Reconstruction of adjacent large finger pulps with the modified sensate free proximal ulnar artery perforator flap

Objective To study the surgical techniques and the clinical curative effect of the reconstruction of adjacent large finger pulps with the modified sensate free proximal ulnar artery perforator flap. Methods From February, 2013 to May, 2016, 20 fingers in 10 patients with adjacent large finger pulp defects crossing the DIP joint were reconstructed by the modified senate free proximal ulnar artery perforator flap. All the pulps of every patient were recovered by 1 flap in the first stage and the artificial syndactyly of two digits was divided in 7 weeks after the flap transfer in the second stage. In order to reconstruct the sensation of two pulps in each patient, firstly both of the proximal and distal ends of the cutaneous nerve in flaps were dissected and anastomosed with the most lateral and medial palmar digital nerves of two adjacent fingers respectively, which were divided into 2 groups. Secondly the cutaneous nerve in the middle part of flap was cut and the two ends were anastomosed with the other two palmar digital nerves in the second surgery. There were 8 fingers in 4 patients with the index and middle finger pulp defects, 12 fingers in 6 patients with the middle and ring finger defects. The flap size was from 5.0 cm×3.5 cm to 5.5 cm×4.0 cm, and the perforator artery was anastomosed with the palmar digital artery in 6 cases and with the joint branch of digital artery in 4 cases. Results Nine flaps survived uneventfully except the venous congestion was found in 1 flap which was salvaged successfully by acupuncture bleeding. Also, no congestion or ischemia of all the 20 pulp flaps occurred right after releasing the artificial syndactyly. The time of followed-up was from 11 months to 32 months with the average of 17 months after the second surgery. The static two point discrimination of the 2 groups of the sensate pulp flap was (7.3±1.2) mm and (8.6±2.4) mm respectively. There was no significant difference between groups (P > 0.05). These 20 pulp flaps were also assessed by the Semmes - Weinstein monofilament test with the result of diminished light touch in 14 pulps and diminished protective touch in 6 pulps. The total active motion in all 20 fingers was (248.0±4.5) °. No patients suffered cold intolerance and local pain but 1 had hypersensitiveness in the pulp flap. Conclusion The modified sensate free proximal ulnar artery perforator flap is a practical alternative for the reconstruction of two large adjacent pulps with satisfactory functional and aesthetic outcomes. Key words: Ulnar artery perforator flap; Proper palmar digital artery; Finger injuries; Reconstruction fo sensate