Reverse-Flow Island Flap from the Thenar Area of the Hand

Abstract

A reverse-flow island flap from the thenar eminence of the hand was applied in six patients to treat palmar skin defects, and amputation injuries of the thumb. There was one female and five males, and the patients' ages at the time of surgery averaged 48 years. A 3 x 2 to 5 x 3.5-cm fasciocutaneous flap from the radial aspect of the thenar eminence, located over the abductor pollicis brevis muscle, was designed and transferred in a retrograde fashion, to cover skin and soft-tissue defects of the thumb. The flap was based on the superficial palmar branch of the radial artery and, in three patients, was made sensate by the palmar branch of the superficial radial nerve. Follow-up periods averaged 61 months. The postoperative course was uneventful, and all the flaps survived without significant complications. The donor site was primarily closed in five patients, and one patient required flap coverage. A reverse island flap from the thenar area is easily elevated, contains durable fasciocutaneous structures, and has good color and texture, matching to the finger pulp. This flap offers a good alternative for reconstruction of palmar skin and soft-tissue defects of the thumb in selected patients.

Thumb Reconstruction Using the Radial Midpalmar (Perforator-Based) Island Flap (Distal Thenar Perforator-Based Island Flap)

“…In 2005, Kim and Hwang 5 described this flap (which they named the "radial midpalmar island flap") and the underlying concept involved, and described its clinical use for the reconstruction of the first web space and thumb base. Although the thenar area can be included in the radial midpalmar island flap, Kim and Hwang 5 used the term "radial midpalm" rather than "thenar," because perforators from the terminal branch of the superficial palmar arch, the princeps pollicis artery, and the radial palmar digital artery of the index finger are located mainly in the radial midpalm, not in the thenar area, because several "thenar flaps" had been previously described, 3,11,17,18 and because the term "radial midpalm" had been used by the surgeons who contributed to the development of the flap. 9,10 In addition, because short perforators of the hand were not usually referred to as perforators at the time their article was published, they chose to use the term "island flap" rather than "perforator(-based) island flap."…”

“…Although there are some variations of the superficial palmar arch and of its connections with other vessels, these anatomic findings are relatively well defined. [5][6][7][8][9][10][11] Omokawa and colleagues, 9 in their cadaver hand studies, noted that the terminal branch of the superficial palmar arch (average diameter, 1.3 mm) consistently divides into three to six cutaneous perforators (diameter range, 0.1 to 0.5 mm) and supplies the radial aspect of the midpalmar area, which is located over the ulnar half of the adductor pollicis muscle. These perforators are located from 2 to 38 mm distal to the superficial palmar arch.…”

Fourteen Cases of Free Thenar Flap

“…4 In such case, a wider distal dissection is needed to obtain more freedom of the flap. Stretching of the pedicle might represent a problem when attempting to reach the tip of the thumb.…”

“…Its thickness and adherence to the underlying fibroadipose tissue provide great stability, better than any other fasciocutaneous flap from distant regions such as forearm, lateral arm, or groin flaps. The superficial palmar artery or a branch of the radial artery nourishes the flap, with no need to sacrifice any major vessel, as described by Omokawa et al 1,4,14,15 The recipient vessel is usually represented by the digital artery, which is easily exposed without need of extensive dissections, as in the reverse digital artery flap or neurovascular island flap. Disadvantages are related to the complexity that any microsurgical transfer implies and the possibility of an enlarged scar in the donor area, potentially unpleasant.…”

“…In about 60% of the cases, the artery has connections either to one of the digital arteries of the thumb or other arteries in the radial aspect of the palm. 4 Despite its terminal course, the superficial palmar artery is rarely absent. Dye-injection studies conducted by Omokawa et al 1 in 30 fresh-frozen cadavers showed that a flap of 5.1 ϫ 3.4 cm (length by width) can be safely elevated based on the superficial palmar artery.…”