Sarah A. Hosgood

Renal Transplantation After Ex Vivo Normothermic Perfusion: The First Clinical Study

Ex vivo normothermic perfusion (EVNP) is a novel method of preservation that restores circulation and allows an organ to regain function prior to transplantation. The aim of this study was to assess the effects of EVNP in kidneys from marginal donors. Eighteen kidneys from extended criteria donors (ECD) underwent a period of EVNP immediately before transplantation. Kidneys were perfused with a plasma free red‐cell based solution at a mean temperature of 34.6°C. The outcome of these kidneys was compared to a control group of 47 ECD kidneys that underwent static cold storage (CS). The mean donor age was 61 ± 1 years in the EVNP and 62 ± 6 years in the CS group (p = 0.520). EVNP kidneys were perfused for an average of 63 ± 16 min and all were transplanted successfully. The delayed graft function rate (DGF), defined as the requirement for dialysis within the first 7 days was 1/18 patients (5.6%) in the EVNP group versus 17/47 (36.2%) in the CS group (p = 0.014). There was no difference in graft or patient survival at 12 months (p = 0.510, 1.000). This first series of EVNP in renal transplantation demonstrates that this technique is both feasible and safe. Our preliminary data suggests that EVNP offers promise as a new technique of kidney preservation.

First in man renal transplantation after ex vivo normothermic perfusion.

Background. Normothermic perfusion is an alternative but little studied method of organ preservation. Herein, we report the first case of ex vivo normothermic renal transplant perfusion in man. Methods. The 62-year-old extended criteria donor died of an intracranial hemorrhage and had undergone cardiopulmonary resuscitation for a 30-min cardiac arrest. After 11 hr of static cold storage and immediately before transplantation, the left kidney was perfused at a mean temperature of 33.9°C for 35 min with a plasma-free red cell-based solution. The ex vivo perfusion circuit consisted of a centrifugal pump, a membrane oxygenator, and a heat exchanger. The paired right kidney underwent static cold storage for 14 hr. Results. After transplantation, the 55-year-old female recipient of the normothermic perfused kidney had slow graft function but the patient remained dialysis independent; serum creatinine at 3 months posttransplant was 132 &mgr;mol/L. The paired static cold-stored kidney was transplanted into a 52-year-old male recipient. This kidney had delayed graft function for a period of 26 days, and the 3-month serum creatinine was 218 &mgr;mol/L. Conclusion. We conclude that ex vivo normothermic kidney perfusion with a plasma-free red cell-based solution is a feasible method of preservation. This first case was performed without compromising the transplant kidney.

Leucocyte depletion improves renal function during reperfusion using an experimental isolated haemoperfused organ preservation system.

Leucocytes have been implicated as mediators of renal ischaemia–reperfusion injury. This study aimed to demonstrate the effect of white cells in early renal reperfusion injury using an isolated haemoperfused porcine kidney model.

The relative effects of warm and cold ischemic injury in an experimental model of nonheartbeating donor kidneys.

Background. Ischemia reperfusion injury (I/R) leads to delayed graft function and remains an important problem in renal transplantation. The aim of this experimental study was to assess the effects of warm (WI) and cold ischemia (CI) in models of heartbeating (HBD) and controlled/uncontrolled nonheartbeating donor (NHBD) kidneys. Methods. A reperfusion model utilizing cardiopulmonary bypass technology was used to perfuse isolated porcine kidneys with autologous blood after the following conditions: 0 min WI + 2 h cold storage (CS); 0 min WI + 18 h CS; 10 min WI + 2 h CS; 10 min WI + 18 h CS; 25 min WI + 2 h CS; 25 min WI + 18 h CS. Renal function was measured over a period of 3 hr. Results. Renal functional parameters were not significantly different between 0, 10, 25 WI with 2 h CS [AUC creatinine (Cr) decrease of 1057±177, 1102±260, and 1245±143 &mgr;mol/L h, P=0.338; AUC creatinine clearance (CrCl) of 37.7±15.8, 36.2±21.7, 19.8±9.1 ml/min/100 g h, P=0.099]. After 18 h CS, renal function was severely impaired in the 10 and 25 WI groups compared to 0 min WI [AUC Cr of 2156±401, 2287±148, 1563±395 &mgr;mol/L h, P=0.037; AUC CrCl of 2.2±1.7, 1.5±1.5, 21.7±13.4 ml/min/100 g h, P=0.007). Conclusion. Warm ischemia of up to 25 min was only detrimental to renal function when kidneys were subsequently preserved in cold storage for 18 hr. This data suggests that limiting the cold storage period is of paramount importance when transplanting kidneys subjected from nonheartbeating donors.

