OBJECTIVES: To examine the impact of procedure volume on 30-day all-cause readmissions among patients undergoing laparoscopic or robotic bariatric surgery.

METHODS: We extracted hospital discharge records from the Premier Healthcare Database for patients aged≥18 undergoing elective laparoscopic or robotic bariatric surgery (Roux-en-Y gastric bypass, sleeve gastrectomy) between 1-1-2015 and 12-31-2017 (first admission=index). For each patient, we used the month of index and 12 months prior to measure their hospital’s annual procedure volume of the specific procedure/approach that they underwent (Roux-en-Y/laparoscopic, Roux-en-Y/robotic, sleeve/laparoscopic, sleeve/robotic); we then used multivariable generalized estimating equations to quantify the association between the annual procedure volume (categorized in quartiles [Q1-Q4] from low-to-high volume) and 30-day all-cause readmission to the same hospital in which the bariatric surgery was performed, accounting for hospital-level clustering and adjusting for patients’ demographics, body mass index, comorbidities, and provider/hospital characteristics.

RESULTS: The study included 30,301 Roux-en-Y/laparoscopic, 2,751 Roux-en-Y/robotic, 66,788 sleeve/laparoscopic, and 6,227 sleeve/robotic patients from 294 hospitals. In analyses of the laparoscopic approach, higher annual procedure volume was significantly associated with lower adjusted risk of 30-day all-cause readmission (Roux-en-Y/laparoscopic: Q1=6.5%, Q2=5.9%, Q3=4.8%, Q4=4.6%, P=0.002; sleeve/laparoscopic: Q1=3.3%, Q2=2.8%, Q3=2.9%, Q4=2.3%, P=0.006). In contrast, for the robotic approach, procedure volume was not significantly associated with adjusted risk of 30-day all-cause readmissions (Roux-en-Y/robotic: Q1=7.1 %, Q2=7.2%, Q3=7.0%, Q4=5.6%, P=0.836; sleeve/robotic: Q1=2.8%, Q2=2.5%, Q3=2.9%, Q4=3.9%, P=0.335).

CONCLUSIONS: Among patients undergoing elective bariatric surgery, higher hospital procedure volume was significantly associated with lower adjusted risks of 30-day all-cause readmission for laparoscopic procedures but not robotic procedures. The robotic approach is a relatively new and less common technique in bariatric surgery; readmission data may reflect the fact that robotics is in early experience with hospitals and surgeons still advancing on their learning curves. More research is needed to understand the hospital and surgeon-specific factors which influence outcomes in robotic bariatric surgery.