Endoscopic Endonasal Transclival Approaches: Case Series & Outcomes for Different Clival Regions

Introduction: Traditional approaches to the clivus and surrounding structures are limited in that they often require extensive bone removal and brain retraction while placing critical neurovascular structures between the surgeon and site of pathology. It has been proposed that these limitations are mitigated with the use of endoscopic endonasal transclival approaches to the skull base. Extended endoscopic endonasal approaches to the clivus have been increasingly described by several groups, however few studies have investigated clinical outcomes by clival region involved. Additionally, there is limited data regarding the use of this approach for benign and malignant intradural lesions. This study provides much needed clinical data for this increasingly utilized approach.

Methods: A retrospective chart review of 49 patients treated by this approach from 2008–2012 at a tertiary-care academic medical center was conducted and analyzed. Patient data including demographics, clinical presentation, pathology, mean intraoperative time, intraoperative complications, gross total resection (GTR), intraoperative cerebrospinal fluid (CSF) leak, postoperative CSF leak, postoperative complications, and postoperative clinical course were recorded. The follow-up period was defined as the time between surgery to the latest clinical appointment or death. To more specifically evaluate the outcomes of endoscopic endonasal transclival approaches, three regions of the clivus were defined and outcomes examined according to the involved clival segments.

Results: Forty-nine patients underwent 55 endoscopic endonasal transclival approaches. Pathology included 43 benign and 12 malignant lesions. Mean follow-up was 15.4 months. Mean operative time was 167.9 minutes, with one patient experiencing an intraoperative internal carotid artery injury. Of the 15 cases with intraoperative CSF leaks, 1 developed postoperative CSF leak (6.7%). For all cases, there were 4 systemic complications, one case of meningitis, and one retro-pharyngeal abscess. GTR was achieved for all malignancies approached with curative intent. Mean follow-up for patients undergoing surgical resection for curative intent was 19.7 months. GTR was achieved for 2 clival chordomas and there was no evidence of disease at 13.5 and 32.3 months.

Conclusions: This study suggests that endoscopic endonasal transclival approaches are a safe and effective strategy for the surgical management of a variety of benign and malignant lesions with a low risk of complications for carefully selected patients.

Clival Region	Number of Procedures (n = 55)	Intradural Procedures	Malignant Pathology (n = 12)	Ext. Beyond Clivus, n (%)	Intraop High-flow CSF Leak	Intraop Low-flow CSF Leak	Skull Base Defect≥ 2cm	Postop CSF Leak	Intraop Lumbar Drain	Postop Compli-cations
Superior	9	4	1	7 (78%)	1	2	8	0	0	1
Superior-Middle	11	7	4	7 (64%)	5	1	10	1	1	1
Middle	22	3	3	3 (14%)	2	2	18	0	0	2
Middle-Inferior	4	1	2	2 (50%)	1	0	4	0	0	2
Inferior	6	1	2	3 (50%)	1	0	4	0	0	0
Entire Clivus	3	0	0	1 (33%)	0	0	3	0	0	0