Hypothermic perfusion preservation of the isolated dog lung

A total of 13 left lower canine pulmonary lobes were perfused with glucose-enriched autologous blood. Of these, 5 test lobes were perfused at 28°C. for periods ranging from 6 to 21 hours and were subsequently evaluated during a 1-hour period of normothermic (37°C.) perfusion. Excellent preservation of lobe function was shown by comparison with the initial normothermic perfusion interval of control lobes. Elevated pulmonary vascular resistance noted with hypothermic perfusion did not adversely affect respiratory gas exchange or compliance and may have been due to subnormal pulmonary venous pressures.In a second group of 12 dogs, 3 whole left lungs subjected to extended hypothermic perfusion exhibited normal functional adequacy following allotransplantation compared with nonpreserved controls. The salutory effect of hypothermia permitted perfusion preservation of pulmonary function and morphology for a longer period than has hitherto been reported.     

Optimal pH for simple cold storage or machine perfusion of dog kidneys with UW solution

Metabolic suppression by temperature is a key to successful organ preservation. Additional methods for inducing metabolic suppression may further improve organ preservation. Extracellular acidosis has been shown to suppress warm anoxic injury to various isolated cells. Acidosis may suppress enzymes with a pH optimum at the pH of the cytosol (pH 7.3). In this study, the combination of hypothermia and acidosis was used to determine if it would improve renal preservation. Dog kidneys were cold-stored (CS) for 48 h in University of Wisconsin (UW) solution with the pH adjusted to 6.4, 6.8, 7.4, or 7.8. Kidneys were also machine-perfused (MP) for 3 days with the gluconate perfusion solution (Belzer's machine perfusion solution, MPS) at pHs similar to those tested for CS. Renal function (serum creatinine, SCr) and survival were recorded in immediate contralateral nephrectomized recipients. On the basis of maximum SCr values, kidneys preserved by CS or MP were best preserved at pHs of 7.4 or 7.8. At a pH of 6.8, SCr values were elevated and returned to normal at a slower rate than in those preserved at higher pHs. This study shows that acidosis is not cytoprotective to cold-stored dog kidneys and causes preservation/reperfusion injury. Received: 25 August 1997 Received after revision: 18 November 1997 Accepted: 14 January 1998     

Hypothermic renal protection using cold histidine-tryptophan-ketoglutarate solution perfusion in suprarenal aortic surgery

We examined data of 21 patients who were treated with selective perfusion of both renal arteries with 500 mL of 8 degrees C histidine-tryptophan-ketoglutarate (HTK) solution each for renal protection during aortic surgery. Only the data from aortic surgeries with unavoidable suprarenal aortic cross-clamping for juxtarenal or suprarenal abdominal aortic aneurysms (AAAs) or high Leriche syndrome accompanied with stenosis of renal arteries are presented. Five patients underwent immediate surgery because of perforation of an AAA; the other 16 patients went through elective surgeries. In three cases (14%) stenosis of the renal arteries was diagnosed; nevertheless, implantation of an aortorenal bypass was necessary in seven patients. In total, 14 aortorenal bypasses were implanted (five venous grafts and nine prosthesis grafts). Four (19%) patients needed catecholaminergic support to establish stable circulatory conditions; in two (9%) of these cases additional ischemia of the colon was observed and sigmoidectomy was performed. All of these four patients underwent immediate surgery, and one died after surgery because of severe sepsis. In four cases postsurgical renal insufficiency was observed. Three of these patients were admitted for emergency surgery because of their hemodynamic situation due to perforation of the AAA. None of the patients needed chronic dialysis after surgery. Whereas in all patients who underwent elective surgery the renal function remained stable as judged by postoperative serum creatinine values, in five out of seven patients with aortorenal bypass surgery the renal function improved. Perfusion with cold HTK solution offers an additional procedure to protect renal function in patients undergoing elective surgery with suprarenal cross-clamping of the aorta.     

Sequential cold storage and normothermic perfusion of the ischemic rat liver

Extending transplant criteria to include livers obtained from donors after cardiac death (DCD) could increase the liver donor pool, but conventional simple cold storage of these ischemic organs can lead to poor graft function after transplantation. Experimental normothermic machine perfusion has previously proven to be useful for the recovery and preservation of DCD livers, but it is more complicated than conventional cold storage, and, therefore, is perhaps not practical during the entire preservation period. In clinical situations, the combined use of simple cold storage and normothermic perfusion preservation of DCD livers might be more realistic, but even a brief period of cold storage prior to normothermic preservation has been suggested to have a negative impact on graft viability. In this study we show that rat livers subjected to 45 minutes of ex vivo warm ischemia followed by 2 hours of simple cold storage can be reclaimed by 4 hours of normothermic machine perfusion. These livers could be orthotopically transplanted into syngeneic recipients with 100% survival after 4 weeks (N = 10), similar to the survival of animals that received fresh livers that were stored on ice in University of Wisconsin (UW) solution for 6 hours (N = 6). On the other hand, rats that received ischemic livers preserved on ice in UW solution for 6 hours (N = 6) all died within 12 hours after transplantation. These results suggest that normothermic perfusion can be used to reclaim DCD livers subjected to an additional period of cold ischemia during hypothermic storage.     

