OPTN/SRTR 2022 Annual Data Report: Vascularized Composite Allograft

OPTN/SRTR 2022 Annual Data Report: Vascularized Composite Allograft

J. Andres Hernandez1, Jonathan M. Miller2,3, Emmanuel Emovon III4, Jesse N. Howell5, Guiliano Testa6, Ajay K. Israni2,3,7, Jon J. Snyder2,3,7, Linda C. Cendales1,4

1Department of Surgery, Duke University, Durham, NC

2Scientific Registry of Transplant Recipients, Hennepin Healthcare Research Institute, Minneapolis, MN

3Department of Medicine, Hennepin Healthcare, University of Minnesota, Minneapolis, MN

4Duke University School of Medicine, Durham, NC

5Organ Procurement and Transplantation Network, United Network for Organ Sharing, Richmond, VA

6Baylor University Medical Center, Dallas, TX

7Department of Epidemiology and Community Health, University of Minnesota, Minneapolis, MN

Abstract

This year’s chapter on vascularized composite allograft (VCA) encompasses reviews of data collected from 2014 (when VCA was included in the Final Rule) through 2022. The present Annual Data Report shows that the number of VCA recipients in the United States continues to be small and has remained consistent from the prior report. The data continue to be limited by sample size, with trends persistently demonstrating a predominance of White males in the young/middle-aged population as both donors and recipients for nonuterus VCA transplants, and White women younger than 35 years as the predominant recipients of uterus transplant. Similar to the 2021 report, there were only eight failed uterus grafts and one failed nonuterus VCA graft reported from 2014 through 2022. Standardization of definitions of success and failure as well as outcome measures for the different VCA types remain unmet needs in VCA transplantation.

Keywords: Abdominal wall transplant, face transplant, multiorgan transplant, upper limb transplant, vascularized composite allograft (VCA)

1 Introduction

In 2014, vascularized composite allograft (VCA) was included within the Final Rule, which established regulatory oversight by the Organ Procurement and Transplantation Network (OPTN).1,2 The Final Rule defined VCA transplantation as the transplant of any body part that meets the following nine criteria:

  1. Vascularized and requires blood flow by surgical connection of blood vessels to function after transplant

  2. Contains multiple tissue types

  3. Recovered from a human donor as an anatomical/structural unit

  4. Transplanted into a human recipient as an anatomical/structural unit

  5. Minimally manipulated (ie, processing that does not alter the original relevant characteristics of the organ relating to the organ’s utility for reconstruction, repair, or replacement)

  6. For homologous use (the replacement or supplementation of a recipient’s organ with an organ that performs the same basic function or functions in the recipient as in the donor)

  7. Not combined with another article such as a device

  8. Susceptible to ischemia and, therefore, only stored temporarily and not cryopreserved

  9. Susceptible to allograft rejection3

This chapter on VCA in the OPTN/SRTR 2022 Annual Data Report encompasses reviews of data collected since 2014, with a particular emphasis on the year 2022, with the aim being to depict and examine trends within VCA transplantation. In this chapter, Hispanic is defined as Hispanic/Latino ethnicity with no race reported. White, Black, Asian, Native Hawaiian, and Native American categories are all defined as non-Hispanic. Multiracial includes persons reported to be multiple races or Hispanic/Latino with at least one reported race (eg, White Hispanic). When the Non-White category is shown, Non-White is defined as Black, Asian, Hispanic, American Indian/Alaska Native, Native Hawaiian/Pacific Islander, and Multiracial. When the Other race category is shown, Other is defined as Asian, American Indian/Alaska Native, Native Hawaiian/Pacific Islander, and Multiracial. The Other/multiple category of organ for nonuterus VCA transplant includes larynx transplant or transplants that involve multiple VCA organs. Detailed information on VCA candidates, donors, and recipients, as well as VCA access and patient outcomes, in the United States from 2014 through 2022 is presented below.

