Venous Thromboembolic Events Following Revisional Gastric Bypass: An Analysis of the MBSAQIP Database from 2015 to 2019 Using Propensity Matching.

Background: Primary bariatric surgery is associated with moderate-to-high risk of venous thromboembolic events (VTE); however, the risk for revisional surgery lacks granularity. Our primary objective was to define the risk of VTE following revisional Roux-en-Y gastric bypass (RYGB) compared to primary RYGB.

Methods: Adults who underwent primary or revision/conversion RYGB between January 1, 2015, and December 31, 2019, with a BMI ≥ 35 kg/m were identified in a bariatric specific database. VTE was defined as pulmonary embolus and/or deep venous thrombosis. Thirty-day VTE and transfusion rates were compared between the two groups using propensity score matching of 3:1.

Results: Primary RYGB was performed in 197,186 (92.4%) patients compared to 16,144 (7.6%) in the revisional group. Patients in the revisional group had fewer comorbidities than those undergoing primary RYGB. In the matched cohort of 64,258 procedures, there were 48,116 (74.9%) primary RYGB cases compared to 16,142 (25.1%) RYGB revisions. The rate of VTE was similar in the revisional surgery group compared to the propensity matched primary RYGB group (0.4% vs. 0.3%, p > 0.580); however, transfusion was more common in the revisional group (1.4% vs. 1.0%, p = 0.005). Revisional group had higher rates of readmission, reoperation, increased length of stay, and operation length ≥ 180 min compared to matched primary RYGB group (p < 0.001).

Conclusions: VTE rates for both primary and revisional RYGB are similar. Revisional RYGB cases impose increased risk of bleeding among other outcomes. Thus, identifying those at higher risk of complications is critical.