Petechiae Post-dangling in Lower Extremity Free Tissue Transfer and Proposed Management

The anterolateral thigh (ALT) flap is often used by microsurgeons, with few reports of skin flap complications outside of partial flap necrosis. This study describes three unusual cases of flap dangle intolerance secondary to the development of immediate petechial hemorrhage of the skin paddle at the onset of dangle trials. Potential causes and management are described. A retrospective review was conducted of all free tissue transfers utilizing an ALT flap for lower extremity reconstruction performed by a single surgeon at a level 1 trauma center from October 2020 to May 2024. Patient risk factors were compared to identify potential causes of the dangle intolerance. Thirty-five free tissue transfers to reconstruct lower extremity defects with an ALT flap had a normal postoperative course until the initiation of the progressive dangle protocol. Evidence of petechial skin flap compromise was noted in three patients (8.6%) within five minutes of the initial dangle. These three flaps required up to a week of additional elevation to allow the full resolution of skin changes, only to have immediate return of the skin changes at the next trial of dangle. This process was repeated for up to six weeks before the flaps were able to tolerate a progressive dangle protocol without skin changes. No evidence of deep venous thrombosis (DVT) or thrombocytopenia was noted on Doppler ultrasound or laboratory work, respectively. In comparison to the control group, patient age, diabetes, hypertension, and smoking status were identified as potential risk factors. Delayed postoperative petechiae with progressive dangle protocols are an underreported issue that warrants more investigation. Increased patient age and comorbidities, including diabetes, hypertension, and current smoking, were identified in three patients who developed petechiae upon dangling. The reconstructions were completed successfully with a prolonged dangle protocol that others may utilize.