Does routine upper gastrointestinal swallow study after metabolic and bariatric surgery lead to earlier diagnosis of leak?

Background It is unclear whether routine upper gastrointestinal swallow study (SS) in the immediate postoperative period is associated with earlier diagnosis of gastrointestinal leak after bariatric surgery. Objective To investigate the relationship between routine SS and time to diagnosis of postoperative gastrointestinal leak. Setting MBSAQIP-accredited hospitals in the United States and Canada. Methods We conducted an observational cohort study of adults who underwent laparoscopic primary Roux-en-Y gastric bypass (RYGB) (n=82,510) and sleeve gastrectomy (SG) (n=283,520) using the MBSAQIP 2015-2019 database. Propensity scores were used to match patient cohorts who underwent routine v. no routine SS. Primary outcome was time to diagnosis of leak. Median days to diagnosis of leak were compared. The Nelson-Aalen estimator was used to determine the cumulative hazards of leak. Results In our study, 36,280 (23%) RYGB and 135,335 (33%) SG patients received routine SS. Routine SS was not associated with earlier diagnosis of leak (RYGB routine SS median 7 [IQR 3-12] days v. no routine SS 6 [2-11] days, p=0.9; SG routine SS 15 [9-22] days v. no routine SS 14 [8-21] days, p=0.06) or lower risk of developing leak (RYGB HR 1.0, 95%-CI 0.8-1.2; SG HR 1.1, 95%-CI 1.0-1.4). More routine SS patients had a length of stay 2 days or greater (RYGB 78.3% v. 61.1%; SG 48.6% v. 40.3%). Conclusion Routine SS was not associated with earlier diagnosis of leaks compared to the absence of routine SS. Surgeons should consider abandoning the practice of routine SS for the purpose of obtaining earlier diagnosis of postoperative leaks.