Transoral-transpharyngeal approach to the craniocervical junction

Lesson learned in endoscopic endonasal dens resection for C1-C2 spinal cord decompression

PURPOSE

Endoscopic endonasal approach (EEA) is the safest and most effective technique for odontoidectomy. Nevertheless, this kind of approach is yet not largely widespread. The aim of this study is to share with the scientific community some tips and tricks with our ten-year-old learned experience in endoscopic endonasal odontoidectomy (EEO), which remains a challenging surgical approach.

MATERIAL AND METHODS

Our case series consists of twenty-one (10 males, 11 females; age range of 34-84 years) retrospectively analyzed patients with ventral spinal cord compression for non-reducible CVJ malformation, treated with EEA from July 2011 to March 2019.

RESULTS

The results have recently been reported in a previous paper. The only intraoperative complication observed was intraoperative cerebrospinal fluid (CSF) leak (9.5%), without any sign of post-operative CSF leak.

CONCLUSIONS

Considering our experience, EEO represents a valid and safe technique to decompress neural cervical structures. Despite its technical complexity, mainly due to the use of endoscope and the challenging surgical area, with this study we encourage the use of EEO displaying our experience-based surgical tips and tricks.

Full-endoscopic uniportal retropharyngeal odontoidectomy: A preliminary case report

Summary of background data

Odontoidectomy aims to decompress the medulla oblongata and is usually performed through the classical transoral approach, which affects oropharynx and accompanied with high rate of complications comprising swallowing and respiratory tract. We have developed a minimal invasive method via a standard cervical anterior approach: full-endoscopic trans-cervical odontoidectomy, which provides an alternative access for the resection of odontoid process and medulla oblongata decompression without traversing potentially contaminated cavities.

Methods

From 2018 to 2020, three patients with either odontoid process lesion or basilar invagination underwent full-endoscopic uniportal trans-cervical odontoidectomy with/without combining the posterior instrumentation. With fluoroscopic guidance, a uniportal endoscope sleeve was placed inside of the odontoid process; then odontoid process was gradually resected from the inside to outside under endoscopic monitoring. Postoperative images and clinical data were collected during post-op follow-up.

Result

Patients were soon extubated after surgery when patients wake up from general anesthesia. There were no severely perioperative complications, especially dysphagia and airway obstruction, and the symptoms and neurological function was improved immediately after surgery. The final pathology of one patient with odontoid osteolytic lesion was confirmed as plasmacytoma. The postoperative CT scans proved that the range of odontoid process resection was consistent with the preoperative expectation.

Conclusion

In summary, our proposed endoscopic trans-cervical odontoidectomy provides a valid choice for non-oral approach, which would reduce postoperative approach related complications and accelerate postoperative recovery.

Treatment of irreducible atlantoaxial dislocation by bony deformity osteotomy, remodeling, releasing, and plate fixating through transoral approach

OBJECTIVE

Investigate a novel method for treating irreducible atlantoaxial dislocation (IAAD) or with basilar invagination (BI) by bony deformity osteotomy, remodeling, releasing, and plate fixating through transoral approach.

METHOD

From March 2015 to December 2019, 213 consecutive patients diagnosed as IAAD/BI were treated with transoral bony deformity remodeling and releasing combined with plate fixation. The main clinical symptoms include neck pain, headache, numbness of the limbs, weakness, unstable walking, inflexible hand-held objects, and sphincter dysfunction. The bony factors that impact reduction were divided into as follows: type A1 (sloping of upper facet joint in C2), type A2 (osteophyte in lateral mass joints between C1 and C2), type A3 (ball-and-socket deformity of lateral mass joint), type A4 (vertical interlocking between lateral mass joints of C1-C2), type A5 (regional bone fusion in lateral mass joints), type B1 (bony factor hindering reduction between the atlas-dens gap), type B2 (uncinate odontoid deformity), and type B3 (hypertrophic odontoid deformity). All of them were treated with bony deformity osteotomy, remodeling, and releasing techs.

RESULT

The operation time was 144 [Formula: see text] 25 min with blood loss of 102 [Formula: see text] 35 ml. The average pre-operative ADI improved from 7.5 [Formula: see text] 3.2 mm pre-surgery to 2.5 [Formula: see text] 1.5 mm post-surgery (p < 0.05). The average VDI improved from 12.3 [Formula: see text] 4.8 mm pre-surgery to 3.3 [Formula: see text] 2.1 mm post-surgery (p < 0.05). The average pre-operative CMA improved from 115 [Formula: see text] 25° pre-surgery to 158 [Formula: see text] 21° post-surgery (p < 0.05); the pre-operative CAA changed from 101 [Formula: see text] 28° pre-surgery to 141 [Formula: see text] 10° post-surgery. After the operation, the clinic symptoms improved, and the JOA score improved from 9.3 [Formula: see text] 2.8 pre-operatively to 13.8 [Formula: see text] 2.5 in the sixth months of follow-up.

CONCLUSION

In addition to soft tissue factors, bony obstruction was another important factor impeding atlantoaxial reduction. Transoral bony deformity osteotomy, remodeling, releasing combined with plate fixating was effective in treating IAAD/BI with bony obstruction factors.

Transoral vertebroplasty for the treatment of C2 painful metastatic lesions; evaluation and outcome

OBJECTIVE

A small number of studies supports vertebroplasty at the C2 vertebral body due to the documented technical challenges, the rarity of C2 osteolytic metastatic lesions, and the existence of potentially serious consequences linked to this particular anatomical area. Vertebroplasty, in such a situation, can be performed through a transoral, an anterolateral, or an open approach. All are supported by a limited number of studies with absence of a significant clinical trial assessing the efficacy, safety, and feasibility of vertebroplasty for the C2 vertebral body. We, herein, summarize a single-institution experience on C2 transoral vertebroplasty.

PATIENTS AND METHODS

This is a retrospective analysis of the records of a single tertiary institute hospital and the clinical visits of nine patients with C2 osteolytic metastatic lesions treated by transoral fluoroscopically guided vertebroplasty between May 2016 and May 2021.

RESULTS

The median period of the last clinical follow-up was 23 months (range, 9-60 months). The intraoperative amount of polymethyl methacrylate (PMMA) injected and recorded in the surgical report was 2 mL (1.5-2.5 mL). Postoperative immediate imaging showed that the cement filling percentage in relation to the C2 mass was 70% (40-85%). The PMMA leakage through the needle track and into the paravertebral spaces was observed in only one patient (11.1%), without significant vascular and neurological consequences. Stability was maintained during the follow-up period. The postoperative median pain rating scale (PRS) score was 1 (0-2) immediately after the end of the operation and 0 (0-2) at the last visit. The recorded postoperative Pain Rating Scale (PRS) score was correlated with the cement filling percentage (rs= -0.9, p = 0.0008; Spearman correlation).

CONCLUSION

Transoral vertebroplasty is considered feasible and efficient technique in the treatment of secondary osteolytic lesions in the C2 vertebra. Further long-term and larger comparative randomized studies are required to perform a more comprehensive analysis of this technique.

Calcium pyrophosphate dihydrate crystal deposition disease and retro-odontoid pseudotumor rupture managed via posterior occipital cervical instrumented fusion: illustrative case

BACKGROUND

Craniocervical junction and subaxial cervical spinal manifestations of calcium pyrophosphate deposition disease are rarely encountered. The authors presented a severe case of retro-odontoid pseudotumor rupture causing rapid quadriparesis and an acute comatose state with subsequent radiographic and clinical improvement after posterior occipital cervical fusion.

