Labiomandibular, transoral approach to chordomas in the clivus and upper cervical spine

Endoscopic transoral resection for an upper cervical chordoma in a pediatric patient

BACKGROUND

Upper cervical chordoma (UCC) is a rare disease, and although transoral approaches are the methods of choice, minimally invasive techniques have not been established.

METHOD

We report the successful use of endoscopic transoral surgery for upper cervical chordoma at the C1-3 levels in the midline epidural space in an 8-year-old girl who presented with neck pain and quadriplegia. Three months after occipitocervical posterior fixation, endoscopic transoral surgery was performed and the tumor was nearly totally removed.

CONCLUSION

Endoscopic transoral surgery in pediatric patients with UCCs is a minimally invasive and safe technique.

Transcervical, retropharyngeal odontoidectomy - Anatomical considerations

Context

Anterior craniocervical junction lesions have always been a challenge for neurosurgeons. Presenting with lower cranial nerve dysfunction and symptoms of brainstem compression, decompression is often required. While posterior approaches offer indirect ventral brainstem decompression, direct decompression via odontoidectomy is necessary when they fail. The transoral and endoscopic endonasal approaches have been explored but come with their own limitations and risks. A novel retropharyngeal approach to the cervical spine has shown promising results with reduced complications.

Aims

This study aims to explore the feasibility and potential advantages of the anterior retropharyngeal approach for accessing the odontoid process.

Methods and Surgical Technique

To investigate the anatomical aspects of the anterior retropharyngeal approach, a paramedian skin incision was performed below the submandibular gland on two cadaveric specimens. The subcutaneous tissue followed by the platysma is dissected, and the superficial fascial layer is opened. The plane between the vascular sheath laterally and the pharyngeal structures medially is entered below the branching point of the facial vein and internal jugular vein. After reaching the prevertebral plane, further dissection cranially is done in a blunt fashion below the superior pharyngeal nerve and artery. Various anatomical aspects were highlighted during this approach.

Results

The anterior, submandibular retropharyngeal approach to the cervical spine was performed successfully on two cadavers highlighting relevant anatomical structures, including the carotid artery and the glossopharyngeal, hypoglossal, and vagus nerves. This approach offered wide exposure, avoidance of oropharyngeal contamination, and potential benefit in repairing cerebrospinal fluid fistulas.

Conclusions

For accessing the craniocervical junction, the anterior retropharyngeal approach is a viable technique that offers many advantages. However, when employing this approach, surgeons must have adequate anatomical knowledge and technical proficiency to ensure better outcomes. Further studies are needed to enhance our anatomical variations understanding and reduce intraoperative risks.

En bloc resection of a high cervical chordoma followed by reconstruction with a free vascularized fibular graft: illustrative case

BACKGROUND

Wide excision of chordoma provides better local control than intralesional resection or definitive radiotherapy. The en bloc excision of high cervical chordomas is a challenging endeavor because of the complex anatomy of this region and limited reconstructive options.

OBSERVATIONS

This is the first case report to describe reconstruction with a free vascularized fibular graft following the en bloc excision of a chordoma involving C1-3.

LESSONS

This report demonstrates the durability of this construct at 10-year follow-up and is the first case report demonstrating satisfactory long-term oncological outcomes after a true margin-negative resection of a high cervical chordoma.

Surgical Strategy for Skull Base Chordomas : Transnasal Midline Approach or Transcranial Lateral Approach

OBJECTIVE

The clinical management paradigm of skull base chordomas is still challenging. Surgical resection plays an important role of affecting the prognosis. Endonasal endoscopic approach (EEA) has gradually become the preferred surgical approach in most cases, but traditional transcranial surgery cannot be completely replaced. This study presents a comparison of the results of the two surgical strategies and a summary of the treatment algorithms for skull base chordomas.

METHODS

We retrospectively analyzed the surgical outcomes and follow-up data of 48 patients with skull base chordomas diagnosed pathologically who received transnasal midline approaches (TMA) and transcranial lateral approaches (TLA) from 2010 to 2020.

RESULTS

Among the 48 patients, 36 cases were adopted TMA and 12 cases were performed with TLA. In terms of gross total resection (GTR) rate, 27.8% in TMA and 16.7% in TLA and with EEA alone it was increased to 38.9%, while 29.7% in primary surgery. In TMA, the cerebrospinal fluid (CSF) leak remains the most common complication (13 cases, 36.1%), other main complications included death, cranial nerve palsy, hypopituitarism, all the comparisons were no statistical significance. The Karnofsky Performance Scale scores in TMA were all better than those in TLA at different time, and the overall survival (OS) and recurrence free survival/progression free survival was just the reverse.

CONCLUSION

The EEA for skull base chordomas resection has improved the GTR rate, but transcranial approach is still an alternative approach. It is necessary to select an appropriate surgical approach based on the location and the pattern of tumor growth in order to obtain the best surgical outcomes.

Surgical Approaches to Tumors of the Occipito-Cervical, Subaxial Cervical, and Cervicothoracic Spine: An Algorithm for Standard versus Extended Anterior Cervical Access

OBJECTIVE

To propose a surgical approach algorithm for the tumors of the cervicothoracic spine.

METHODS

All patients operated for vertebral column tumors involving the occipito-cervicothoracic spine were reviewed. Oncologic characteristics and surgical approach were gathered. Approach was classified by the use of staging and trajectory (posterior, transnasal, transoral, transmandibular, transcervical, transsternal). Angle of attack was defined for the occipitocervical junction tumor as the angle inscribed by the inferior mandibular plane and line connecting the superior tumor pole and mandibular angle. For lesions extending below the thoracic inlet, angle of attack was that inscribed by the plane of the thoracic inlet and the line connecting the jugular notch and inferior tumor pole.