A comparison of hypothermic machine perfusion versus static cold storage in an experimental model of renal ischemia reperfusion injury.

Introduction. There is increasing support for the use of hypothermic machine perfusion (HMP) in an attempt to reduce preservation injury. However, experimental evidence is needed to further examine the effects of HMP on renal ischemia reperfusion injury. Methods. Porcine kidneys were subjected to 10 min of warm ischemia followed by 18 hr of static cold storage with hyperosomolar citrate (HOC), histidine-tryptophan-ketoglutarate (HTK), or University of Wisconsin (UW) solutions or 18 hr HMP with Kidney Perfusion Solution using the Lifeport perfusion system. Renal function, oxidative damage, and morphology were assessed during 3 hr of reperfusion with autologous blood using an isolated organ perfusion system. Results. During reperfusion, intrarenal resistance was significantly lower in the HMP group compared with HOC and UW (area under the curve; HMP 3.8±1.7, HOC 9.1±4.3, UW 7.7±2.2, HTK 5.6±1.9 mm Hg/min; P=0.006), and creatinine clearance was significantly higher compared with the UW group (area under the curve creatinine clearance; HMP 9.8±7.3, HOC 2.2±1.7, UW 1.8±1.0, HTK 2.1±1.8 mL/min/100 g; P=0.004). Tubular function was significantly improved in the HMP group (P<0.05); however, levels of lipid peroxidation were significantly higher (P=0.005). Conclusion. HMP demonstrated a reduced level of preservation injury compared with the static techniques resulting in improved renal and tubular function and less tubular cell inflammation during reperfusion.

Carbon monoxide protects against ischemia-reperfusion injury in an experimental model of controlled nonheartbeating donor kidney.

Background. CO-releasing molecule-3 (CORM-3) is a transitional metal carbonyl that liberates carbon monoxide under appropriate conditions. Carbon monoxide exerts effects on intracellular apoptotic and inflammatory pathways, which suggest a role in reducing the effects of renal ischemia/reperfusion (I/R) injury. This study investigated the effects of CORM-3 administered at the time of reperfusion in a model of controlled nonheartbeating donor kidneys. Methods. Porcine kidneys (n=4) were subjected to 10 min warm ischemia and 18 hr cold storage (CS) and then treated as follows: CORM-3 (50, 100, 200, and 400 &mgr;M doses), iCORM-3 (inactive carbon monoxide-releasing molecule, 50 &mgr;M), and control (no further intervention). Renal hemodynamics and function were then measured during 3-hr reperfusion with autologous blood using an isolated organ-perfusion system. Results. CORM-3 at a concentration of 50 &mgr;M improved renal blood flow (RBF) compared with the iCORM and control groups (area under the curve 774±19 vs. 448±88 vs. 325±70, respectively, P=0.002). CO-releasing molecule-3 at a concentration of 50 &mgr;M also improved renal function during reperfusion with a greater area under the curve for creatinine clearance (CORM-3: 14±6 vs. iCORM: 3.3±0.1 vs. control: 2.2±2 mL/min, P=0.006) and higher urine output (CORM-3: 793±212 vs. iCORM: 368±72 vs. control: 302±211 mL, P=0.01). CO-releasing molecule-3 at a concentration of 100 &mgr;M exerted similar effects. Treatment with CORM-3 at higher doses (200 and 400 &mgr;M) led to poor renal hemodynamics and function after reperfusion. Conclusion. Low-dose CORM-3 significantly ameliorates the effects of ischemia/reperfusion in a porcine model of controlled nonheartbeating donor kidney transplantation.

