Chimeric Free Flaps Based on End-to-Side Anastomosis for Complex Lower Extremity Reconstruction.

[BACKGROUND] Complex lower extremity defects are difficult to cover and often require multiple free tissue transfers. Chimeric anterolateral thigh free flaps (ALTF) and peroneal artery perforator free flaps (PAPF) have been designed specifically as an alternative for reconstruction with arterial end-to-side (ETS) anastomosis. We aimed to assess our institutional experience with this technique and to define its role in complex lower extremity reconstruction.

[METHODS] From July 2012 to March 2023, 27 patients with complex lower extremity defects underwent reconstruction with chimeric ALTF or PAPF. Patients were performed with retrograde flaps for repairing refractory wounds of tibia plateau fracture and antegrade flaps for distal 2/3 tibia and beyond. Demographic, clinical, and follow-up data on the patients were recorded with a special focus on complication profiles during a follow-up of 6 to 60 months.

[RESULTS] The mean defect size measured 121.1 ± 215.1 cm 2 , and the chimeric ALTF or PAPF flaps measured 143.9 ± 177.8 cm 2 . One patient lost the first free flap but successfully had a chimeric PAPF then. Three patients suffered partial free flap loss, and another 3 had minor complications. All 6 survived after an additional exploration, wound dressing, or antibiotics treatment. The retrograde flaps achieved similar blood flow to the antegrade flaps. Patients are all satisfied with functional and aesthetic outcomes.

[CONCLUSIONS] Given the incidence of complications, utilizing chimeric ALTF and PAPF either with retrograde or antegrade flow based on arterial ETS anastomosis is a reliable surgical option for complex lower extremity reconstructions.