Successful Use of Delayed Reverse Sural Artery Flap in Single Vessel Legs with Severe Atherosclerotic Disease and Venous Insufficiency

Summary:

Distal lower extremity wounds are a challenging problem for reconstructive surgeons and can lead to major lower extremity amputations in patients with comorbid conditions. The reverse sural artery flap (RSAF) is a local flap supplied by perforators of the peroneal artery that can cover defects of the distal lower extremity, ankle, and foot. There has been concern over performing the RSAF in patients with venous insufficiency, peripheral artery disease, and diabetes, and in older patients due to the increased risk of flap necrosis. In patients who are not microsurgical candidates, the RSAF may be the final option for reconstruction before undergoing major lower extremity amputation. We describe our experience with two patients with significant comorbidities and single vessel runoff from the peroneal artery due to atherosclerotic disease who successfully underwent RSAF reconstruction for distal lower extremity wounds.

Distal lower extremity defects in the setting of peripheral atherosclerotic disease (PAD) and venous insufficiency (VI) remain a challenge for reconstructive surgeons, as local flap options for complex wounds in the distal third of the leg and ankle are limited. Since its original description by Masquelet,¹ the reverse sural artery flap (RSAF) has become a popular option for reconstruction of defects involving the distal lower extremity, ankle, and foot. The RSAF receives dominant arterial supply from peroneal artery perforators and venous drainage from the lesser saphenous vein.² Compared with microsurgical reconstruction, the RSAF has a shorter operative duration and does not require specialized microsurgical technique.³

PAD, VI, diabetes, and old age have been considered relative contraindications to RSAF reconstruction due to increased risk of flap loss.^2,4,5 In older and multimorbid patients, complication rates up to 50% have been reported.⁶ Although RSAF reconstruction in a traumatic single vessel leg has been reported, studies exploring the use of the RSAF in single vessel anatomy due to severe PAD are lacking.⁷ In patients with distal lower extremity wounds who are not microsurgical candidates, the RSAF could be the singular option for limb preservation.⁴

We present two high-risk patients with single vessel runoff from the peroneal artery in which successful limb preservation was performed using the delayed RSAF flap.

CASE 1

A 91-year-old woman with history of severe VI, PAD, hypertension, and lower extremity edema presented with a 9 × 10 cm wound of the left anterior ankle with exposure of the tibialis anterior tendon, stemming from radiation treatment of a squamous cell carcinoma 1 year prior (Fig. 1). Angiography demonstrated chronic total occlusion of the anterior and posterior tibial arteries resistant to angioplasty, with single vessel peroneal runoff to the foot (Fig. 2). Given her age and comorbidities, she was not a candidate for free tissue transfer. She refused amputation. Because the peroneal artery was the sole supply for potential local flap reconstruction, a delayed RSAF flap was planned. Flap delay was performed by completely islanding the flap and elevating it on a pedicle 3–4 cm in width to the distal pivot point, and then replacing it in its native position. Rotation and inset were performed 2 weeks following delay, and the donor site was skin grafted. Severe venous hypertension was noted, with high-pressure bleeding from subcutaneous veins within the wound. Postoperatively, the flap exhibited venous congestion that resolved in 3 weeks. She underwent hyperbaric oxygen therapy throughout the perioperative period, given the prior radiation. Compression wrapping was used at 3 weeks postoperatively for the severe VI. Due to exacerbation of her existing medical conditions, her subsequent follow-up was at 9 months after reconstruction. Examination demonstrated a fully healed flap with complete coverage of the wound and appropriate contour (Figs. 3, 4).

Fig. 1.

Left anterior ankle wound with exposed tibialis anterior tendon and history of radiation treatment for squamous cell carcinoma 1 year prior in a 91-year-old patient with severe peripheral vascular disease and VI.

Fig. 2.

Left lower extremity angiography demonstrating chronic total occlusion of the anterior and posterior tibial arteries with single vessel peroneal runoff to the foot.

Fig. 3.

Fully healed flap with smooth contour 9 months after RSAF reconstruction, anterior view.

Fig. 4.

Fully healed flap donor site 9 months after reconstruction, posterior view.

CASE 2

A 77-year-old man with poorly controlled type 2 diabetes, hypertension, PAD, and VI presented with a 5 × 5 cm left lateral malleolar wound and underlying osteomyelitis that had been present for 4 years. Angiography revealed single vessel runoff from the peroneal artery despite angioplasty of the anterior tibial artery. The wound had not improved despite serial surgical and nonsurgical debridements. Given his multiple comorbidities, he was not a candidate for free tissue transfer. RSAF reconstruction was undertaken in identical fashion to case 1. At the time of discharge on postoperative day 10, his flap was fully viable with no evidence of necrosis or venous congestion. Two months after surgery, the flap was fully healed with stable coverage of the ankle defect.

DISCUSSION

Severe PAD with single vessel perfusion to the foot and VI makes pedicled and free flap reconstruction of the distal lower extremity challenging. In the case of advanced PAD with single vessel perfusion via the peroneal artery, the RSAF may represent the only local flap option for complex wounds when microsurgery is contraindicated or unavailable. Although several reports have mentioned higher complication rates in the setting of diabetes, PAD, and VI, no reports have described successful use of the RSAF in elderly patients with VI and chronic PAD advanced to the point of single vessel perfusion.

Successful use of the RSAF in a single vessel leg due to the traumatic occlusion of the anterior and posterior tibial arteries has been described.⁷ However, single vessel anatomy due to PAD rather than trauma is more nuanced, as the remaining vasculature is also severely affected by atherosclerotic disease. Healing of any incision in such a situation, let alone flaps, is at risk of compromise.

Parrett et al⁸ described 58 RSAF flaps with a 50% postoperative complication rate. Patients with a history of smoking, diabetes, or PAD had a complication rate of 80.8%, which was significantly higher than that of noncomorbid patients. Baumeister et al⁴ referred to the presence of VI, PAD, and diabetes as the “unhappy triad.” They found that two of three flaps are prone to necrosis when one risk factor is present, and 100% necrosis rate with all three factors present. Subsequent studies show conflicting results, describing higher complication rates in the setting of PAD, VI, and diabetes without reaching statistical significance.⁶ Due to conflicting significance of these risk factors in the literature, many surgeons may not consider the RSAF flap as an option for reconstruction in comorbid patients.

Patients with comorbid conditions should be appropriately counseled on the risks of postoperative complications and flap loss after RSAF. However, given additional morbidity attributed to major lower extremity amputation, the RSAF should be considered an option for limb salvage despite these comorbidities.⁹ In the two cases presented, the RSAF was successfully utilized for limb salvage despite numerous detrimental factors including chronic PAD with a single vessel leg, severe VI, radiation, and advanced age. Although the utility of flap delay for the RSAF has been debated in the literature, high-risk cases in particular may benefit from delay. Although previously synonymous with flap necrosis, the “unhappy triad” of VI, PAD, and diabetes should not preclude consideration of the RSAF in cases where it is the only option for limb salvage.