Thromboprophylaxis timing and duration in bariatric surgery: impact on thromboembolism and bleeding

Abstract Introduction Deep vein thrombosis (DVT) and pulmonary embolism (PE) are recognized complications following bariatric surgery, with incidences reported between 0.3% and 2.2%. While thromboprophylaxis is recommended, the optimal duration, dosage, and timing remain debated. This study evaluates the association between thromboprophylaxis regimens and postoperative DVT/PE and bleeding complications in a nationwide cohort. Method A retrospective cohort study was conducted using data from the Scandinavian Obesity Surgery Registry (SOReg) from 2010 to 2023. Data included demographics, surgical details, thromboprophylaxis regimens, and six-week follow-up on DVT/PE and bleeding. Thromboprophylaxis duration (<7, 7–10, 11–14, >14 days) and initiation (preoperative vs. postoperative) were analysed using univariable and multivariable logistic regression, adjusting for risk factors. Result Among 83,801 patients, 48,344 had thromboprophylaxis data, and 30,800 had recorded initiation timing. The overall incidence of DVT/PE was 0.09%, with no significant differences across treatment durations or initiation timing (p=0.33 and 0.12). Prior DVT/PE (OR 4.10, 95% CI 1.40–12.03, p=0.010) and intraoperative bleeding (OR 6.39, 95% CI 1.46–27.98, p=0.014) were associated with higher DVT/PE risk. Postoperative thromboprophylaxis initiation was linked to lower intraoperative bleeding risk (OR 0.66, 95% CI 0.47–0.93, p=0.046), while male sex, older age, cardiovascular disease, and antidepressant use were associated with increased postoperative bleeding risk. Discussion Thromboprophylaxis duration and timing did not significantly affect DVT/PE incidence. However, postoperative initiation was associated with a lower risk of intraoperative bleeding. These findings may guide thromboprophylaxis strategies in bariatric surgery patients.