OBSERVATIONS

The authors surveyed the literature and outlined multiple described operative management strategies for compressive cervical and craniocervical junction calcium pyrophosphate deposition disease manifestations ranging from neck pain to paresthesia, weakness, myelopathy, quadriparesis, and cranial neuropathies. In this report, radiographic features of cervical and craniocervical junction calcium pyrophosphate deposition disease were explored. Several previously described surgical strategies were compiled, including patient characteristics and outcomes.

LESSONS

With this case report, the authors presented for the first time an isolated posterior occipital cervical fusion for treatment of a compressive retro-odontoid pseudotumor with rupture into the brainstem. They demonstrated rapid clinical and radiographic resolution after stabilization of cranial cervical junction only 12 weeks postsurgery.

Preoperative management and postoperative complications associated with transoral decompression for the upper cervical spine

Purpose

This review aimed to describe the preoperative management and postoperative complications associated with transoral decompression of the upper cervical spine, and to clarify the risk factors, related issues and complication management.

Methods

Studies on transoral decompression for the upper cervical spine were reviewed systematically. The preoperative management and postoperative complications associated with transoral decompression for upper cervical deformities were analyzed.

Results

Evidence suggests that preoperative management in patients undergoing transoral decompression for the upper cervical spine is closely related to the occurrence of postoperative complications. Hence, preoperative surgical planning, preoperative preparation, and oral nursing care should be seriously considered in these patients. Moreover, while being established as an effective and safe method, transoral decompression is associated with several postoperative complications, which could be prevented by elaborate preoperative management, improved surgical skills, and appropriate precautionary measures.

Conclusions

The effectiveness and safety of transoral decompression has been improved by the constant development of operative techniques and advanced auxiliary diagnostic and therapeutic methods, with the understanding of the anatomical structure of the craniocervical joint. Therefore, the incidence rates of postoperative complications have decreased. The application of individualized anterior implants and less-invasive endoscopic endonasal approach has improved the effectiveness of transoral decompression and reduced the associated complications.

LABIOMANDIBULAR GLOSSOTOMY APPROACH FOR CRANIOCERVICAL PATHOLOGIES - SPINE RECONSTRUCTION

ABSTRACT Objectives: Exposing the clivus and upper cervical spine should, ideally, provide an adequate surgical field in which the surgeon can safely decompress and stabilize the craniovertebral junction (CVJ). We present a series of four cases with a narrative review of the literature in which Median Labiomandibular Glossotomy was used to treat CVJ disorders, in order to highlight the importance and indications of this access. Methods: We performed a retrospective analysis of patients who underwent MLMG for several pathologies. The group comprised four patients (two men and two women). Five approaches were performed (one revision surgery). Results: The approach was suitable for all cases, clivus was achieved when necessary. Distally, C4 was exposed to obtain satisfactory osteosynthesis. Laterally, we had a good view of the tumor borders and control of the vertebral artery. Complications encountered were a superficial wound infection that was easily healed, a later pharyngeal wound dehiscence and pseudoarthrosis, all in the same patient. There are 3 main anterior surgical techniques for managing lesions of the clivus, foramen magnum or upper cervical vertebrae. We chose Median Labiomadibular Glossotomy (MLMG) as a primary option, which provided a direct view of the clivus, C3 – C4 caudally and a wider surgical field. The main advantages of the MLMG technique include direct access to spinal pathology, an avascular plane through the median pharyngeal raphe, and a wider surgical field in both the transverse and sagittal dimensions. Conclusion: This approach provides excellent exposure of the craniocervical junction and upper cervical spine. Level of evidence IV; Series of cases analyzed retrospectively.

Multiprofessional Management of Giant Cell Tumors in the Cervical Spine: A Systematic Review

BACKGROUND

Giant cell tumors of the bone (GCTB) are rare bone tumors, especially in the cervical spine. Generally considered benign, local aggressiveness and metastatic growth have been described. Surgical concepts for GCTB are challenged by complex neurovascular anatomy. Specific clinical management guidelines are nonexistent. This systematic review aims to compile existing evidence on the treatment of GCTB of the cervical spine.

METHODS

Four electronic databases were searched: Medline, Embase, Web of Science, and Cochrane Library. All clinical studies reporting the treatment of GCTB in the human cervical spine in English language were found eligible for review.

RESULTS

Seven studies were included in the synthesis including a total number of 54 patients. Of those patients, 46 (85%) were treated for naive nonrecurrent GCTB. Only 1 study is considered a cohort study; all other studies were case reports. Generally, intralesional procedures were performed in 13 (24%) cases. Subtotal resections were reported for 11 (20%) patients. Twenty-eight (52%) patients were surgically treated with piecemeal resection, en-bloc resection, or spondylectomy. Thirty-six (67%) patients underwent adjuvant radiotherapy. A combination of radiotherapy and chemotherapy was reported in 2 (4%) cases. Bisphosphonates were prescribed for 9 (17%) patients. Inconsistent reporting of outcome data did not allow for comparative analyses.

CONCLUSIONS

Best available evidence suggests that the most aggressive surgical approach should be the main goal of any GCTB surgery. No specific adjuvant or neoadjuvant treatment can be recommended as superior due to a lack of comparative data. Therapeutic approaches need to be planned thoroughly on an individual basis.

Endoscopic endonasal approaches to the craniovertebral junction: The Otolaryngologist's perspective

Objective

To review indications and techniques for the endoscopic endonasal approach to the craniovertebral junction (CVJ), analyze postoperative outcomes, and discuss important technical considerations.

Methods

A retrospective analysis was performed on all patients undergoing endonasal endoscopic approaches to the CVJ from May 2007 to June 2017. Demographic information, presenting symptoms, imaging results, treatment course, postoperative functional status, and follow-up were recorded.

Results

There was a total of 30 patients in this series, with a mean follow-up of 11.7 months. The average age was 33.6 years (range, 5–75 years), with 18 females and 12 males. The majority of patients (n = 22, 73.3%) had Chiari malformation type 1 with basilar invagination and symptomatic cervicomedullary compression as the indication for surgery. Intraoperative cerebrospinal fluid leak (CSF) was noted in 3 cases of odontoid resection and a single case of skull base resection. There were no postoperative CSF leaks. Overall, 81% of patients resumed regular diet by post-operative day 2 (range, 0–8 days). Severe postoperative dysphagia occurred in two cases with one requiring gastrostomy tube placement and another utilizing total parenteral nutrition for support prior to eventual gastrostomy. On average, patients were extubated by postoperative day 0.93 (range 0–3 days), with 85% extubated by postoperative day 1. A tracheotomy was required in one patient.

Conclusion

The endonasal endoscopic approach is a valuable technique for access to the CVJ with minimal disruption of respiratory and alimentary function.

Motion-Preserving Navigated Primary Internal Fixation of Unstable C1 Fractures

Study Design

Prospective observational study.

Purpose

To assess the safety, efficacy, and benefits of computed tomography (CT)-guided C1 fracture fixation.

Overview of Literature

The surgical management of unstable C1 injuries by occipitocervical and atlantoaxial (AA) fusion compromises motion and function. Monosegmental C1 osteosynthesis negates these drawbacks and provides excellent functional outcomes.

