Microsurgery: Transplantation and Replantation by Harry J. Buncke, MD, et al.
  Table of Contents / Chapter 1:
Great Toe Transplantation
 
  Adequate venous pedicle length is seldom a problem unless the donor foot has a previous injury. An extra amount of venous pedicle can be taken and any excess can be used for vein grafts, if needed on the arterial side. Branches such as the proximal communicating branch in the first metatarsal space can be cut long in case they are needed for internal shunts, particularly with multiple toe transplants. If the dorsum of thehand has not been severely traumatized, the cephalic vein andthe dorsal venous arch are available for anastomosis to thevenous pedicle of the toe.

It is not unusual to have the entire superficial venous system destroyed by previous injury such as extensive deep bums. In this instance, a vena comitans with the radial artery must be used to drain the venous system of the toe. The recipient tendons in the hand are usually available unless the initial thumb trauma involved an avulsive injury with loss of the long flexor or extensor tendons. In such situations, tendon transfers using the index proprius on the extensor side or the palmaris longus or flexor carpi radialis on the flexor side should be considered rather than suturing to scarred shortened tendons and muscles. In most instances, the tendons can be located either at the amputation stump or, more proximally, above the wrist. Tendon repairs should be performed away from the level of transplantation to reduce secondary scarring. It follows that the long flexor of the toes should be cut well back in the sole of the foot so that it can be drawn out at the wrist proximal to the flexion crease. Exposure of the long flexor is most easily accomplished through an incision along the medical side of the instep, where the long flexor can be found deep to the abductor hallucis muscle. If an exceedingly long length of flexor tendon is needed, it can be transected at the ankle level behind the medial malleolus, where it is the most deeply located posterior structure behind the neurovascular bundle. The flexor hallucis longus and the common flexors to the other toes are anterior to the neurovascular bundle. Extraction of the tendon may be complicated if connections are present between the flexor hallucis and the long flexors to the toes. A tendon stripper may have to be used to separate these connections.

 

Recipient nerves in the hand are usually not a problem. The neuromas of the digital nerves and the dorsal radial nerves can usually be found in the scar at the level of amputation. If these have been avulsed more proximally, exposure of the median nerve in the forearm may be necessary to locate the proximal neuromas. If this is not possible, nerve transfers from the digital nerves from the ulnar side of the ring or long fingers may occasionally be undertaken, but the donor deficit must be carefully considered. A more functional sensation can probably be achieved by anastomosing the digital nerves of the transplanted toe to the dorsal radial sensory nerves, if the thumb palmar digital nerves are not present.

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