Hand allotransplantation

Amputation of an extremity may result from trauma, surgery carried out to control pain or a disease process in the affected limb. The usual way to restore some hand function after amputation of the arm is to fit a prosthesis. It may be possible to reimplant the hand after traumatic amputation.

Hand allotransplantation aims to provide a hand that looks more natural than a mechanical prosthesis, and which restores some sensation and movement.

Before the procedure, psychological assessment is required of a patient's motivation and likely compliance with postoperative rehabilitation and immunosuppressive medication.

A cadaveric limb removed surgically from a donor, below the elbow, is used for the transplant. Its suitability for the recipient is assessed by basic matching for sex, size, appearance, and sometimes genetic matching.

Hand allotransplantation is carried out with the patient under general anaesthesia, which may be supplemented by a regional nerve block. A tourniquet may be used for haemostasis. The radius and ulna from the donor limb are fixed to those of the recipient using intramedullary pins or plates. Arteries and veins are anastomosed using standard techniques. The major nerves are repaired and others are joined if possible. Tendons are repaired either individually or in groups.

Following the procedure the limb may be immobilised in a plaster splint for a number of weeks. The patient should undergo intensive rehabilitation, including physiotherapy, occupational therapy and possibly electrostimulation for best restoration of function. Long-term immunosuppression is needed to reduce the possibility of rejection.

A case series of 30 patients (38 hands) reported that more than 70% of patients had improved quality of life following hand allotransplantation and that 'most' patients returned to work (absolute figures and follow-up not stated).

The case series of 30 patients reported 100% (37 of 37) graft survival at 1- and 2-year follow-up; however, graft failure occurred later in 10 hands because of non-compliance with the immunosuppression regimen (timing not stated). Acute rejection episodes occurred in 85% of patients within the first year; all episodes were reversed when promptly reported and treated.

A case report of 1 patient (1 hand) described re-amputation of the transplanted hand after 12 hours because of thrombosis of the radial artery distal to the entry site of a cannula in the donor arm. A case report of 5 patients (5 hands) reported re-amputation of 1 hand at 9-month follow-up because of intractable ischaemia.

The case series of 30 patients reported that 90% of patients achieved tactile sensibility and 72% developed discriminative sensibility at follow-ups ranging from 6 months to 9 years (absolute figures not stated).

The case report of 5 patients reported an 'excellent' functional outcome in 1 patient, intrinsic muscle recovery in another patient, good function but no intrinsic muscle recovery in 2 patients, and good early progress in the remaining patient (2-month to 10‑year follow-up).

The specialist advisers listed key efficacy outcomes as hand function, rejection-free survival of the transplant and patient satisfaction.

Arterial thrombosis and venous thrombosis each occurred in 1 of 37 procedures in the case series of 30 patients; both patients required additional surgery (timing of events not stated).

Multiple arteriovenous fistulae requiring additional surgery were reported in 1 of 37 procedures in the case series of 30 patients (timing of events not stated).

Indolent (marginal zone) lymphoma was reported in 1 patient in the case report of 5 patients (follow-up ranged from 2 months to 10 years).

The case series of 30 patients reported opportunistic infections in 65% of the 29 patients receiving immunosuppression at follow-ups ranging from 6 months to 9 years. These included cytomegalovirus reactivation, cutaneous mycosis, herpes virus and Clostridium difficile. Most infections resolved with treatment.

The case series of 30 patients reported that metabolic complications related to immunosuppression therapy occurred in 52% (15 of 29) of patients at follow-ups ranging from 6 months to 9 years.

The specialist advisers listed adverse events reported in the literature as acute and chronic rejection (when immunosuppression was stopped), poor neurological function of the hand and immunosuppression-induced diabetes. They considered theoretical adverse events to include malignant changes or tumour development and graft–versus–host disease.