Microsurgical outcomes of free flaps in patients with sickle cell trait: A case series

Sickle cell trait (SCT) is considered a benign carrier state. Though not associated with vaso-occlusive crises of sickle cell disease (SCD), physiological stress like hypoxia, hypothermia, and sympathetic activation experienced during surgery can lead to sickling in patients with SCT. Some reports suggest that perioperative sickling may lead to thrombosis or flap loss. In the context of microsurgery, SCT is assumed to pose less risk than SCD due to lower hemoglobin S (HbS) levels. This study aims to characterize microsurgical outcomes in patients with SCT.

We identified a series of patients with confirmed SCT who underwent microsurgical free flap reconstruction at one institution. Patient demographics, flap type, perioperative factors, postoperative complications, and overall flap survival were analyzed.

Six free flaps were identified in five patients with sickle cell trait, including 4 DIEP flaps, 1 ALT flap, and 1 RFFF. All flaps survived with an average follow-up of 9.5 months. Four of six flaps (67%) experienced postoperative complications, including seroma (n = 1), donor site hematoma (n = 2), and wound dehiscence (n = 1). One patient developed venous thrombosis on postoperative day 1 requiring re-anastomosis. All but one maintained normothermia and adequate oxygenation. Preoperative hemoglobin averaged 11.1 g/dL, decreasing to 9.2 g/dL postoperatively, without transfusion.

Despite concern for sickling events, this series of patients with SCT appear to tolerate free flap reconstruction. Even with transient intraoperative hypoxia and hypothermia, flap viability was preserved. Larger studies are needed to define microsurgical risk in SCT patients, particularly in relation to HbS levels and comorbidities.