Reconstruction of Digit Soft Tissue Defects With the Fourth Common Digital Artery Perforator Flap.

[PURPOSE] The hand has unique skin characteristics. Intrinsic flap donors are limited due to functional specificity and compactly connected structures. The hypothenar area is a reliable option for the reconstruction of finger defects. We performed anatomic studies elucidating the blood supply of this area and hypothesized that the fourth common palmar digital artery perforator free flap can be used to reconstruct soft tissue defects in fingers with minimal donor site morbidity.

[METHODS] From November 2017 to February 2020, 30 procedures of fourth common digital artery perforator free flaps were performed to cover digital skin defects. A retrospective chart review was performed, and the cases were analyzed.

[RESULTS] The mean patient age was 42.4 years (range, 1-75 years; median age, 40 years). Defects were located at the fingertip (n = 12), the dorsum (n = 3), the palmar (n = 9) aspect of the finger, and both the dorsal and palmar aspects of the finger (n = 6). Indications included emergent coverage (n = 13), coverage after necrosis (n = 11), oncological resection (n = 1), and contracture release (n = 5). The defect size ranged from 1.5 × 0.8 cm (1.2 cm) to 6 × 2.5 cm (15 cm). The perforator was located approximately 1 cm proximal to the distal palmar crease as it arose from the fourth common digital artery at a right angle. It continued to the ulnar border of the hand through the superficial fascia of the hypothenar muscles before running in a proximoulnar direction toward the dorsum of the hand. The diameter of the perforator was between 0.5 and 0.7 mm. All flaps survived. One case required a split-thickness skin graft for donor site closure, and all others could be closed primarily.

[CONCLUSIONS] The fourth common digital artery perforator is a versatile flap and can be used for both palmar and dorsal defects, including for the fingertip. The location of the perforator used differs from previous descriptions but is routinely and reliably located.

[TYPE OF STUDY/LEVEL OF EVIDENCE] Therapeutic IV.