Methods

The patients were positioned in a prone position, and cranial traction was applied using Mayfield tongs to restore the C0–C2 height and obtain a reduction in the displaced fracture fragments. An intraoperative, CT-based navigation system was used to enable the optimal placement of C1 screws. A transverse rod was then placed connecting the two screws, and controlled compression was applied across the fixation. The patients were prospectively evaluated in terms of their clinical, functional, and radiological outcomes, with a minimal follow-up of 2 years.

Results

A total of 10 screws were placed in five patients, with a mean follow-up of 40.8 months. The mean duration of surgery was 77±13.96 minutes, and the average blood loss was 84.4±8.04 mL. The mean combined lateral mass dislocation at presentation was 14.6±1.34 mm and following surgery, it was 5.2±1.64 mm, with a correction of 9.4±2.3 mm (p <0.001). The follow-up CT showed excellent placement of screws and sound healing. There were no complications and instances of AA instability. The clinical range of movement at 2 years in degrees was as follows: rotation to the right (73.6°±9.09°), rotation to the left (71.6°±5.59°), flexion (35.4°±4.5°), extension (43.8°±8.19°), and lateral bending on the right (28.4°±10.45°) and left (24.8°±11.77°). Significant improvement was observed in the functional Neck Disability Index from 78±4.4 to 1.6±1.6. All patients returned to their occupation within 3 months.

Conclusions

Successful C1 reduction and fixation allows a motion-preserving option in unstable atlas fractures. CT navigation permits accurate and adequate monosegmental fixation with excellent clinical and radiological outcomes, and all patients in this study returned to their preoperative functional status.

Clinical Outcomes of Endoscopic Endonasal Odontoidectomy: A Single-Center Experience

BACKGROUND

Odontoidectomy for basilar invagination and craniovertebral junction pathology traditionally has been performed using a transoral route. However, the endoscopic endonasal approach to the anterior craniovertebral junction may offer safer and more effective access when compared with transoral approaches. The objective of this study is to review the surgical outcomes and complications associated with endoscopic endonasal odontoidectomy.

METHODS

This study is a retrospective chart review of all adult patients who underwent an endoscopic endonasal odontoidectomy at a single tertiary care center between January 2011 and May 2019.

RESULTS

Seventeen patients who underwent endoscopic endonasal odontoidectomy were included. The median age at admission was 67 years (range: 33-84 years) and 65% of the patients were female. One patient (1/17, 6%) had vertebral artery injury, which had to be coiled with no neurologic deficits, and 4 patients (4/17, 24%) had intraoperative CSF leaks with no postoperative leak. Fourteen (14/17, 82%) patients were extubated by postoperative day 1. Three patients (3/17, 18%) developed postoperative sinus infections and required antibiotics. Eight patients (8/17, 47%) developed transient postoperative dysphagia. One patient (1/17, 6%) had postoperative epistaxis and 1 patient (1/17, 6%) had postoperative lower cranial nerve symptoms. The median length of hospital stay was 13 days (range: 2-44 days).

CONCLUSIONS

Although the transoral approach has been the traditional route for anterior decompression of the craniovertebral junction, endoscopic endonasal odontoidectomy is a feasible and well-tolerated procedure associated with satisfactory patient outcomes and low morbidity.

Posterior transdural approach for odontoidectomy in a child: case report

The transoral transpharyngeal approach is the standard approach to resect the odontoid process and decompress the cervicomedullary spinal cord. There are some significant risks associated with this approach, however, including infection, CSF leak, prolonged intubation or tracheostomy, need for nasogastric tube feeding, extended hospitalization, and possible effects of phonation. Other ventral approaches, such as transmandibular and circumglossal, endoscopic transcervical, and endoscopic transnasal, are also viable alternatives but are technically challenging or may still traverse the nasopharyngeal cavity. Far-lateral and posterior extradural approaches to the craniocervical junction require extensive soft-tissue dissection. Recently, a posterior transdural approach was used to resect retro-odontoid cysts in 3 adult patients. The authors present the case of a 12-year-old girl with Down syndrome and significant spinal cord compression due to basilar invagination and a retro-flexed odontoid process. A posterior transdural odontoidectomy prior to occiptocervical fusion was performed. At 12 months after surgery, the authors report satisfactory clinical and radiographic outcomes with this approach.

Computer-aided analysis for optimal screw insertion in lateral mass of C1: An anatomical study

INTRODUCTION

Motion preserving techniques in C1 ring fractures are increasingly used especially in young patients. Therefore, lateral mass screws are inserted in the first vertebra and connected by a rod. The purpose of this study was to determine safe zones regarding the vertebral arteries and the medulla oblongata for optimal lateral mass screw positioning when fusing the C1-ring.

MATERIALS AND METHODS

Images of the cervical spine of 50 patients (64-line CT scanner) were evaluated and virtual screws were positioned in both lateral masses of the first vertebra using 3D-reconstructions of CT scans. The length of the screws, the insertion angles in two planes, the distance to the vertebral artery, and the spinal canal was investigated. Descriptive statistics was used and gender-dependent differences were calculated using student t-test. A diameter of 4 mm was chosen for the screws.

RESULTS

The mean screw length was 30.0 ± 2.3 mm on the right and 30.1 ± 2.1 mm on the left side. The arithmetic mean for the transverse angle was 16.4 ± 5.6° on the right and 15.6 ± 6.3° on the left, the sagittal angle averaged 8.3 ± 3.8° on the right, and 11.0 ± 4.9° on the left side. The mean distance between screw and spinal canal has been determined on the right with 2.4 ± 0.7 mm and 2.2 ± 0.6 mm on the left side. The distance from the C1 lateral mass screw to the vertebral artery was on average 7.1 ± 1.5 mm on the right side (significant correlation with gender, p value: 0.03) and 7.4 ± 1.4 mm on the left side.

CONCLUSIONS

Screws should be positioned with a slightly converging angle of 16° and a slightly ascending angle of 10°. Due to the required high precision technique intraoperatively multiplanar 2 D or 3 D imaging is recommended to avoid harm to the vertebral artery or the spinal canal.

Surgical Site Infections Following the Transoral Approach: A Review of 172 Consecutive Cases

STUDY DESIGN

A retrospective review.

OBJECTIVE

The aim of this study was to discuss the characteristics, treatment, and incidence of surgical site infection (SSI) following transoral approach surgery.

SUMMARY OF BACKGROUND DATA

One of the primary risks associated with transoral approach surgery is postoperative SSI. Few reports exist detailing the specific circumstances, treatment options, and incidence of SSIs following transoral approach surgery in a large series of consecutive cases.

MATERIALS AND METHODS

From January 2005 to September 2010, 172 consecutive transoral surgeries were performed at a single tertiary referral center. Information on patients, treatment methods, and complication incidence and resolution was collected.

RESULTS

There were 6 cases of SSI (3.5%), all in complex craniocervical patients. Of the 6 cases, 2 (1.2%) were isolated local infections, whereas 4 (2.3%) resulted in intracranial infection. Of those with intracranial infections, 3 (75%) were instrumented, whereas 1 (25%) was uninstrumented. Four intraoperative dural lacerations occurred in the entire series (2.3%), all of which developed into intracranial infections. Full SSI resolution occurred in 4 (67%) patients following active treatment: in 3 of 4 patients (75%) with intracranial infections and in 1 of 2 patients (50%) with local infections. Of the 2 remaining unresolved cases, one patient (intracranial) refused removal of instrumentation and subsequently discontinued the treatment, and the other (local) experienced a delayed postoperative infection and died after not receiving treatment because of economic reasons. Following full implementation of care guidelines to avoid SSI in transoral patients, no further SSIs were observed.

