Perioperative risk factors for vascularized composite allotransplantation: A systematic review and proposal of identity-defining VCA

Social support criteria in vascularized composite allotransplantation versus solid organ transplantation: Should the same ethical considerations apply?

The field of vascularized composite allotransplantation (VCA) is evolving, with some procedures poised to transition from highly experimental research toward standard of care. At present, the use of social support as an eligibility criterion for VCA candidacy is at the discretion of individual VCA programs, allowing VCA teams to consider the unique needs of each potential candidate. Yet this flexibility also creates potential for bias during the evaluation process which may disproportionately impact members of certain communities where social configurations may not resemble the model considered "optimal." We examine the extent to which ethical considerations for social support in solid organ transplantation (SOT) may be applied to or adapted for VCA, and the ethically meaningful ways in which VCA procedures differ from SOT. We conclude that VCA programs must retain some flexibility in determining criteria for candidacy at present; however, considerations of equity will become more pressing as VCA procedures evolve toward standard of care, and further empirical evidence will be needed to demonstrate the association between social support and post-operative success. The field of VCA has an opportunity to proactively address considerations of equity and justice and incorporate fair, inclusive practices into this innovative area of transplantation.

Are We Prepared for the Inevitable? A Survey on Defining and Managing Failure in Face Transplantation

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Background:

Facial transplantation (FT) experience has grown but success in this innovative and complex field has yet to be defined. The purpose of this study is to determine attitudes regarding the failures in FT and the appropriate management of these failures.

Methods:

An anonymous, 20-question survey elicited opinions regarding FT failure management. This survey was administered to attendees of 2 FT-focused national meetings. Demographics included sex, age, and personal/institutional FT experience. Attitudes related to FT recipient education, definition of FT failure, and management of complications were gathered.

Results:

Eighty of 271 attendees completed the survey (29.5%). Respondents were predominantly male (81.3%) and 50 years of age or younger (80.5%). Thirty-eight percentage previously performed an FT and 53.8% were a part of an institution with a vascularized composite allotransplantation (VCA)-related Institutional Review Board (IRB). Respondents almost unanimously agreed it was “absolutely essential” to discuss possibility of FT failure (93.8%), mortality (91.1%), and treatment for chronic rejection (78.8%). However, uncertainty of failure rate existed, with 56.4% citing failure rate as unknown, 25.6% citing <25% and 18.0% citing >25%. 51.2% of those with direct FT experience lacked clear criteria for defining FT success or an institutional protocol for managing chronic rejection. 78.8% believed failed FT patients should be considered for retransplantation, but only about 25% cited functional concerns or esthetic dissatisfaction as appropriate indications.

Conclusion:

There is a lack of consensus regarding definition of FT failure and rates mortality amongst experts. Even institutions with FT experience lack protocols for managing chronic rejection. Expert consensus and institutional regulations surrounding these issues are warranted.

OPTN Vascularized Composite Allograft Waiting List: Current Status and Trends in the United States

BACKGROUND

Vascularized composite allograft (VCA) transplantation is a developing area in the field of transplantation.

METHODS

This study used Organ Procurement and Transplantation Network (OPTN) VCA waiting list and transplant data from July 3, 2014 through February 28, 2018, to characterize the OPTN VCA waiting list in terms of composition, removal patterns, waiting time, resulting transplants, and trends over time.

RESULTS

Between implementation of the OPTN VCA waiting list on July 3, 2014 and February 28, 2018, 54 candidates-53.7% were male, 79.6% were white, and 70.4% aged 18 to 44 years-were added to the OPTN VCA waiting list. Of these, 22 received deceased donor VCA transplants (6 bilateral upper limb, 4 unilateral upper limb, 5 craniofacial, 1 scalp, 1 abdominal wall, 1 penile, and 4 uterine), and 6 received living donor uterine transplants. Registrations increased in 2016 after uterine and penile transplants were introduced in the United States, resulting in a large shift in the composition of the VCA waiting list. Waiting times for VCA candidates vary greatly, with some VCA candidates receiving deceased donor transplants quickly and others waiting more than 3 years before transplantation.

