Endoscopic Transclival Research Articles

Endoscopic Transclival Approach for Evacuation of Retroclival Hematoma: 2-Dimensional Operative Video.

Retroclival hematomas are a rare entity, presenting anteriorly to the brainstem in the epidural, subdural, or subarachnoid space. Although those that develop in the epidural space often arise from trauma, subdural retroclival hematomas frequently occur spontaneously in the setting of coagulopathy, aneurysm rupture, or pituitary apoplexy, with many cases having an unknown etiology.1-4 Although most are treated with conservative management, surgical intervention is preferred for those presenting with evidence of brainstem compression, hydrocephalus, worsening neurological deficits, and clinical deterioration.5 In this report, we present the case of a 75-year-old woman with a medical history of mitral regurgitation, nonischemic cardiomyopathy, and atrial fibrillation on warfarin presenting with 4 days of temporoparietal headaches and double vision. On examination, the patient demonstrated right abducens and hypoglossal nerve palsies. Computed tomography revealed a subdural hemorrhage within the retroclival cistern, extending into the dorsal inferior aspect of the C2 vertebral body, resulting in posterior displacement of the pons, medulla, and proximal cervical spinal cord. Spinal and cerebral angiograms did not show evidence of any vascular malformation. An endoscopic transclival approach was selected for hematoma evacuation. Key surgical steps included harvesting of nasoseptal flap, endoscopic transnasal approach to the sellar/subsellar space, transclival drilling, retroclival hematoma evacuation, and clival reconstruction. The patient tolerated the procedure well and was discharged 15 days postoperatively with resolution of prior cranial nerve deficits. Postoperative computed tomography imaging revealed complete retroclival hematoma evacuation. At her 3-month follow-up, the patient remained neurologically intact with imaging confirming no residual subdural hematoma. Institutional Review Board approval was obtained for this submission (2018-9379). Patient consent was not obtained as personal identifying information was kept confidential, following guidelines set forth by Institutional Review Board requirements.

Endoscopic endonasal transclival approach for a ventral brainstem epidermoid cyst: illustrative case.

Intracranial epidermoid cysts are benign, slow-growing malformations that most commonly arise at the skull base. Maximizing resection of the cyst contents and the capsule reduces long-term recurrence but can be made difficult by cyst wall adherence to critical neurovascular structures. Expanded endonasal approaches (EEAs) offer an alternative to traditional open transcranial approaches for accessible epidermoid cysts. In this case report, the authors demonstrate a transclival EEA for a large, ventral brainstem epidermoid cyst. A 41-year-old woman who presented with progressive headaches, diplopia, malaise, and fatigue was found to have a 4.7-cm midline, ventral brainstem epidermoid cyst. She underwent an expanded endonasal transclival approach that exposed the brainstem from the level of the dorsum sella to the tip of the basion. A near-total resection was completed with removal of all cyst contents and most of the capsular wall. Reconstruction was completed with Duragen, an autologous fat graft, and a nasoseptal flap. Postoperatively, she had a partial left cranial nerve VI palsy that remained stable 8 weeks after surgery. The expanded endoscopic transclival approach can facilitate effective resection of midline, ventral epidermoid cysts.

Development of a Cadaveric Multiport Model of Posterior Circulation Aneurysm Clipping for Neurosurgery and Otolaryngology Residents.

Posterior circulation aneurysms are difficult to treat with the current methods of coiling and clipping. To address limitations in training, we developed a cadaveric model to train learners on endoscopic clipping of posterior circulation aneurysms. An endoscopic transclival approach (ETA) and a transorbital precaruncular approach (TOPA) to successfully access and clip aneurysms of the posterior circulation are described. The model has flexibility in that a colored silicone compound can be injected into the cadaveric vessels for the purpose of training learners on vascular anatomy. The other option is that the model could be connected to a vascular perfusion pump allowing real-time appreciation of a pulsatile or ruptured aneurysm. This cadaveric model is the first of its kind for training of endoscopic clipping of posterior circulation aneurysms. Learners will develop proficiency in endoscopic skills, appropriate dissection, and appreciation for relative anatomy while developing an algorithm that can be employed in a real operative arena. Going forward, various clinical scenarios can be developed to enhance the realism, allow learners from different specialties to work together, and emphasize the importance of teamwork and effective communication.

