The prognostic role of extended preoperative hypercoagulability work-up in high-risk microsurgical free flaps: a single-center retrospective case series of patients with heterozygotic factor V Leiden thrombophilia.

[INTRODUCTION] Hypercoagulability is associated with an increased risk of microvascular complications and free flap failures. The authors present their experience and approach to diagnosing and treating patients with heterozygotic factor V Leiden (hFVL) thrombophilia undergoing free flap reconstruction.

[METHODS] Between November 2009 and June 2018, 23 free flap surgeries were performed in 15 hypercoagulable patients with hFVL. According to the timing of perioperative hypercoagulability work-up, they were grouped into flaps with established diagnoses prior to surgery (Group A) versus flaps with unknown diagnoses prior to surgery (Group B). Baseline characteristics and perioperative complications were compared between both groups, including revision surgeries due to microvascular thromboses, acute bleedings, hematomas, flap necroses, and reconstructive failures.

[RESULTS] HFVL mutations had been confirmed preoperatively in 14 free flap surgeries (61%, Group A), whereas in 9 free flap surgeries (39%, Group B), mutations were only diagnosed postoperatively after the occurrence of microvascular thromboses had warranted extended hypercoagulability work-up. The overall rate of intraoperative flap thromboses was 9% (n = 2), whereas the overall rate of postoperative flap thromboses was 43% (n = 10). The corresponding salvage rates were 100% (n = 2/2) for intraoperative and 40% (n = 4/10) for postoperative pedicle thromboses. A total of five free flaps were lost (22%). Upon comparison, flaps with an unconfirmed diagnosis prior to surgery were at ten times higher risk for developing total necroses (flaps lost in Group B = 4/9 versus Group A = 1/14; OR: 10.4; 95% CI 1.0, 134.7; p = 0.03).

[CONCLUSION] Meticulous preoperative work-up of patients with any history of hypercoagulability can help reduce free flap loss rates, thus improving surgical outcomes and increasing patient safety.