Limb Salvage Surgery Following Resection of a Melanoma: Foot and Ankle Reconstruction Using Cutaneous Flaps

SLR - October 2015 - Adam Falivene

Podiatric Relevance: Melanoma is a malignant tumor of melanocytes, and although it is rare, 3 – 15 percent of melanomas affect the foot region and are associated with poor prognosis. Treatment is usually surgical excision with wide margins, which in the foot can pose a challenge to podiatric surgeons because of large soft tissue defects created by the treatment. Preservation of lower extremity function is of importance to podiatric surgeons following excisional treatment of melanomas of the foot, and this article describes three methods to do this with the use of cutaneous flaps and the effectiveness of each.

Methods: A retrospective review of 21 patients ( males, n=14, females, n=7) was carried out at the First Hospital of Jilin University during a 12-year period (1999-2010) in which each patient had a melanoma that was confined to the foot and ankle, and each skin lesion was post-operatively validated by biopsy. Ten of the patient’s underwent amputation (Group A) and 11 underwent salvage surgery with cutaneous flap soft tissue reconstruction (Group S). All Group S patients had the lesions widely excised with a margin of 3-5 cm with frozen tumor sections undergoing pathological testing to confirm clean margins and the size of the lesions. For Group S, one of three types of cutaneous flaps were employed following excision of the skin lesion based on the location of the soft tissue defect. Specifically, the three were: the medial plantar, the reverse sural artery neurocutaneous, and the lateral supramalleolar skin flaps. The patients were followed up for an additional six to 96 months postoperatively, with one patient lost to follow up at 25 months.

Results: Of the 21 patients, 14 were male and seven were female. Nine melanomas were on the left foot and 12 were on the right. The sites of the foot affected were as follows: sole of the foot (n=7), the heel (n=4), the dorsum of the foot (n=3), the toe (n=5) and the ankle (n=2). Three patients, one in Group S and two in Group A, exhibited ipsilateral inguinal lymph node metastases further confirmed by lymph node biopsy. Groups S and A showed similar oncologic outcomes: two patients in both groups showed recurrence and three patients in both groups died from the disease. In Group S, the size of the soft tissue defect after wide excision of the melanoma ranged between 4x4 cm to 8x11 cm. The reverse sural artery neurocutaneous flap was used in six cases, the medial plantar flap was used in four cases, and a lateral supramallelolar flap was used in one case. All cutaneous flaps survived transfer, providing defect coverage, and nine out of 11 were able ambulate with full weight bearing and no pain. Each patient who received the medial plantar and lateral supramalleolar flaps achieved good recovery of sensation, however three out of six patients who received the reverse sural artery neurocutaneous flap complained of loss of sensation on the lateral aspect of their foot. Complications associated with Group S salvage surgeries were observed in four patients: two patients developed a mild infection at the incision site, onepatient developed edema, one patient in addition to mild infection developed distal tip necrosis of the cutaneous flap. This patient experienced full recovery two weeks after debridement. One patient experienced a limitation of ankle plantar flexion with their heel unable to touch the ground when squatting following receiving the reverse sural artery neurocutaneous flap.

Conclusions: The authors were able to show in this retrospective study that limb salvage using cutaneous flaps is a viable option when treating melanoma with similar oncologic outcomes as outright amputation. The authors also showed in this subset of patients that those receiving cutaneous flaps were able to heal and completely cover the soft tissue defects created by excision of the melanoma. It is of interest to note that use of the reverse sural artery neurocutaneous flap was most associated with complications, namely edema, mild infection +/-  necrosis and limited ankle range of motion. Podiatric surgeons should be aware of this during surgical planning.