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).