Endoscopic endonasal surgery of recurrent skull base chordomas

Objective To discuss the strategy and technique of endoscopic endonasal surgery of recurrent skull base chordomas. Methods The data of 123 patients with recurrent skull base chordomas were retrospectively studied who underwent surgical treatment between August 2007 and March 2018 at Neurosurgery Department of Beijing Tiantan Hospital, Capital Medical University. Recurrent skull base chordomas were classified into 4 types based on the tumor location: total clivus type (n=43) superior-middle clivus type (n=51), middle-inferior clivus type (n=8), and extensive type (n=21). All tumors were resected through EEA (endoscopic endonasal approach). Results Among all 123 cases, gross total resection was achieved in 39 (31.7%) cases, near-total resection in 58 (47.2%) and partial resection in 26 (21.1%). Following the surgery, cerebrospinal fluid leakage occurred in 9 cases and secondary surgical repair was performed. Intracranial infection occurred in 3 patients among the 9 cases who received the secondary repair. Among them, 2 patients recovered and 1 died. Postoperative new cranial nerve palsy occurred in 14 cases. Intraoperative internal carotid artery rupture occurred in 3 cases. The rupture in 2 cases was minor and complete hemostasis was achieved during operation. The rupture in 1 case was severe and endovascular covered stent was used for complete hemostasis. No new functional deficits was noted post operation for all 3 cases. Within 6 months post surgery, the improvement rates of hypopsia and visual field defects, diplopia, facial numbness and pain, tinnitus and hearing loss, dysphagia and hoarseness and cough, headache and dizziness, nasal obstruction, and dyskinesia were 47.6% (10/21), 32.3% (10/31), 41.7% (5/12), 30.0% (3/10), 25.0% (4/16), 86.6% (58/67), 100% (9/9) and 66.7% (8/12), respectively. Conclusions The resection of recurrent skull base chordomas seems difficult, in which endoscopic endonasal surgery might be more advantageous. Correct surgical strategy and techniques combined with the uses of neuronavigation, neurophysiological monitoring and Doppler ultrasound are the key factors for high-quality operation. Key words: Chordoma; Skull base neoplasms; Recurrence; Natural orifice endoscopic surgery