The effect of inadequate in situ perfusion in the non heart-beating donor.

In situ aortic perfusion in the nonheart-beating donors (NHBD) is an important procedure to reduce primary warm ischaemic injury prior to formal donor organ retrieval. It allows an interim period to obtain donor family consent and theatre preparation. This study describes our experience of inadequate aortic perfusions resulting from difficult aortic cannulations and associated adverse outcome despite reasonable viability tests. Since 1998, all NHBD in our institution are perfused in situ using a double balloon triple lumen (DBTL) catheter inserted through a femoral artery cut-down procedure. The DBTL catheter is positioned with distal occlusive balloon at the aortic bifurcation using the "pull-back" technique, the proximal occlusive balloon lies above the renal arteries. This provides selective aortic perfusion in particular the kidneys. Venous decompression using a femoral vein catheter enables a "two-way infusion system". Pre-transplant viability status of retrieved kidneys is determined by measuring pressure/resistance characteristics to the flow and biochemical markers for ischaemic injury. There were 90 NHBD renal transplants performed from 72 donors. Three renal transplants were carried out from three donors of ineffective in situ perfusion secondary to cannulation difficulties. Femoral cannulation was difficult as a result of extensive atherosclerosis of donor vessels. The comparison of allograft outcome from effective and ineffective in situ perfusion of donors showed high rate of primary nonfunction (PNF) from ineffective perfusion (chi-squared, P < 0.0001). The cases demonstrated poor outcome from ineffective perfusion related to the cannulation difficulties. Therefore a strict policy should be taken in cases where aortic cannulation and perfusion is inadequate, despite pretransplant assessment. In these circumstances, the primary warm ischaemia time should be extended to include this period of ineffective perfusion.

Renal transplants from non-heart beating paracetamol overdose donors.

INTRODUCTION: Non-heart beating donors (NHBD) are widely encouraged to avert the critical shortage in the kidney donor pool. Ischaemic injury at the time of cardiac arrest in the NHBD is more pronounced and therefore the kidneys resulting are considered marginal. This review describes our experience with four kidneys from two controlled NHBDs who were exposed to paracetamol intoxication and subsequently were treated with mannitol prior to organ donation. MATERIALS AND METHOD: Two patients with fulminant liver failure following paracetamol overdose were referred as 'withdrawal of treatment' NHBD. As the two patients had developed hepatic encephalopathy they were treated with mannitol to reduce intra-cerebral oedema. The two donors were oligoanuric for at least 24 h prior to cardiac arrest. Following cardiac arrest, in situ perfusion was carried out and the kidneys were removed. One pair of kidneys were machine perfused while the second pair of kidneys were cold stored prior to transplantation. RESULTS: Pre-transplant assessment of NHBD kidneys resulted in three of four kidneys being transplanted. The NHBD kidneys exhibited a period of delayed graft function (DGF). The early transplant biopsies showed evidence of diffuse cytoplasmic vacuolation. These histological features disappeared with time and the renal function improved until the time of discharge. DISCUSSION: Non-heart beating donor kidneys are considered marginal and the effect of mannitol and paracetamol drug intoxication will induce reversible sub-lethal injury. A period of dialysis is inevitable in clearing the reactive intermediates of mannitol and paracetamol. The kidneys behaved as traditional controlled NHBD at time of discharge.

Do tissue damage biomarkers used to assess machine-perfused NHBD kidneys predict long-term renal function post-transplant?

BACKGROUND: Renal transplantation in many units is limited by the availability of donor organs. Kidneys obtained from non-heart-beating donors (NHBD) represent an important resource, with the potential to substantially increase the available donor organ pool. Such kidneys are associated with increased warm ischaemic tissue injury which may be assessed by hypothermic machine perfusion. Within our transplant centre, a key component of such damage assessment and viability screening involves the quantification of the tissue damage biomarkers glutathione S-transferase in kidney perfusates. METHODS: Since 1998, 126 NHBD kidneys were machine-perfused prior to implantation, resulting in 74 transplants. Kidney perfusate samples were assayed for glutathione S-transferase in "real time", and alanine aminopeptidase and fatty acid binding protein in "retrospect". RESULTS: The pre-transplant concentration of these tissue injury biomarkers determined pre-transplant did not correlate with subsequent longer-term renal function, as assessed by measurement of serum creatinine (tGST: Spearman correlation r=-0.02; Ala-AP: r=0.02; H-FABP: r=-0.05) and creatinine clearance (tGST: r=0.08; Ala-AP: r=-0.02; H-FABP: r=0.14) for those kidneys that had passed their viability tests. CONCLUSIONS: Thus whilst these biomarkers may represent reliable pre-transplant indicators of immediate kidney viability and short-term kidney function, they do not predict the efficacy of renal function in the longer term.

Comparison of perfusate activities of glutathione S-transferase, alanine aminopeptidase and fatty acid binding protein in the assessment of non-heart-beating donor kidneys.

