment of congenital bony abnormalities that exert irreducible ventral compression of the cervicomedullary junction. In this paper, based on our experience with the transoral approach over the past three decades, we briefly describe the surgical strategies and the operative nuances that allow effective decompression of the craniovertebral junction (CVJ) while minimizing postoperative morbidity.

METHODS

The surgical strategy is dictated by the type and severity of the malformation. Fibre-optic nasotracheal intubation obviates the necessity of preoperative tracheostomy, and avoidance of a soft-palate incision significantly reduces oropharyngeal morbidity. When feasible, the atlas-sparing technique minimizes postoperative instability. The transoral transatlas approach is generally required in patients with severe basilar invagination and allows wider exposure of the anterior CVJ at the price of a higher incidence of postoperative instability.

CONCLUSION

The transoral approach is extremely effective in providing excellent decompression of the anterior cervicomedullary junction in patients with fixed malformations. Tailoring the approach to the peculiar anatomy of each malformation reduces iatrogenic instability and minimizes postoperative complications.

Metastasis Affecting Craniocervical Junction: Current Concepts and an Update on Surgical Management

STUDY DESIGN

Literature review.

OBJECTIVES

Metastatic disease affecting the craniovertebral junction (CVJ) only accounts for 0.5% of all spine metastases. The management of these disease processes is complex, which involves multimodality radiological studies and various surgical approaches. We aimed to review the available evidence and summarize the findings in this review.

METHODS

The authors conducted search of PubMed and Google Scholar with the following search terms: metastasis, craniovertebral junction (CVJ), occipitocervical, approaches, stability, and radiotherapy. Articles were reviewed by the authors and determined for inclusion based on relevance and level of evidence.

RESULTS

The majority of relevant research reviewed composed of literature reviews of particular aspects regarding metastatic disease affecting the craniovertebral junction, including diagnosis, surgical approach, and radiotherapy.

CONCLUSIONS

Prompt evaluation of rotational neck pain with or without occipital neuralgia may reveal early metastatic disease within a stable CVJ. Magnetic resonance imaging appears to be the gold standard imaging modality in detecting this pathology, with nuclear bone scan playing a role in distinguishing benign and malignant processes. Unfortunately, no level 1 evidence exists for use of either radiotherapy or surgery in these cases; however, from the available literature, spinal instability and evidence of progressive neurology are relative indications for operative intervention.

Walk the Line. The Surgical Highways to the Craniovertebral Junction in Endoscopic Approaches: A Historical Perspective

BACKGROUND

We compiled a comprehensive literature review on the anatomic and clinical results of endoscopic approaches to the craniocervical junction (CVJ) to better contribute to identify the best strategy.

METHODS

An updated literature review was performed in the PubMed, OVID, and Google Scholar medical databases, using the terms "Craniovertebral junction," "Transoral approach," "Transnasal approach," "Transcervical approach," "Endoscopic endonasal approach," "Endoscopic transoral approach," "Endoscopic transcervical approach." Clinical series, anatomic studies, and comparative studies were reviewed.

RESULTS

Pure endonasal and cervical endoscopic approaches still have some disadvantages, including the learning curve and the deeper surgical field. Endoscopically assisted transoral surgery with 30° endoscopes represents an emerging option to standard microsurgical techniques for transoral approaches to the anterior CVJ. This approach should be considered as complementary rather than an alternative to the traditional microsurgical transoral-transpharyngeal approach.

CONCLUSIONS

The transoral approach with sparing of the soft palate still remains the gold standard compared with the pure transnasal and transcervical approaches because of the wider working channel provided by the former technique. The transnasal endoscopic approach alone appears to be superior when the CVJ lesion exceeds the upper limit of the inferior third of the clivus.

Direct and Oblique Approaches to the Craniovertebral Junction: Nuances of Microsurgical and Endoscope-Assisted Techniques Along with a Review of the Literature

PURPOSE

The aim of this review is to provide an update of the technical nuances of microsurgical and endoscopic-assisted approaches to the craniovertebral junction (transnasal, transoral, and transcervical), and to report on the available clinical results in order to identify the best strategy.

METHODS

A nonsystematic update of the reviews and reporting on the anatomical and clinical results of endoscopic-assisted and microsurgical approaches to the craniovertebral junction (CVJ) was performed.

