Analysis of 22 Posterior Ulnar Recurrent Artery Perforator Flaps: A Type of Proximal Ulnar Perforator Flap

Analysis of patients

The elbow and forearm defects of 22 cases were reconstructed by PURAP flaps between 2000 and 2008. The patients were between 6 and 48 years of age. These cases were analyzed in terms of the cause of injury, the recipient site, the vascular pedicle of the flap, flap size, flap survival, and the quality of the outcome. The latter parameter was evaluated by 3 different plastic surgeons who designated the outcome as excellent, good, or poor on the basis of the color and texture matches between the flap and the recipient site. Moreover, donor site morbidity, including the development of scars and numbness, was also evaluated.

Operative methods

In all cases, the flaps were designed after debridement of wounds or complete resection of burn scars at the recipient sites. Generally, there are 2 perforators that originate from PURAP, namely, the medial and posterior perforators. Consequently, 2 flaps, one based on the medial perforator and one based on the posterior perforator, are possible. This flap is designed on the medial aspect of the posterior upper arm, immediately above the posterior ulnar recurrent artery in 2 locations depending on whether the medial or posterior perforator arising from the posterior ulnar recurrent artery is to be used. As a result, 2 flaps are designed before surgery, both of which are located more laterally than the conventional posterior ulnar recurrent artery flap (medial upper arm flap), which is located between the 2 PURAP flap types (Fig 1b). In all 22 cases, both flaps were designed on the medial and posterior sides of the distal upper arm, respectively, and the flap that seemed more reliable was then selected intraoperatively (Fig 1b).

Depending on the size and shape of the recipient site, a flap was designed such that the donor site could be closed primarily. In our experience, the elevation of a flap with a maximum width of 6 cm leaves a donor site that can be closed primarily without any problems. The length of the flaps ranged from 7 to 15 cm, with an average of 10–12 cm. In all cases, flap dissection was performed on a tourniquet. In 18 patients older than 21 years, only a brachial plexus block was used.

Flap elevation was initiated from the medial margin to identify the ulnar nerve, the posterior ulnar recurrent artery, and its medial and posterior perforators in the septocutaneous components. At this time, we determined which of the 2 perforators was larger and thus most suitable as the main pedicle of the flap. The lateral border of the selected flap was then incised, and the flap was islanded completely. All cutaneous veins were dissected and ligated. After elevation of the flap, the donor site was closed primarily while a tourniquet was applied.

Case 1 (Fig 2)

An 8-year-old boy suffered an electrical burn accident, and the soft tissues on the middle part of his forearm, including the skin, had necrotized completely. Six months later, the wound was reconstructed by a PURAP flap that was designed on his upper arm. Both medial and posterior perforators were detected preoperatively by Doppler ultrasonography and identified intraoperatively. The 2 perforators were similar in terms of vascular condition. The medial perforator was selected as the vascular pedicle because a flap based on this perforator would leave a more easily closed donor site. The length of the vascular pedicle was 6 cm and the flap size was 7 × 3 cm. The donor site could be closed primarily. The flap survived completely.

Figure 2. The electrical burn wound was reconstructed by the PURAP flap. The medial perforator was selected for this flap. The length of the vascular pedicle was 6 cm, and the flap size was 7 × 3 cm. The donor site could be closed primarily. The flap survived completely. (a) Preoperative view; (b) flap elevation; (c) view immediately after the operation; and (d) view 1 year after the operation.

Case 2 (Fig 3)

An injury to the right forearm of a 23-year-old man was inflicted by a rotation machine in a factory. The wound on the middle part of the forearm became deeply infected and necrosis developed on the proximal part of the forearm. While the original wound could be closed secondarily by direct suturing, the proximal wound could not be covered by the surrounding skin. Thus, the wound had to be reconstructed by a PURAP flap 2 months after the injury was sustained. The 2 perforators resembled each other intraoperatively in terms of vascular condition. The medial perforator was selected because a flap based on this perforator would leave a more easily closed donor site. The length of the medial perforator was 6 cm and the flap size was 14 × 6 cm. The donor site could be closed primarily. The flap survived completely.

Figure 3. The right forearm became infected and had to be reconstructed by a PURAP flap. The medial perforator was selected for this flap. The length of the medial perforator was 6 cm. The flap size was 14 × 6 cm. The donor site could be closed primarily. The flap survived completely. (a) Preoperative view; (b) flap elevation and transfer; (c) view immediately after the operation; and (d, e) view 1 year after the operation.