RESULTS

In total, 115 patients were included (mean age 56.7 years, 64 [56%] male, average size 26.5 cm³, 39 [34%] primary tumors). Sixty-nine (60%) of patients had single-stage procedures (57 [49.6%] posterior-only, 12 [10.4%] anterior-only), 35 (30.4%) had 2-stage procedures, and 11 (9.6%) had 3- or 4-stage approaches. Lesions requiring a combined transmandibular-transcervical approach all involved the C2 and C3 levels and had a significantly steeper angle of attack (42.5 ± 9.5 vs. 6.1 ± 13.3°; P = 0.01) and greater superior tumor extent above the inferior plane of the mandible (3.69 ± 2.18 vs. 0.33 ± 0.78; P = 0.002). Lateral tumor extent, tumor size, nor inferior angle of attack differed significantly between approach groups.

CONCLUSIONS

Here, we present a preliminary decision-making algorithm for the management of vertebral column tumors of the cervicothoracic spine. Based on this single-center experience, we suggest which patients, assessed via a combination of tumor histology and regional anatomy, may benefit from extended anterior surgical access.

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.

Proton beam therapy in the management of skull base chordomas: systematic review of indications, outcomes, and implications for neurosurgeons

BACKGROUND

Chordomas are rare tumours affecting the skull base. There is currently no clear consensus on the post-surgical radiation treatments that should be used after maximal tumour resection. However, high-dose proton beam therapy is an accepted option for post-operative radiotherapy to maximise local control, and in the UK, National Health Service approval for funding abroad is granted for specific patient criteria.

OBJECTIVES

To review the indications and efficacy of proton beam therapy in the management of skull base chordomas. The primary outcome measure for review was the efficacy of proton beam therapy in the prevention of local occurrence.

METHODS

A systematic review of English and non-English articles using MEDLINE (1946-present) and EMBASE (1974-present) databases was performed. Additional studies were reviewed when referenced in other studies and not available on these databases. Search terms included chordoma or chordomas. The PRISMA guidelines were followed for reporting our findings as a systematic review.

RESULTS

A total of 76 articles met the inclusion and exclusion criteria for this review. Limitations included the lack of documentation of the extent of primary surgery, tumour size, and lack of standardised outcome measures. Level IIb/III evidence suggests proton beam therapy given post operatively for skull base chordomas results in better survival with less damage to surrounding tissue.

CONCLUSIONS

Proton beam therapy is a grade B/C recommended treatment modality for post-operative radiation therapy to skull base chordomas. In comparison to other treatment modalities long-term local control and survival is probably improved with proton beam therapy. Further, studies are required to directly compare proton beam therapy to other treatment modalities in selected patients.

Endoscopic Endonasal Approaches to the Craniovertebral Junction: A Systematic Review of the Literature

Background We reviewed the current literature pertaining to extended endoscopic endonasal approaches to the craniovertebral junction. Methods A systematic literature review was utilized to identify published surgical cases of endoscopic endonasal approaches to the craniovertebral junction. Full-text manuscripts were examined for various measures of surgical indications, patient characteristics, operative technique, and surgical outcomes. Results We identified 71 cases involving endoscopic endonasal approaches for surgical management of a variety of pathologies located within the craniovertebral junction. Patient ages ranged from 3 to 87 years, with 40 females and 31 males. Five patients required tracheostomy, two were reintubated, and all others experienced an average intubation duration of 0.54 days following surgery. Fifty-eight patients (81.7%) underwent an additional posterior decompression or fusion either before or after the endonasal procedure. A complete resection of the pathologic lesion was reported in 57 cases (83.8%), another five were successful biopsies, and four resulted in partial resection. The follow-up time ranged from 0.5 to 57 months. Conclusion Although the transoral approach has been the standard for anterior surgical management for the past several decades, our systematic review illustrates that the extended endoscopic endonasal approach is a safe and effective alternative for most pathologies affecting the craniovertebral junction.

Operative technique for en bloc resection of upper cervical chordomas: extended transoral transmandibular approach and multilevel reconstruction

Anterior exposure for cervical chordomas remains challenging because of the anatomical complexities and the restoration of the dimensional balance of the atlanto-axial region. In this report, we describe and analyze the transmandibular transoral approach and multilevel spinal reconstruction for upper cervical chordomas. We report two cases of cervical chordomas (C2 and C2-C4) that were treated by marginal en bloc resection with a transmandibular approach and anterior-posterior multilevel spinal reconstruction/fixation. Both patients showed clinical improvement. Postoperative imaging was negative for any residual tumor and revealed adequate reconstruction and stabilization. Marginal resection requires more extensive exposure to allow the surgeon access to the entire pathology, as an inadequate tumor margin is the main factor that negatively affects the prognosis. Anterior and posterior reconstruction provides a rigid reconstruction that protects the medulla and decreases axial pain by properly stabilizing the cervical spine.

Clival chordomas: A pathological, surgical, and radiotherapeutic review

BACKGROUND

The purpose of this study was to discuss the optimal management of patients with clival chordomas and provide an up-to-date review of the field.

METHODS

A schematic description of the anatomy of the clivus and its surrounding structures is provided based on the modular classification of the surgical corridors used in endoscopic skull base surgery. Postoperative radiotherapy (RT) techniques are described.

RESULTS

The optimal treatment is gross total resection. Recent advances in endoscopic endonasal skull base surgery have allowed very high rates of macroscopic and radiographic complete tumor resection in spite of the challenging location of these lesions. When the tumor location or extension is too lateral or inferior to be effectively resected with an endoscopic approach, an open approach or a combination of endoscopic and open approaches in stages should be considered. Postoperative RT is usually indicated because the likelihood of recurrence is high in spite of complete surgical resection. The main site of recurrence is local and late recurrences are relatively common. The probability of cure is approximately 50% at 10 years and significantly increases when complete tumor resection has been achieved.

CONCLUSION

The preferred treatment for patients with clival chordoma is gross total resection (via endoscopic endonasal surgery when possible) followed by postoperative RT. Treatment at experienced multidisciplinary cranial base centers is key to minimize complications and to enhance the probability of total removal of the tumors.

