Composite tissue allotransplantation--a new era in plastic surgery?

Facial Transplantation: A Comprehensive Review of the Literature

PURPOSE

Composite tissue allotransplantation has become a clinical reality and a major breakthrough in reconstructive surgery. The current boundary of dispute on composite tissue allotransplantation is regarding the full-face transplantation. The aim of this article is to provide a comprehensive overview of how facial allotransplantation has been approached in the scientific literature.

MATERIAL AND METHODS

The selection of articles was conducted using PubMed at between January 2000 and September 2005. The search terms were "facial graft," "facial transplantation," and "facial allotransplant." The criteria of analysis were the category of articles and the presence of 6 items: 1) issues regarding the donor; 2) psychological impact on the recipient; 3) surgical risks; 4) immunologic risks; 5) socio-cultural aspects; and 6) expense.

RESULTS

Thirty-eight articles were included. The first article was published in 2002. Most articles over the last 4 years dealt with issues of medical ethics. The annual rate of basic research articles was relatively stable. Conversely, the rate of 'view points,' notably regarding ethics aspects, increased dramatically in 2004. The issues regarding the donor were found in 26% of the articles, the psychological echo on the recipient in 53% of the articles but in 81% of the medical ethics papers, the immunologic risks in 81% of the articles, the surgical risks in 66% of the articles, socio-cultural aspects in 34% of the articles, and expense problems in 5% of the articles.

CONCLUSION

Psychological, immunologic, and surgical risks are the problems addressed most in the literature. Cost, donor, social, and cultural aspects are least addressed. There is a lack of hard data in the literature regarding those problems.

From experimental rat hindlimb to clinical face composite tissue allotransplantation: Historical background and current status

The purpose of this article is to review the historical background and clinical status of composite tissue allotransplantation and to discuss the scientific evolution of clinical face transplantation. Composite tissue allotransplantation (CTA) rapidly progressed in the 1980s with the discovery of cyclosporine. Although the most success has been achieved with hand transplantation, others have made progress with allografts of trachea, peripheral nerve, flexor tendon apparatus, vascularized knee, larynx, abdominal wall, and most recently, partial face. The world's first partial face allotransplantation occurred in November 2005 in France. In April of 2006, there was a second performed in China. As of today, there are now multiple institutions with plans to attempt the world's first full facial/scalp transplant. Complete facial/scalp allotransplantation offers a viable alternative for unfortunate individuals suffering severe facial disfigurement and is a product of many decades of experimental research, beginning with rat hindlimb allografts.

Facial transplantation: adding to the reconstructive options after severe facial injury and disease

The ability to reconstruct complex facial injuries is still a considerable challenge despite the development of microsurgical techniques. The reconstructive options for conditions such as panfacial burns are severely limited. The result after multiple surgical procedures in this group is often poor in terms of function and cosmesis. Facial transplantation provides a potential solution, but opinion is currently divided about the extent to which the potential benefits to the quality of life can be justified when weighed against the technical, psychological and immunological risks. This paper reviews the current status of the debate and argues that a rigorous research strategy is the only logical basis for countering the ethical objections to a procedure that offers considerable benefits over existing reconstructive options.

Strategies for Tolerance Induction in Nonhuman Primates

Recent advances in the field of reconstructive surgery and immunology resulted in increased interest in composite tissue allograft (CTA) transplantation. Up to date, more than 50 CTA transplants have been reported in humans. A significant number of experimental studies on CTA transplants under different protocols of tolerance-inducting strategies have been reported in small-animal models. There is however, a limited number of CTA transplants performed in nonhuman primates. To reach the ultimate clinical success in CTA transplantation, more experimental studies on tolerance induction in nonhuman primates are needed to apply these immunomodulatory protocols to CTA transplants in humans. In this review, strategies for tolerance induction in the nonhuman primate model in solid organ and CTA transplants are presented in 3 major categories: chimerism induction, T-cell depletion, and costimulatory receptor blockade.

The Penile Flap in the Rat

Considering both its unique structural and functional properties, the reconstruction of the penis is still a challenging problem in reconstructive surgery. Reconstruction may be required in many situations, including traumas, congenital abnormalities, and female-to-male transsexual surgery. Currently, the only natural reconstructive method for the penis is its microvascular reattachment in amputation cases. In all other situations, and in nonreplantable amputations, there is no alternative but to reconstruct the penis using autologous tissues to create the most similar substitute, hoping for a possible allogeneic transplantation in the future. There are many unresolved issues and unanswered questions related to functional recovery after replantation of the penis. In this study, to overcome these drawbacks and to guide and show the feasibility of allogeneic transplantation of the penis in humans in the future, we describe a penile composite tissue flap based on the internal pudendal artery and its autotransplantation in an economical animal species. Fifty adult male Sprague-Dawley rats weighing 400 to 500 g were used. In 20 rats, the vascular anatomy of the male perineal region was determined by anatomic dissections. Based on this anatomic study, the penile composite flap was created based on the internal pudendal vessels. In 10 rats, the penile flap was raised as an island flap based on its vascular pedicle and replaced in situ. In 10 rats, distant flap transfer was accomplished to determine the feasibility of the flap being transferred as a free flap and to demonstrate the viability of the flap components in a heterotopic region. For this purpose, the flap was transferred to the groin region performing anastomoses between internal pudendal vessels and superficial epigastric vessels. In the control group (n=10), while the same surgical procedure was performed, the flap was transferred to the groin region but no anastomosis was performed. The procedure required approximately 3 to 4 hours of operating time in the free flap group. Five of the animals died in the early postoperative days, while all others survived. Direct observation and microangiography were used to assess the viability of the flaps. On the basis of direct observation on the seventh postoperative day, all the pedicled flaps survived completely. In the free-flap group, all but 1 of the vascularized flaps showed complete survival, whereas all the nonvascularized flaps completely necrosed. The authors conclude that the penile flap of the rat offers the following advantages: (1) the composite tissue flap is harvested from a small animal species, (2) the flap is an exact representation of the clinical original penile composition, (3) it can be transferred as a free flap without the need for an isogeneic animal, (4) the vascular pedicle is consistent and allows for microvascular anastomoses. The flap will provide a means for future physiological studies, especially for replantation cases. The feasible autotransplantation of the penile flap with successful results will also guide researchers towards the future allogeneic transfer of the penis in humans.

Allotransplantation of the Face: How Close Are We?

Reconstruction of patients with severe facial disfigurements due to burns, trauma, or cancer is a challenging task for plastic surgeons. Currently, available reconstructive options rarely result in satisfactory functional and aesthetic outcomes. In this article the authors present the rationale and experimental basis for the introduction of composite facial allograft transplantation in humans. They outline the ethical, social, and media-related issues in facial allograft transplantation.