2 Uterus Transplant

2.1 Candidates

Twelve candidates were on the waiting list for uterus transplant in 2022 (Figure VCA 1). Since 2016 (the year of the first uterus transplant in the United States), most uterus transplant candidates were younger than 35 years (81.1%; Figure VCA 2) and White (86.8%; Figure VCA 3), with blood types A (56.6%) or O (34.0%; Figure VCA 4).

2.2 Transplants

As of December 2022, 37 uterus transplants were performed in the United States (Figure VCA 5). Most uterus transplants were performed in White (33 of 37 recipients; Figure VCA 7) women younger than 35 years (31 of 37 recipients; Figure VCA 6). Uterus transplant recipients predominantly had blood type A (21 of 37 recipients) or O (12 of 37 recipients; Figure VCA 8). Primary diagnosis of absolute uterine factor infertility due to congenital absence of the uterus was present in 28 of 37 recipients (Figure VCA 9).

2.3 Donors

Unlike transplants for other VCA organs that use only deceased donor organs, living donor uterus transplants are performed: 21 of 37 uterus transplants (56.8%) since 2016 used living donors (Figure VCA 10). Only one living uterus donor was older than 50 years; all other donors, living or deceased, were younger than 50 years, with most aged 18-34 years (Figure VCA 11).

2.4 Posttransplant Outcomes

Unlike other organ transplants, uterus grafts are always removed after the recipient has finished having children. Data reported to the OPTN show 25 functioning uterus grafts and 8 failed uterus grafts of 37 transplants (67.6% and 21.6%, respectively; Figure VCA 12). However, uterus transplantation is a small and growing field, and the authors are aware of 17 uterus grafts that have, in fact, been removed after successful child delivery. The essential outcome variable for a uterus transplant is a live birth. Although number of births is not yet captured in the data, as of December 2022, the authors are aware of 21 children who were born to 19 uterus transplant recipients.

2.5 Access

Uterus transplants through 2022 were performed at centers in four states: Alabama, Ohio, Pennsylvania, and Texas. Of these, most transplants were performed in Texas (22 of 37 [59.5%]; Table VCA 1).

3 VCA Transplant Other Than Uterus

3.1 Candidates

Since the implementation of the Final Rule and OPTN guidance in 2014, there has been an increase in the number of candidates for VCA transplant other than uterus (referred to as nonuterus VCA transplant herein). However, despite this growth, the overall number of listed candidates remained stable compared with the previous year, with a total of 17 candidates reported in 2022 (Figure VCA 13). An examination of candidate listings by organ type since 2014 reveals that the most common category is upper limb (23 of 56 [41.1%]), while the least common is scalp (1 of 56 [1.8%]). Note that due to the limited sample size, evaluating annual data remains challenging. Nevertheless, as of the end of 2022, there were nine patients listed for abdominal wall transplant, two for face transplant, four for upper limb transplant, and one for Other/multiple transplant (Figure VCA 13 and Figure VCA 14).

Despite the challenges posed by a limited sample size, the demographic data of candidates undergoing nonuterus VCA transplant are presented. Candidates were primarily aged 18-34 years (33.9%) and 50-64 years (30.4%), with a substantial portion listed in the 35-49 years age group (25.0%; Figure VCA 15). In terms of race and ethnicity, White candidates constituted the majority (71.4%), while candidates in the Black, Hispanic, and Other categories represented 10.7%, 16.1%, and 1.8%, respectively (Figure VCA 16). Since 2014, male candidates have consistently outnumbered female candidates among nonuterus VCA recipients (39 of 56 [69.6%] and 17 of 56 [30.4%], respectively) (Figure VCA 17). The distribution of blood types among nonuterus VCA candidates since 2014 reveals most having blood type O (46.4%), followed by type A (33.9%), type B (16.1%), and type AB (3.6%) (Figure VCA 18). The median waiting time for organ-specific transplant among patients who had undergone transplant since 2014 was notably the longest for scalp transplant (355 days), followed by face (342 days), penis (262 days), Other/multiple (238 days), upper limb (186 days), and abdominal wall (102 days) (Figure VCA 19).

