Procurement strategies for combined multiorgan and composite tissues for transplantation. Curr Opin Organ Transplant. 2015;20:121-126. [PMID: 25856175 DOI: 10.1097/mot.0000000000000172]

Composite tissue xenopreservation: Preliminary results of staged VCA in rat to mouse model

BACKGROUND

The time between procurement and transplantation of composite tissues, especially regarding the limited donor pool, is a challenge effecting the outcomes of the transplantation. Current preservation techniques mainly include either cold preservation with a solution or machine perfusion using blood or certain oxygen-carrying solutions. However, none enables preservation beyond 24 h. Increasing this time to several days will provide better usage of the donor pool, safer transplantation of VCA with significant muscle content, and gives time to stabilize a patient before long surgical procedures. Herein, we described a novel strategy of xenopreservation (preservation via xenotransplantation) to preserve composite tissues for 7 days, followed by staged transplantation.

MATERIALS AND METHODS

We used two concordant species, female Sprague Dawley rats (n = 10) and female CF-1 mice (n = 10) in this study. Four of pair of animals are used for anatomical study. The groin flap of the rat was used as a xenograft and xenotransplanted to the neck area of the carrier mouse. Cyclosporine (CsA) was administered used as immunosuppressant. After 7 days of preservation on the mouse neck, xenotransplanted groin flap (called xenopreserved flap) was re-harvested, skin and vessels samples were collected for histopathological evaluation, and the xenopreserved flap was transplanted to the donor rat's opposite groin area. Anastomoses were performed between the flap's pedicle and the femoral vessels. Clinical observation regarding inflammation and tissue perfusion of the xenopreserved flap was monitored daily. Fifteen days after the second surgical procedure, the rats were euthanized, and skin and vessel samples were collected. Histologic evaluation, including inflammatory cell numbers, was performed. Wilcoxon test was used to compare the changes in inflammation severity and p < .05 was set for statistical significance.

RESULTS

All xenopreserved groin flaps except one survived. Mean lymphocyte count before the second operation (at the end of the xenopreservation procedure) was 20,22 ± 0.44 and reduced to 13,14 ± 0.47 at the end of 15 days, and the difference was statistically significant (p < .05).

CONCLUSION

This proof-of-concept study with preliminary results showed that xenotransplantation might be a novel strategy for preservation of VCA for a certain period of time. However, additional translational studies are needed to modulate the tissue changes following xenopreservation.

Technique for Rapid Hand Transplant Donor Procurement Through the Elbow

Background: Hand and distal forearm allotransplantation has advanced over the last 20 years from experimental to a viable treatment option for bilateral upper extremity amputation. Despite widespread growth of this field, there are few technical reports that elaborate the details of donor arm procurement. This article details a technique for rapid donor procurement through the elbow for mid to distal forearm-level hand allograft procurement. Methods: Nine arm procurements were performed on deceased tissue-only donors provided by the local organ procurement organization, including two bilateral and five unilateral cases. Technique highlights include using a fishmouth incision through the lateral and medical epicondyles, identification of the neurovascular structures, and disarticulating the elbow joint. Results: Procuring through the elbow provides straightforward anatomy, bypasses the need to cut through bone, and allows tissue allotransplantation teams to achieve procurement, flushing, and packaging within 20 minutes. Conclusions: Procurement through the elbow is a simple procedure that streamlines the process for multi-organ donors by minimizing the time needed for hand allograft procurement. Team coordination and surgical rehearsals are essential for successful hand and upper extremity procurement and allotransplantation.