CONCLUSIONS

SSI rate following transoral exposure has increased from the authors' earlier reports (0%), likely because of the increasing complexity and instrumentation of transoral approach cases. Cerebrospinal fluid leakage caused by dural injury highly predisposes to intracranial infection. Lumbar puncture, cranial computed tomography, continuous drainage diversion, and intrathecal injection of antibiotics are adequate methods of treatment. Strict consideration of surgical indications, adequate preoperative preparation, careful surgical technique to avoid dural injury, and postoperative oropharyngeal care are important steps for preventing SSI through the transoral approach.

Single-stage Anterior Release and Sequential Posterior Fusion for Irreducible Atlantoaxial Dislocation

STUDY DESIGN

A retrospective study.

OBJECTIVE

To introduce the method of single-stage anterior release and reduction with posterior fusion in irreducible atlantoaxial dislocation (IAAD) and to evaluate the clinical effects of this surgery.

SUMMARY OF BACKGROUND DATA

In previous clinical studies, several techniques have been introduced to manage IAAD. But all these treatments have intrinsic disadvantages. A single-stage anterior release and reduction with posterior fusion can offer a new alternative which can avoid these disadvantages.

METHODS

From January 2003 to January 2009, 22 cases of IAAD were diagnosed consecutively. Anterior atlantoaxial release was performed through anterior retropharyngeal approach, after traction reduction conducted on the monitoring of C-arm fluoroscopy. C1-C2 were then fixed posteriorly and fused by single stage. Neurological status was evaluated using the Japanese Orthopaedic Association scoring system.

RESULTS

All patients were observed for an average of 32 months, ranging from 15 to 40 months. All cases achieved anatomic reduction and solid fusion. The Japanese Orthopaedic Association score of 12 patients with myelopathy improved from 8.3 to 13.9, 6 months postoperatively, and the mean improving rate was 87.5%. No graft or implant-related complications were observed in any patient during the entire follow-up period.

CONCLUSIONS

The method of single-stage anterior release and reduction with posterior fusion is an effective method for management of IAAD, proving its value as a technique for achieving complete reduction with solid bony fusion.

Unilateral lag-screw technique for an isolated anterior 1/4 atlas fracture

STUDY DESIGN

Fractures of the atlas are classified based on the fracture location and associated ligamentous injury. Among patients with atlas fractures treated using external immobilization, nonunion of the fracture could be seen.

OBJECTIVE

Ideally, treatment strategy for an unstable atlas fracture would involve limited fixation to maintain the fracture fragments in a reduced position without restricting the range of motion (ROM) of the atlantoaxial and atlantooccipital joints.

SUMMARY OF BACKGROUND DATA

Such a result can be established using either transoral limited internal fixation or limited posterior lateral mass fixation. However, due to high infection risk and technical difficulty, posterior approaches are preferred but none of these techniques can fully address anterior 1/4 atlas fractures such as in this case.

MATERIALS AND METHODS

A novel open and direct technique in which a unilateral lag screw was placed to reduce and stabilize a progressively widening isolated right-sided anterior 1/4 single fracture of C1 that was initially treated with a rigid cervical collar is described.

RESULTS

Radiological studies made after the surgery showed no implant failure, good cervical alignment, and good reduction with fusion of C1.

CONCLUSIONS

It is suggested that isolated C1 fractures can be surgically reduced and immobilized using a lateral compression screw to allow union and maintain both C1-0 and C1-2 motions, and in our knowledge this is the first description of the use of a lag screw to achieve reduction of distracted anterior 1/4 fracture fragments of the C1 from a posterior approach. This technique has the potential to become a valuable adjunct to the surgeon's armamentarium, in our opinion, only for fractures with distracted or comminuted fragments whose alignment would not be expected to significantly change with classical lateral mass screw reduction.

Variations of mucosal-sparing septectomy for endonasal approach to the craniocervical junction

OBJECTIVES/HYPOTHESIS

Recent advances in surgical techniques have rendered the craniocervical junction (CCJ) accessible transnasally. Endoscopic endonasal transclival and transodontoid approaches are routinely performed in leading skull base centers. Usually, these approaches involve a posterior bony and mucosal septectomy, which may compromise the vascularized pedicled nasoseptal flap (PNSF), a robust reconstructive option for repair of large skull base defects. With the possibility of an intraoperative cerebrospinal fluid leak and the reported success of the PNSF for repair of these defects, preserving the integrity of the PNSF is beneficial during the endoscopic endonasal approach to the CCJ. We describe three new variations/refinements of the endoscopic endonasal approach to the CCJ that preserve the mucosal integrity of the posterior nasal septum and PNSF.

METHODS

Photo and video documentation of cadaveric dissections.

RESULTS

The steps required for the different variations in approaching the CCJ are demonstrated. These three options are: 1) nonopposing Killian incisions with submucosal elevation of PNSFs laterally under the inferior turbinates (the PNSFs are retracted laterally and left attached superiorly onto the nasal septum and laterally under the inferior turbinate); 2) bilateral non-opposing PNSFs tucked beneath their respective middle turbinate or into the sphenoid sinus; and 3) a hybrid approach combining option 1 performed on one side and option 2 on the contralateral side. All three options allowed for a mucosal-sparing septectomy to provide ample access to the CCJ.

CONCLUSION

These variations/refinements of the mucosal-sparing approach to the CCJ allowed adequate surgical access with sufficient maneuverability while preserving both PNSFs.

LEVEL OF EVIDENCE

NA. Laryngoscope, 126:2220-2225, 2016.

C1 anterior arch preservation in transnasal odontoidectomy using three-dimensional endoscope: A case report

BACKGROUND

The transoral ventral corridor is the most common approach used to reach the craniovertebral junction (CVJ). Over the last decade, many case reports have demonstrated the transnasal corridor to the odontoid peg represents a practicable route to remove the tip of the odontoid process. The biomechanical consequences of the traditional odontoidectomy led to the necessity of a cervical spine stabilization. Preserving the inferior portion of the C1 anterior arch should prevent instability.

CASE DESCRIPTION

This is the first report in which the technique to remove the tip of the odontoid while preserving the C1 anterior arch is described by means of a three-dimensional (3D) endoscope. A 53-year-old man underwent a transnasal 3D endoscopic approach because of a complex CVJ malformation. The upper-medial portion of the C1 anterior arch was removed preserving its continuity, and the odontoidectomy was performed. After surgery, a dynamic X-ray scan showed no difference in CVJ motility in comparison with the preoperative one.

CONCLUSIONS

The stereoscopic perception augmented the precision of the surgical gesture in the deep field. The importance of a 3D view relates to the depth of field, which a two-dimensional endoscopy cannot provide. This affects the preservation of the C1 anterior arch because of the presence of critical structures that are exposed to potential damage if not displayed.

The selective odontoidectomy: endoscopic endonasal approach to the craniocervical junction

OBJECTIVE

The resection of the odontoid process via an extended endoscopic endonasal approach has been recently proposed as an alternative to the microscopic transoral method. We aimed to delineate a minimally invasive endoscopic transnasal odontoidectomy and to describe the endoscopic anatomy of the anterior craniovertebral junction (CVJ).

