[Anatomical study and clinical application of the sensory perforator flap from the ulnar palmar digtal artery of the little finger].

Objective: To study the anatomical basis of the sensory perforator flap from the ulnar palmar digtal artery of the little finger and its application in reconstruction of soft tissue defect on the finger pulp.

Methods: The origins and distributions of the blood vessels and nerves of the hypothenar region were observed in 6 fresh cadavers whose upper limbs were perfused with red latex. From September 2013 to November 2015,13 cases with soft tissue defects on the finger pulp were treated. All patients received the sensory perforator flap from the ulnar palmar digtal artery of the little finger. The donor site was sutured directly.

Results: Through anatomical study, we found that the ulnar palmar digital artery of the little finger gives off constant cutaneous perforarter to nourish the skin of the hypothenar region, so do the ulnar palmar digital nerve of the little finger. The diameter of the artey is about 1.28 mm and suitable for microvascular anastomosis. All the 13 flaps survived. The patients were followed up for 3 months to 15 months. All the flaps had a good appearance. The sensation of the flaps recovered to S3 and two-point discrimination was 8-9 mmm. All the fingers had good function. There was only one linear scar on the hypothenar region without any discomfort.

Conclusions: The ulnar palm digital artery of the little finger contains constant branches to nourish the skin of the hypothenar region, so do the ulnar palrnar digital nerve of the little finger. So we can design a flap with sensory nerve on the hypothenar region. It is an effective method to repair soft tissue defect of the finger pulp with the free sensory perforator flap from the ulnar palmar digtal artery of the little finger.