Additive Manufacturing for Personalized Skull Base Reconstruction in Endoscopic Transclival Surgery: A Proof-of-Concept Study

Endoscopic transnasal transclival intradural surgery is limited by a high postoperative cerebrospinal fluid leak rate. The aim of this study was to investigate the role of three-dimensional printing to create a personalized, rigid scaffold for clival reconstruction. Two different types of clivectomy were performed in 5 specimens with the aid of neuronavigation, and 11 clival reconstructions were simulated. They were repaired with polylactide, three-dimensional-printed scaffolds that were manually designed in a computer-aided environment based either on the real or on the predicted defect. Scaffolds were printed with a fused filament fabrication technique and different offsets. They were positioned and fixed either following the gasket seal technique or with screws. Postdissection radiological evaluation of scaffold position was performed in all cases. In 3 specimens, the cerebrospinal fluid leak pressure point was measured immediately after reconstruction. The production process took approximately 30 hours. The designed scaffolds were satisfactory when no offset was added. Wings were added during the design to allow for screw positioning, but broke in 30% of cases. Radiological assessment documented maximal accuracy of scaffold positioning when the scaffold was created on the real defect; accuracy was satisfactory when the predicted clivectomy was performed under neuronavigation guidance. The cerebrospinal fluid leak pressure point was significantly higher when the scaffold was fixed with screws compared with the gasket technique. In this preclinical setting, additive manufacturing allows the creation of customized scaffolds that are effective in reconstructing even large and geometrically complex clival defects.

Endoscopic transsphenoidal drainage of a petrous apex cholesterol granuloma using a frontal sinus nasal stent: a case report with long term follow up

Background Cholesterol granulomas of the petrous apex are benign cysts affecting 0.6 patients per 1 million. The pathophysiology involves cholesterol crystals and lipids that are surrounded by giant cells. The cholesterol deposits induce an inflammatory response likely from acute hemorrhage leading to the formation of a fibrous capsule. The capsule expands over time compressing nearby cranial nerves (VI–VIII), which can cause worsening symptoms. Surgical resection has been shown to provide excellent improvement in symptoms. Historically, open approaches such as the infracochlear, infralabyrinthine, and middle fossa have been used. Herein we present a case showing the feasibility and clinical utility of using an endoscopic endonasal transclival approach for treatment of these tumors. Case A 44-year-old female presented with history of intermittent double vision, dizziness, nausea, and headaches for 3 years. She developed a partial left CN6 palsy with significant diplopia and episodes of left facial weakness. The worsening symptoms prompted presentation to the ED where MRI and CT scan revealed a left petrous apex lesion (1.8 × 1.7 cm) with hyperintensity on T1 and T2 imaging, suggestive of cholesterol granuloma. She underwent an endoscopic transclival resection of the lesion: drainage of left petrous apex cholesterol granuloma and stent placement from left petrous apex into sphenoid sinus (novel technique). This was done to allow continued communication and drainage of the tumor bed from the petrous apex into the sphenoid sinus with the intent to minimize the risk of recurrence. At the postop visit both 6th nerve palsy and diplopia had resolved. Imaging is stable 2 years after the surgery. Discussion The placement of the stent in this case was done to prevent symptom recurrence. 11% of patients that do not receive a stent will have symptom recurrence within one year. From the historical literature, only 4% of patients who had stent placement developed cyst recurrence or expansion on follow-up imaging. Stent placement has been shown to prevent cyst enlargement within the first few months after surgery. We demonstrate that the endoscopic endonasal transclival approach provided good visualization of the tumor, allowed for an adequate working window for resection, and provided a sufficient approach for stent placement.

Expanded Endoscopic Endonasal Approach for Resection of Intradural Chordoma: Surgical and Anatomic Nuances: 2-Dimensional Operative Video.

The expanded endoscopic endonasal approach (EEA) has been growing as a surgical alternative for the treatment of clival chordomas because of their frequent midline location and bone erosion. The endoscopic transclival approach provides with a safer and more direct anatomic route for tumors located predominantly in the midline contributing to minimize postoperative comorbidities. In this video, we demonstrate the step-by-step technique for resection of such challenging clival pathology. This is an operative video of an extended endoscopic resection of a clival chordoma with stepwise description of the surgical technique. We present the case of a 49-yr-old man in whom, incidentally in the context of low testosterone level, a clival lesion with purely midline location with intradural extension into the ventral brainstem and occupation of the left cerebellopontine angle was discovered. The patient was submitted to an expanded endoscopic transclival approach and a macroscopic gross total resection was successfully achieved. The final pathology was compatible with a conventional chordoma. This video details the surgical anatomy of the clival region to facilitate the identification of surgical landmarks and anatomic boundaries with the goal of avoiding injury to the neurovascular structures involved in this approach. Extended endoscopic transclival surgery is a useful and safer option for the management of midline chordomas because it provides with a dissection corridor free of major neurovascular structures. Endoscopic techniques are associated with good outcomes in terms of macroscopic gross total resection and low surgical risks in these selected tumors.