Critical appraisal of extent of resection of clival lesions using the expanded endoscopic endonasal approach

Objectives To present a critical evaluation of our experience using an expanded endoscopic endonasal approach (EEEA) to clival lesions and evaluate, based on the location of residual tumor, what the anatomic limitations to the approach are. Design A retrospective review of all endoscopic endonasal operations performed at our institution identified 19 patients with lesions involving the clivus. Extent of resection was determined by preoperative and postoperative tumor volumes. Results Three patients underwent planned subtotal resections. Of the remaining patients, gross total resection was achieved in 8/16 (50%), > 95% in 5/16 (31%), and < 95% in 3/16 (19%). Residual tumor occurred, most commonly with extension posterior and lateral to the internal carotid artery, with inferior, lateral invasion of the occipital condyle and with deep inferior extension to the midportion of the dens. Conclusions The EEEA represents a safe and effective technique for the resection of clival lesions. Despite excellent overall visualization of this region we found that adequate exposure of the most lateral and inferior portions of large tumors is often difficult. Knowledge of these limitations allows us to determine which tumors are best suited for an EEEA and which may be more appropriate for an open skull base or combined technique.

Open-door maxillotomy approach for lesions of the clivus

The transpalatal route to the clival region has been used to approach both extradural and intradural lesions. Classic transpalatal surgery, however, entails a partial splitting of the soft palate or some form of palatal retraction, which leaves behind a bony palate that hinders surgical exposure. When necessary, operative exposure can be enhanced by an open-door maxillotomy approach that uses a combination of a Le Fort I osteotomy of the maxilla and a paramedian sagittal split of the hard palate. The nasal septum is translocated to create a wide contiguous oronasal aperture through which the clival region can be reached unobstructed. This technique was used in three patients. No significant complications were observed in any patient. Features of this extended transpalatal approach, including indications and adjunctive measures to minimize potential complications, are discussed.

Transoral surgery: an anatomic study

The transoral approaches have become commonplace in modern neurosurgical practice for treatment of ventral midline lesions of the clivus and upper cervical spine. Although the standard technique of transoral surgery is conceptually simple, anatomic relationships are not so readily appreciated. The present study was undertaken in an effort to define more clearly the midline anatomic relationships as they pertain to the standard transoral and transpalatine operations. The anatomic relationships involved in planning microsurgical transoral approaches were examined in 15 human cadavers. Landmarks approximating the midline of the skull base and the upper cervical spinal canal were defined to assist the surgeon's orientation. Measurements were made in axial, sagital, and parasagittal planes to various neurovascular structures in the posterior cranial fossa and upper cervical spinal canal. The study revealed that, for the standard transoral and transoral-transpalatine dissections, the carotid arteries, abducens nerves, interior petrosal sinuses, hypoglossal nerves, and vertebral arteries would be a greatest risk being 0.76, 1.06, 1.51, 1.34, and 1.52 cm from the midline at specified locations. The measurements and the computed tomography images provide a useful reference for the surgeon.

Transoral approach and extended modifications for lesions of the ventral foramen magnum and craniovertebral junction

OBJECTIVES

To describe our method of performing the transoral approach and the extended approaches to the ventral foramen magnum and craniovertebral junction and review the technical aspects and operative nuances.

DESIGN

Review.

RESULTS

The transoral approach provides direct midline exposure to access extradural disease located at the craniovertebral junction and ventral foramen magnum. The corridor of exposure is generally limited by the extent to which the patient can open his or her mouth. The location of the hard palate relative to the craniovertebral junction limits superior exposure, whereas the mandible and base of the tongue limit the inferior exposure. In most cases, exposure can be obtained from the inferior clivus to the middle to lower C2 vertebral body. Extended transoral approaches can be performed to increase exposure if necessary. These approaches include transmaxillary (Le Fort I maxillotomy), transmaxillary with a midline palatal split (extended "open-door" maxillotomy), transpalatal, and median labiomandibular glossotomy (transmandibular split).

CONCLUSIONS

The transoral approach effectively provides direct access to extradural midline lesions of the craniovertebral junction. A specialized retractor system can expose the inferior clivus to the C2 body. Extended approaches as described can access lesions that extend beyond these limits.

Extended Transsphenoidal Approach with Sigma-shape Osteotomy of the Maxilla: Technical Note

The traditional sublabial transsphenoidal approach offers a limited operative field. This report describes a simple surgical technique to widen the sublabial transsphenoidal window to access the midline lesions from the planum sphenoidale to the lower clivus. This technique was developed on the basis of clinical experience and on data obtained by cadaveric dissection study. Following a sublabial incision and separation of the bilateral septal mucosa, a small Sigma-shape osteotomy of the maxilla, including the anterior nasal spine, was performed with a surgical saw. The width of the entrance to the nasal cavity ranged from 32 to 38 mm. Although the plexus of the anterior superior alveolar nerve was partially cut, our clinical experience revealed no significant sensory loss of the incisors after the Sigma-shape osteotomy. The nasal orests of the maxilla and palatine bone were drilled out, and the roof of the nasopharynx was then incised to expose the lower clival bone. Although extradural sellar or clival lesions were the focus of this approach, the intradural anatomical structures examined by cadaveric study were presented. The extended transsphenoidal approach with Sigma-shape osteotomy of the maxilla is a simple technique and provides widened access to the sellar and clival regions.

A comprehensive analysis of intracranial chordoma and survival: a systematic review

OBJECTIVE

Despite the published information on cranial chordoma, most of the data regarding survival in these patients has come from a single institution. Here, we perform a systematic review of the literature to evaluate across multiple institutions the overall survival after treatment for intracranial chordoma.

MATERIALS AND METHODS

We systematically analysed every study published in English and found a total of over 2000 patients being treated for intracranial chordoma. The overall 5-year and 10-year survivals in these patients were stratified according to the age (<5 years vs. >5 years and  <40 years vs. >40 years), treatment (surgery and radiation vs. surgery alone) and histological findings (chondroid vs. typical). Data were analysed via Pearson chi-square test and student t-test when appropriate.