Hypothermic reconditioning after cold storage improves postischemic graft function in isolated porcine kidneys

Delayed graft function still represents a major complication in clinical kidney transplantation. Here we tested the possibility to improve functional outcome of cold stored kidneys a posteriori by short‐term hypothermic machine perfusion immediately prior to reperfusion. A total of 18 kidneys from female German Landrace pigs was flushed with Histidine‐Tryptophan‐Ketoglutarate solution and cold‐stored for 18 h (control). Some grafts were subsequently subjected to 90 min of hypothermic reconditioning by hypothermic machine perfusion with (HR+O₂) or without (HR?O₂) oxygenation of the perfusate. Early graft function of all kidneys was assessed thereafter by warm reperfusion in vitro (n = 6, respectively). Renal function upon reperfusion was significantly enhanced by HR+O₂ with more than threefold increase in renal clearances of creatinine and urea. HR+O₂ also led to significantly higher urinary flow rates and abrogated the activation of caspase 3. By contrast, HR?O₂ was far less effective and only resulted in minor differences compared to control. It is derived from the present data that initial graft function can be significantly improved by 2 h of oxygenated machine perfusion after arrival of the preserved organ in the transplantation clinic.     

Hypothermic oxygenated machine perfusion of the human pancreas for clinical islet isolation: a prospective feasibility study

Due to an increasing scarcity of pancreases with optimal donor characteristics, islet isolation centers utilize pancreases from extended criteria donors, such as from donation after circulatory death (DCD) donors, which are particularly susceptible to prolonged cold ischemia time (CIT). We hypothesized that hypothermic machine perfusion (HMP) can safely increase CIT. Five human DCD pancreases were subjected to 6 h of oxygenated HMP. Perfusion parameters, apoptosis, and edema were measured prior to islet isolation. Five human DBD pancreases were evaluated after static cold storage (SCS). Islet viability, and in vitro and in vivo functionality in diabetic mice were analyzed. Islets were isolated from HMP pancreases after 13.4 h [12.9–14.5] CIT and after 9.2 h [6.5–12.5] CIT from SCS pancreases. Histological analysis of the pancreatic tissue showed that HMP did not induce edema nor apoptosis. Islets maintained >90% viable during culture, and an appropriate in vitro and in vivo function in mice was demonstrated after HMP. The current study design does not permit to demonstrate that oxygenated HMP allows for cold ischemia extension; however, the successful isolation of functional islets from discarded human DCD pancreases after performing 6 h of oxygenated HMP indicates that oxygenated HMP may be a useful technology for better preservation of pancreases.     

低温机械灌注与冷藏保存在尸体肾移植中的应用

随着尸体肾移植的文泛开展,冷藏保存技术作为常规的供肾保存技术受到了研究者的挑战.近年来不断有回顾性的研究表明低温机械灌注保存能改善肾移植的近期效果,但是大规模的多中心前瞻性研究还未见报道.     

Comparison of pulsatile perfusion and cold storage for paired kidney allografts

Use of pulsatile perfusion to optimize outcomes in deceased donor kidney transplantation remains controversial. This study is a retrospective analysis of all cadaveric renal allografts procured locally by our center over a 3-year period. Kidney pairs were identified in which one kidney underwent pulsatile perfusion and transplantation at our center, whereas the contra-lateral kidney underwent cold storage and transplantation at another center. Eighty-eight percent of the exported kidneys were six-antigen matches. Study outcomes included 1-year graft and patient survival, delayed graft function, and need for posttransplant dialysis. Recipients had similar demographic and disease characteristics. Survival for pulsatile perfusion and cold storage were 95% and 88% (graft, P=0.43) and 98% and 90% (patient, P=0.36), respectively. The incidence of delayed graft function was 5% and 35% (P<0.01), whereas posttransplant dialysis was 5% and 30% (P<0.01), for pulsatile perfusion and cold storage, respectively. These data support routine use of pulsatile perfusion.     

Advantages of normothermic perfusion over cold storage in liver preservation

BACKGROUND: To minimize the ischemia-reperfusion injury that occurs to the liver with the current method of preservation and transplantation, we have used an extracorporeal circuit to preserve the liver with normothermic, oxygenated, sanguineous perfusion. In this study, we directly compared preservation by the standard method of simple cold storage in University of Wisconsin (UW) solution with preservation by perfusion. METHODS: Porcine livers were harvested from large white sows weighing between 30 and 50 kg by the standard procedure for human retrieval. The livers were preserved for 24 hr by either cold storage in UW solution (n=5) or by perfusion with oxygenated autologous blood at body temperature (n=5). The extracorporeal circuit used included a centrifugal pump, heat exchanger, and oxygenator. Both groups were then tested on the circuit for a 24 hr reperfusion phase, analyzing synthetic function, metabolic capacity, hemodynamics, markers of hepatocyte and reperfusion injury, and histology. RESULTS: Livers preserved with normothermic perfusion were significantly superior (P=0.05) to cold-stored livers in terms of bile production, factor V production, glucose metabolism, and galactose clearance. Cold-stored livers showed significantly higher levels of hepatocellular enzymes in the perfusate and were found to have significantly more damage by a blinded histological scoring system. CONCLUSIONS: Normothermic sanguineous oxygenated perfusion is a superior method of preservation compared with simple cold storage in UW solution. In addition, perfusion allows the possibility to assess viability of the graft before transplantation.