Effect of Institutional Volume on Acoustic Neuroma Surgical Outcomes: State Inpatient Database 2009–2013

BACKGROUND: Evolving technologies and health care quality metrics have altered treatment algorithms for acoustic neuromas (ANs), increasing trends toward observation and radiosurgery, with proportionate declines in use of microsurgery. A correlation between increasing surgical volumes and superior outcomes has been investigated previously in numerous surgical diseases, including AN. OBJECTIVE: To re-evaluate the volume-outcome relationship of AN resection in a changing health care system, with evolving treatment strategies. METHODS: Patients who underwent AN resection between 2009 and 2013 were retrospectively identified in the State Inpatient Database subset of the Healthcare Cost and Utilization Project. Generalized linear mixed-effect models were used to assess odds of various outcome measures (length of stay [LOS], discharge disposition, and facial nerve or severe clinical complications). Institutions were grouped into low-volume centers (1-6 cases/year) and high-volume centers (HVC; >= 31 cases/year) for analysis. RESULTS: A total of 1873 patients underwent AN resection between 2009 and 2013 with a mean age of 50.1 +/- 14.1 years (+/- standard deviation). For each additional case treated annually, patients were 2% (odds ratio [OR], 0.98; 95% confidence interval, 0.96-0.99) less likely to experience a severe complication (P = 0.004). Each additional case also trended toward a decreased rate of facial nerve complications and nonroutine discharge. Inpatient LOS was also shorter for patients at HVCs (median, 4 vs. 5 days; P < 0.001). CONCLUSIONS: Despite a relative decline in microsurgery compared with previous eras, care at HVCs is still associated with superior short-term outcomes, such as decreased LOS, facial nerve or other severe complications, and nonroutine discharges.