3.2 Donors

Since the regulation of VCA transplant in 2014, donor data for nonuterus VCA transplant have been limited. Similar to in previous years,4 most donors in 2014-2022 were aged 18-34 years (50.0%), with the remainder 35-49 years (35.2%), younger than 18 years (11.8%), and 50-64 years (2.9%) (Figure VCA 27).

3.3 Recipients

Of the total 56 listed nonuterus VCA candidates, 34 individuals (60.7%) underwent transplant in 2014-2022. There has been no substantial change in the number of nonuterus VCA transplants performed. Upper limb transplant was the most frequently performed (44.1%), followed by face (32.4%), abdominal wall (11.8%), penis (5.9%), scalp (2.9%), and Other/multiple (2.9%) (Figure VCA 21).

The demographic profile of the 34 patients who underwent nonuterus VCA transplant in 2014-2022 can be summarized as follows: the primary causes leading to transplant were trauma (41.2%), infection (23.5%), and burn/explosion (5.9%). However, a portion of etiologic data was missing (17.6%) (Figure VCA 26), which is consistent with the findings of the previous year’s report.4 The age distribution of nonuterus VCA transplant recipients during this period was as follows: the most prevalent age group was 18-34 years (41.1%), followed by 50-64 years (26.5%), 35-49 years (20.6%), 65 years or older (8.8%), and younger than 18 years (2.9%) (Figure VCA 22). These recipients were stratified into two distinct categories for race and ethnicity data collection: White (27 of 34 [79.4%]) and non-White (7 of 34 [20.6%]) (Figure VCA 23). Among nonuterus VCA recipients during this period, males continued to make up the largest portion, accounting for 70.6% (24 of 34), while females were the remaining 29.4% (10 of 34) (Figure VCA 24). When analyzing the distribution of blood types among nonuterus VCA transplant recipients since 2014, it is evident that type O blood is the most prevalent (50.0%), followed by type A (29.4%) and type B (20.6%). Note that no transplants were performed in individuals with type AB blood (Figure VCA 25).

3.4 Access and Outcomes

Currently, 21 programs in 11 states have performed nonuterus VCA transplant (Figure VCA 28, Table VCA 3). When assessing the distribution of programs according to organ type, upper limb transplant emerges as the most prevalent procedure, with nine programs having performed it from 2014 through 2022. Face transplant has been carried out at five programs, and abdominal wall transplant has been done at three programs. Transplants in the Other/multiple category were performed at one program; penis and scalp transplant were conducted at two programs and one program, respectively (Figure VCA 28). Compared with the previous year’s report,4 there was an increase in the number of programs providing abdominal wall transplant from two to three.

The examination of patient outcomes in nonuterus VCA transplant involved the classification of results into “functioning graft” and “failed graft.” Over the recorded timeframe of 2014-2022, there was one occurrence of upper limb VCA failure reported (1 of 15 [6.7%]), while abdominal wall, face, Other/multiple, penis, and scalp VCA transplants were reported with a 100% functioning graft rate, similar to earlier observations (Table VCA 2).

4 Observations

The number of VCA recipients in the United States did not significantly increase in the past year. It is important to note that missing data entries continue to improve compared with prior annual reports. Like in previous years, factors such as limited funding availability, as well as the cost of and limited dedicated resources available for these low-volume, complex cases, may be contributing to the number of VCA transplants not increasing at a faster rate. The VCA transplant community continues to actively work to address unmet needs, such as unstandardized definitions and nonvalidated outcome tools specific to VCA transplant. Continuing education, data sharing, training, and collaborations continue to be adopted; these will provide insights and contribute to the advancement of the field.