CONCLUSIONS

The field of VCA transplantation and the composition of the OPTN VCA waiting list are evolving rapidly. Additional research is needed to understand these changes and investigate whether differences in need or differences in access have resulted in the variation seen on the VCA waiting list.

Vascularized composite allotransplantation in the United States: A descriptive analysis of the Organ Procurement and Transplantation Network Data

On July 3, 2014, the Organ Procurement and Transplantation Network/United Network for Organ Sharing was charged with the oversight of vascularized composite allograft (VCA) procurement and transplantation in the United States. As of December 31, 2017, 61 VCA programs at 27 centers were approved in the United States. Fifty candidates have been added to the waiting list at 15 centers. Twenty-eight VCA transplants have been performed at 14 programs (10 upper limb, 10 uterus, 5 craniofacial, 1 scalp, 1 abdominal wall, and 1 penile). Twenty-two VCAs were procured from 21 deceased donors, resulting in 109 non-VCA organs transplanted (15 hearts, 3 intestine, 40 kidney, 20 livers, 24 lungs, and 7 pancreata). Six uterus transplants were performed from living donors. Fourteen candidates were still waiting at 9 centers on December 31, 2017. Two of the 10 uterus recipients had live births and 3 still had viable grafts. Seventeen of 18 nonuterus recipients had functioning grafts. At present, VCA is an emerging field with a small number of patients transplanted. Data on posttransplant survival and functional outcomes continue to be collected to further the understanding of this complex and evolving field. Further systematic data are important for policy refinement and assurance of patient safety.

VCA Deceased Donors in the United States

BACKGROUND

Vascularized composite allograft (VCA) transplants include diverse organ types and are made possible primarily by deceased donors.

METHODS

We used Organ Procurement and Transplantation Network data to characterize VCA deceased donors (n = 66 of 70) in the United States from 1998 to 2017 and compare their characteristics with those of kidney donors in 2017.

RESULTS

Through December 31, 2017, 20 transplant programs performed 72 deceased-donor VCA transplants, with organs donated by 70 donors, including 30 upper limb (17 unilateral and 13 bilateral) and 11 face donors. Other donors donated both upper limbs and face (n = 2), uterus (n = 4), abdominal wall (n = 19), larynx (n = 2), penis (n = 1), and scalp (n = 1). About a third of VCA donors were female, and the majority (86.4%) were white. Almost half (45.5%) were between the ages 18 and 34 years. Smaller proportions were younger than 18 years (19.7%), 35 to 44 years (15.2%), 45 to 54 years (13.6%), and older than 55 years (6.1%). Median body mass index for all VCA donors was 24.9 and varied widely, especially for upper limb and face donors. There was considerable variation in Kidney Donor Profile Index among VCA donors (median, 27.5; interquartile range, 11-59). Donor causes of death included head trauma (39.4%), cerebrovascular/stroke (25.8%), and anoxia (31.8%). VCA donors also donated solid organs that were transplanted, including 87.1% of kidneys, 93.9% of livers, 40.2% of lungs, and 56.1% of hearts.

CONCLUSIONS

donors are a demographically and clinically diverse group. Understanding this diversity and future trends in VCA donor characteristics is critical in supporting this life-changing field of transplantation.

Orthotopic forelimb allotransplantation in the rat model

In this report, we present a rat orthotopic forelimb allotransplantation model. Eight forelimbs were transplanted from Brown Norway rats to Lewis rats. Axillary vessels of transplant were used as the vascular pedicles, which were anastomosed to the external jugular vein and common carotid artery of the recipient rat. The ulnar, radial, and median nerves were also repaired. Among rats, a tapered dose of cyclosporine was administered in five rats. In other three rats, no immunosuppressive therapy was given. The viability and signs of rejection of transplanted forelimbs, sensation recovery, bone healing, and histology were assessed up to the 90^th postoperative day. All of rats but one survived surgery. All of transplanted forelimbs survived. In the rats treated with cyclosporine the transplanted forelimbs achieved long-term survival with motion and sensation recovery. On 90^th day after surgery, bone healing was achieved. There was no sign of rejection in histology. In the rats without cyclosporine treatment, the transplanted forelimbs experienced tissue necrosis started from day 12 postoperatively. This experimental study showed the feasibility of orthotopic forelimb allotransplantation in the rat model. © 2015 Wiley Periodicals, Inc. Microsurgery 36:672-675, 2016.

