Center case volume and minimally invasive liver surgery: a study based on the Italian Group of minimally invasive liver surgery registry

Abstract

Introduction: The outcome of liver surgery is associated with the hospital case volume. To analyze the impact of the center case volume on the minimally invasive liver surgery (MILS). Methods: All patients enrolled in the prospective registry of the Italian Group of MILS from November 2014 to August 2016 were considered. Only centers with an accrual ≥6 months were included. The center case volume was defined as the number of MILS performed per month. Results: 919 MILS performed by 37 centers were analyzed. Ten centers performed >2 MILS/month (n=600 patients), 7 performed 1-2 MILS/month (n=142), and 20 performed < 1 MILS/month (n=177). Centers performing < 1 MILS/month resected more benign tumors and tumors in anterolateral segments (28.2% vs. 20.9%, p=0.035; 87.0% vs. 72.6%, p< 0.001). Major hepatectomies increased with the case volume (3.4% if < 1 MILS/month, 7.7% if 1-2, 13.7% if >2, p< 0.001). The R1 resection rate was higher in centers performing >2 MILS/month (10.9% vs. 2.6%, p< 0.001). The conversion, overall morbidity, and severe morbidity rates were similar among groups. The overall and severe morbidity rates of major hepatectomies were higher in centers performing < 2 MILS/month (52.9% vs. 29.3%, p=0.060; 23.6% vs. 8.5%, p=0.092). Conclusions: The center case volume does not impact the outcome of minor hepatectomies; however, it impacts the outcome of minimally invasive major hepatectomies (morbidity rates increase as the MILS volume decreases). Low-volume centers can safely perform MILS of anterolateral segments with excellent outcomes. High-volume centers approach more complex resections with adequate safety.