MATERIALS AND METHODS

The anterior CVJ of 14 fresh adult cadavers were selectively accessed via a binostril endoscopic endonasal approach using 0- and 30-degree endoscopes.

RESULTS

The nasopharynx was widely exposed without removing any of the turbinates and without performing a sphenoidotomy. Occipital condyles and lateral masses of the C1 vertebra have been exposed inferiorly at lateral margins of the exposure, in addition to the foramen lacerum, which came into view at the superolateral corner of the operative field. The anterior arch of C1 and the upper 1.5 cm of the odontoid process of C2 have been removed via a minimally invasive endoscopic transnasal approach in all dissections.

CONCLUSIONS

We propose the selective odontoidectomy as a minimally invasive method for the endoscopic endonasal removal of the odontoid process. By using this approach, turbinates and the sphenoid sinus remain unharmed. In addition, this approach may be used in exposing pathologies situated laterally at the anterior CVJ, such as the lateral masses of atlas and occipital condyles.

Endoscopic Endonasal Transclival Transcondylar Approach for Foramen Magnum Meningiomas

BACKGROUND

The endoscopic endonasal approach provides a direct route to ventral foramen magnum (FM) lesions like meningiomas, which are difficult to access. Endonasal access at the FM is limited laterally by the occipital condyles and inferiorly by the C1 anterior arch and the odontoid process, which may need partial resection.

OBJECTIVE

We investigated the surgical anatomy and technical nuances for endonasally increasing the surgical corridor at the FM region both laterally and inferiorly. Unique to our report, we quantified the amount of required medial condyle resection to obtain exposure of the lateral aspects of the FM.

METHODS

Five fresh human head silicone-injected specimens underwent endonasal inferior transclival, transcondylar approaches. The lateral limit of medial condyle resection was defined using a vertical line extending inferiorly from foramen lacerum and its intersection with the occipital condyle. The condylectomy was limited posteriorly by the cortical bone surrounding the hypoglossal canal. The volume of the resected condyle (cubic centimeters) for 10 sides was measured using the pre- and postdissection computed tomography-volumetric analysis.

RESULTS

The mean percentage condylar volume resected during a unilateral medial condylectomy was 18% (9.7%-28.3%). The surgical corridor was extended inferiorly in all specimens without violating the transverse ligament by drilling the superior aspects of C1 anterior arch and the exposed odontoid tip. These operative nuances were successfully applied in the operating room.

CONCLUSION

Anatomical landmarks can reliably guide an endonasal anteromedial condyle resection. Minimal condyle resection is required to widen lateral access at the FM, which minimizes the risk of craniocervical instability.

Odontoid pseudotumor and serial postfusion radiographic evaluation in a patient with a C1–2 mass

Odontoid pseudotumor is a mass occurring around the odontoid process in the cervical spine and can cause significant neurological symptoms at the craniocervical junction due to compression of the spinal cord and cervicomedullary junction at this level. A literature review was performed to provide input on options for treatment and prognosis for this lesion. The literature search found 12 papers in which pseudotumor was treated with posterior decompression and fixation. Posterior decompression and fixation with serial imaging to monitor the size of the pseudotumor postsurgery is a safe and effective treatment option for odontoid pseudotumors.

Purely endoscopic endonasal surgery of the craniovertebral junction: A systematic review

BACKGROUND

Endoscopic endonasal surgery (EES) is a relatively novel approach to the craniovertebral junction (CVJ). The purpose of this analysis is to determine the surgical outcomes of patients who undergo purely EES of the CVJ.

METHODS

A search for articles related to EES of the CVJ was performed using the MEDLINE/PubMed database. A bibliographic search was done for additional articles. Demographics, presenting symptoms, imaging findings, complications, follow-up, and patient outcomes were analyzed.

RESULTS

Eighty-five patients from 30 articles were included. The mean patient age was 47.9 ± 24.8 years (range, 3 to 96 years), with 44.7% being male. The most common presenting symptom was myelopathy (n = 64, 75.3%). The most common indications for surgery were brainstem compression secondary to basilar invagination (n = 41, 48.2%) and odontoid pannus (n = 20, 23.5%). Odontoidectomy was performed in 97.6% of cases. Intraoperative complications occurred in 16 patients (18.8%) and postoperative complications occurred in 18 patients (21.2%). Six patients developed postoperative respiratory failure necessitating a tracheostomy. Neurologic improvement was seen in 89.4% of patients at a mean follow-up of 22.2 months.

CONCLUSION

Our analysis found that EES of the CVJ results in a high rate of neurologic improvement with acceptable complication rates. Given its minimally invasive nature and high success rate, this approach appears to be a reasonable alternative to the traditional transoral approach in select cases. This study represents the largest pooled sample size of EES of the CVJ to date. Increasing use of the endoscopic endonasal approach will allow for further studies with greater statistical power.

Mucosal-sparing posterior septectomy for endoscopic endonasal approach to the craniocervical junction

Recent technological advances and developments in surgical technique have made the craniocervical junction (CCJ) accessible through the transnasal surgical corridor. Endoscopic endonasal transclival and transodontoid approaches have been previously described in the literature. Traditionally, these approaches entail a posterior bony and mucosal septectomy. This posterior bony and mucosal septectomy can compromise the integrity of the posterior septum and damage the vascularized pedicled nasoseptal flap (PNSF), a robust reconstructive option. With the possibility of an intraoperative cerebrospinal fluid (CSF) leak and the reported success of the PNSF for repair of these defects, preserving the integrity of the PNSF is beneficial during the endoscopic endonasal approach to the CCJ. Here, we present a new variation which preserves the mucosal integrity of the posterior nasal septum and PNSF. This mucosal-sparing variation of the traditional endoscopic endonasal transclival and transodontoid approaches allows for the preservation of posterior mucosal nasoseptal integrity, and salvages a reconstructive option for future usage. This is accomplished at no expense to visualization, surgical access, or maneuverability.

Treatment of C-2 metastatic tumors with intraoperative transoral or transpedicular vertebroplasty and occipitocervical posterior fixation

OBJECT

Metastatic spinal tumors of the atlantoaxial region are quite uncommon, and surgery is challenging. The aim in this study was to evaluate the safety and efficacy of transoral or transpedicular vertebroplasty combined with posterior fixation in C-2 metastatic disease.

METHODS

The authors collected from a hospital database all cases of C-2 metastatic tumor treated in the period from January 2009 to December 2012. Cases with histologically confirmed metastatic disease were included, but those with epidural tumorous propagation and signs of spinal cord compression were excluded.

RESULTS

Five patients (3 females, 2 males) with osteolytic C-2 metastasis were eligible for this study. In 3 cases a purely posterior approach was taken to perform a dorsal open C-2 biopsy and transpedicular vertebroplasty followed by posterior occipitocervical fixation. In the other 2 cases a transoral C-2 biopsy and vertebroplasty were performed in combination with dorsal occipitocervical fixation during the same operative session. Patients were followed up with regular fluoroscopy, MRI, and CT studies as well as neurological examinations. During an average follow-up of 13 months (range 8-19 months), no surgical or neurological complications were associated with this combined approach. In all cases spinal stability and pain reduction were detected. The average pain score according to the visual analog scale was 3.5 after surgery (range 2-5); before surgery, the average score was 7 (range 6-8). The average volume of polymethylmethacrylate injected was 4 ml. The body and dens of the C-2 vertebra was filled more than 60% for each patient.