Case 3 (Fig 4)

A 21-year-old man suffered an amputation injury to the right forearm during a car crash. The distal end of the wound was reconstructed by a PURAP flap 3 weeks after the injury was sustained. The posterior perforator was larger and longer (6 cm) than the medial perforator (4 cm). Consequently, we used the posterior perforator. The size of flap was 7 × 4 cm, and the donor site was closed primarily. Complete flap survival was achieved.

Figure 4. The right forearm suffered an amputation injury during a car crash and its distal end had to be reconstructed by a PURAP flap. The posterior perforator was larger and longer (6 cm) than the medial perforator (4 cm) and thus was used in this case. The size of the flap was 7 × 4 cm, and the donor site was closed primarily. Complete flap survival was achieved. (a) Preoperative view; (b) flap elevation and transfer; (c) view immediately after the operation; and (d–g) view 1 year after the operation.

Anatomy of the ulnar recurrent arteries and their perforators

The proximal large branches of the ulnar artery are the anterior and posterior ulnar recurrent arteries (Fig 1a). The anterior ulnar recurrent artery is also referred to as the epitrochlear artery.⁸ The anterior ulnar recurrent artery arises immediately below the elbow joint, runs upward between the Brachialis and Pronator teres, supplies twigs to those muscles, and, in front of the medial epicondyle, anastomoses with the superior and inferior ulnar collateral arteries.⁹ The posterior ulnar recurrent artery is much larger than the anterior ulnar recurrent artery and arises from the ulnar artery below it. It passes backward and medialward on the Flexor digitorum profundus, behind the Flexor digitorum sublimis, and ascends behind the medial epicondyle of the humerus. In the interval between this process and the olecranon, it lies beneath the Flexor carpi ulnaris, and ascending between the heads of that muscle (in relation to the ulnar nerve), it supplies the neighboring muscles and the elbow joint, and anastomoses with the superior and inferior ulnar collateral and the interosseous recurrent arteries.⁹ In our study, a perforator derived from the posterior ulnar recurrent artery was used for all 22 patients.

The recurrent arteries supply the medial aspect of the elbow (Fig 1b). Thomas et al¹ reported that an average of 2 ± 1 perforators could be found in the ulnar recurrent artery territory. The mean vessel diameter was 0.8 ± 0.2 mm and the superficial length was 35 ± 12 mm.¹ In our experience, we could harvest a maximum perforator pedicle length of 6 cm. All flaps in our 22 cases were vascular pedicled island flaps, but it may be possible to use these flaps as free flaps.

The average area¹ supplied by each perforator is 63 ± 20 cm² and the musculocutaneous/septocutaneous perforator ratio is 3:7.¹ Prantl et al⁷ reported that the largest perforator of the posterior ulnar recurrent artery is generally located 10 cm proximal to the medial epicondyle. This description is compatible with our observations.

Surgical indications for the PURAP flap

From a historical point of view, flaps based on the ulnar recurrent arteries include “recurrent flaps,”¹⁰ “medial upper arm fasciocutaneous flaps,”⁵ “ulnar recurrent fasciocutaneous⁴ or adipofascial⁶ flaps,” and “distal pedicled medial upper arm flaps.”⁷ Maruyama et al⁴ have reported elbow reconstruction, using an island fasciocutaneous flap based on the fasciocutaneous perforators of the ulnar recurrent vessels. Of the 10 cases that were reported, there was 1 case of sensory disturbance. This may reflect the proximity of the posterior ulnar recurrent artery to the ulnar nerve, and thus it is advisable that the ulnar nerve be identified before major dissection occurs. Maruyama et al have also reported adipofascial flaps that have been used to cover forearm wounds left after tumor resection.⁶ In addition, Bhattacharya et al⁵ have reported a free flap form of the distally based medial upper arm fasciocutaneous flap for use with palmar defects.

The flap described in this study is based on the posterior ulnar recurrent artery itself. During surgery, we select which of the 2 perforators seems more reliable (Fig 1b). We believe that these features of our PURAP flap mean it offers greater safety and flexibility and less donor-site morbidity. If much larger flaps are needed, it is possible to combine the 2 types of PURAP flap and harvest them using the posterior ulnar recurrent artery itself as the pedicle. In addition, this combined flap could be divided into 2 parts based on the medial and posterior perforators.

Indications for the use of the PURAP flap could also be upper limb defects. The proximal forearm, elbow, and the anterior aspect of the upper arm can be covered by a type of vascular pedicled island flap, while other regions on the upper limb could be reconstructed by a type of free flap. The PURAP flap is advantageous for upper limb reconstruction because of the color and texture match and the simplicity and speed of the operation (only a brachial plexus block is needed for ipsilateral reconstruction). That the donor site can be closed primarily is another significant benefit of this flap.