A Pilot Study Assessing the Feasibility of a Short Period of Normothermic Preservation in an Experimental Model of Non Heart Beating Donor Kidneys

BACKGROUND Restoring metabolism to an organ after hypothermic storage and before transplantation could reverse some of the detrimental effects of ischemic injury. This may be particularly beneficial for kidneys from non-heart-beating (NHBD) donors that sustain significant periods of warm and cold ischemic injury. This pilot study assessed the feasibility of a short period of normothermic preservation (NP) in a porcine autotransplant model. METHODS Kidneys were subjected to 30 min of warm ischemia, then preserved by hypothermic machine perfusion (HMP) for 22 h or 20 h HMP followed by 2 h of NP using autologous blood. Kidneys were then re-implanted, a contralateral nephrectomy performed, and renal function measured over 10 d. RESULTS Post-transplant, 4/6 animals survived in the NP group compared with 5/6 in the HMP group (P = 1.00). Creatinine levels fell below 250 μmol/L in all four of the surviving animals in the NP group compared with 2/5 in the HMP group (P = 0.608). There was no difference in levels of renal function (peak creatinine, HMP = 1736 ± 866 versus NP = 1553 ± 516 μmol/L; P ≥ 0.990). Levels of lipid peroxidation were significantly lower 60 min post-transplant in the NP group (NP = 477 ± 118.0 versus HMP = 671 ± 99.4 pg/mL; P = 0.026). CONCLUSION A period of NP at the end of the renal preservation period in NHB kidneys is a feasible method of kidney preservation. NP could prove to be a useful technique to predetermine graft function and allow pre-transplant modification of organs.

Effects of arterial pressure in an experimental isolated haemoperfused porcine kidney preservation system

Normothermic preservation provides metabolic support to an ischaemically damaged organ before use as a kidney transplant. Optimal conditions for ex vivo preservation have not yet been established. This study examined the effects of arterial pressure on renal preservation using isolated haemoperfused kidneys.

Effects of hydrogen sulphide in an experimental model of renal ischaemia–reperfusion injury†

Renal ischaemia–reperfusion injury (IRI) is a major cause of acute renal failure and renal transplant dysfunction. The aim of this study was to investigate the efficacy of the endogenous gaseous signalling molecule hydrogen sulphide in protecting against renal IRI.

A comparison of renal preservation by cold storage and machine perfusion using a porcine autotransplant model

Background. Pulsatile machine perfusion offers theoretical advantages as a method of preserving kidneys before transplantation. This may be particularly the case for organs taken from non–heart-beating donors (NHBD), but there is still a lack of data to support this view. The aim of this study was to compare the effectiveness of static cold storage in ice (CS) and hypothermic pulsatile machine perfusion (MP) as methods of renal transplant preservation. Methods. Groups of large white pigs (n=5) underwent left nephrectomy after warm ischemic times (WIT) of 0 or 30 min. Kidneys were preserved by CS or by cold (3°–8°C) MP for 24 hr. The left kidney was then autotransplanted into the right iliac fossa and an immediate right nephrectomy was performed. Renal function was assessed daily for 14 days. Results. Fourteen-day animal survival rates for 0 and 30 min WIT were four of five and one of five after both CS and MP. In the zero WIT groups, there was improved recovery of renal function after MP (area under the creatinine curve, 4,722±2,496 [MP] vs. 8,849±2,379 [CS]; P<0.05). MP did not improve renal function after 30 min of WIT (mean daily area under the creatinine curve, 1,077±145 [MP] vs. 1,049±265 [CS]). Conclusions. In this model, MP improved 24-hr preservation of kidneys not subjected to warm ischemia (heart-beating donor model), but there was no evidence that MP was a better method of preservation than CS for kidneys exposed to 30 min of WIT (NHBD model).