RESULTS

A total of 560 non-duplicated patients treated for cranial chordoma met inclusion criteria for this systematic analysis. The survival rate among these patients was 63% (299 patients) and 16% (176 patients) for 5-year and 10-year survivals, respectively. There was no difference in overall survival between the two groups when a cut-off age of 40 years was used (<40 years = 50% vs.  >40 years = 51% at 5-year survival; p = 0.1), but when 5 years was used as the cut-off age, then survival was better for patients in the group older than 5 years of age (<5 years = 14% vs.  >5 years = 66%; p = 0.001). There was no difference between 5-year survival in patients with chordoma with histological chondroid features and those with chordoma possessing typical histology (45% vs. 67%; p = 0.06). When patients who only received surgery were compared to those patients who were treated with surgical intervention in combination with adjuvant radiation treatment, no difference in survival rate was found (54% vs. 56% at 5 years; p = 0.8).

CONCLUSION

The results of our systematic study provide data to predict the survival of intracranial chordoma patients across multiple institutions. Our data suggest that patients younger than 5 years of age may be associated with a worse prognosis, and adjuvant radiation therapy and histological type were not associated with the improvement of survival rates.

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.

Extended Transoral Approaches

BACKGROUND

The transoral approach provides the most direct exposure to extradural lesions of the ventral craniovertebral junction. Lesions that extend beyond the exposure provided by the standard transoral approach require an extended transoral modification. The exposure can be expanded in the sagittal and axial planes by adding mandibulotomy, mandibuloglossotomy, palatotomy, and transmaxillary approaches to the standard transoral approach. Extended transoral approaches increase the surgical complexity and the risk of cosmetic and functional complications. Until recently, selection of an extended approach has been arbitrary and dependent on the surgeon's familiarity with the surgical approach.

OBJECTIVE

We review the literature of extended transoral approaches and analyze the different modifications in terms of the technical aspects, added exposure, and complications.

METHODS

Classic approaches and recently published morphometric studies that objectively document the gain in exposure provided by several modifications were analyzed and tabulated to outline the limits of exposure and risk of complications associated with the various modifications.

RESULTS

Transmaxillary approaches expand the exposure to include the sphenoid sinus and upper lateral clivus. To expand the exposure more inferiorly to C4–C5, mandibulotomy or mandibuloglossotomy can be applied. Mandibuloglossotomy increases the rostral exposure as well to the upper third of the clivus. Palatotomy increases rostral exposure without requiring a facial incision or perioperative tracheostomy, but is associated with a significant risk of velopharyngeal insufficiency.

CONCLUSION

Surgical decisions can be based on comprehensive preoperative evaluation of anatomy, pathology, and radiographic studies to maximize exposure while minimizing complications.

Adjuvant radiation therapy and chondroid chordoma subtype are associated with a lower tumor recurrence rate of cranial chordoma

Cranial chordomas are rare tumors that have been difficult to study given their low prevalence. Individual case series with decades of data collection provide some insight into the pathobiology of this tumor and its responses to treatment. This meta-analysis is an attempt to aggregate the sum experiences and present a comprehensive review of their findings. We performed a comprehensive review of studies published in English language literature and found a total of over 2,000 patients treated for cranial chordoma. Patient information was then extracted from each paper and aggregated into a comprehensive database. The tumor recurrences in these patients were then stratified according to age (<21 vs. >21 years), histological findings (chondroid vs. typical) and treatment (surgery and radiation vs. surgery only). Data was analyzed via Pearson chi-square and t-test. A total of 464 non-duplicated patients from 121 articles treated for cranial chordoma met the inclusion criteria. The recurrence rate among all patients was 68% (314 patients) with an average disease-free interval of 45 months (median, 23 months). The mean follow-up time was 39 months (median, 27 months). The patients in younger group, patients with chordoma with chondroid histologic type, and patients who received surgery and adjuvant radiotherapy had significantly lower recurrence rate than their respective counterparts. The results of our systematic analysis provide useful data for practitioners in objectively summarizing the tumor recurrence in patients with cranial chordomas. Our data suggests that younger patients with chondroid type cranial chordoma treated with both surgery and radiation may have improved rates of tumor recurrence in the treatment of these tumors.

Surgery for clival lesions: open resection versus the expanded endoscopic endonasal approach

OBJECT

Clival lesions pose significant challenges with regard to their surgical management. The expanded endoscopic endonasal (EEE) approach is a promising minimally invasive technique for lesions of the central skull base. The authors' aim in the current paper was to discuss the surgical treatment of clival lesions and to present the technical details, indications, and limitations of the EEE approach. Data from a recent endoscopically treated group will be compared with findings in a previous cohort of patients treated via classic open anterior and lateral approaches.

METHODS

Since June 2005, 17 patients with clival lesions underwent surgery via the EEE approach. Suitable candidates were chosen according to lesion characteristics, clinical parameters, and surgical goals. Neurological outcomes, Karnofsky Performance Scale scores, the extent of lesion resection, and complications were evaluated among these patients. Eighteen percent of the patients in the endoscopic group presented with recurrent disease. Another series of 43 patients, who had undergone resection of clival lesions via an anterior (rhinotomy, maxillectomy, microscopic transsphenoidal surgery, or transoral surgery) or lateral (pterional, frontoorbitozygomatic, or combined suprainfratentorial retrosigmoid) approach, was similarly reviewed. Twenty-three of these patients (53%) presented with recurrent disease and thus had undergone prior surgery.

RESULTS

Following the EEE approach, 11 (79%) of 14 patients who had presented with neurological symptoms experienced improvement, and gross-total resection was achieved in 59% of the patients and subtotal removal in 41%. Complications included CSF leakage (24%), tension pneumocephalus (6%), and intracranial hematoma (6%). The patient with the latter complication was the only one who experienced permanent neurological worsening. In the open resection group, neurological worsening occurred in 33% of the patients (14 of 43). Total and grosstotal removals were achieved in 84% of patients and subtotal removal in 14%.