Clinical outcomes of an endoscopic transclival and transpetrosal approach for primary skull base malignancies involving the clivus.

OBJECTIVE The endoscopic endonasal approach for treating primary skull base malignancies involving the clivus is a formidable task. The authors hypothesized that tumor involvement of nearby critical anatomical structures creates hurdles to endoscopic gross-total resection (GTR). The aim of this study was to retrospectively review the clinical outcomes of patients who underwent an endoscopic endonasal approach to treat primary malignancies involving the clivus and to analyze prognostic factors for GTR. METHODS Between January 2009 and November 2015, 42 patients underwent the endoscopic endonasal approach for resection of primary skull base malignancies involving the clivus at 2 independent institutions. Clinical data; tumor locations within the clivus; and anatomical involvement of the cavernous or paraclival internal carotid artery, cisternal trigeminal nerve, hypoglossal canal, and dura mater were investigated to assess the extent of resection. Possible prognostic factors affecting GTR were also analyzed. RESULTS Of the 42 patients, 37 were diagnosed with chordomas and 5 were diagnosed with chondrosarcomas. The mean (± SD) preoperative tumor volume was 25.2 ± 30.5 cm3 (range 0.8-166.7 cm3). GTR was achieved in 28 patients (66.7%) and subtotal resection in 14 patients (33.3%). All tumors were classified as upper (n = 17), middle (n = 17), or lower (n = 8) clival tumors based on clival involvement, and as central (24 [57.1%]) or paramedian (18 [42.9%]) based on laterality of the tumor. Univariate analysis identified the tumor laterality (OR 6.25, 95% CI 1.51-25.86; p = 0.011) as significantly predictive of GTR. In addition, the laterality of the tumor was found to be a statistically significant predictor in multivariate analysis (OR 41.16, 95% CI 1.12-1512.65; p = 0.043). CONCLUSIONS An endoscopic endonasal approach can provide favorable clinical and surgical outcomes. However, the tumor laterality should be considered as a potential obstacle to total removal.

Extended endoscopic endonasal posterior (transclival) approach to tumors of the clival region and ventral posterior cranial fossa. Part 2. Topographic and anatomical aspects and surgical technique

to present the main topographic and anatomical features of the clivus and adjacent structures for improving and optimizing the extended endoscopic transnasal posterior (transclival) approach in removal of clival and ventral posterior cranial fossa lesions. We performed a topographic and anatomical study of 25 cadaver heads, the vascular bed of which was filled with colored silicone using the original technique for visualizing the bed features and individual variability. We present the main anatomical landmarks necessary for performing the extended endoscopic endonasal posterior approach. Superior, medial, and inferior transclival approaches provide access to the anterior surface of the upper, middle, and lower neurovascular complexes of the posterior cranial fossa. The endoscopic transclival approach can be used to reach ventral posterior cranial fossa lesions. The endoscopic transnasal transclival approach is an alternative to transcranial approaches to clival lesions.

Extended endoscopic endonasal posterior (transclival) approach to tumors of the clival region and ventral posterior cranial fossa. Part 1. Topographic and anatomical features of the clivus and adjacent structures

