Surgical management of endolymphatic sac tumor: a systematic review and meta-analysis

The aim of our study was to report rates of facial nerve palsy and residual tumor following surgical intervention and subsequent tumor recurrence in patients with endolymphatic sac tumors. A systematic literature review of preoperative assessment and surgical management is also included. Studies including patient/s affected by sporadic or von Hippel-Lindau disease related endolymphatic sac tumors, reporting levels of facial nerve function, residual and recurrence pathology following a surgical procedure, were considered. Data were combined for proportional meta-analysis, and the selected studies' methodological quality was also evaluated. Overall 34 papers, including 202 subjects (209 cases of endolymphatic sac tumors) were analyzed. Pooled proportion rate (95% CI) of overall facial nerve palsy was 39.7% (28.2-51.9) and residual tumor was 16.5% (10.3-23.7) after surgical procedure. Pooled proportion rate (95% CI) of tumor recurrence was 14.0% (9.7-19.3) during a mean follow-up period of 49.7 months (8-136). Our results showed that preoperative facial nerve function is impaired in almost 30% of patients with endolymphatic sac tumors. Surgical management of endolymphatic sac tumor may cause a worsening of facial nerve function in a low percentage of treated subjects. Residual and/or recurrence of endolymphatic sac tumors are not rare events, and follow-up strategies should be designed accordingly.