Evaluation of the Suprafascial Thin ALT Flap in Foot and Ankle Reconstruction.

Background:  Distal lower extremity reconstruction can be challenging in terms of flap design. Bulky flaps result in limited mobility accompanied with the need of customized footwear. Raising the ALT-flap in a superficial fascial plane (thin ALT-flap) can be beneficial. This study evaluates thin ALT-flaps for lower distal extremity reconstruction.

Methods:  In a retrospective study, patients that underwent microvascular extremity reconstruction at the level of the ankle and dorsal foot at the University of Freiburg from 2008-2018 were reviewed.

Results:  95 patients could be included in the study (35 perforator flaps, 8 fascia flaps and 54 muscle flaps).Among the perforator flaps, 21 ALT-flaps were elevated conventionally and 14 in the superficial fascial plane (thin ALT-flap). Among the conventional ALT-flaps, there was one flap loss (5%) and one successful revision (5%). 5(24%) flaps received secondary thinning. 57%( = 12) were able to wear conventional footwear. There were 2(15%) successful revisions of thin ALT-flaps. 100% of thin ALT-flaps survived and 85%( = 11) of the patients wore ordinary footwear after defect coverage.Among fascial flaps, 50%( = 4) had to be revised with 2(25%) complete and 1 (13%) partial flap loss. All patients achieved mobility in ordinary shoes ( = 8).In muscle flaps, there were 7(13%) revisions and 5(9%) flap losses. 5(9%) flaps received secondary thinning. Only 33%( = 18) were mobile in ordinary footwear.

Conclusion:  The thin ALT-flap is a save one-stage evolution for lower distal extremity reconstruction with a favorable flap survival rate. Compared with conventional ALT-flaps it might be beneficial in reducing the need for expensive custom fitted shoes and secondary thinning procedures.