to describe the main topographic and anatomical features of the clival region and its adjacent structures for improvement and optimization of the extended endoscopic endonasal posterior (transclival) approach for resection of tumors of the clival region and ventral posterior cranial fossa. We performed a craniometric study of 125 human skulls and a topographic anatomical study of heads of 25 cadavers, the arterial and venous bed of which was stained with colored silicone (the staining technique was developed by the authors) to visualize bed features and individual variability. Currently, we have clinical material from more than 120 surgical patients with various skull base tumors of the clival region and ventral posterior cranial fossa (chordomas, pituitary adenomas, meningiomas, cholesteatomas, etc.) who were operated on using the endoscopic transclival approach. We present the main anatomical landmarks and parameters of some anatomical structures that are required for performing the endoscopic endonasal posterior approach. The anatomical landmarks, such as the intradural openings of the abducens and glossopharyngeal nerves, may be used to arbitrarily divide the clival region into the superior, middle, and inferior thirds. The anatomical landmarks important for the surgeon, which are detected during a topographic anatomical study of the skull base, facilitate identification of the boundaries between the different clival portions and the C1 segments of the internal carotid arteries. The superior, middle, and inferior transclival approaches provide an access to the ventral surface of the upper, middle, and lower neurovascular complexes in the posterior cranial fossa. The endoscopic transclival approach may be used to access midline tumors of the posterior cranial fossa. The approach is an alternative to transcranial approaches in surgical treatment of clival region lesions. This approach provides results comparable (and sometimes better) to those of the transcranial and transfacial approaches.

Endoscopic Endonasal Transclival Approach versus Dual Transorbital Port Technique for Clip Application to the Posterior Circulation: A Cadaveric Anatomical and Cerebral Circulation Simulation Study.

Purpose Simulation training offers a useful opportunity to appreciate vascular anatomy and develop the technical expertise required to clip intracranial aneurysms of the posterior circulation. Materials and Methods In cadavers, a comparison was made between the endoscopic transclival approach (ETA) alone and a combined multiportal approach using the ETA and a transorbital precaruncular approach (TOPA) to evaluate degrees of freedom, angles of visualization, and ergonomics of aneurysm clip application to the posterior circulation depending on basilar apex position relative to the posterior clinoids. Results ETA alone provided improved access to the posterior circulation when the basilar apex was high riding compared with the posterior clinoids. ETA + TOPA provided a significantly improved functional working area for instruments and visualization of the posterior circulation for a midlevel basilar apex. A single-shaft clip applier provided improved visualization and space for instruments. Proximal and distal vascular control and feasibility of aneurysmal clipping were demonstrated. Conclusions TOPA is a medial orbital approach to the central skull base; a transorbital neuroendoscopic surgery approach. This anatomical simulation provides surgical teams an alternative to the ETA approach alone to address posterior circulation aneurysms, and a means to preoperatively prepare for intraoperative anatomical and surgical instrumentation challenges.

Endoscopic Resection of a Giant Intradural Retroclival Ecchordosis Physaliphora

Objective: We report the first complete resection of a giant ecchordosis physaliphora (EP) using an endoscopic transclival approach. We describe the surgical technique employed and provide a current review of the literature.

Extended endoscopic endonasal transclival approach to the ventrolateral brainstem and related cisternal spaces: anatomical study

Advances in endoscopic endonasal skull base surgery have led to the development of new routes to areas beyond the midline skull base. Recently, feasible surgical corridors to the lateral skull base have been described. The aim of this study was to describe the anatomical exposure of the ventrolateral brainstem and posterior fossa through an extended endoscopic endonasal transclival transpetrosal and transcondylar approach. Six human heads were used for the dissection process. The arterial and venous systems were injected with red- and blue-colored latex, respectively. A pre- and postoperative computed tomography (CT) scan was carried out on every head. The endoscopic endonasal transclival approach was extended through an anterior petrosectomy and a medial condylectomy. A three-dimensional model of the approach was reconstructed, using a dedicated software, from the overlapping of the pre- and post-dissection CT imaging of the specimen. An extended endoscopic transclival approach allows to gain access through an extradural anterior petrosectomy and medial condylectomy to the anterolateral surface of the brainstem and the posterior fossa. Two main intradural anatomical corridors can be described: first, between the V cranial nerve in the prepontine cistern and the VII-VIII cranial nerves in the cerebellopontine and cerebellomedullary cistern; second, between the VII-VIII cranial nerves and the IX cranial nerve, in the premedullary cistern. Extending the transclival endoscopic approach by performing an extradural anterior petrosectomy and a medial condylectomy provides a safe and wide exposure of the anterolateral brainstem with feasible surgical corridors around the main neurovascular structures.

Endoscopic endonasal transclival approach to a ventral pontine pediatric ependymoma

The authors report a case of a recurrent pediatric ventral pontine ependymoma that they resected through an endonasal endoscopic transclival approach. Regarding the options for a surgical approach to ventral pontine tumors, traditional far-lateral approaches are associated with considerable morbidity due to the required muscle mobilization, brain retraction, and in-line obstruction of cranial nerves before reaching the target. The endoscopic endonasal transclival approach was made appealing by eliminating all of these concerns. The patient's fully pneumatized sphenoid sinus, laterally displaced basilar artery, and the direct ventral location of the bulky disease all further supported this unconventional choice of surgical corridor to achieve a palliative brainstem decompression of an incurable recurrence.

