American Journal of Transplantation 2007; 7: 264 _C

2006 The Authors

Blackwell Munksgaard Journal compilation _C

2006 The American Society of

Letter to the Editor Transplantation and the American Society of Transplant Surgeons

doi: 10.1111/j.1600-6143.2006.01570.x

Transplantation of En Bloc Kidneys from Very Small Pediatric Donors To the Editor: We read with interest the article by Pelletier and colleagues

entitled ‘Recovery and utilization of deceased donor kid-neys

from small pediatric donors’ (1). The authors docu-mented

that in the United States, between 1993 and 2002, recovery

rates of kidneys from donors weighing <10 kg was very low

compared to donors weighing from 10 to 21 kg (42.9% vs.

90.8%, respectively). Further compound-ing low recovery,

discard rates of kidneys from donors weighing 10 kg was

higher than the 10–20 kg subgroup (40.3% vs. 10.5%).

Whereas this report found that donor weight independently

predicted a higher risk of graft loss, there was no significant

difference in long-term graft sur-vival between kidneys from

donors weighing 10 kg trans-planted en bloc compared to

solitary kidney transplants from donors weighing 15–21 kg.

These data suggest that acceptable outcomes can be

obtained with very small pe-diatric donors (≤10 kg).

Over the past year, we have adopted a more aggressive

ap-proach to the utilization of anatomically challenged

kidneys. At the University of Pittsburgh Medical Center, 8

recipients received en bloc kidneys from donors between

21 days of age and 13 months with weights between 4

and 10 kg. Seven of the 8 recipients achieved immediate

graft func-tion and demonstrate mean creatinine levels of

1.2 mg/dL (range 0.9–1.8 mg/dL) at 5 months follow-up

(range 3– 9 months). One pair failed (3 months old, 8.1

kg) because of poor reperfusion characteristics and

subsequent primary nonfunction. Among the 7 recipients with allograft function, 2 pairs of en

bloc kidneys had been recovered with insufficient aor-tic cuff

and were salvaged by utilizing the suprarenal aorta and vena

cava as the sites of arterial and venous anasto-moses,

respectively (2). Another en bloc pair, declined by other

centers because of short ureteral length (4 cm), was

anastomosed to the distal external iliac vessels; the infe-rior

ureter joined to the bladder and the superior ureter to

the native ureter. Lastly, one pair of en bloc kidneys had

been recovered from a 2-month-old donor (5 kg) in which an

aortic intimal flap, induced that the time of cannulae in-

sertion during recovery, resulted in suboptimal perfusion of

the liver and intestine. One kidney demonstrated areas of

under-perfusion; the other appeared completely perfused.

Following en bloc transplantation the under-perfused kid-ney

remained blue and was immediately removed. The re-

maining kidney functioned immediately; the creatinine is 1.8

mg/dL at 4 months posttransplant. Currently en bloc kidney transplants comprise less than

10% of all renal transplants per year in the United States (3). Kidneys from very small pediatric donors are

generally considered ”marginal” kidneys because of the

higher risk of technical failure and/or thrombosis usually

due to the small vessel size. Many of the anatomic

challenges can be overcome; however, once

successfully transplanted, these kidneys have excellent

renal reserve and long-term survival. Greater efforts

should be directed towards the recovery and

transplantation of kidneys from very small donors. Abigail Martin, Antik Basu, Ron Shapiro, Liise Kayler

Department of Surgery The Thomas E. Starzl

Transplantation Institute University of

Pittsburgh Medical Center Pittsburgh, PA,

USA References

1. Pelletier SJ, Guidinger MK, Merion RM et al. Recovery and

utiliza-tion of deceased donor kidneys from small pediatric

donors. Am J Transplant 2006; 6: 1646–1652. 2. Kayler LK, Blisard D, Basu A et al. Transplantation of en bloc

pediatric kidneys when the proximal vascular cuff is too short.

Transplantation (in press). 3. G, Howard RJ. En-bloc kidney transplantation in the United

States: An analysis of United Network of Organ Sharing (UNOS)

data from 1987 to 2003. Am J Transplant 2005; 5: 1513–1517.

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