Harvest of Supraspinal Nerve Grafts
Anatomy of the Sural Nerve
The sural nerve consists of two parts: a medial sural cuteus nerve and lateral sural cuteus nerve.
This nerve arises from the tibial nerve just below the knee joint and runs downward between the gastronemius heads.
Located on the posterolateral side of the calf, the lateral sural cutaneous nerve arises from the common peroneal nerve.
A sensory cutaneus nerve (also known as short saphenous nerve), except for some unmyelinated autonomic fibers, emerges from the root of the S1 or S2 nerve.With a relatively easy technique, up to 25 cm of nerve graft can be harvested. The sural nerve innervates the lateral third of the leg, the side of the foot, the heel, and the side of the ankle. Sural nerve grafts are frequently used as cable grafts.
The graft is accessible to the distal and proximal segments of an intact motor or sensory nerve.
Peripheral neuropathy with compromised sensation to the lower extremity may also create a contraindication if the patient requires intact foot and lower leg sensation (for employment or sports reasons).
Graft Harvesting Technique
It is best to identify the sural nerve approximately 2 cm posterior to the lateral malleolus and approximately 2 to 3 cm proximal. In this area, it has not undergone significant branching.It is necessary to make a longitudinal incision in the region above, and if the saphenous vein is visible, the nerve or a branch of it is close by. The nerve can be traced proximally through this incision or through a series of “stairstep” transverse incisions.
After exposing the nerve proximally and distally, the nerve is cut proximally and distally and placed on moist gauze. The proximal incisions are determined by gently pulling the nerve at the distal incision.Sutures of 4-0 Vicryl are used to close the donor site, and staples or nylons are used to close the skin.