LAUSR

Background: Patients undergoing autologous breast reconstruction are at high risk of perioperative venous thromboembolic events. The efficacy of chemoprophylaxis in decreasing venous thromboembolic events is well established, but the timing of chemoprophylaxis remains controversial. The authors compare the incidence of bleeding following preoperative versus postoperative initiation of chemoprophylaxis in microvascular breast reconstruction. Methods: A retrospective chart review was performed from August of 2010 to July of 2016. Initiation of chemoprophylaxis changed from postoperative to preoperative in 2013, dividing subjects into two groups. Patient demographics, comorbidities, and complications were reviewed. Results: A total of 196 patients (311 flaps) were included in the study. A total of 105 patients (166 flaps) received preoperative enoxaparin (40 mg) and 91 patients (145 flaps) received postoperative chemoprophylaxis. A total of five patients required hematoma evacuation (2.6 percent). Of these, one hematoma (1 percent) occurred in the preoperative chemoprophylaxis group. Seven patients received blood transfusions: three in the preoperative group and four in the postoperative group (2.9 percent versus 4.4 percent; p = 0.419). There was a total of one flap failure, and there were no documented venous thromboembolic events in any of the groups. Conclusions: This study demonstrates that preoperative chemoprophylaxis can be used safely in patients undergoing microvascular breast reconstruction. The higher rate of bleeding in the postoperative group may be related to the onset of action of enoxaparin of 4 to 6 hours, which allows for intraoperative hemostasis in the preoperative group and possibly potentiating postoperative oozing when administered postoperatively. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.