New Avenues of Vascularized Composite Allotransplantation and their Potential Risks and Benefits
Restorative transplantation holds the promise to replace virtually any body part that is needed, and has also been attempted for penis,2–5 uterus,6 and larynx7,8 in the past. Each transplanted unit can be further tailored and customized for each patient to include all tissues that are needed. Following this approach, the field has transitioned from partial to complex full face transplants, and others. Replacement of larger tissue units may often be technically easier, but irreversible rejection more devastating. This concept was elegantly employed in the featured article by Grajek et al, wherein the authors report on the first complex allotransplantation of composite neck tissues. The recipient was a young patient left with a devastating defect after resection of an advanced squamous cell larynx cancer and with unsatisfying results after conventional reconstructive procedures. At the time of transplant, the patient was already under life-long immunosuppression secondary to having received a kidney transplant.
Remarkably, two years after the transplantation, the patient has fully regained swallowing and breathing and has adequate function of endocrine glands (thyroid, parathyroid) as confirmed by laboratory values within normal ranges. Satisfactory movement of the vocal cords, perfect esthetic outcomes and significantly improving phonation and communication are demonstrated as well.
We commend the colleagues from Poland for performing the first complex allotransplantation of neck tissues and organs as an innovative reconstructive option. It constitutes a great example of the continuously evolving field of VCA and its novel applications. Although encouraging and promising, there are some points that we would like to raise.
As many of the pioneer VCA patients in the past, the presented patient is quite unique. He had already been on immunosuppression, thus diminishing the ethical dilemma of non-lifesaving tissue transplantation. He had also had an extensive functional defect that without a doubt impeded his quality of life.
Just like with other “firsts,” there will be challenges. Diagnosis of acute rejection in VCAs is a vexing problem as both clinical and pathological changes of skin rejection may be nonspecific.9,10 Moreover, in the case of complex tissue allotransplantation, and specifically in the case of neck tissue allotransplantation, we should keep in mind that rejection might not only present at the surface of the skin level. Deeper structures (esophagus, trachea, larynx, endocrine tissues) are more difficult to monitor, as they are less accessible and should periodically be assessed for rejection through endoscopy and appropriate function tests.
Although in this type of transplant, endocrine function deterioration may herald a rejection problem, by the time it is detectable it has the potential to have reached dangerous and life-threatening qualities, such as derangements in calcium levels, or thyroid hormone levels. Should there be irreversible rejection, a salvage plan could be challenging, and if not implemented in time, may lead to cerebral vascular disasters.