RESULTS

Pure endonasal and cervical endoscopic approaches still have some disadvantages, including their steep learning curves and their deeper surgical fields. Endoscopically assisted transoral surgery with 30° endoscopes represents an emerging option compared with standard microsurgical techniques for transoral approaches to the anterior CVJ. This approach should be considered as complementary to, rather than as an alternative to the traditional transoral-transpharyngeal approach.

CONCLUSIONS

The transoral (microsurgical or video-assisted) approach with sparing of the soft palate still remains the gold standard compared with the "pure" transnasal and transcervical approaches, due to the wider working channel provided by the former technique. The transnasal endoscopic approach alone appears to be superior when the CVJ lesion exceeds the upper limit of the inferior third of the clivus. Of particular interest is the evidence that advances in reduction techniques can avoid the ventral approach.

Selection of surgical procedures for basilar invagination with atlantoaxial dislocation

BACKGROUND CONTEXT

Basilar invagination (BI) is a malformation of craniovertebral junction. However, surgical procedures on BI with atlantoaxial dislocation (AAD) remain controversial.

PURPOSE

This research aimed to investigate the selection of surgical procedures and its significance in the surgical treatment of patients with BI and AAD.

STUDY DESIGN

This was a retrospective study.

PATIENT SAMPLE

This study enrolled 33 patients who were diagnosed with BI and AAD and were followed up for at least 6 months.

OUTCOME MEASURE

All of the patients were assessed for neurologic recovery observation in terms of Japanese Orthopaedic Association scores and Odom criteria. X-ray, magnetic resonance imaging, or computed tomography scanning was used to determine reduction, compression, bone graft, and internal fixation before and after operation.

METHODS

Thirty-three patients who suffered from BI with AAD were treated in our department from July 2000 to October 2014. Preoperatively, the patients were divided into two types on the basis of whether dislocation was reduced after anesthesia and traction were performed: reducible dislocation (Type A) and irreducible dislocation (Type B). Reducible dislocation was further divided into two subtypes: full reducible dislocation (Type A1) and partial reducible dislocation (Type A2). Type A1 patients were treated with direct posterior fixation and fusion after traction and reduction. Type A2 patients received posterior atlantoaxial release, fixation, and fusion under traction. Type B patients underwent transoral atlantoaxial release, posterior fixation, and fusion.

RESULTS

There were 5 Type A1 patients, 10 Type A2 patients, and 18 Type B patients treated in accordance with the proposed scheme. Postoperatively, sufficient reduction and decompression were achieved for all cases. Two Type B patients died. Other patients were followed up from 6 months to 42 months (average=16.6 months); follow-up results showed sufficient decompression, effective fixation and fusion, and no reduction loss. The Japanese Orthopaedic Association Score increased from preoperative 4-12 (average, 7.8) to postoperative 10-17 (average, 14.3), and neurologic recovery was satisfactory.

CONCLUSIONS

Under traction, simple posterior fixation and fusion were effective for Type A patients suffering from BI with AAD; anterior atlantoaxial release and posterior fixation and fusion were effective for Type B patients with BI and AAD.

Videoassisted anterior surgical approaches to the craniocervical junction: rationale and clinical results

PURPOSE

In this narrative review, we aim to give an update on the anatomic fundamentals of endoscopic assisted surgery to the craniocervical junction (transnasal, transoral and transcervical), and to report on the available clinical results.

METHODS

A non-systematic review and reporting on the anatomical and clinical results of endoscopic assisted approaches to the craniocervical junction (CVJ) is performed.

RESULTS

Pure endonasal and cervical endoscopic approaches still have some disadvantages, including the learning curve and the lack of 3-dimensional perception of the surgical field. Endoscopically assisted transoral surgery with 30° endoscopes represents an emerging alternative to standard microsurgical techniques for transoral approaches to the anterior CVJ. Used in conjunction with traditional microsurgery and intraoperative fluoroscopy, it provides a safe and improved method for anterior decompression with or without a reduced need for extensive soft palate splitting, hard palate resection, or extended maxillotomy.

CONCLUSIONS

Transoral (microsurgical or video-assisted) approach with sparing of the soft palate still remains the gold standard compared to the "pure" transnasal and transcervical approaches due to the wider working channel provided by the former technique. Transnasal endoscopic approach alone appears to be superior when the CVJ lesion exceeds the upper limit of the inferior third of the clivus. Combined transnasal and transoral procedures can be tailored according to the specific pathological and radiological findings.

