Cold Pulsatile Perfusion of Pediatric Kidney Allografts

Abstract

Kidney transplantation from small pediatric donors is increasingly being used as a means to optimize the organ supply (1); however, transplantation of small pediatric kidneys from unstable or donation after cardiac death (DCD) donors is rarely performed. Although pulsatile perfusion (PP) is being used to evaluate the viability of marginal or DCD adult donor organs (2) only one report of its application to pediatric kidneys has been published (3). The underutilization of PP in small pediatric kidneys is probably because of concerns of mechanical injury to the pediatric kidney vasculature that has an already established increased risk of thrombosis. We describe the use of PP to test the viability of small pediatric kidneys from a category four DCD donor. The donor, a 2-year-old boy, was in a drowning accident and required cardiopulmonary resuscitation for 35 min before arrival to the hospital. The terminal creatinine was 0.8 mg/dL. During transfer to the operating room for organ recovery the donor became unstable and vital signs were nondetectable. The patient was quickly prepped and draped and the aorta rapidly cannulated. Approximately 20 min had passed between loss of vital signs and organ perfusion with preservation solution. The left ureter was injured near the hilum during the aortic cannulation because of difficulty of exposure from scar tissue related to a prior gastroschisis repair. The right kidney was intact. Because of concerns about the instability of the donor before recovery, PP was performed to test the viability of the right kidney. The kidneys were perfused en bloc by the technical staff of The University of Florida Medical Center at 4°C to 6°C with 1 L of Belzer Machine Perfusion Solution (Organ Recovery Systems, Des Plaines, IL) on an RM3 organ PP machine (Waters Medical Instruments, Rochester, MN) at 60 bmp. The suprarenal aorta was clamped and the infrarenal aorta was cannulated with a 6F aortic cannula (Waters) (Fig. 1). The perfusion pressure was initially set at 40/32 mm Hg and resulted in a perfusion flow of 30 mL/min and resistance of 0.89 mm Hg/mL/min. Two hours later the flow and resistance was 71 mL/min and 0.37 mm Hg/mL/min, respectively (pressure 38/30 mm Hg). Perfusion flow and resistance did not improve after additional time of PP. These kidneys met our acceptance criteria (resistance ≤0.40 mm Hg/mL/min) for adult kidneys undergoing PP.FIGURE 1.: Pulsatile perfusion of en bloc pediatric kidneys.After ligation of the left hilum and discard of the left kidney, transplantation was performed in a 38-year-old man (weight 62 kg) by anastomosing the donor infrarenal aorta and vena cava to the recipient external iliac artery and vein, respectively, with continuous 6-0 nonabsorbable suture. The cold ischemia time was 22 hr. The kidney functioned immediately. At 6 months posttransplantation the recipient creatinine is 1.5 mg/dL. According to the Organ Procurement and Transplant Network data 93 kidneys from donors younger than 2 years have been evaluated with machine perfusion between 1994 and 2007 (accessed April 15, 2008). To our knowledge there is one published report describing PP of pediatric kidneys. In 1978 Munda et al. (2) performed PP in 12 en bloc kidneys from donors 6 days to 8 years of age. The mean perfusion pressure for the en bloc kidneys was 57/27 mm Hg. Flow rates were similar to adult values. Pulsatile perfusion is being used to evaluate the viability of marginal or DCD adult donor organs (3). Pulsatile perfusion of small pediatric kidneys is feasible and should be considered as an option to test the viability of kidneys when the donor is unstable or DCD. Future studies are needed to determine acceptable perfusion resistances in pediatric subgroups. Ivan Zendejas Maximilian Polyak Liise K. Kayler Division of Transplantation and Hepatobiliary Surgery Department of Surgery University of Florida College of Medicine Gainesville, FL