Technical, Immunological, and Ethical Similarities and Differences Between Vascularized Composite Allotransplantation and Solid Organ Transplantation in Current Practice

Vascularized composite allotransplantation versus solid organ transplantation: innate-adaptive immune interphase

PURPOSE OF REVIEW

Vascularized composite allotransplantation (VCA), a life-enhancing treatment for patients with complex tissue defects, trauma or illness, expounds upon the foundation of solid organ transplantation (SOT), the gold standard in end-stage organ failure. As innate and adaptive immunity remain the fundamental concern, this review highlights divergent immunobiology responses in VCA and SOT recipients.

RECENT FINDINGS

Host innate immune activation drives peritransplant tissue ischemia-reperfusion injury (IRI). Despite the direct relationship between ischemia-reperfusion (IR)-stress and cell-mediated acute rejection, the mechanism of how IRI may affect VCA loss needs investigation. With skin grafts being highly immunogenic, the incidence of cell-mediated rejection is higher in VCA than SOT; whereas ex-vivo perfusion may exert cytoprotection against IRI in VCA and SOT. New treatment concepts, such as topical immunosuppression or cell-based tolerogenic therapies, may avoid systemic immunosuppression in VCA. Although antibody-mediated rejection is relatively rare in VCA and its disease seems to be distinct from that in SOT, little is known as to whether and how IRI may influence humoral immune rejection cascade in VCA or SOT.

SUMMARY

Further understanding of the innate-adaptive immune crosstalk should contribute to much needed development of novel therapies to improve VCA outcomes, based on strategies established in SOT.

Analysis of factors involved in brain-death donor processing for face transplantation in Korea: How much time is available from brain death to transplantation?

Background

Face transplantation has naturally evolved from reconstructive procedures. However, few institutions perform face transplantations, because it is time-consuming and it is necessary to justify non-vital organ transplantation. We investigated the process of organ donation from brain-dead patients and the possibility of incorporating face transplantation into the donation process.

Methods

A retrospective review was performed of 1,074 brain-dead patients from January 2015 to December 2016 in Korea. We analyzed the time intervals from admission to brain death decisions (first, second, and final), the causes of brain death, and the state of the transplanted organs.

Results

The patient base (n=1,074) was composed of 747 males and 327 females. The average period between admission to the first brain death decision was 8.5 days (±15.3). The average time intervals between the first brain death decision and medical confirmation using electroencephalography and between the first brain death decision and the final determination of brain death were 16 hours 58 minutes (±14 hours 50 minutes) and 22 hours 57 minutes (±16 hours 16 minutes), respectively. The most common cause of brain death was cerebral hemorrhage/stroke (42.3%), followed by hypoxia (30.1%), and head trauma (25.2%).

Conclusions

When face transplantation is performed, the transplantation team has 22 hours 57 minutes on average to prepare after the first brain death decision. The cause of brain death was head trauma in approximately one-fourth of cases. Although head trauma does not always imply facial trauma, surgeons should be aware that the facial tissue may be compromised in such cases.