Advances in videoassisted anterior surgical approach to the craniovertebral junction

At the present time, an update to the classical microsurgical transoral decompression is supported by the most recent literature dealing with the introduction of the endoscopy in spine surgery. In this paper, we present all the reported experience on the surgical approaches to anterior cranioveretebral junction (CVJ) compressive pathology managed by endoscopy. Surgical strategies dealing with decompressive procedures by using an open access, microsurgical technique, neuronavigation and endoscopy are summarized.Endoscopy represents a useful complement to the standard microsurgical approach to the anterior CVJ. Endoscopy can be used via transnasal, transoral and transcervical routes; it facilitates visualisation and better decompression without the need for soft palate splitting, hard palate resection, or extended maxillotomy. Although neuronavigation enhances orientation within the surgical field, intraoperative fluoroscopy helps to recognize residual compression.Under normal anatomical conditions, there appear to be no surgical limitations for the endoscopically assisted transoral approach compared with the pure endonasal and transcervical endoscopic approaches.The endoscope has a clear role as "support" to the standard transoral microsurgical approach since 30° angulated endoscopy increases the surgical area exposed over the posterior pharyngeal wall and the extent of the clivus.

Transoral approach to extradural non-neoplastic lesions of the craniovertebral junction

BACKGROUND

The transoral approach allows for an unobstructed anterior view of the craniovertebral junction from the lower clivus to C1 and C2. It can be applied to a heterogeneous spectrum of pathological lesions involving this area including craniovertebral junction malformations, atlanto-axial synovial cysts, pseudoarthrosis following odontoid fractures, selected cases of retro-odontoid pannus, and vertical translocation in rheumatoid patients.

METHODS

Microsurgical strategy is dictated by the nature and site of the target lesion. Atlas preservation during transoral approach (atlas-sparing technique) minimizes postoperative instability and is suitable for the majority of extradural non-neoplastic lesions of the craniovertebral junction. The transoral trans-atlas approach allows for a wider exposure of the anterior craniovertebral junction, but at the price of a higher incidence of postoperative instability; it is usually required in patients with severe basilar invagination or irreducible vertical translocation in rheumatoid arthritis.

CONCLUSIONS

The transoral corridor is an effective route to approach a variety of anterior extradural lesions of the craniovertebral junction. Tailoring the approach to each specific lesion provides the needed exposure whilst limiting postoperative instability.

The influence of cervical spine position on the three anterior endoscopic approaches to the craniovertebral junction: an imaging study

BACKGROUND CONTEXT

Three endoscopic anterior approaches, the transnasal, transoral, and transcervical approaches, are used for ventral lesions of the craniovertebral junction and have been compared regarding surgical working distances and approach angles. However, how the position of the cervical spine influences the depths of surgical corridors and approach angles for the three approaches has not been evaluated.

PURPOSE

To evaluate the depths of surgical corridors and the approach angles for the three endoscopic approaches, taking the influence of cervical spine position into account.

STUDY DESIGN

A radiographic study comparing three anterior endoscopic approaches to the craniovertebral junction.

PATIENT SAMPLE

Cervical extension and flexion radiographs for 34 patients and cross-sectional computed tomography scans for 30 additional patients were assessed.

OUTCOME MEASURES

The depths of the surgical corridors and the approach angles for the three endoscopic approaches in the midsagittal planes.

METHODS

We determined the mean angles of the surgical trajectories for the endoscopic transoral and transcervical approaches on cervical extension and flexion radiographs. In addition, we measured the depths of the surgical corridors and the approach angles for the three approaches in the midsagittal plane.

RESULTS

The average depths of surgical corridors were as follows: endonasal, 93.65 mm; transoral, 85.27 mm; transcervical, 62.97 mm (in extension). The average approach angles were as follows: endonasal, 31.22°; transoral, 30.87°; transcervical, 36.58° (in extension).

CONCLUSIONS

The position of the cervical spine does not influence the surgical convenience of the endoscopic transnasal approach, but it can influence the endoscopic transoral and transcervical approaches, especially the latter. The endoscopic transcervical approach offers several advantages over the endoscopic transoral and endonasal approaches.

Endoscopic image-guided transcervical odontoidectomy: outcomes of 15 patients with basilar invagination

BACKGROUND

Ventral decompression with posterior stabilization is the preferred treatment for symptomatic irreducible basilar invagination. Endoscopic image-guided transcervical odontoidectomy (ETO) may allow for decompression with limited morbidity.