References

1.
McDiarmid SV, Levin LS, Luskin RS. Vascularized composite tissue allografts (VCA): the policy side. Curr Transplant Rep. 2016;3:50-56. doi:10.1007/s40472-016-0094-9
2.
Cherikh WS, Cendales LC, Wholley CL, Wainright J, Gorantla VS, Klassen DK, McDiarmid SV, Levin LS. Vascularized composite allotransplantation in the United States: A descriptive analysis of the Organ Procurement and Transplantation Network data. Am J Transplant. 2019;19(3):865-875. doi:10.1111/ajt.15062
3.
Wholley CL. List Covered Body Parts Pertaining to VCA. OPTN/UNOS Vascularized Composite Allograft (VCA) Transplantation Committee. Published online 2016. Accessed September 6, 2023. https://optn.transplant.hrsa.gov/media/1864/vca_briefingpaper_201606.pdf
4.
Hernandez JA, Testa G, Naga HI, Pogson KB, Miller JM, Booker SE, Howell J, Poff K, Johannesson L, Israni AK, Snyder JJ, Cendales LC. OPTN/SRTR 2021 Annual Data Report: Vascularized Composite Allograft. Am J Transplant. 2023;23(2 Suppl 1):S523-S545. doi:10.1016/j.ajt.2023.02.012

List of Figures

List of Tables




**Number of prevalent uterus candidates.** Candidates listed at multiple centers are counted once per listing. Includes active and inactive candidates on the list any time during the year.

Figure VCA 1: Number of prevalent uterus candidates. Candidates listed at multiple centers are counted once per listing. Includes active and inactive candidates on the list any time during the year.




**Number of  uterus candidates by age, 2016-2022.** Candidates listed at multiple centers are counted once per listing. Includes active and inactive candidates on the list any time.

Figure VCA 2: Number of uterus candidates by age, 2016-2022. Candidates listed at multiple centers are counted once per listing. Includes active and inactive candidates on the list any time.




**Number of  uterus candidates by race and ethnicity, 2016-2022.** Candidates listed at multiple centers are counted once per listing. Includes active and inactive candidates on the list any time.  Non-White race and ethnicity includes Black, Asian, Hispanic, American Indian/Alaska Native, Native Hawaiian/Pacific Islander, and Multiracial.

Figure VCA 3: Number of uterus candidates by race and ethnicity, 2016-2022. Candidates listed at multiple centers are counted once per listing. Includes active and inactive candidates on the list any time. Non-White race and ethnicity includes Black, Asian, Hispanic, American Indian/Alaska Native, Native Hawaiian/Pacific Islander, and Multiracial.




**Number of  uterus candidates by blood type, 2016-2022.** Candidates listed at multiple centers are counted once per listing. Includes active and inactive candidates on the list any time.

Figure VCA 4: Number of uterus candidates by blood type, 2016-2022. Candidates listed at multiple centers are counted once per listing. Includes active and inactive candidates on the list any time.




**Number of  uterus transplants, 2016-2022.** All uterus transplants, including retransplant and multiorgan recipients.

Figure VCA 5: Number of uterus transplants, 2016-2022. All uterus transplants, including retransplant and multiorgan recipients.




**Number of  uterus transplants by age, 2016-2022.** All uterus transplants, including retransplant and multiorgan recipients.

Figure VCA 6: Number of uterus transplants by age, 2016-2022. All uterus transplants, including retransplant and multiorgan recipients.




**Number of  uterus transplants by race and ethnicity, 2016-2022.** All uterus transplants, including retransplant and multiorgan recipients. Non-White race and ethnicity includes Black, Asian, Hispanic, American Indian/Alaska Native, Native Hawaiian/Pacific Islander, and Multiracial.

Figure VCA 7: Number of uterus transplants by race and ethnicity, 2016-2022. All uterus transplants, including retransplant and multiorgan recipients. Non-White race and ethnicity includes Black, Asian, Hispanic, American Indian/Alaska Native, Native Hawaiian/Pacific Islander, and Multiracial.