LAUSR

OBJECTIVES Thoracic outlet syndrome (TOS) surgery is relatively rare and controversial given the challenges in diagnosis as well as wide variation in symptomatic and functional recovery. Our aims were to measure trends in utilization of TOS surgery, complications, and mortality rates in a nationally representative cohort and compare higher- versus lower-volume centers. METHODS The National Inpatient Sample was queried using ICD-9 codes for rib resection and scalenectomy paired with axillo-subclavian aneurysm [arterial (aTOS)], subclavian DVT [venous (vTOS)], or brachial plexus lesions [neurogenic (nTOS)]. Basic descriptive statistics, non-parametric tests for trend, and multivariable hierarchical regression models with random intercept for center were used to compare outcomes for TOS types, trends over time, and higher- and lower-volume hospitals, respectively. RESULTS There were 3,547 TOS operations (for an estimated 18,210 TOS operations nationally) performed between 2010-2015 (89.2% nTOS, 9.9% vTOS, 0.9% aTOS) with annual case volume increasing significantly over time (p=0.03). Higher-volume centers (≥10 cases/year) represented 5.2% of hospitals and 37.0% of cases, and these centers achieved significantly lower overall major complication (defined as neurologic injury, arterial or venous injury, vascular graft complication, pneumothorax, hemorrhage/hematoma or lymphatic leak) rates [adjusted Odds Ratio (OR) 0.71 (95% confidence interval 0.52-0.98); p=0.04], but no difference in neurologic complications such as brachial plexus injury (aOR 0.69 (0.20-2.43); p=0.56) or vascular injuries/graft complications [aOR 0.71 (0.0.33=1.54); p=0.39]. Overall mortality was 0.6%, neurologic injury was rare (0.3%), and the proportion of patients experiencing complications decreased over time (p=0.03). However, vTOS & aTOS had >2.5 times the odds of major complication compared to nTOS [OR 2.68 (1.88-3.82) & aOR 4.26 (1.78-10.17); p<0.001], and ∼10 times the odds of a vascular complication [aOR 10.37 (5.33-20.19) & aOR 12.93 (3.54-47.37); p<0.001], respectively. As the number of complications decreased, average hospital charges also significantly decreased over time (p<0.001). Total hospital charges were on average higher when surgery was performed in lower-volume centers (< 10 cases/year) compared to higher-volume centers [mean $65,634 (standard deviation 98,796) vs. $45,850 (59,285), p<0.001]. CONCLUSION The annual number of TOS operations have increased in the United States from 2010-2015, while complications and average hospital charges have decreased. Mortality and neurologic injury remain rare. Higher-volume centers delivered higher-value care: less or similar operative morbidity with lower total hospital charges.