CONCLUSIONS

The EEE approach has been shown to be a safe and effective technique for the resection of clival lesions with limited lateral extension. The choice of surgical approach must be tailored according to both patient and tumor characteristics. Although the 2 patient series featured in this paper are not comparable-because of a selection bias-higher rates of neurological morbidity and total and gross-total resections were observed in the open resection group. Given the long survival of some patients, the EEE approach should be favored whenever reasonable.

Anterior clivectomy: surgical technique and clinical applications

OBJECT

Midline clival lesions, whether involving the clivus or simply situated anterior to the brainstem, present a technical challenge for adequate exposure and safe resection. The authors describe, as a minimally invasive technique, an anterior clivectomy performed via an expanded transsphenoidal approach coupled with the use of a neuronavigation on mobile head and endoscopic-assisted technique. Wide and direct exposure, with the ability to resect extra- and intradural tumors, was achieved without mortality and with a low rate of complications.

METHODS

Cadaveric dissections were performed to outline the landmarks and measure the window that is created by resecting the clivus anteriorly. The technique was used in 43 patients to resect tumors located at or invading the clivus. The initial exposure of the clivus was obtained via the sublabial transsphenoidal approach. The wall of the anterior maxilla, often on 1 side, was removed to allow a wide side-to-side opening of the nasal speculum. Using neuronavigation, the authors made clivectomy windows by drilling the clivus between anatomical landmarks. Bilateral intraoperative neurophysiological monitoring was used (somatosensory evoked potentials, brainstem auditory evoked responses, and cranial nerves VI-XII).

RESULTS

Of the 43 patients, 26 were female and 17 were male, and they ranged in age from 3.5 to 76 years (mean 41.5 years). Thirty-eight patients harbored a chordoma and 5 a giant invasive pituitary adenoma. Gross-total resection of the tumor was achieved in 34 cases (79%). Nine patients (21%) had residual tumor unreachable through the anterior clivectomy, and this required a second-stage resection. Four patients developed new transient extraocular movement deficits. One patient developed a permanent cranial nerve VI palsy. Twenty-seven patients with chordoma underwent postoperative proton-beam radiotherapy. Tumor recurred in 19% of these cases. In 3 patients a cerebrospinal fluid leak developed during hospitalization and was treated successfully. Two other patients presented with a delayed cerebrospinal fluid leak after radiotherapy. Only 1 patient, who had previously undergone Gamma Knife surgery, experienced postoperative hemiparesis.

CONCLUSIONS

A complete anterior clivectomy via a simple extension of the transsphenoidal approach allows the surgeon access to different lesions involving the clivus or situated anterior to the brainstem. The exposure is similar to that provided by more extensive transfacial approaches. Instrument manipulation is easy. Neuronavigation, endoscopy, and intraoperative monitoring are easily incorporated and enhance the capability and safety of this approach.

Median labiomandibular glossotomy approach to the craniocervical region

INTRODUCTION

In children as well as adults, adequate access to the craniocervical junction and upper cervical vertebra can usually be achieved with a transoral-transpalatopharyngeal route. However, when access is necessary to achieve the C5 level and the upper cervical spine in children, this is very difficult. This is particularly so when the incisor opening is less than 2.5 cm. The median labiomandibular glossotomy provides such an approach.

MATERIALS AND METHODS

Our experience with five children is presented in a representative case: a 4-year-old male with a family history of spondyloepiphyseal dysplasia presented with mild quadriparesis, 2 years earlier. This had rapid progression with severe upper cervical kyphosis. A standard transoral-transpalatopharyngeal approach or a lateral extrapharyngeal approach would not achieve exposure of the pathology. Hence, a median labiomandibular glossotomy was utilized for ventral decompression with an anterior interbody fusion between C2 and C4. Crown halo cervical traction was placed intraoperatively before a tracheostomy and tonsillectomy. A median labiomandibular glossotomy was then made with resection of the displaced odontoid process and the vertebral bodies of C3 and C4. This was followed by an anterior interbody fusion between the C2 and C4 vertebrae with costal rib grafts.

RESULT AND CONCLUSION

He was successfully decannulated during the second postoperative week upon resolution of lingual edema. A planned staged dorsal occipitocervical fusion was performed 6 months later, at which time the ventral fusion was quite solid. He had full neurological recovery.

Modifications of the transoral approach to the craniovertebral junction: anatomic study and clinical correlations

OBJECTIVE

This study was designed to more precisely characterize the changes in exposure achieved by modifying the standard transoral approach by sequential mandibulotomy and mandibuloglossotomy with or without palatotomy.

METHODS

A series of cadaveric dissections was performed and the operative distance and angle of exposure in both axial and sagittal planes was evaluated for each approach, with and without palatotomy. Intraoperative measurements were made in patients undergoing transoral approaches to assess the validity of the anatomic model. The use of this model was then assessed by a retrospective analysis of a group of 19 patients operated on through transoral approaches between 1991 and 2006.

RESULTS

The simple transoral approach exposed the region from the lower third of the clivus to the middle of the C2 vertebral body at an operative distance of 12.9 +/- 1.0 cm from the dura. The axial and sagittal angles of exposure were 39.4 +/- 3.5 degrees and 36.8 +/- 3.5 degrees, respectively. Mandibulotomy significantly increased the sagittal exposure to 59.0 +/- 1.0 degrees (P < 0.001), exposing the area from the midclivus to the C2-C3 interspace while simultaneously increasing the axial angle of exposure to 51.9 +/- 7.4 degrees (P < 0.01) and decreasing the operative distance to the dura to 10.7 +/- 1.7 cm (P < 0.05). Mandibuloglossotomy augmented sagittal exposure to 85.3 +/- 0.3 degrees (P < 0.001), revealing the region between the upper one-third of the clivus and the C4-C5 interspace (P < 0.001) while decreasing the operative distance to the dura to 8.7 +/- 0.3 cm (P < 0.05). Palatotomy significantly increased the rostral exposure achieved by each approach by 8.5 to 12.3 degrees (P < 0.01) without altering caudal or axial exposure or the operative distance.