CONCLUSIONS

In this small series, simultaneous intraoperative transoral or transpedicular vertebroplasty and dorsal occipitocervical fixation proved to be a safe and effective treatment for patients with osteolytic C-2 metastatic tumors. These techniques may provide excellent pain relief and improvements in quality of life. The true value of these combined techniques should be evaluated in larger series.

Transnasal endoscopic approach to the pediatric craniovertebral junction and rostral cervical spine: case series and literature review

The endoscopic transnasal approach to the rostral pediatric spine and craniovertebral junction is a relatively new technique that provides an alternative to the traditional transoral approach to the anterior pediatric spine. In this case series, the authors provide 2 additional examples of patients undergoing endoscopic transnasal odontoidectomies for ventral decompression of the spinal cord. Both patients would have required transection of the palate to undergo an effective transoral operation, which can be a cause of significant morbidity. In one case, transnasal decompression was initially incomplete, and decompression was successfully achieved via a second endoscopic transnasal operation. Both cases resulted in significant neurological recovery and stable long-term spinal alignment. The transnasal approach benefits from entering into the posterior pharynx at an angle that often reduces the length of postoperative intubation and may speed a patient's return to oral intake. Higher reoperation rates are a concern for many endoscopic approaches, but there are insufficient data to conclude if this is the case for this procedure. Further experience with this technique will provide a better understanding of the indications for which it is most effective. Transcervical and transoral endoscopic approaches have also been reported and provide additional options for pediatric anterior cervical spine surgery.

Unstable Jefferson fractures: Results of transoral osteosynthesis

BACKGROUND

Majority of C1 fractures can be effectively treated conservatively by immobilization or traction unless there is an injury to the transverse ligament. Conservative treatment usually involves a long period of immobilization in a halo-vest. Surgical intervention generally involves fusion, eliminating the motion of the upper cervical spine. We describe the treatment of unstable Jefferson fractures designed to avoid these problems of both conservative and invasive methods.

MATERIALS AND METHODS

A retrospective review of 12 patients with unstable Jefferson fractures treated with transoral osteosynthesis of C1 between July 2008 and December 2011 was performed. A steel plate and C1 lateral mass screw fixation were used to repair the unstable Jefferson fractures. Our study group included eight males and four females with an average age of 33 years (range 23-62 years).

RESULTS

Patients were followed up for an average of 16 months after surgery. Range of motion of the cervical spine was by and large physiologic: Average flexion 35° (range 28-40°), average extension 42° (range 30-48°). Lateral bending to the right and left averaged 30° and 28° respectively (range 12-36° and 14-32° respectively). The average postoperative rotation of the atlantoaxial joint, evaluated by functional computed tomography scan was 60° (range 35-72°). Total average lateral displacement of the lateral masses was 7.0 mm before surgery (range 5-12 mm), which improved to 3.5 mm after surgery (range 1-6.5 mm). The total average difference of the atlanto-dens interval in flexion and extension after surgery was 1.0 mm (range 1-3 mm).

CONCLUSIONS

Transoral osteosynthesis of the anterior ring using C1 lateral mass screws is a viable option for treating unstable Jefferson fractures, which allows maintenance of rotation at the C1-C2 joint and restoration of congruency of the atlanto-occipital and atlantoaxial joints.

Endoscopic transnasal odontoidectomy combined with posterior reduction to treat basilar invagination: technical note

OBJECT

Transoral microscopic odontoidectomy has been accepted as a standard procedure to treat basilar invagination over the past several decades. In recent years the emergence of new technologies, including endoscopic odontoidectomy and posterior reduction, has presented a challenge to the traditional treatment algorithm. In this article, the authors describe 1 patient with basilar invagination who was successfully treated with endoscopic transnasal odontoidectomy combined with posterior reduction. The purpose of this report is to validate the effectiveness of this treatment algorithm in selected cases and describe several operative nuances and pearls based on the authors' experience.

METHODS

One patient with basilar invagination caused by a congenital osseous malformation underwent endoscopic transnasal odontoidectomy combined with posterior reduction in a single operative setting. The purely endoscopic transnasal odontoidectomy was first conducted with the patient supine. The favorable anatomical reduction was then achieved through a posterior approach after the patient was moved prone.

RESULTS

The patient was extubated after recovery from anesthesia and allowed oral food intake the next day. No complications were noted, and the patient was discharged 4 days after the operation. Postoperative imaging demonstrated excellent decompression of the anterior cervicomedullary junction pathology. The patient was followed up for 12 months and remarkable neurological recovery was observed.

CONCLUSIONS

The endoscopic transnasal odontoidectomy is a better minimally invasive approach for anterior decompression and can make the posterior reduction easier because the anterior resistant force is eliminated. The subsequent posterior reduction can make decompression of the ventral side of the cervicomedullary junction more effective because the C-2 vertebral body is pushed forward. A combination of these 2 approaches has the advantages of minimally invasive access and a faster patient recovery, and thus is a valid alternative in selected cases.

Endonasal access to the upper cervical spine, part one: radiographic morphometric analysis

Objectives To determine the anatomical relationships that may influence endonasal access to the upper cervical spine. Setting We retrospectively analyzed computed tomography of 100 patients at a single institution. Participants Participants included adults with imaging of the hard palate, clivus, and cervical spine without evidence of fracture, severe spondylosis, or previous instrumentation. Main Outcome Measures Morphometric analyses of hard palate length and both distance and angle between the hard palate and odontoid process were based on radiographic measurements. Descriptive zones were assigned to cervical spine levels, and endoscopic visualization was simulated with projected lines at 0, 30, and 45 degrees from the hard palate to the cervical spine. Results We found an inverse relationship between hard palate length and the lowest zone of the cervical spine potentially visualized by nasal endoscopy. The distance between the posterior tip of the hard palate and the odontoid tip, and the angle formed between the two, directly influenced the lowest possible cervical exposure. Conclusions Radiographic relationships between hard palate length, distance to the odontoid, and the angle formed between the two predict the limits of endonasal access to the cervical spine. These results are supported by cadaveric data in Part Two of this study.

Endoscopic endonasal odontoidectomy in a child with chronic type 3 atlantoaxial rotatory fixation: case report and literature review

INTRODUCTION

Although the transoral transpharyngeal approach has been the standard approach to decompress the odontoid process, it bears some disadvantages including risk of infection, prolonged intubation or tracheostomy, need for nasogastric tube feeding, extended hospitalization, and possible effects of phonation. The endoscopic transnasal approach is a viable alternative, managing to avoid some of the pitfalls of the more accepted transoral transpharyngeal approach. However, there have only been a handful of adult cases and only three pediatric cases.

CASE REPORT

We present the case of a 10-year-old girl with a chronic type 3 atlantoaxial rotator fixation and significant spinal cord compression from basilar invagination and a displaced odontoid process. We performed an endoscopic endonasal odontoidectomy prior to posterior occiptocervical fusion on the patient. She was neurologically intact with a well-healed wound at 7-month follow-up.

Endoscopic excision of C2 Osteoid Osteoma: a technical case report

PURPOSE

The Authors illustrate the feasibility of an open biopsy and complete excision of Osteoid Osteoma involving the C2 vertebral body performed via endoscopic anterior cervical approach.

