Skull base chordomas: Endonasal endoscopic transclival approach

Abstract

The current management paradigm for clival chordomas includes cytoreductive surgery with adjuvant radiotherapy. Surgical approaches have traditionally utilized extensive bone drilling, brain retraction, and manipulation of cranial nerves. The endoscopic transclival approach represents a minimal access, maximally aggressive alternative providing a direct route to the tumor that may be preferable in a subgroup of patients. We present a consecutive series of patients undergoing endonasal, endoscopic resection of clival chordomas. Extent of resection was determined by post-operative volumetric MRI scan, and divided into greater and less than 95%. In addition, we performed a MEDLINE (1950–2010) search to identify relevant studies for a systematic review of the literature. Comparisons were made between open and endoscopic series for patient and tumor characteristics as well as recurrence, survival and mortality. Statistical analyses of categorical variables were undertaken using Chi-square and Fisher’s exact tests. In our retrospective Case Series, even patients underwent 10 operations. Greater than 95% resection was achieved in 7 of 8 operations in which radical resection was the goal (87%). All tumors with volume < 50 cm3 had > 95% resection p = (0.05). Cranial neuropathies resolved in all three patients with VI palsy. One patient with recurrent naso-pharyngeal chordoma died due to disease progression; another recurred twice before receiving radiation. All surviving patients remain progression-free. There were no intraoperative complications; one developed a pulmonary embolus postoperatively. There were no postoperative CSF leaks. We also performed a systematic analysis and literature review of 37 studies, involving 766 patients, were included. Compared with the open surgery cohort, the endoscopic cohort had a significantly higher percentage of gross total resection (61.0% vs. 48.1%; p = 0.010); fewer cranial nerve deficits (1.3% vs. 24.2%, p < 0.001); fewer incidences of meningitis (0.9% vs. 5.9%, p = 0.029); less mortality (4.7% vs. 21.6%, p < 0.001); and fewer local recurrences (16.9% vs. 40.0%, p = 0.0001). There was no significant difference in the incidence of postoperative CSF leak (p = 0.084). Follow-up was longer in the open compared with the endoscopic cohort (59.7 vs. 18.5 months, p < 0.001). Our systematic analysis supports the endonasal endoscopic approach as a safe and effective alternative for the treatment of certain clival chordomas. Although the overall literature supports this technique in carefully selected patients, longer follow-up is needed to more definitively address therapeutic efficacy. Nevertheless, the advent of this new approach heralds a paradigm shift in the surgical management of these difficult tumors.