Objective To summarize the clinical experiences of various types of the second dorsal metacarpal artery (SDMA) flap for hand reconstruction. Methods From 1988 to 2003, 139 SDMA flaps were transferred for hand injuries. The flaps were used in 5 types according to vascularization and technique in transplantation:orthograde pedicled island SDMA flaps in 37 cases (cutaneous in 24and teno-cutaneous in 13), retrograde pedicled island SDMA flaps in 25 cases(cutaneous in 19 and teno-cutaneous in 6),double pivot SDMA flaps in 36 cases(cutaneous in 28 and teno-cutaneous in 8), distal perforator branch pedicledflaps in 19cases (cutaneous in 16 and composite in 3), free SDMA flaps in 22 cases (cutaneous in 15 and composite in 7). The skin islands were 3.0 cm×1.5 cm to 6.3 cm×5.0 cm in size. Results Of the 139 flaps, 135 flaps survived completely, 3 survived partially, and1 failed in the operation because of intractable vascular spasm. Follow-up wasdone in 116 cases for 12 to 57 months. The flap had good texture and color match. The twopoint discrimination was 5 to 9 mm in 78 sensate flaps, while it was 10 to 15 mm in 38 nonsensate flaps. In 21 tenocutaneous flaps, the TAM score of range of motion was 60% to 70% of the healthy side. Conclusion The SDMA flap has a constant and reliable vessel and a thin, pliable, and good-quality skin. It is versatile in creatingcomposite flaps. It is a good flap resource for hand and finger reconstruction.
Objective To provide the anatomic bases for clinical application of the second dorsal metacarpal artery(SDMA) island flap with double pivot points. Methods The origin,branches and distribution of the recurrent cutaneous branch of the SDMA were observed in 30 adult fresh cadaver specimens, which were illustrated with special dye.Eighteen cases of skin defets of the thumb were repaired with the SDMA island flap. The defect locations were the dorsal part in 11 cases and palmar part in 7 cases, including 3 cases of defect in association with long pollical extensor defect and 2 cases of defect in association with dorsal skin defect of proximal finger. The flap area ranged from 2 cm×3 cmto 3 cm×5 cm. Results The appearance of therecurrent cutaneous branch of the SDMA was observed in all cases(100%), which originated 0.5±0.2 cm distant from the distal intersectiones between the SDMA and the index extensor and disappeared 1.2±0.5 cm distant from the proximal metacarpophalangeal joint. The branches of 1.7±0.7 were seen with a longitudinal fan-like distributionforward proximal part on the deep surface of the dorsal superficial vein. The exradius and the length of the recurrent cutaneous branch of the SDMA were 0.3±0.1 mm and 6.5±0.8 mm, respectively. The transplanted flaps survived in all cases and 16 cases were followed up for 8-14 months. The colour and appearance of the skin were satisfactory. The two-point discriminations were 0.9 mm in 3 cases by bridging digital nerve and 1.1 mm in 9 cases by anastomosing dorsal digital nerve; while the two-point discrimination was 13-15 mm in 4 cases without anastomosing nerve. Conclusion The origin,branches and distribution of the recurrent cutaneous branch of the SDMA is constant, which provide a potentially longer pedicle and increase the possibility to rotate the flap and also avoid the donor skin defect of rotation of the flap.
The applied anatomy and clinical application were described in this paper. The blood supply of this flap was based on the second dorsal metacarpal artery. It gave some advantages of as easy of application, safe and reliable. Since November 1990, we had successfully used six such flaps in covering the soft tissue defects of the hand.