Association of venous thromboembolism prophylaxis with postoperative bleeding in bariatric surgery: an observational study.

BACKGROUND

Patients undergoing bariatric surgery are at an increased risk of postoperative venous thromboembolism (VTE). VTE prophylaxis protocols vary and can contribute to postoperative bleeding.

OBJECTIVE

Evaluate whether implementation of a VTE prophylaxis protocol is associated with a change in frequency of postoperative bleeding after bariatric surgery.

SETTING

Single United States university hospital.

METHODS

Patients who underwent sleeve gastrectomy or gastric bypass between 2020 and 2024 were assigned to the preprotocol or postprotocol group based on the date of surgery. Preprotocol patients received 40 mg of enoxaparin intraoperatively followed by 40 mg twice daily, whereas postprotocol patients received 60 mg of enoxaparin intraoperatively followed by 60 mg daily. Frequency of bleeding requiring transfusion and/or endoscopic or surgical intervention was compared using Fisher exact tests. A multivariable analysis identified characteristics associated with bleeding.

RESULTS

Six hundred sixty preprotocol and 797 postprotocol patients met inclusion criteria (mean [standard deviation] age, 45.4 [10.8] years; 85.5% White; 82.0% female; 60.6% sleeve gastrectomy). Bleeding frequency was similar between groups (2.3% preprotocol versus 3.0% postprotocol; P = .419). A multivariable analysis revealed that gastric bypass was associated with increased odds of bleeding (odds ratio, 1.94; confidence interval, 1.02‑3.70; P = .044), whereas higher body mass index was associated with decreased odds (odds ratio, .50; confidence interval, .29‑.87; P = .015).

CONCLUSIONS

A standardized VTE prophylaxis protocol using a higher intraoperative enoxaparin dose but lower total once daily dose was not superior to a twice daily regimen in regards to the frequency of clinically significant bleeding. These results suggest that protocolized prophylaxis can be applied safely but that patients with lower preoperative weights may be at a higher risk of bleeding and warrant dose adjustment.