Endoscopic versus Open Clival Chordoma Resection: A Systematic Review

Objective: Microscope-based surgical approaches to the clivus require large openings to allow the passage of sufficient light to the lateral extent of clival chordomas, and have traditionally utilized extensive bone drilling, brain retraction, and manipulation of cranial nerves that lie along the operative trajectory. A ventral approach to the tumor is a more logical trajectory, but transoral approaches are limited by the hard palate, and transfacial approaches may be cosmetically undesirable. The endoscopic transclival approach represents a new paradigm in surgical philosophy, offering a minimal access, maximally aggressive alternative that may be preferable in a subgroup of patients. We performed a systematic analysis of the literature to assess the efficacy and complications of this approach compared with more standard cranial base approaches.

Endoscopic Endonasal Minimal Access Approach to the Clivus

The endoscopic endonasal transclival approach is a novel minimal-access method of managing clival pathology. Limited cases have been published. To summarize our clinical experience with this approach and discuss technical nuances. We retrospectively reviewed a prospective database of 250 endoscopic, endonasal skull base surgeries. Patients in whom a transclival approach was performed were identified. Extent of resection, complications, and clinical outcome were analyzed. Seventeen patients underwent 21 procedures. Pathology included chordoma, meningioma, hemangiopericytoma, enterogenous cyst, epidermoid, and metastasis. Lumbar drain was placed intraoperatively in 9 cases and maintained for approximately 2 days postoperatively. Mean operative time was 252.8 minutes. Intraoperative cerebrospinal fluid (CSF) leak occurred in 10 cases. Greater than 95% resection was achieved in 11 of 12 cases (92%) in which it was the surgical goal. The risk of postoperative CSF leak was 4.8% for all procedures, 9.1% for procedures with large skull base defect, and 0% if a gasket-seal closure was achieved. A nasoseptal flap was used in 2 patients. There was one perioperative infarct, one case of deep vein thrombosis, and one postoperative pulmonary embolus. Mean follow-up was 8.5 months. All but one patient with preoperative cranial nerve deficits improved at last follow-up. All patients were free of disease progression at last follow-up. The endonasal endoscopic transclival approach provides a minimal-access approach to the ventral midline posterior fossa skull base. The risk of CSF leak is low if appropriate closure techniques are applied.

Endoscopic endonasal transclival resection of chordomas: operative technique, clinical outcome, and review of the literature

Transcranial approaches to clival chordomas provide a circuitous route to the site of origin of the tumor often involving extensive bone drilling and brain retraction, which places critical neurovascular structures between the surgeon and pathology. For certain chordomas, the endonasal endoscopic transclival approach is a novel minimal access, but it is an equally aggressive alternative providing the most direct route to the tumor epicenter. The authors present a consecutive series of patients undergoing endonasal endoscopic resection of clival chordomas. Extent of resection was determined by postoperative volumetric MR imaging and divided into > 95% and < 95%. Seven patients underwent 10 operations. Preoperative cranial neuropathies were present in 4. The mean patient age was 52.0 years. The mean tumor volume was 34.9 cm3. Intraoperative lumbar drainage was used in 1 patient, and the tumors extended intradurally in 3. One patient underwent 2 intentionally palliative procedures for subtotal debulking. Greater than 95% resection was achieved in 7 of 8 operations in which radical resection was the goal (87%). All tumors with volumes < 50 cm3 had > 95% resection (p = 0.05). The overall mean follow-up was 18.0 months. Cranial neuropathies resolved in all 3 patients with cranial nerve VI palsies. One patient with recurrent nasopharyngeal chordoma died of disease progression; another experienced 2 recurrences before receiving radiation therapy. All surviving patients remain progression free. There were no intraoperative complications; however, 1 patient developed a pulmonary embolus postoperatively. There were no postoperative CSF leaks. The endonasal endoscopic transclival approach represents a less invasive and more direct approach than a transcranial approach to treat certain moderate-sized midline skull base chordomas. Longer follow-up is necessary to determine comparability to transcranial approaches for long-term control. Large tumors with significant extension lateral to the carotid artery may not be suitable for this approach.