OBJECTIVE

To describe the perioperative outcomes of patients undergoing anterior decompression of basilar invagination with the use of ETO.

METHODS

Fifteen patients who had a follow-up of at least 16 months were retrospectively reviewed. Intraoperatively, the vertebral body of C2 was removed and the odontoid was resected in a "top-down" manner using endoscopic visualization and frameless stereotactic navigation. Posterior instrumented stabilization was subsequently performed.

RESULTS

The average (± standard deviation) age of the patients was 42.6 ± 24.5 (range, 11-72) years. Postoperative complications occurred in 6 patients, including a urinary tract infection (n = 2), upper airway swelling (n = 2), dysphagia (n = 2), gastrostomy tube placement (n = 1), and an asymptomatic pseudomeningocele (n = 1). No patients required a tracheostomy, had bacterial meningitis, or developed a venous thromboembolic event; only 1 patient was intubated for more than 48 hours postoperatively. With a mean follow-up of 41.9 ± 14.4 (range, 16-59) months, myelopathy improved in all patients and no patient experienced late neurological deterioration. The mean modified Japanese Orthopedic Association (JOA) score increased from 11.2 ± 4.2 to 15.9 ± 1.4 (P = .002). Patients with a diagnosis other than rheumatoid arthritis or who had a higher preoperative JOA score had a significantly better postoperative neurological recovery (P = .005).

CONCLUSION

ETO may be a valid treatment for patients with symptomatic irreducible basilar invagination that avoids some of the morbidity of transoral surgery and leads to long-term improvement in myelopathy.

Endoscope-assisted microsurgical transoral approach to the anterior craniovertebral junction compressive pathologies

At the present time, an update to the classical microsurgical transoral decompression is strongly provided by the most recent literature dealing with the introduction of the endoscopy in spine surgery. In this paper, we present our experience on the endoscope-assisted microsurgical transoral approach to anterior craniovertebral junction (CVJ) compressive pathology. We analysed seven patients (3 paediatrics and 4 adults ranging from 6 to 78 years) operated on for CVJ decompressive procedures using an open access, microsurgical technique, neuronavigation and endoscopy. All techniques mentioned were simultaneously employed. Among the endoscopic routes described in the literature, we have preferred the transoral using 30° endoscopes. In all the cases endoscopy allowed a radical decompression compared to the microsurgical technique alone, as confirmed intraoperatively with contrast medium fluoroscopy. In conclusion, endoscopy represents a useful complement to the standard microsurgical approach to the anterior CVJ; it provides information for a better decompression with no need for soft palate splitting, hard palate resection, or extended maxillotomy. Moreover, intraoperative fluoroscopy helps to recognize residual compression. Virtually, in normal anatomic conditions, no surgical limitations exist for endoscopically assisted transoral approach, compared with the pure endonasal and transcervical endoscopic approaches. In our opinion, the endoscope deserves a role as "support" to the standard transoral microsurgical approach since 30° angulated endoscopy significantly increases the surgical area exposed at the level of the anterior CVJ.

Video-assisted microsurgical transoral approach to the craniovertebral junction: personal experience in childhood

PURPOSE

This paper outlines the perspectives of transoral craniosurgery for anterior craniovertebral junction (CVJ) compressive abnormalities in the specific subset of paediatric patients. In particular we analyzed the opportunity for endoscopic video-assisted approach to the CVJ along with neuronavigation for anterior decompression by the transoral approach in paediatric patients.

METHODS

Among 30 patients ranging 6-78 years undergoing CVJ decompressive procedures, we operated transorally 3 paediatric patients (ranging 11-15 years) by using open access, microsurgical technique, neuronavigation, and endoscopy.

RESULTS

The microscope was the main stone of the transoral procedure; a complete CVJ decompression was accomplished in all the cases by using the 30-degree endoscope that allowed to identify residual compression not clearly visible by using the microscope alone. The use of an angled-lens endoscope can significantly improve the exposure of the clivus without splitting the soft palate.

CONCLUSIONS

Endoscopically assisted transoral surgery represents an emerging alternative to the standard microsurgical approach to the anterior CVJ. Used in conjunction with traditional microsurgery and intraoperative fluoroscopy, endoscopy provides information for a better decompression with a reduced need for extensive soft-palate splitting, no need for hard-palate resection, or extended maxillotomy. Transoral video-assisted microsurgical approach should be considered the gold standard especially in the paediatric patient.