CONCLUSION

The cadaveric data correlated well with intraoperative measurements and the need for modifications of the transoral approach in 15 of the 16 adult patients (93.8%). Pediatric patients, patients with limited mouth opening, elevated craniovertebral junctions, and particularly deep lesions required more extensive exposure. This analysis may be useful for determining the optimal approach for patients undergoing transoral surgery.

Endoscopic transcervical odontoidectomy for pediatric basilar invagination and cranial settling. Report of 4 cases

Pediatric basilar invagination and cranial settling have traditionally been approached through a transoral-transpharyngeal route with or without extended maxillotomy or mandibulotomy for resection of the anterior portion of C-1 and the odontoid. The authors hypothesize that application of a recently described endoscopic transcervical odontoidectomy (ETO) technique would allow an alternative approach for the treatment of ventral pathological entities at the craniocervical junction in pediatric patients. The authors performed ETO in a consecutive series of pediatric patients presenting with myelopathy or bulbar dysfunction resulting from basilar invagination or cranial settling. All clinical, radiographic, surgical, and follow-up data were prospectively collected. The initial experience with ETO in the pediatric population is analyzed and outcomes are reported. Three patients required ETO for basilar invagination and 1 required ETO with anterior C-1 arch and distal clivus resection for cranial settling. All patients presented with myelopathy. One patient was wheelchair bound with severe quadriparesis. The mean age was 14 +/- 3 years (mean +/- standard deviation [SD]) in the 2 male and 2 female patients. The ETO and posterior fusion were performed as a 2-stage procedure in 2 (50%) and as a single-stage procedure in 2 (50%) cases. Prolonged intubation or postoperative placement of a gastrostomy tube was not needed in any case. The postoperative hospitalization lasted 9 +/- 4 days (mean +/- SD). At last follow-up (mean 5 months), head and neck pain had resolved and motor strength had improved or stabilized in all cases. All 4 children were independently functioning and ambulatory at the last follow-up. In the authors' initial experience, ETO has allowed ventral brainstem decompression without the need for prolonged intubation, worsening dysphagia requiring enteral tube feeding, or prolonged hospitalization, and has resulted in cosmetically appealing results. The ETO technique allows an alternative approach for the treatment of ventral pathological entities at the craniocervical junction in pediatric patients.

Tumor-biology and current treatment of skull-base chordomas

Chordomas are rare, slow growing tumors of the axial skeleton, which derive from the remnants of the fetal notochord. They can be encountered anywhere along the axial skeleton, most commonly in the sacral area, skull base and less commonly in the spine. Chordomas have a benign histopathology but exhibit malignant clinical behavior with invasive, destructive and metastatic potential. Genetic and molecular pathology studies on oncogenesis of chordomas are very limited and there is little known on mechanisms governing the disease. Chordomas most commonly present with headaches and diplopia and can be readily diagnosed by current neuroradiological methods. There are 3 pathological subtypes of chordomas: classic, chondroid and dedifferentiated chordomas. Differential diagnosis from chondrosarcomas by radiology or pathology may at times be difficult. Skull base chordomas are very challenging to treat. Clinically there are at least two subsets of chordoma patients with distinct behaviors: some with a benign course and another group with an aggressive and rapidly progressive disease. There is no standard treatment for chordomas. Surgical resection and high dose radiation treatment are the mainstays of current treatment. Nevertheless, a significant percentage of skull base chordomas recur despite treatment. The outcome is dictated primarily by the intrinsic biology of the tumor and treatment seems only to have a secondary impact. To date we only have a limited understanding this biology; however better understanding is likely to improve treatment outcome. Hereby we present a review of the current knowledge and experience on the tumor biology, diagnosis and treatment of chordomas.

Lateral approach for resection of the C3 corpus: technical case report

OBJECTIVE AND IMPORTANCE

The C3 level is the transition zone between the upper and lower cervical spine. Because of its high position and anatomic relationships to significant structures, exposing C3 is challenging, and the surgical approach is controversial.

CLINICAL PRESENTATION

A 16-year-old girl was admitted to our institution with a 3-year history of neck pain and progressive quadriparesis. Neuroradiological examination revealed severe spinal cord compression from kyphosis at the C3 level.

TECHNIQUE

We used the lateral approach to resect the C3 corpus and realign the cervical spine. Resecting the transverse processes of C2-C4 and mobilizing the V2 segment of the vertebral artery adequately exposed C3 for resection. Bilateral occipitocervical fusion was performed in a second procedure, and no postoperative complications occurred. The patient's neurological status improved drastically after surgery, and she has had no craniocervical instability during the follow-up period.

CONCLUSION

The lateral approach to the C3 corpus offers the greatest degree of cord decompression and easy access to the lesion in a wide and sterile operative field. We describe the surgical technique of this approach as an alternative to the anterior transmucosal or anterolateral retropharyngeal approach.

Degloving transfacial approach with Le Fort I and nasomaxillary osteotomies: alternative transfacial approach

OBJECTIVE

We present surgical results obtained with the use of an alternative transfacial approach to the central cranial base.

METHODS

A degloving transfacial approach, which is a combination of the midface degloving procedure, the Le Fort I osteotomy with a pediculated cartilaginous septum, and a nasomaxillary osteotomy, was used in 13 procedures for 8 patients. The lower clivus and upper cervical spine were approached via a submucosal route, without opening of the oropharyngeal mucosa. The wall of the nasopharynx was closed with the mucosa of the bony septum. Several patients had previously undergone other surgical procedures and received radiotherapy.

