The versatile reverse flow sural artery neurocutaneous flap: a case series and review of literature

Abstract

Background: Reverse flow sural neurocutaneous flap has been utilized more frequently during the past decade to cover vital structures around the foot and ankle area. The potential advantages are the relatively constant blood supply, ease of elevation and preservation of major vascular trunks in the leg. The potential disadvantages remain venous congestion, donor site morbidity and lack of sensation.

Methods: This descriptive case series was conducted at Queen Mary Hospital, Hong Kong, from 1997 to 2003. Ten patients having undergone reverse flow sural neurocutaneous flap were identified through medical records. There were six females (60%) and four males (40%), with an average age of 59.8 years. The defects occurred as a result of trauma in five patients (50%), diabetic ulcers in four (40%) and decubitus ulcer in one (10%) paraplegic patient. The defect site included non weight bearing heel in four (40%), tendo Achilles in two (20%), distal tibia in two (20%), lateral malleolus in one (10%) and medial aspect of the midfoot in one patient (10%). The maximum flap size harvested was 14 x 6 cm. Preoperative doppler evaluation was performed in all patients to identify perforators and modified plaster of paris boot was used in the post operative period. A detailed questionnaire was developed addressing variables of interest.

Results: There was no flap failure. Venous congestion was encountered in one case. The donor site was relatively unsightly but acceptable to all patients. The loss of sensation in the sural nerve distribution was transient in all patients.

Conclusion: Reverse sural artery flap remains to be the workhorse flap to resurface the soft tissue defects of the foot and ankle. Anastomosis of the sural nerve to the digital plantar nerve can potentially solve the issue of lack of sensation in the flap especially when used for weight bearing heel.

Figure 1

POP boot. A 'modified plaster of paris boot' is designed to make sure that there is no pressure on the flap pedicle even if the patient is lying supine in bed. One can appreciate the built in walls of the boot on the posterior aspect, with the flap visible from within them.

Figure 2

A – CR. 1, flap elevation. 72 years lady was suffering from ulcer on dorso medial aspect of midfoot as a result of long standing diabetes mellitus leading to peripheral neuropathy. Sural artery flap was utilized; its elevation is seen from the proximal aspect of the posterior calf area, modified by the inclusion of midline gastrocnemius muscle cuff around the sural pedicle. B – CR. 1, Post op. Adequate coverage seen in the immediate post operative period. The pedicle was kept wide and not passed through subcutaneous tunnel. It required split thickness skin grafting for coverage. The flap developed mild distal congestion which resolved spontaneously with foot elevation without any problems.

Figure 3

A – CR. 2, pre op. 19 years lady suffered road traffic accident resulting in skin necrosis of the posterior aspect of the heel. B – CR. 2, post debrima. After debridement, area of skin loss can be seen, optimal for flap coverage.

Figure 4

A – CR. 2, flap marking. The sural artery neurocutaneous flap is marked on the skin with dimensions, 14 × 6 cm. B – CR. 2 – flap rotation. The reverse flow sural artery neurocutaneous flap is being rotaed through an arc 180 degrees on its pedicle. C – CR. 2 – outcome. The flap inset into the defect after rotation with excellent coverage.