Limitation of microdissected thinning in free anterolateral thigh flap for hand reconstruction

Hand defects, especially complex defects involving tendon or bone exposure, are challenging to reconstruct. With the limited size and options of local flaps, the free-thinned anterolateral thigh (ALT) flap remains an excellent choice. However, many authors have described thinning procedures differently, leading to inconsistent outcomes. We present our clinical experience of immediate thinning ALT flaps depending on the anatomical structure of the perforator.

Between 2007 and 2021, we used a free ALT flap in 42 cases to cover hand defects after crushing and friction injuries, burning and burn scars, and animal bite wounds. There were 38 males and 4 females; the mean patient age was 31.2 years. Thinning procedure was performed in all flaps. The primary and microdissected thinning procedure was performed for 35 single flaps and 7 chimeric flaps, including 14 flaps for the fingers (29%), 4 flaps for the palm (8%), 12 flaps for the hand dorsum (24%), and 19 flaps for combined areas (39%).

The mean flap thickness was 18.6 (11–30) mm before defatting and 6.0 (3–12) mm after defatting, an approximately 65% reduction. The retained fascia island around the perforator was ≤ 1 cm in 73.5% of cases, 2–3 cm in 18.4%, and the remaining 8.1% had a fascia size ≥ 4 cm. The incidence of a well-survive flap was 93.9%. Three cases had partial to total necrosis. None of the patients required a secondary defatting procedure.

Every case has a perforator pattern after running through the fascia, which allows surgeons to choose the appropriate thinning method. Perforators that run parallel to the superficial fascia are not good candidates for thinning. Instead, the thinning process should be performed with more perpendicular perforators.

Level of evidence: Level IV, therapeutic study