Revisiting the Relationship Between Hospital Case Volume and Outcomes in Abdominally Based Free Flap Breast Reconstruction.

Abstract

Increased operative volume has been associated with benefits in patient outcomes for a variety of surgical procedures. In autologous abdominally based breast reconstruction, however, there are few studies assessing the association between procedure volume and patient outcomes. The objectives of this study are to evaluate the associations between abdominal-based free flap breast reconstruction and patient outcomes. The 2013-2014 Healthcare Cost and Utilization Project National Inpatient Sample was queried for all female patients with a diagnosis of breast cancer who underwent mastectomy and immediate abdominally based breast reconstruction (deep inferior epigastric perforator or transverse rectus abdominus muscle free flaps). Outcomes included occurrence of major or surgical site in-hospital complications, hospital cost, and length of stay (LOS). High-volume (HV) hospitals were defined as the 90th percentile of annual case volume or higher (>18 cases/y). Multivariate regressions and generalized linear modeling with gamma log-link function were performed to access the outcomes associated with HV hospitals. Overall, 7145 patients at 473 hospitals were studied; of these, 42.4% of patients were treated at HV hospitals. There were significant differences in unadjusted major complications (2.1% vs 4.3%; P < 0.001) and unadjusted surgical site complications (3.5% vs 6.1%; P < 0.001) between HV and non-HV hospitals. After adjustments for clinical and hospital characteristics, patients treated at HV hospitals were less likely to experience a major complication (odds ratio, 0.488; 95% confidence interval, 0.353-0.675; P < 0.001) or surgical site complication (odds ratio, 0.678; 95% confidence interval, 0.519-0.887; P = 0.005). There was no difference in inpatient cost between HV and non-HV hospitals ($26,822 vs $26,295; marginal cost, $528; P = 0.102); however, HV hospitals had a shorter LOS (4.31 vs 4.40 days; marginal LOS, -0.10 days; P = 0.005). Hospitals that perform a larger volume of immediate abdominal-based breast reconstructions after mastectomy, when compared with those that perform a lower volume of these procedures, seem to have an associated lower rate of major complications and a shorter LOS. However, these same HV centers demonstrate no decrease in costs. Further research is needed to understand how these HV centers can reduce hospital costs.