Robot-assisted transoral odontoidectomy : experiment in new minimally invasive technology, a cadaveric study

OBJECTIVE

In the field of spinal surgery, a few laboratory results or clinical cases about robotic spinal surgery have been reported. In vivo trials and development of related surgical instruments for spinal surgery are required before its clinical application. We investigated the use of the da Vinci® Surgical System in spinal surgery at the craniovertebral junction in a human cadaver to demonstrate the efficacy and pitfalls of robotic surgery.

METHODS

Dissection of pharyngeal wall to the exposure of C1 and odontoid process was performed with full robotic procedure. Although assistance of another surgeon was necessary for drilling and removal of odontoid process due to the lack of appropriate end-effectors, successful robotic procedures for dural sutures and exposing spinal cord proved its safety and dexterity.

RESULTS

Robot-assisted odontoidectomy was successfully performed in a human cadaver using the da Vinci® Surgical System with few robotic arm collisions and minimal soft tissue damages. Da Vinci® Surgical System manifested more dexterous movement than human hands in the deep and narrow oral cavity. Furthermore, sutures with robotic procedure in the oral cavity demonstrated the advantage over conventional procedure.

CONCLUSION

Presenting cadaveric study proved the probability of robot-assisted transoral approach. However, the development of robotic instruments specific to spinal surgery must first precede its clinical application.

Transnasal endoscopic odontoidectomy after occipito-cervical fusion during the same operative setting--technical note

Recently, a purely transnasal endoscopic approach (TNEA) for decompression of the anterior cranio-cervical junction has been described. At present, there is only a limited number of patients having been operated on in a few specialized centers. The possibilities, safety, and limits of this approach are still under investigation. The relationship between TNEA and occipito-cervical fusion, especially, which may typically be considered in this kind of pathologies, should be further elucidated. So far, the feasibility of TNEA after previous occipito-cervical fusion has only been reported for a single case. In that case, there was a posterior atlanto-axial subluxation and basilar invagination. In the present paper, another example of a surgical procedure of TNEA after previous posterior fusion during the same operative setting is given. It differs from the other case concerning the pathophysiology. In fact, here, there was anterior atlanto-axial subluxation and no basilar invagination. The possibilities and limits of this novel approach are thoroughly discussed. Special interest is given to the problem of CCJ instability and previous occipito-cervical fusion. Technical hints and pitfalls are described in detail.

Microendoscopic anterior approach for irreducible atlantoaxial dislocation: surgical techniques and preliminary results

STUDY DESIGN

Surgical techniques and preliminary results.

OBJECTIVE

To describe and evaluate the safety and efficacy of a new minimal invasive technique for the irreducible atlantoaxial dislocation (IADD).

SUMMARY OF BACKGROUND DATA

Endoscope has been widely used in minimal invasive spinal surgery. However, there are no clinical reports regarding anterior approach for IADD in the literature.

METHODS

Ten consecutive patients with IADD were treated by anterior release with microendoscopic aide and subsequently reduction, anterior transarticular screw fixation and morselized autologous bone grafts. There were 3 cases of odontoid dysplasia, 4, chronic odontoid fracture, 1, odontoid absence, 1 fasilar impression, and 1 malunion of odontoid fracture. According to Symon and Lavender's classification of disability, 6 cases were moderate disability, 3 severe nonbedbound, and 1 severe bedridden. The procedure was performed by the same surgeon (Yong-Long Chi).

RESULTS

The new technique was performed successfully in all cases. All the patients underwent transarticular screw fixation and anterior morselized autograft fusion. The average operation time was 120 min (range, 90 to 150 min) and the mean estimated blood loss was 150 mL (range, 100 to 250 mL). Postoperative radiographs demonstrated that 9 cases restored anatomic position and 1 had partial reduction. According to the postoperative computed tomography all the screws were appropriately placed. Follow-up after surgery, longest is 16 months and minimal 8 months with a mean of 12 months, neurologic status was improved in all patients. There was no loss of fixation and solid fusion was achieved in all cases.

CONCLUSIONS

Surgical technique of microendoscopic anterior release, reduction, fixation, and fusion is safe and reliable minimally invasive for treating IADD.

Basilar invagination

BACKGROUND

Basilar invagination is a developmental anomaly of the craniovertebral junction in which the odontoid abnormally prolapses into the foramen magnum. It is often associated with other osseous anomalies of the craniovertebral junction, including atlanto-occipital assimilation, incomplete ring of C1, and hypoplasia of the basiocciput, occipital condyles, and atlas. Basilar invagination is also associated with neural axis abnormalities, including Chiari malformation, syringomyelia, syringobulbia, and hydrocephalus. Patients frequently present with neurologic symptoms and deficits and warrant surgical treatment to prevent progression.