METHODS

A 23-year-old male patient with history of delayed diagnosis of cervical Osteoid Osteoma underwent evaluation and surgical treatment: the minimally invasive procedure and techniques were described. The clinical features, the radiological findings and the outcome were assessed. Complications and local recurrences were also recorded.

RESULTS

There were no intra- or post-operative complications. Immediately after surgery the typical Osteoid Osteoma related pain disappeared. At three years follow-up the patient was asymptomatic and considered disease-free: CT-scan and x-Ray showed no local recurrence and C2-C3 interbody fusion with cervical plate in site.

CONCLUSIONS

The endoscopic transcervical surgery represents an interesting option for the treatment of these diseases in difficult areas of the upper cervical spine, also minimizing soft tissue trauma and collateral damage allows patients a faster and complete return to normal function. To our knowledge this is the first report of cervical spine tumor removal using this minimally invasive approach.

The transverse occipital ligament: an anatomic, histologic, and radiographic study

BACKGROUND CONTEXT

The craniocervical region is an osteoligamentous complex that provides structural stability and movement by means of numerous ligaments. Fundamental knowledge of these ligaments is important for physicians who treat patients with disorders of this region to reduce morbidity and mortality. There is a paucity of data in the literature regarding the morphology, function, and classification of the transverse occipital ligament (TOL).

PURPOSE

The purpose of this study was to investigate the prevalence, morphology, and variations of the TOL in a large number of adult human cadavers using dissection, histology, and digital radiography.

STUDY DESIGN

Cadaveric laboratory study.

SAMPLE

Thirty-two formalin-fixed human adult cadavers were dissected in the study. Fourteen cadavers were found to have a TOL.

OUTCOME MEASURES

Measurements using a digital caliper, high-resolution digital photography, histologic staining with bright-field microscopy, and digital radiography.

METHODS

The posterior musculature and related soft tissues were dissected and underlying bony elements removed. The TOL was identified, isolated, measured, and then removed for histologic preparation with hematoxylin and eosin staining. Anteroposterior open-mouth digital radiographs of the upper cervical spine with monofilament attached to the TOL were used to demonstrate its relations to the occiput, atlas, and axis.

RESULTS

The TOL was present in 14 of 32 (44%) of the dissected cadavers (six male and eight female). Three types of TOLs were identified. Type 1 had bilateral connections to the alar ligaments and had fibers inserting onto the dens. Type 2 also had bilateral connections to the alar ligaments but did not have fibers inserting onto the dens. Type 3 neither had any connections to the alar ligaments nor had fibers that connected to the dens. Male cadavers always had a Type 1 TOL compared with 3 of 8 (38%) female cadavers and this difference was significant (p=.031). The TOL consisted of dense regular connective tissue with parallel arrangements of collagen fibers and interposed fibroblasts.

CONCLUSIONS

Our data suggest that the TOL is not an anatomic variant and can be classified into three types. Future biomechanical studies can be designed to investigate the function of the TOL, although we hypothesize that it may act as a fulcrum during flexion and extension of the head because it is located between the apical ligament and superior crus of the cruciform ligament. Anteroposterior open-mouth digital radiographs revealed the location of the TOL with respect to the upper two cervical vertebrae. Future research should investigate the radiologic characteristics of the TOL using magnetic resonance imaging.

Sequentially staged resection and 2-column reconstruction for C2 tumors through a combined anterior retropharyngeal-posterior approach: surgical technique and results in 11 patients

BACKGROUND

Surgical treatment of C2 tumors remains challenging. Because of the deep location and unique anatomical complexity, anterior exposure in this region is considered difficult and dangerous, and few reports concerning anterior tumor resection and reconstruction exist.

OBJECTIVE

To describe a technique of sequentially staged resection and 2-column reconstruction for C2 tumors through a combined anterior retropharyngeal-posterior approach.

METHODS

Eleven patients with C2 tumors underwent sequentially staged tumor resection and 2-column reconstruction in our institute. Eight primary lesions and 3 metastases were involved. Tumor resections and anterior reconstructions with conventional constructs were accomplished by an anterior retropharyngeal approach, and occipitocervical fusions through posterior access were performed in the same anesthesia.

RESULTS

No operative mortality occurred in this series. All patients experienced pain relief and neurological improvement after surgery. Except for 1 incidence of screw pullout, which was corrected by revision surgery, solid fusion was achieved in all patients. A follow-up period of 12 to 37 months was available for this study. Two patients with chordoma relapsed; 1 died of disease, and the other was alive with disease. Two patients with metastasis died of multiple remote metastases. No evidence of local recurrence was found in the other patients.

CONCLUSION

The anterior retropharyngeal approach is a favorable route to treat tumor lesions of the C2 vertebral body that allows tumor resection and placement of anterior constructs between C1 and the subaxial vertebral body. Tumor resection and 2-column reconstruction could safely be accomplished simultaneously through the combined anterior retropharyngeal-posterior approach.

The importance of platybasia and the palatine line in patient selection for endonasal surgery of the craniocervical junction: a radiographic study of 12 patients

OBJECTIVE

Ventral decompressive surgery of the craniocervical junction is performed to manage a variety of conditions, including basilar invagination, which can be associated with platybasia. We have noted that the anatomic changes of platybasia could affect the height of the odontoid over a line drawn along the nasal cavity floor, the palatine line (PL). This anatomic change may influence the use of nasal endoscopic surgery for patients with platybasia who also have basilar invagination. We investigated whether the height of the craniocervical junction is elevated over the PL in patients with and without platybasia.

METHODS

We conducted a retrospective review of consecutive craniovertebral junction surgical cases during a 14-month period. During that time we treated 12 patients, including 4 with platybasia and 8 without. The average age was 50 years (range, 18-64 years). Preoperative and postoperative radiographic images were evaluated and charts reviewed.

RESULTS

The mean height of the odontoid over the PL without platybasia was 3.5 mm (range, 0-19.0 mm). In those with platybasia, it was 15.5 mm (range, 7-26.0 mm; P=.021). There was a statistically significant increase in the height of the clival tip and C1 ring in patient with platybasia as well.

CONCLUSIONS

Platybasia is associated with an increase in the odontoid and craniocervical junction over the PL. This increase in height has implications for endoscopic approach selection in patients with platybasia. Platybasia patients with basilar invagination may be better suited to a transnasal approach.

Posterior osteosynthesis of the atlas for nonconsolidated Jefferson fractures: a new surgical technique

STUDY DESIGN

Case report and surgical technique.

OBJECTIVE

To describe a new technique to treat atlas burst fractures by selectively reconstructing the atlas from a posterior approach.

SUMMARY OF BACKGROUND DATA

The two surgical techniques reported until now for stabilizing atlas burst fractures are associated with some drawbacks. Posterior C0-C2 or C1-C2 fixations significantly reduce head rotation, while the transoral C1 lateral masses osteosynthesis can be associated with oropharyngeal and neurological complications. We propose a new surgical technique for the treatment of unstable Jefferson fractures aimed at avoiding these problems.

METHODS

A 25-year-old man presented with a Jefferson type III atlas fracture after a traffic accident. The fracture failed to consolidate after 3 months of halo brace immobilization. Surgery consisted in inserting bilateral posterior C1 lateral mass screws interconnected by a transversal rod, thereby creating a second C1 posterior arch under the fractured one.

