Transnasal Endoscopic Resection of Clival Chordoma

Abstract

We retrospectively reviewed a database of all patients undergoing endoscopic endonasal surgery at UCLA Medical Center from the years 2008 through 2010. Patients with a final pathology of Chordoma were then identified for inclusion within our study. The patients’ characteristics are outlined in Table 1. The senior authors, neurosurgeons (MB) and (NM) and otolaryngologists (MW) and (JS) were the primary surgeons in all of the cases. The patient demographics, lesion size and volume, pathology, complications, adjuvant treatment and clinical outcomes were analyzed. Extent of resection was compared with initial tumor volume on Pre and Post-operative MRI. Results were then divided into patients in which (1)Gross Total Resection was achieved, defined as no tumor on post-operative MRI, (2) >95% tumor bulk was removed, and (3) those in whom 95% resection without significant neurologic sequelae. Case Selection: In the two patients where there was subtotal resection, gross disease was left behind in the operating room due to invasion of vital structures (internal carotid artery and the basilar artery). While, gross tumor resection is the primary goal, in the face of significant neurological or vascular morbidity, a subtotal resection with post-operative radiation provides the best alternative. Complications: Two patients in our series had CSF leaks (25%). We employed a nasoseptal flap in all cases where a leak was noted during the operation. In case 5, a significant defect was noted during the case and the patient underwent a fascia lata graft prior to tissue sealant (the “Gasket-seal”). (14) However, the patient still developed a CSF leak on post-op day 6 which resolved with a Lumbar Drain and conservative management. Case 2 presented a complex past surgical history, with two courses of radiation which likely contributed to the failure of the initial surgical repair. Advantages of Endoscopic Approach: The transnasal endoscopic approach allows for dynamic visualization of the clivus. When operating with the microscope, the surgeon has a static, tunneled view of the operative field; with the angled endoscopes, the surgeon is able to maneuver the scopes and achieve improved access to the lateral, superior, and inferior aspects of the clivus with more complete tumor removal. Further Follow-up: Maximum follow up time in our series was 27 months with a mean of 15 months. Of those that obtained >95% resection or GTR none of the patients were noted to have a recurrence. Chordomas are rare benign tumors theorized to originate from embryonic notochord remnant. (1) These lesions are typically slow growing but locally aggressive tumors. While they only make up 0.15% of all primary intracranial neoplasms, (2) of these lesions, approximately 25-35% arise in the clivus. They have been found in all age groups and appear to have an equal sex distribution. Various external surgical approaches have been attempted for treatment; however approaching midline tumors with lateral/paramedian approaches requires significant brain retraction and increases the morbidity resection. A microscopic trans-sphenoidal approach was first described in the 1980s. More recently, with the incorporation of the rigid endoscope and active collaboration between sinus surgeons and neurosurgeons, extended endonasal endoscopic approaches have become well-accepted, minimally invasive routes to the midline/paramedian skull base. The aim of this present study is to present a series of patients successfully treated with endonasal endoscopic resection of clival chordomas. We demonstrate the technical feasibility of endonasal endoscopic approach for excision of clival chordomas and also elucidate regions of the skull base which are difficult to treat from this approach. INTRODUCTION