OBJECTIVE

To review the management of basilar invagination.

METHODS

The literature was reviewed in reference to the evaluation and management of basilar invagination, with particular emphasis on the surgical treatment.

RESULTS

Reducible basilar invagination may be treated with posterior decompression and stabilization. Ventral decompression may be necessary for basilar invagination with neural compression that is not reducible with axial cervical traction. Posterior cervical stabilization is necessary after ventral decompression. Modern rod and screw systems combined with autogenous bone graft enable correction of deformity, immediate stabilization, and high fusion rates.

CONCLUSION

Basilar invagination is a developmental anomaly and commonly presents with neurologic findings. Treatment is typically surgical and involves anterior decompression followed by posterior stabilization for irreducible invagination and posterior decompression and stabilization for reducible invagination.

Transoral Approaches to the Cervical Spine

A NUMBER OF anterior approaches to the craniocervical junction have been described to allow exposure to the midline and lateral aspects of both the cranial base and upper cervical spine. The transoral-transpharyngeal approach, a technique that is well known to many spine surgeons, provides surgical access to the anterior clivus, C1, and C2. Transoral approaches provide the fundamental anatomy and technique upon which the more complex jaw-splitting approaches are based. This article discusses fundamental concepts regarding anatomy, perioperative considerations, and technical aspects critical to this important approach to the craniocervical junction. The transoral-transpharyngeal approach remains the “gold standard” for anterior approaches to the cervical spine. Endoscopic endonasal and endoscopic transcervical approaches are promising alternatives that may become more mainstream as experience with these approaches increases.

Endoscopically assisted anterior release and reduction through anterolateral retropharyngeal approach for fixed atlantoaxial dislocation

STUDY DESIGN

A prospective study.

OBJECTIVE

To evaluate a novel technique involving an endoscopically assisted anterior release and reduction through an anterolateral retropharyngeal approach with minimum follow-up interval of 31 months.

SUMMARY OF BACKGROUND DATA

Irreducible atlantoaxial dislocation is typically a chronic process that requires surgical treatment. However, the current literature does not agree on the single best method of treatment. Previously, the best outcomes have been reported with transoral reduction followed by anterior or posterior fixation. Despite recent innovations, numerous complications remain associated with this approach.

METHODS

About 21 consecutive irreducible atlantoaxial dislocation patients with mean age of 32 years underwent endoscopically assisted anterior release and reduction through the anterolateral retropharyngeal approach followed by posterior fixation. The primary pathologies included 8 late odontoid fractures, 7 cases of os odontoideum, 5 with laxity of the transverse ligament, and 1 with atlanto-occipital assimilation with a hypoplastic odontoid. Neurologic status was evaluated using the Japanese Orthopedic Association scoring system. Radiographic parameters including the atlantodental interval (ADI) and cervicomedullary angle were also measured. Follow-up data were obtained for a minimum of 31 months.

RESULTS

Anatomic reduction was achieved in 20 cases and near-anatomic reduction in 1 case. All patients had an uneventful recovery with significant improvement in neurologic function and radiographic parameters. No complications were seen. The atlantodental interval was corrected from an average 6.3 mm before surgery to 2.7 mm after surgery (P < 0.01). The cervicomedullary angle was also corrected from an average 109 degrees before surgery to 152 degrees after surgery (P < 0.01). Preoperative muscle strength was on average 3.5 (on scale from 1 to 5) and improved after surgery to 4.5 (P < 0.01). The average preoperative and postoperative Japanese Orthopedic Association scores were 9.6 and 15.5, respectively, indicating 82.8% improvement.

CONCLUSION

Endoscopically assisted anterior retropharyngeal release combined with posterior fixation is a safe and effective alternative for the treatment of irreducible atlantoaxial dislocation.

Minimally invasive spine surgery: a historical perspective

Minimally invasive spine surgery has gained considerable momentum and increased acceptance among spine surgeons throughout the years. An understanding and awareness of the development of minimally invasive spine surgery and its role in the operative treatment of various spine conditions is imperative. This article provides a succinct historical perspective of the development of spine surgery from the more traditional, open procedures to the use of more "minimal access" or minimally invasive spine surgery procedures.