Rat model of heterotopic toe allotransplantation

BACKGROUND

Finger allotransplantation is a promising treatment for severe finger destruction. However, more research is required to decrease the risks of this procedure to a level at which the clinical use of this non-life-saving procedure is justified. A proper animal model is essential for the required experiments.

METHODS

In this article, we established a toe transplantation model based on anatomic studies. A tapered dose of Cyclosporine A (CsA) was used as an immunosuppressive therapy in the Brown Norway-to-Lewis allotransplantation experimental group, whereas isotransplantation or allotransplantation without treatment or with ligated pedicles was performed on the control groups. Recipients were assessed daily after operation for any signs of rejection and complications. On postoperative day 90, skin graft test was used to test the level of donor-specific tolerance in the recipients. On postoperative day 120, x-rays and micro-computed tomographies were performed for bone morphology evaluation. The chimerism in the recipient peripheral blood, lymph node, spleen, and thymus was tested by flow cytometry and immunohistochemical staining. And histologic study of the toe grafts and skin grafts were carried out.

RESULTS

The blood supply of the toe graft was confirmed, and accordingly, transplantations were performed. The isografts survived indefinitely. The allografts with ligated pedicles experienced necrosis within 5 d. The allografts without treatment exhibited necrosis within 14 d. Forty percent, 20%, and 40% of the allografts associated with the CsA treatment experienced severe rejection, mild rejection, and nonrejection, according to gross graft appearance, respectively. Skin grafting tests showed three different types of results. X-rays and micro-computed tomographies reveal nearly normal bone morphologies in the bone structures of all surviving animals with grafts. Low levels of donor-specific chimerism were detected in the peripheral blood samples. Spleen, lymph node, and thymus chimerism were also confirmed in the long-term surviving animals with allografts. Histologic evaluation of the long-term survivals revealed similar graft morphologies in the isografts and the nonrejected allografts, inflammatory cell infiltration in the mildly rejected allografts, and degraded cutaneous appendages in the severely rejected allografts.

CONCLUSIONS

We established a toe allotransplantation model. Moreover, the low rate of chimerism did not introduce specific tolerance, which might explain the high rejection rate. This model might facilitate future research in finger allotransplantation.

Two-stage face transplantation: a new concept in vascularized composite allotransplantation

BACKGROUND

Animal models and clinical cases of facial allotransplantation have been performed as a single stage procedure. A staged surgery might offer some advantages in selected cases. In this study, a two-stage face transplantation approach was performed on rat and the feasibility and safety were evaluated.

METHODS

Brown Norway rats were used as donors and Lewis rats as recipients in the allotransplantation groups. A total of 33 hemiface-scalp transplantations were performed. Syngeneic orthotopic transplantations were performed either in one-stage (one single stage surgery; N = 3), local two-stage [heterothopic transplantation to the neck during the first stage and graft rotation as a pedicled flap to cover the facial defect on postoperative day (POD) 2; N = 3], or distant two-stage approaches (heterothopic transplantation to the groin during the first stage and free graft transfer to the face on postoperative day 2; N = 3). In the allotransplantation groups using the same approaches, 12 received no treatment (N = 4 each subgroup) and 12 received the same tapering dose of cyclosporine (10 to 2 mg/Kg/day; N = 4 each subgroup). Graft survival and the rejection grades were assessed clinically and pathologically.

RESULTS

All syngeneic transplants survived for the follow-up period of 180 days. The mean rejection-free survival and total survival of the allograft in the no treatment group was 6 ± 0.3 and 14.3 ± 4.5 days in the one-stage group, 6 ± 0.4 and 18.5 ± 1 days in the local two-stage group and 6 ± 0.2 and 14.3 ± 5.7 (P > 0.05). All allografts in the treatment groups did not develop rejection during the 42 days follow-up period.

CONCLUSIONS

It is feasible, reliable, reproducible, and safe to perform a two-stage face transplantation in rats. This novel approach has the potential to be applied in research and eventually in selected clinical cases of facial allotransplantation.