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.