The following is the summary of “Optimal Timing of Perioperative Chemoprophylaxis in Patients With High Thromboembolic Risk Undergoing Major Abdominal Surgery” published in the January 2023 issue of Surgery by Liu, et al.
The purpose of this study is to compare the risk of venous thromboembolism (VTE) and hemorrhage in patients undergoing major abdominal surgery and receiving chemoprophylaxis either before or after skin closure in a group at high risk for VTE. The dangers of venous thromboembolism and hemorrhaging are present with major abdominal surgery. Patients with a high risk of VTE before surgery benefit the most from chemoprophylaxis, but they also have a higher risk of bleeding complications. When chemoprophylaxis should be used in the perioperative period to reduce the risk of both VTE and hemorrhage is not understood.
A synthesis of 5 multicenter studies using data from only patients with a high thromboembolic risk (Caprini score >4). Radiographic evidence of disease within <30 days of surgery was used to establish a diagnosis of clinical VTE. The severity of bleeding was measured by a hemoglobin drop of >20 g/L or the requirement for a blood transfusion or other intervention. The findings showed that out of 5,501 instances, chemoprophylaxis was started early in 1,752 (31.8%) patients and later in 3,749 (68.2%) patients following surgery. Similarities existed at the outset between the groupings. However, there was no correlation between when chemoprophylaxis was given and the occurrence of clinical VTE (0.7% in the early group versus 0.7% in the post operative group, OR: 1.11, 95% CI: 0.60-2.15, P=0.730).
Early usage, in contrast to postoperative chemoprophylaxis, was associated with a higher risk of bleeding overall (5.1% vs. 2.6%, OR: 2.04, 95% CI: 1.52-2.73, P<0.001), serious bleeding (3.6% vs. 1.8%, OR: 1.99, 95% CI: 1.40-2.81, P<0.001), and reintervention (2.0% vs. 1.0%, OR: 2.10, 95% CI: 1. Postoperative bleeding was predicted by early chemoprophylaxis (OR: 1.71, 95% CI: 1.25-2.34, P<0.001) but not VTE. In high-risk patients for venous thromboembolism undergoing major abdominal surgery, chemoprophylaxis starts after the procedure has begun, decreasing the risk of bleeding without increasing the clinical VTE risk.