RESULTS

Postoperative course was uneventful. Immediate postoperative stability was confirmed on dynamic X-ray films and head rotation was preserved. Delayed computed tomography scan demonstrated fracture consolidation.

CONCLUSION

The surgical technique described is new and effective for treating atlas burst fractures. This posterior procedure allows mobility preservation, with a low morbidity rate.

Diseases of the odontoid and craniovertebral junction with management by endoscopic approaches

Surgical approaches to the craniovertebral junction (CVJ) can result in dysfunction of the upper aerodigestive tract. However, few data are available regarding the incidence of complications after such surgery. Evaluation of a CVJ lesion for treatment must establish the biology, transverse and longitudinal extent of the lesion, and the preoperative and postoperative stability of the spine. Endoscopic approaches to the CVJ, which should reduce the expected morbidity of an open transoral approach, have been described recently. This article reviews common pathologies of the CVJ and surgical approaches, and provides an evidence-based analysis of whether endoscopic approaches reduce velopharyngeal insufficiency.

Comparison of extraoral and transoral approaches to the craniocervical junction: morphometric and quantitative analysis

BACKGROUND

The transoral (TO) approach to the craniocervical junction provides similar access to the periclival and subaxial spine compared with the extraoral anterolateral prevascular (EAP) approach, but the additional exposure gained by the EAP approach has not been quantified. This study quantitatively compared the two surgical exposures.

METHODS

Ten silicon-injected fixed cadaver heads were used for the TO approach and another 5 heads (10 sides) were dissected for the EAP approach. For the TO approach, mouth opening was standardized to 5.5 cm using a Spetzler-Sonntag retractor, and the soft palate was split 1.5 cm to access the periclival area. A frameless stereotactic device was used to calculate the lengths, angles, and areas of surgical exposure for different anatomic targets.

RESULTS

The vertical working length on the dura progressively increased 61% (336 ± 26 mm to 539 ± 16 mm [mean ± standard deviation]; P < 0.001), and the vertical working angle increased 23% (98 ± 3 degrees to 121 ± 5 degrees; P < 0.0) using the TO versus the EAP approach. In the TO approach, the bilateral average horizontal working length on the C1 arch was less on the ipsilateral side than for the EAP approach (11 ± 1 mm vs. 17 ± 1 mm, 61%; P < 0.01). The mean periclival and subaxial exposures were 546 ± 72 mm(2) and 932 ± 70 mm(2) with the TO approach and 874 ± 75 mm(2) and 1644 ± 107 mm(2) with the EAP approach (mean increases 62% and 77%, respectively; both P < 0.001).

CONCLUSIONS

Both the TO and EAP approaches improved surgical exposure, but the EAP approach provides more significant and consistent gains to the anterolateral periclival and subaxial areas.

Sublabial approach for the treatment of symptomatic basilar impression in a patient with Klippel-Feil syndrome

BACKGROUND

Basilar impression (BI) is an uncommon condition in which there is upward displacement of the elements forming the foramen magnum, causing translocation of vertebral elements into the brainstem. Most commonly a developmental anomaly, BI is often associated with congenital conditions such as Down syndrome. Symptomatic BI is often difficult to treat surgically secondary to the anatomic variants associated with many of the coinciding congenital syndromes.

OBJECTIVE

To present a feasible approach for the treatment of BI.

METHODS

We present an alternative surgical approach for the treatment of symptomatic BI in a 37-year-old woman with Klippel-Feil syndrome. Because of the altered anatomy, traditional approaches such as the transoral-transpharyngeal, transmandibular circumglossal, and transcervical endoscopic routes were not feasible.

RESULTS

We chose a staged sublabial, transnasal, transpalatal route for the anterior brainstem decompression followed by posterior fixation. The patient tolerated the procedures well and at last follow-up had nearly complete resolution of symptoms.

CONCLUSION

The sublabial route is an alternative approach for anterior decompression in patients with symptomatic basilar impression and altered anatomic circumstances such as that caused by Klippel-Feil syndrome.

Video-assisted anterior transcervical approach for the reduction of irreducible atlantoaxial dislocation

STUDY DESIGN

Technique note.

OBJECTIVE

To describe a modified minimally invasive approach for the treatment of irreducible atlantoaxial dislocation (IAAD).

SUMMARY OF THE BACKGROUND DATA

Currently, the most frequently used route for the treatment of symptomatic IAAD is transoral-transpharyngeal approach. Although it provides the most direct route to the atlantoaxial joint, potential problems may arise because of traverse oral cavity, such as the potential risks of infection, postoperative disturbances of breathing, and swallowing. The aim of this study was to describe a less-invasive approach for IAAD.

METHODS

Four consecutive patients with IAAD underwent the combined video-assisted atlantoaxial transcervical release (VAAT) procedure and posterior occipital-cervical fusion or C1-C2 screw fixation at Tongji Hospital. Clinical characteristics, images data, operative variables, and follow-up data were recorded.

RESULTS

Four cases presented with signs and symptoms of spinal cord dysfunction caused by IAAD underwent 1-stage anterior release, reduction, and posterior fixation. Three cases received C1-C2 screw fixation, and 1 case with occipitocervical fixation. Postoperative imaging studies showed that complete decompression was achieved in all the cases. No systemic infections, cerebrospinal fluid leaks, or adverse neurologic sequelae were found. None of the patients required prolonged intubation, tracheostomy, or enteral tube feeding. All patients started to oral intake after anesthesia. Neurologic status in 1 case remained at baseline whereas it improved in the others. The mean follow-up period was 9 months (6 approximately 12 months). All cases achieved solid fusion, without implants failure.

CONCLUSION

Our initial experience showed that the VAAT procedure for IAAD is a safe supplement and alternative to conventional and transcervical procedures.

Radiographic and anatomic basis of endoscopic anterior craniocervical decompression: a comparison of endonasal, transoral, and transcervical approaches

OBJECTIVE

To evaluate surgical access to the craniocervical junction using 3 endoscopic approaches: endonasal, transoral, and transcervical.

METHODS

Nine cadaveric specimens were used. Image guidance was used in 1 specimen for each approach; fluoroscopy was used in every case. The Vitrea imaging station (Vital Images Inc., Minnetonka, MN) was used to evaluate the angles and distances to the target of the approach, centered on the tip of the odontoid. The entry site was defined as: 1) the endonasal approach (inferior midline of the nasal bone), 2) the transoral approach (the tip of the upper incisor), and 3) the transcervical approach (the skin at the C4-C5 level).

RESULTS

Adequate lower clivus and craniocervical decompression was achieved using the endonasal and transoral approaches. Lower clivus decompression was not achieved with the transcervical approach. The average distance to the surgical target was as follows: endonasal (94 mm), transoral (102 mm), and transcervical (100 mm). The angle of attack was as follows: endonasal (28 degrees), transoral (30 degrees), and transcervical (15 degrees). The working area at the base of the field was as follows: endonasal (1305 mm2), transoral (1406 mm2), and transcervical (743 mm2).

CONCLUSION

The endonasal and transoral approaches allow wide exposure with large working angles to the craniocervical junction. The transcervical approach accesses the odontoid for resection from the body of C2 to the lip of the basion. The angles of attack in the transcervical approach when centered on the surgical target are limited, but this approach offers a clean, sterile operative field. Clinical investigation will be required to determine the optimal indications for each approach.