Maximizing donors' gifts: A comparison of actual and expected solid organ yield among VCA donors

Vascularized Composite Allograft (VCA) transplantation provides life-changing transplants, but VCA adds complexity to the donation process and timing, possibly impeding solid organ donation. Expanding upon descriptive analyses, this study examines risk-adjusted predictions versus the observed number of organs donated by VCA donors. Our cohort included VCA donors in the United States during January 1, 2008-December 31, 2017 (n = 51), using OPTN Deceased Donor Registration Form data and the Scientific Registry of Transplant Recipients (SRTR) donor yield models to calculate observed-to-expected (O:E) yield ratios. Almost all VCA donors' livers (48/51; 94.1%) and kidneys (92/102; 90.2%) were transplanted, with fewer hearts (28/51; 54.9%), lungs (46/102; 45.1%), pancreata (15/51; 29.4%), and intestines (3/51; 5.9%) transplanted. O:E ratios for overall organ yield were slightly greater than expected for VCA donors (1.10; 95% CI: 1.02-1.17). Liver (1.17: 1.08-1.27) and lung yields (1.38: 1.07-1.68) were both greater than expected, while kidney, heart, and pancreas yields were similar to expected. Across VCA types, bilateral upper limb and abdominal wall donors had better-than-expected yields while uterus, face, and unilateral upper limb donors all had similar-to-expected yields. Solid organ yield among VCA donors was as good or better than predicted, suggesting that VCA donation does not compromise recovery and transplantation of lifesaving organs.

Have We Achieved Optimal Skin Color Matching in Partial Facial Transplantation? A Survey Study of the General Public and Medical Professionals

BACKGROUND

Skin color matching is an essential factor in achieving optimal aesthetic outcome in partial facial transplantation. However, there is no published literature evaluating the success of color matching to date. Furthermore, a medical professional's perception of an optimal color match may not necessarily translate to that of the general public. The purpose of our study was to evaluate skin color matching between the donor allograft and recipient native tissue in partial facial transplantations to determine the level of success perceived by the general public and medical professionals.

METHODS

Published photographs of partial face transplant recipients were used to create a survey where recipient native and donor allograft skin samples were juxtaposed. Thirty-three members of the general public and 30 medical professionals were asked to rate skin color match on a scale from "excellent match" to "not a match."

RESULTS

Overall, 47% of given ratings were positive, indicating an "excellent" or "good match," and 53% of ratings were negative, indicating a "poor match" or "lack of match" between the skin sample pairings shown. Of the 19 partial face transplant patients who were rated, 9 patients received >50% positive ratings, and 10 patients received <50% positive ratings. Medical professionals consistently gave more positive ratings, with statistically significant differences in 7 of the 19 rated patients (P < 0.05).

CONCLUSION

The results suggest that there is need for improvement in color matching in partial facial transplantation, and that the general public is more critical of skin color matching compared to medical professionals.

First two bilateral hand transplantations in India (Part 2): Technical details

Introduction:

This article deals with two patients who underwent bilateral hand transplantation following amputation of both upper limbs at the distal third of the foream.

Materials and Methods:

The first patient had a history of loss of hands in a train accident , with possiblity of a run over element during the injury. The second patient lost his both hands in a mine blast. The preoperative work up included detailed clinical and psychological evaluation. The donor retrieval was similar in both the cases and the donors were housed in our own instittution. The donor preparation, recipient preparation and the transplant procedure was similar except for the need of primary tendon transfers in the left hand of the first patient.

Results:

The first patient needed a free flap transfer to cover compromised skin flap on the left hand on the second day. The second hand transplant was uneventful. Both the recipients are now back to their normal daily routines.

Conclusions:

Hand transplantation is a potentially life altering procedure, but to optimise the results, it is imperative that there is a meticulous planning and diligent execution with utmost importance to the detail coupled with a synchronised team effort.

Localized delivery of immunosuppressive regulatory T cells to peripheral nerve allografts promotes regeneration of branched segmental defects

Segmental injuries to peripheral nerves (PNs) too often result in lifelong disability or pain syndromes due to a lack of restorative treatment options. For injuries beyond a critical size, a bridging device must be inserted to direct regeneration. PN allografts from immunologically incompatible donors are highly effective bridging devices but are not a regular clinical option because of the expense and health risks of systemic immunosuppression (ISN). We have developed a method to deliver a single administration of ISN localized around a PN allograft that circumvents the risks of systemic ISN. Localized ISN was provided by regulatory T cells (Tregs), a potently immunosuppressive cell type, that was delivered around a PN allograft with a poly(ethylene glycol) norbornene (PEGNB) degradable hydrogel. Tregs are released from the hydrogel over 14 d, infiltrate the graft, suppress the host immune response and facilitate regeneration of the recipient rats equal to the autograft control. Furthermore, this method was effective in a segmental PN defect that included a branch point, for which there currently exist no treatment options. These results show that localized delivery of immunosuppressive cells for PN allografts is an effective new strategy for treating segmental PN defects that can also be used to regenerate complex nerve structures.

