Insight into sensory recovery after face transplantation

Recovery of sensation after facial transplantation is similar to, or even better than, that achieved by conventional surgery to repair nerve injuries, reports a study in the May issue of Plastic and Reconstructive Surgery®, the official medical journal of the American Society of Plastic Surgeons (ASPS).

Surprisingly, recovery of the sense of feeling in the transplanted face is "improved and accelerated" even when the nerves responsible for sensation aren't reattached. "Face transplantation is the only clinical condition where, in the absence of sensory nerve repair, good functional outcome is achieved despite severe trauma causing soft tissue and sensory nerve damage," according to the new study, led by plastic surgeon Dr. Maria Z. Siemionow of the Cleveland Clinic. Dr. Siemionow lead the team that performed the first near-total face transplant procedure in the United States in 2008.

Surprising Results Lend Insight into Sensory Recovery after Face Transplant
Researchers analyzed published data on recovery of sensation in four patients who underwent facial transplantation, and compared the results with sensory recovery after various standard nerve repair techniques.

Just one of the four face transplant recipients underwent direct repair of the sensory nerves. In the other three cases, it was impossible to reconnect the nerves because of technical difficulties or the severity of the patient's injuries.

The study reports all four patients regained sensation in the transplanted face, starting as early as two weeks after surgery. By the end of the first year, all had normal or near-normal sensory function. The extent of recovery was similar to that achieved with simple repair of injured sensory nerves in the face—and even better than that of grafting procedures where tissues are transferred to the face from different areas of the body without reconnecting the nerves.

How can it be that sensation recovered so well even though the sensory nerves weren't reattached? The nerves regenerated across the boundary between the face transplant and the patient's own tissues. Possibly because of the higher density of nerves in the facial area, sensation recovers more readily than in other parts of the body (such as the trunk or limbs). Facial transplantation appears to be unique in the ability to regain sensory function even without nerve reattachment.

Dr. Siemionow and co-authors identify factors that may promote or hinder sensory recovery after face transplant. Certain types of immune-suppressant drugs may aid recovery, while factors such as scarring may provide a barrier to nerve regeneration. Sensory re-education therapy may also help patients to regain feeling in the transplanted face.

The results suggest surprisingly good recovery of sensation after face transplantation. However, the lack of routinely collected data on recovery of sensory function makes it difficult to draw firm conclusions. Dr. Siemionow and co-authors recommend an "objective and simple" technique for sensory assessment for use in future studies, allowing easier comparison of the results between different centers.

Source: Plastic and Reconstructive Surgery