Can The Medial Plantar Artery Flap Be Beneficial For Diabetic Heel Ulcers?
Contraindications or precautions to performing this procedure include: small ulcerations that one can treat with simpler methods; vascular insufficiency; complicated renal or cardiac issues; non-ambulatory status; severe infection; an unsalvageable foot; trauma to the instep; and a non-adherent patient.
A Comprehensive Guide To Performing The Procedure
The surgeon can perform the procedure with the patient in the supine or prone position. Measure the defect and mark the flap on the non-weightbearing instep area with the maximum length parallel to the medial plantar artery. Intraoperative Doppler assessment can assist with incision placement. Mark the course of the medial plantar artery.
Plan the length and width of the desired flap in reverse using a cloth pattern over the defect and transposing it to lie over the marked artery. In many instances, it is difficult to include the vessels exactly in the center. Usually, the pattern lies toward the medial margin of the flap. The exposure is with an incision through the skin, subcutaneous tissue and the plantar fascia. The flap does not include the plantar lateral aspect of the foot. Keep the distal extent of the flap 2 cm behind the metatarsal heads.
Next, it is important to visualize the common plantar artery and the bifurcation of the medial and lateral plantar arteries. The medial plantar neurovascular bundle is located in between the abductor hallucis (ADH) muscle and the flexor digitorum brevis (FDB) muscle.4 Retract the abductor hallucis muscle toward the first metatarsal medially or transect the muscle to permit visualization of the medial plantar artery.
The surgeon will encounter the neurovascular bundle toward the proximal aspect of the septum. Then identify the division of the common plantar artery and elevate the vascular pedicle with overlying tissue. Incise the distal margin and cut the slips of the plantar aponeurosis. Take care not to injure the common nerve trunk to the toes. Continue the dissection until you emerge from the tarsal tunnel. Proximal dissection of the neurovascular bundle requires the division of the abductor hallucis muscle and vascular branches to the muscle. The use of a bipolar electrocautery is helpful.
One should preserve perivascular fat surrounding the pedicle. The typical length of the pedicle is about 4 to 5 cm and the arc of rotation is at the sustentaculum tali. If additional length is required, then release the abductor hallucis muscle and the flexor retinaculum. Also, dividing the lateral plantar vessels can also increase the length of the flap although this is not advised since the lateral plantar artery is the dominant supply of the foot.
One should consider other flap options such as the reverse sural artery flap when needing to cover the Achilles tendon. Incise the lateral margin and the lateral portion of the plantar aponeurosis. The dissection proceeds to the flexor digitorum brevis muscle to include the septum between the flexor digitorum brevis and the abductor hallucis. Divide the proximal attachment of the plantar aponeurosis. One would not typically include muscle since it does not have a significant myocutaneous supply.
After mobilizing the flap, extend an incision to the ulcer or tunnel beneath the skin. A tunnel is not required or preferred since this places tension on the pedicle. Rotate the flap 90 to 180 degrees. Once the flap is transposed into the defect, secure it with a single layer closure and utilize a suction drain. Close the donor defect with a split thickness skin graft (STSG). The split thickness skin graft will only take if you preserve the peritenon over the fascia. In some cases, one may excise the fascia and place the split thickness skin graft over the underlying intrinsic muscles. Surgeons can also use the split thickness skin graft over the pedicle to prevent compression from primary skin closure.