Multiple digit resurfacing with a lateral thoracic free flap: Two-stage mitten hand and division procedures.

[PURPOSE] The conventional abdominal and groin flaps for resurfacing the defect have several disadvantages, including the risk of flap failure due to accidental traction or detachment, immobilization of the arm before division, and aesthetic dissatisfaction because of the flap bulkiness. The aim of this study was to share our experiences with the free lateral thoracic flap and elucidate the optimal timing of division in complex hand reconstruction, which yielded favorable outcomes in terms of both functionality and aesthetics.

[METHODS] This article is a retrospective review of multiple digit resurfacing using free tissue transfer from 2012 to 2022. Patients who underwent two-stage operation including mitten hand creation using superthin thoracodorsal artery perforator (TDAp) free flap and secondary division were included. A flap was elevated over the superficial fascia layer the midportion between the anterior border of the latissimus dorsi and pectoralis major muscles and once the pedicle was found, an outline that matched the defect was created. A process named "pushing with pressure and cutting" was carried out before pedicle ligation until all the superficial fat tissue had been removed except for around the perforator. Two cases (18%) involved defects of the entire fingers reconstructed by TDAp flap with anterolateral thigh flap. Six cases (55%) had a super-thin TDAp flap only. In two cases (18%), non-vascularized iliac bone grafting was required for finger lengthening. One case (9%) was resurfaced with a TDAp chimeric flap including a skin paddle with the serratus anterior muscle. The primary outcome was defined as the survival or failure of the flap, while the secondary outcomes associated complications such as infection and partial flap necrosis. A statistical analysis was not performed due to the size of the case series.

[RESULTS] All 13 flaps survived completely without any complications. Flap dimension ranged from 12 cm × 7 cm to 30 cm × 15 cm. Mitten hand duration prior to division was 41.9 days on average which was essential for the optimal result. During the division procedures, there were nine cases of debulking (82%), six cases of split-thickness skin graft (STSG) (55%), and three cases of Z-plasty performed on the first web space (27%). The mean follow-up period was 20.2 months. Mean Disability of the Arm, Shoulder, and Hand (DASH) Questionnaire score was 10.76.

[CONCLUSIONS] We resurfaced severe soft tissue defects of multiple fingers with thin to super-thin free flaps, mainly TDAp flaps. Surgeons can restore original hand shape using a two-stage reconstructive strategy of mitten hand creation and proper division timing to create a 3-dimensional hand structure, even in severely injured hands with multiple soft tissue defects of the digits.