Transplantation of en bloc kidneys from very small pediatric donors

Identifying potential kidney donors among newborns undergoing circulatory determination of death

BACKGROUND

Over 96,000 patients await kidney transplantation in the United States, and 35,000 more are wait-listed annually. The demand for donor kidneys far outweighs supply, resulting in significant waiting list morbidity and mortality. We sought to identify potential kidney donors among newborns because en bloc kidney transplantation donation after circulatory determination of death (DCDD) may broaden the donor pool.

METHODS

We reviewed discharges from our 84-bed NICU between November 2002 and October 2012 and identified all deaths. The mode of death among potential organ donors (weight ≥ 1.8 kg) was recorded. Patients undergoing withdrawal of life support were further evaluated for DCDD potential. After excluding patients with medical contraindications, those with warm ischemic time (WIT) less than 120 minutes were characterized as potential kidney donors.

RESULTS

There were 11,201 discharges. Of 609 deaths, 359 patients weighed ≥ 1.8 kg and 159 died after planned withdrawal of life support. The exact time of withdrawal could not be determined for 2 patients, and 100 had at least 1 exclusion criterion. Of the remaining patients, 42 to 57 infants were potential en bloc kidney donors depending on acceptance threshold for WIT. Applying a 40% to 70% consent rate range would yield 1.7 to 4 newborn DCDD donors per year.

CONCLUSIONS

A neonatal DCDD kidney program at our institution could provide 2 to 4 paired kidneys for en bloc transplantation each year. Implementing a DCDD kidney donation program in NICUs could add a new source of donors and increase the number of kidneys available for transplantation.

Single versus en bloc kidney transplantation from pediatric donors less than or equal to 15 kg

BACKGROUND

Kidney transplantation from small pediatric donors is being performed with increased frequency as single (SK) or en bloc (EBK) kidneys.

METHODS

Between 2002 and 2006, 19 EBK and 14 SK transplants from pediatric donors less than or equal to 15 kg were performed. SK arterial anastomoses were performed to the aortic patch (n=8), aortic conduit (n=1), or renal artery orifice (n=5).

RESULTS

En bloc kidney donors were on average younger (12+/-10 vs. 24+/-8 months, respectively; P=0.0102) and weighed less (10+/-3 vs. 13+/-3, respectively; P=0.0184). There were no differences between the two groups in recipient age, race, body mass index, degree of sensitization, retransplantation, and cold ischemia time; however, EBK recipients were somewhat better matched at the human leukocyte antigen DR locus (P=0.0515). Delayed graft function was more frequent in the SK group (25% vs. 0%; P=0.0542). Acute rejection occurred in 21% of recipients in both groups. Glomerular filtration rates were significantly higher with EBK than SK at 12-months posttransplantation. At 1 year, graft survival for SK and EBK was 86% and 79%, respectively (P=1.000). Graft thrombosis occurred in 0% (0/9) of SK recipients in which an aortic cuff or conduit was used, 40% (2/5) of SK recipients without an aortic cuff, and 5% (1/19) of EBK recipients (P=0.03).

CONCLUSION

Short-term outcomes of kidneys from small pediatric donors are satisfactory when transplanted as SKs or en bloc; however, the absence of an aortic patch in SK transplantation is a risk factor for early thrombosis.