BACKGROUND: With a universal shortage of donor organs, screening and selection of marginal kidneys from non-heart-beating donors (NHBDs) provides a valuable source for transplantation. Pre-transplant viability assessment is based on a combination of flow characteristics and assessment of ischaemic tissue injury during NHBD kidney machine perfusion by measurement of total glutathione S-transferase (GST) activity. Successful viability screening has facilitated 69 renal transplants from 60 NHBDs within our transplant centre since 1998, with a first-year graft survival of 90.5%. METHODS: We have investigated alanine aminopeptidase (Ala-AP) and fatty acid binding protein (FABP) as alternative biochemical markers to GST for pre-transplantation viability assessment. They were measured, together with GST, in tissue perfusate samples from machine-perfused kidneys from controlled and uncontrolled NHBDs. RESULTS: During machine perfusion, a parallel response was seen for each of the three markers in the perfusates of controlled and uncontrolled NHBD kidneys over the 4-h perfusion. A highly significant correlation was obtained between GST and Ala-AP activities (P<0.0001) and between GST activity and FABP concentration (P<0.0001) in corresponding samples. CONCLUSION: In this study, GST, Ala-AP and FABP represent equivalent biochemical markers in terms of their ability to quantitate renal tissue injury in human NHBD kidneys. However, there may be some advantage in using all three analytes to provide complementary information on kidney allograft viability.

Long-term renal function in kidneys from non-heart-beating donors: A single-center experience.

BACKGROUND: Cadaveric kidneys from brain-stem-dead donors continue to be limited because the number of donors has reached a plateau. Wide recruitment of non-heart-beating donors (NHBD) could significantly increase the donor pool. NHBD renal transplants are underused because of the concern of poor quality graft function from such donors. In response to this perception, we reviewed 46 NHBD renal transplants performed in our center since 1998. METHODS: All NHBD kidneys were machine-perfused using the Newcastle continuous-hypothermic pulsatile preservation system before transplantation. A control heart-beating-donor (HBD) group was taken as the next consecutive HBD renal transplant to the NHBD transplant. The outcome and quality of function of the groups of renal transplants were analyzed for short-term and long-term performance. RESULTS: The renal transplant patients were matched for donor and recipient factors. Survival rates for allografts and patients were similar for 1 to 3 years. There was an increased incidence of delayed graft function in the NHBD renal transplants in the perioperative period. The creatinine clearance was 22.8+/-2.3 mL/minute for NHBD patients and 44.4+/-2.9 mL/minute for HBD patients at the time of discharge from hospital. This difference equalized after 3 months and the creatinine clearance for NHBD was 44.2+/-2.4 mL/minute and for HBD 49.2+/-3.4 mL/minute. CONCLUSIONS: Our results for NHBD renal transplants confirm that such grafts suffer primary warm ischemic injury, shown by the increased incidence of acute tubular necrosis and consequent delayed graft function. This produced poor renal function at the time of hospital discharge. After 3 months, the renal function of NHBD cases improved to the level seen in HBD patients.

Improving the quality of kidneys from non-heart-beating donors, using streptokinase: an animal model.

BACKGROUND: Non-heart-beating donors (NHBD) offer a promising potential to increase the cadaveric organ donor pool, especially for kidneys. However, almost half of NHBD kidneys are discarded after viability assessment. This wastage is costly in both human and monetary terms. Intravascular thrombosis at the time of donor death is an event leading to failure in the viability assessment. We have developed an animal model to investigate the effects of the addition of streptokinase to the in situ flush medium before transplant in an attempt to redress the situation. METHODS: Two groups of eight healthy young Landrace Yorkshire white pigs were entered into the study. Both groups were subjected to approximately 70 min warm ischemia. Both groups received an intravascular flush with 4 L of Marshall's solution with heparin (1000 IU/L); one group of pigs also had streptokinase (1.5 MIU/L) added. After donor nephrectomy, all kidneys were machine perfused for 4 hr. Data on perfusion characteristics were taken and samples of kidney effluent were assayed for tissue damage biomarkers, glutathione S-transferase (GST) and alanine aminopeptidase (Ala-AP). Wedge sections of porcine kidneys were taken at the end of perfusion, for histological analysis. RESULTS: Data on machine perfusion parameters (temperature, mean pressure index, resistance) indicate better cooling, lower resistance, and lower mean pressure index in the streptokinase-treated group of pigs. GST and Ala-AP levels were increased in the nonstreptokinase group perfusates. Histopathological analysis of porcine kidneys indicated more ischemic injury and tissue damage in the nonstreptokinase group. CONCLUSION: The use of streptokinase in this porcine NHBD model conferred benefits to donor kidneys when assessed by machine perfusion. Markers of biochemical injury indicated that less renal tissue damage occurred with the incorporation of streptokinase in the in situ flush medium.