Abdominal Wall Transplant Surgery

The evolution and success of intestinal and multi-visceral transplantation over the past 20 years have raised the issue of difficult or even impossible abdominal closure, a topic rarely encountered in other fields of transplantation. Different techniques have been proposed to address this topic. The choice depends on the transplant team's expertise and/or the availability of a plastic surgery service. Abdominal wall transplant is a type of composite tissue allograft that can be utilized to reconstitute the abdominal domains of patients who undergo intestinal transplant, and the results are encouraging. It is an effective option to achieve primary abdominal closure after intestinal transplant. In its full-thickness form, it may be useful for monitoring rejection or viability of visceral organs. Our aim is to review the role of abdominal wall transplant in achieving tension-free closure of the abdomen.

Role of “reduced-size” liver/bowel grafts in the “abdominal wall transplantation” era

The evolution of multi-visceral and isolated intestinal transplant techniques over the last 3 decades has highlighted the technical challenges related to the closure of the abdomen at the end of the procedure. Two key factors that contribute to this challenge include: (1) Volume/edema of donor graft; and (2) loss of abdominal domain in the recipient. Not being able to close the abdominal wall leads to a variety of complications and morbidity that range from complex ventral hernias to bowel perforation. At the end of the 90’s this challenge was overcome by graft reduction during the donor operation or bench table procedure (especially reducing liver and small intestine), as well as techniques to increase the volume of abdominal cavity by pre-operative expansion devices. Recent reports from a few groups have demonstrated the ability of transplanting a full-thickness, vascularized abdominal wall from the same donor. Thus, a spectrum of techniques have co-evolved with multi-visceral and intestinal transplantation, ranging from graft reduction to enlarging the volume of the abdominal cavity. None of these techniques are free from complications, however in large-volume centers the combinations of both (graft reduction and abdominal widening, sometimes used in the same patient) could decrease the adverse events related to recipient’s closure, allowing a faster recovery. The quest for a solution to this unique challenge has led to the proposal and implementation of innovative solutions to enlarge the abdominal cavity.

Face transplantation: Anesthetic challenges

Face transplantation is a complex vascular composite allotransplantation (VCA) surgery. It involves multiple types of tissue, such as bone, muscles, blood vessels, nerves to be transferred from the donor to the recipient as one unit. VCAs were added to the definition of organs covered by the Organ Procurement and Transplantation Network Final Rule and National Organ Transplant Act. Prior to harvest of the face from the donor, a tracheostomy is usually performed. The osteotomies and dissection of the midface bony skeleton may involve severe hemorrhagic blood loss often requiring transfusion of blood products. A silicon face mask created from the facial impression is used to reconstruct the face and preserve the donor’s dignity. The recipient airway management most commonly used is primary intubation of an existing tracheostoma with a flexometallic endotracheal tube. The recipient surgery usually averages to 19-20 h. Since the face is a very vascular organ, there is usually massive bleeding, both in the dissection phase as well as in the reperfusion phase. Prior to reperfusion, often, after one sided anastomosis of the graft, the contralateral side is allowed to bleed to get rid of the preservation solution and other additives. Intraoperative product replacement should be guided by laboratory values and point of care testing for coagulation and hemostasis. In face transplantation, bolus doses of pressors or pressor infusions have been used intraoperatively in several patients to manage hypotension. This article reviews the anesthetic considerations for management for face transplantation, and some of the perioperative challenges faced.