Cumulative Incidence of Venous Thromboembolic Events In-Hospital, and at 1, 3, 6, and 12 Months After Metabolic and Bariatric Surgery: Systematic Review of 87 Studies and Meta-analysis of 2,731,797 Patients.

Systematic review/meta-analysis of cumulative incidences of venous thromboembolic events (VTE) after metabolic and bariatric surgery (MBS). Electronic databases were searched for original studies. Proportional meta-analysis assessed cumulative VTE incidences. (PROSPERO ID:CRD42020184529). A total of 3066 records, and 87 studies were included (N patients = 4,991,683). Pooled in-hospital VTE of mainly laparoscopic studies = 0.15% (95% CI = 0.13-0.18%); pooled cumulative incidence increased to 0.50% (95% CI = 0.33-0.70%); 0.51% (95% CI = 0.38-0.65%); 0.72% (95% CI = 0.13-1.52%); 0.78% (95% CI = 0-3.49%) at 30 days and 3, 6, and 12 months, respectively. Studies using predominantly open approach exhibited higher incidence than laparoscopic studies. Within the first month, 60% of VTE occurred after discharge. North American and earlier studies had higher incidence than non-North American and more recent studies. This study is the first to generate detailed estimates of the incidence and patterns of VTE after MBS over time. The incidence of VTE after MBS is low. Improved estimates and time variations of VTE require longer-term designs, non-aggregated reporting of characteristics, and must consider many factors and the use of data registries. Extended surveillance of VTE after MBS is required.