Pre-induction and post-discharge venous thromboembolism chemoprophylaxis should be considered in patients after major vascular open abdominal procedures.

Background: Venous thromboembolism (VTE) is a significant morbidity following major open abdominal surgery. While there are clear recommendations for perioperative and post-discharge VTE chemoprophylaxis in general surgery, guidance for vascular patients is unclear. We compared the incidence of VTE in vascular versus general surgery cases and then investigated the timing of VTE in vascular patients.

Methods: Two cohorts of major open abdominal surgery, vascular (open abdominal aortic aneurysm and aortoiliac reconstruction) and general, were compared in ACS-NSQIP database. There were significant preoperative differences between cohorts that were corrected using 1:1 propensity matching and logistic regression. Thirty-day outcomes included incidence and timing of VTE (in-hospital and post-discharge), mortality, and major morbidities.

Results: After propensity matching, there were 14,983 and 15,075 patients had vascular and general surgery, respectively. VTE rate was significantly lower in vascular. The distribution of in-hospital and post-discharge VTE was similar in both groups. Over the last 10 years, the overall incidence of VTE has decreased for both general and vascular surgery, with a corresponding decrease in in-hospital VTE but no change in post-discharge VTE. VTE occurrence showed a bimodal distribution with 76.92% of VTE occurring in early period (<14 days) and 23.08% occurring in late period (>14 days), which coincided with in-hospital (77.91%) and post-discharge (22.09%), respectively.

Conclusion: Although VTE incidence after vascular procedures has decreased, in-hospital VTE may be further reduced if pre-induction subcutaneous heparin is given. Furthermore, 22% VTE developed post-discharge in vascular patients, which suggests post-discharge VTE prophylaxis should be considered in selected high-risk patients.