Safety of DIEP Flap Reconstruction in Patients with Factor V Leiden: A Retrospective Cohort Study.

[BACKGROUND] Factor V Leiden (FVL) is the most common inherited thrombophilia in White people. Thrombotic complications resulting from free flap breast reconstruction in FVL patients have been studied to a limited degree. We evaluated whether patients heterozygous for a FVL mutation undergoing deep inferior epigastric perforator flap reconstruction had increased risk of micro- or macrovascular thrombotic complications compared with patients without a diagnosed thrombophilia.

[METHODS] We performed a retrospective cohort study of deep inferior epigastric perforator flap reconstructions at Brigham and Women's Hospital (1/2015-12/2020) comparing patients diagnosed as FVL heterozygotes compared with matched controls without a diagnosed thrombophilia. Patients were matched using coarsened exact matching algorithm based on clinical characteristics. The primary outcomes were micro- (return to OR for flap compromise, flap loss) and macrovascular (venous thromboembolism) complications.

[RESULTS] A total of 506 patients (812 flaps) were included in this study. Eleven patients (17 flaps) were FVL heterozygotes. After matching, 10 patients (16 flaps) with FVL were matched to 55 patients (94 flaps). The return to OR for flap compromise was 0% in the FVL cohort compared with 5% (n = 5/94, 3/94 flaps lost, = 1.00) in the matched controls (1.9%, n = 15/795 in unmatched controls, 0.6%, n = 5/795 loss rate). There were zero venous thromboembolism events among FVL patients compared with 2% of controls (n = 1/55).

[CONCLUSIONS] FVL heterozygosity did not increase the risk of micro- or macrovascular complications in patients undergoing deep inferior epigastric perforator flap breast reconstruction. This study supports the safety of microvascular reconstruction in this group of patients when appropriate venous thromboembolism prophylaxis is given.