RESULTS

The follow-up periods ranged from 4 months to 6.4 years. The same procedure was repeated three times for one patient, with intervals of 5.5 and 1.5 months, and twice for three patients, with intervals of 8.2, 6.3, and 1.3 years. A maxillary antrotomy or bifrontal craniotomy with removal of the orbital bar was combined with this technique. No significant or insurmountable technical problems were encountered, even among patients who had undergone previous surgery or radiotherapy.

CONCLUSION

Our technique is relatively simple, with good cosmetic results, and affords sufficient access to the central cranial base from the frontal base down to the upper cervical spine, especially for epidural lesions located in the midline between the carotid arteries. It offers much lower risks of damage to vital neurovascular structures, as well as of meningeal or pharyngeal infectious problems, wound dehiscence, and cerebrospinal fluid leakage. This procedure can be repeated without any increase in difficulty.

Transoral resection of axial lesions augmented by intraoperative magnetic resonance imaging. Report of three cases

Transoral decompression of the cervicomedullary junction may be compromised by a narrow corridor in which surgery is performed, and thus the adequacy of surgical decompression/resection may be difficult to determine. This is problematic as the presence of spinal instrumentation may obscure the accuracy of postoperative radiological assessment, or the patient may require reoperation. The authors describe three patients in whom high-field intraoperative magnetic resonance (MR) images were acquired at various stages during the transoral resection of C-2 disease that had caused craniocervical junction compression. All three patients harbored different lesions involving the cervicomedullary junction: one each of plasmacytoma and metastatic breast carcinoma involving the odontoid process and C-2 vertebral body, and basilar invagination with a Chiari I malformation. All patients presented with progressive myelopathy. Surgical planning MR imaging studies performed after the induction of anesthesia demonstrated the lesion and its relationship to the planned surgical corridor. Transoral exposure was achieved through placement of a Crockard retractor system. In one case the soft palate was divided. Interdissection MR imaging revealed that adequate decompression had been achieved in all cases. The two patients with carcinoma required placement of posterior instrumentation for stabilization. Planned suboccipital decompression and placement of instrumentation were averted in the third case as the intraoperative MR images demonstrated that excellent decompression had been achieved. Intraoperatively acquired MR images were instrumental in determining the adequacy of the decompressive surgery. In one of the three cases, examination of the images led the authors to change the planned surgical procedure. Importantly, the acquisition of intraoperative MR images did not adversely affect operating time or neurosurgical techniques, including instrumentation requirements.

Extradural extranasal combined transmaxillary transsphenoidal approach to the cavernous sinus: a minimally invasive microsurgical model

The authors have previously described an extradural transmaxillary approach to the anterior compartment of the cavernous sinus. In an effort to expand the surgical access to that area without necessitating a craniotomy or wide transfacial dissection, they present a modification of the transmaxillary approach to the sellar region and cavernous sinus.

METHODS

The approach was developed on 12 fresh and 12 embalmed cadaveric specimen, and 2 dry skulls. The initial sublabial incision is followed by a maxillotomy to expose the course of the infraorbital nerve (terminal branch of maxillary branch of the trigeminal nerve) on the roof of the maxillary sinus. The route of the infraorbital nerve is traced to the pterygopalatine fossa as a guide to the foramen rotundum. Superomedial drilling of the foramen rotundum is then performed to reveal the contents of the superior orbital fissure. After the nerves are safely identified in the superior orbital fissure, medial enlargement of the window into the cavernous sinus is made possible by drilling the lateral and posterior wall and septum of the sphenoid sinus.

RESULTS

The combined transmaxillary transsphenoidal approach offers an excellent exposure of the sellar and infrasellar region. The approach offers clear visualization of the ipsilateral loop of the carotid artery, the pituitary fossa, and the cranial nerves of the ipsilateral cavernous sinus. Mean operative reach is 38 mm from the posterior wall of the maxillary sinus to the ipsilateral carotid loop and 56 mm to the contralateral loop. The width of the operative window is 26 mm at the base within the cavernous sinus.

CONCLUSION

The model offers a minimally invasive approach that avoids the need for craniotomy or violating the nasal cavity. It may be safely employed to access vascular as well as invasive lesions of the sellar and infrasellar region. The approach offers excellent visualization of the ipsilateral intracavernous carotid artery with both proximal and distal control, as well as cranial nerves III, IV, VI, V2, the hypophyseal region, and the medial aspect of the contralateral cavernous sinus.

The forgotten condyle: Delayed hypoglossal nerve palsy caused by fracture of the occipital condyle

Fracture of the occipital condyle is a rare injury that can be easily overlooked. Palsies of lower cranial nerves can be the only symptom of the fracture. We report a patient with isolated post-traumatic hypoglossal nerve palsy who developed hypoglossal nerve palsy within 2 months after a car accident, indicating that the acute trauma itself did not damage the hypoglossal nerve. Most likely the palsy is caused by pressure to the nerve prior to the entry or within the hypoglossal canal. Since, in the present case, the fracture was stable and the patient showed only moderate neurological deficits, the operation was deferred.

A modified transfacial approach to the clivus

Anterior approaches to the clivus must provide excellent visualization of the lesion, give adequate access for dural repair, and be cosmetically acceptable. Most current approaches enter through the nasopharynx or oropharynx, with either palatal, maxillary, or mandibular splitting for greater exposure. We have modified the transfacial approach described by others, which provides excellent access to the clivus along its rostrocaudal extent. A lateral rhinotomy incision is used and carried along the base of the right alae nasi and columella. The nasal bones are osteotomized bilaterally, and the nose is rotated on a pedicle flap, thus opening the entire nasal cavity to view. The septum and medial maxillary walls are removed. This provides excellent visualization of the ethmoid, sphenoid, posterior nasopharynx, and upper oropharynx. At the conclusion of the procedure, the nasal incision is closed, with good cosmesis. A case of recurrent chordoma of the middle and lower clivus is presented to exemplify this technique. The approach has since been used to approach clivus tumors and midline aneurysms of the vertebrobasilar system.

Chondrosarcoma of the skull base: a series of eight cases

Chondrosarcomas of the skull base are indolent, locally invasive tumors with a marked tendency to recur. Surgery is the mainstay of treatment because these tumors are generally resistant to other forms of treatment. A surgical approach with wide access to the skull base and one that is easily repeatable is required, because recurrence is common. We have used the LeFort I maxillotomy or mobilization of the zygoma at the time of craniotomy to obtain wide access to the skull base in eight cases of chondrosarcoma. Three patients have undergone subsequent procedures by us for recurrent disease. One patient died 30 days after the operation, and one has required an open repair of a cerebrospinal fluid leak. Good palliation of symptoms has been achieved in all survivors. These approaches fulfill the criteria for the surgical management of these difficult tumors by allowing excellent exposure, safe repetition if required, satisfactory palliation, and acceptable morbidity.

Transoral transpalatal removal of a giant premesencephalic clivus chordoma

Due to their surgical inaccessibility and resistance to radiotherapy, clivus chordomas represent a formidable therapeutic challenge. The transoral approach to chordomas of the clivus has been usually restricted to relatively small or midsized neoplasms, located at the lower end of the clivus or at the anterior clival-cervical junction. In this report the transoral transpalatal transclival removal of a giant recurrent chordoma occupying the whole length of the clivus with considerable premesencephalic extension and brain stem compression is described. Regression of preoperative symptoms without additional postoperative morbidity could be achieved by radical transoral tumour extirpation documented by magnetic resonance imaging.

Posterior fossa chordomas--with special reference to transoral surgery

Nine cases of posterior fossa chordomas are presented. The clinical features, treatment, and outcomes are discussed. Two patients underwent transoral surgery. Advantages and disadvantages of this approach are discussed and related to the recent literature.

Surgical management of anteriorly placed lesions at the craniocervical junction--an alternative approach

Lesions ventral to the neuraxis at the craniocervical junction can pose a significant management problem because of their strategic location. Conventional posterolateral approaches sometimes may not permit adequate visualization of the entire base of the tumor without significant manipulation of the brain stem and spinal cord. The anterior transoral and extrapharyngeal approaches are alternate ways of exposing this region without neural retraction. However, these approaches do not provide adequate exposure of the lateral margins of the tumour, there is no control of the vertebral arteries and cranial nerves and the tumor--brain stem interface is not seen till the end of the operation. A lateral approach is described in this report which involves additional bone removal in the region of the mastoid process and the articular pillars in order to provide a true lateral perspective for the removal of these tumors. The advantages include excellent definition of the interface between the tumor and cord/brain stem without manipulation of the neuraxis, control of the ipsilateral vertrebral artery and caudal cranial nerves, ability to remove the intra- and extradural portions of the tumor in one operation and the ability to perform an immediate bony fusion if necessary. The application of this approach in the management of 9 patients with a variety of intra- and extradural lesions at the clivus and foramen magnum is discussed.

Surgical management of midline skull-base tumors: a new approach

Many surgical approaches to the clivus and upper cervical spine have been used in the treatment of skull-base tumors over the past 50 years. However, the outcome of surgery has been complicated by difficulties of access to the whole clivus, together with pharyngeal wound breakdown with subsequent development of cerebrospinal fluid (CSF) fistula and meningitis. A technique described recently utilized Le Fort I osteotomy to improve exposure of the clivus in the approach to vertebrobasilar aneurysms, facilitating control of the aneurysm and reducing the risk of posttraumatic CSF fistula. The same approach, via maxillotomy, has permitted partial or total tumor resection in 13 consecutive procedures carried out at Atkinson Morley's Hospital on 10 patients presenting with tumors of the skull base. Neurological status was either improved or unchanged in all patients postoperatively, and pain relief was obtained in five of eight cases in which this was a presenting symptom. No patient developed a CSF fistula following surgery. Cosmetic results were good, and no problems related to malocclusion were reported. This approach may be used to advantage in the surgical treatment of skull-base tumors, at initial presentation, and can be repeated without undue difficulty should there be tumor recurrence.

A contribution to the anatomic basis of the transoral approach to the atlas and axis

The transoral approach (Fang and Ong 1962) allows direct free exposure of the atlas and axis. However, a morphologic description of certain structures at risk corresponding to the views at operation has so far been lacking. The present study is intended to fill this gap by giving the surgeon a transoral view of the peripharyngeal structures. This is a further instance of how classical gross anatomy needs to be continuously rediscovered in the light of clinical activities.

Transoral transclival removal of a schwannoma anterior to the craniocervical junction. Case report

The transoral route was used to remove a schwannoma situated anteriorly at the craniocervical junction. By a relatively simple technique, a watertight closure of the dura and nasopharynx was obtained combined with continuous cerebrospinal fluid (CSF) diversion, first by lumbar drainage and then via a lumboperitoneal shunt. This modification of the standard procedure provides a useful method to prevent CSF fistula formation following transoral intradural surgery.

Dundee chordomas

All patients with chordomas that have been treated in the Dundee neurosurgical unit are reviewed. Five intracranial and two sacral chordomas have presented since the unit opened in 1966. Survival has ranged from one to fifteen years following treatment. The difficulties in diagnosis and in assessing treatment of these rare slow growing neoplasms are discussed.

Identification and management of high-risk patients with Klippel-Feil syndrome

Patients with Klippel-Feil syndrome are often at high risk for neurological injury. The cervicomedullary junction and cervical spinal cord are especially vulnerable. Twenty-one patients examined and treated over a 20-year period are reviewed. The salient features of the syndrome are identified, and an approach to management is proposed.

Transoral surgery for craniocervical space-occupying processes

Although the number of reports concerning the transoral approach to anteriorly placed lesions of the craniocervical junction are increasing, the development of this technique is still in its early stages. The indications and surgical methods vary widely, and there is much room for discussion of the technical details. Eight cases operated on via transoral surgery during the last 4 years are presented in support of the transoral approach to tumors in the craniocervical region.