Function of autotransplanted kidneys after 24-hour preservation by hypothermic pulsatile perfusion or simple cord storage.

Canine kidneys, flushed with either Collins solution or autologous cryoprecipitated plasma, were then stored for 24 hr by either simple cold storage (submersion) in the flushing solution, or by continuous hypothermic pulsatile perfusion with cryoprecipitated plasma. After autotransplantation without contralateral nephrectomy, detailed split renal function studies were carried out immediately as well as 2 and 7 days later. Measurements were made of inulin clearance, maximal transport of p-aminohippurate, reabsorption of sodium, chloride, and glucose, and the reabsorption of free water. Contralateral nephrectomy was performed 7 days after transplantation, following measurement of renal functions on that day, and plasma urea nitrogen and creatinine were measured periodically over the ensuing 3 weeks. Renal function after transplantation was affected very little by the choice of flushing solution, and the course of azotemia that developed following contralateral nephrectomy was the same in all groups. However, the detailed functional measurements showed that during the 7-day period after transplantation, renal function was depressed to a much greater extent in kidneys treated by simple cold storage than in those that had been perfused.     

UW solution for hypothermic machine perfusion of warm ischemic kidneys

BACKGROUND: Donation of kidneys from non-heart beating donors (NHBD) is increasingly being used to expand the donor pool. Warm ischemic injury of these kidneys suffered at harvest results in DGF at transplantation. In this study, we used hypothermic continuous machine perfusion preservation to mitigate this injury using two available solutions. METHODS: Dog kidneys (beagles) were exposed to 0, 60, or 75 min of in situ warm ischemia (37 degrees C), followed by 24 to 72 hr preservation by machine perfusion with Belzer MPS solution or the UW-solution (Viaspan). Auto-transplantation was performed with immediate contralateral nephrectomy. Survival and renal function (serum creatinine) were evaluated for up to 10 days posttransplant. RESULTS: Both solutions were equally effective for 72 hr machine perfusion preservation of dog kidneys giving 100% survival with only minor renal injury. Both solutions were also equally effective for preservation of kidneys exposed to 60 min of warm ischemia. However, only the UW solution gave reliable preservation (86% survival vs. 25% survival) in kidneys exposed to 75 min of warm ischemia and 24 hr machine perfusion. CONCLUSION: UW solution used with continuous hypothermic machine perfusion preservation can rescue canine kidneys from severe warm ischemic injury.     

Perfusion characteristics of preserved canine kidneys subjected to warm ischaemia.

Canine kidneys were subjected to 0, 15 or 30 min of warm ischaemia followed by 24 hours preservation by perfusion. Changes in perfusate concentration of acid radicles, lactate, free fatty acid and lactice dehydrogenase were assessed at 1 hour and 24 hours. With the exception of LDH concentration at 1 hour, no single parameter was capable of detecting kidneys which were so damaged as to be non-life supporting.     

Recovery of glomerular and tubular function in autotransplanted dog kidneys preserved by hypothermic storage or machine perfusion. Relation of initial function to long-term function

Sixteen male dogs had split renal function studies prior to unilateral nephrectomy and autotransplant. Kidneys were preserved for 24 hr by either simple hypothermic storage in Collins C2 solution (SHS) or machine-perfused (MP) on a Waters machine (MOX 100) with plasmanate perfusate. Renal function studies were repeated at 1 hr and at 7, 14, and 28 days, and the statistical relationship between initial and 1-month function was determined for a number of parameters. All MP kidneys functioned immediately, whereas 1/3 of SHS kidneys had delayed function. Recovery was more rapid in MP kidneys and was essentially complete by 14 days, at which time MP kidneys had higher rates of creatinine clearance and sodium reabsorption. However, by one month 3/7 MP kidneys (P = 0.15 compared with SHS) had lower creatinine clearance rates than at 2 weeks, and para-aminohippurate (PAH) clearance and fractional sodium reabsorption were significantly decreased. During the same period SHS kidneys either showed continued improvement or maintained stable function. Thus, by one month there were no differences between the groups in clearances of creatinine and PAH, plasma creatinine and blood urea nitrogen concentrations, or fractional reabsorption of sodium, potassium, and water. For SHS kidneys, the 1-hr creatinine clearance and the absolute rate of sodium reabsorption were strong predictors of the eventual function of the kidneys at one month (r = 0.93 and r = .83, P less than 0.05, respectively). No such correlations were found in MP kidneys (r = less than .01, P greater than 0.9 for both variables). The data show that MP results in significantly better function early after transplant, but this advantage does not persist, and that SHS kidneys early function is a good predictor of long-term recovery, but this is not true for MP kidneys.     

Study of lesions in reimplanted kidneys preserved by hypothermic storage and perfusion with solution of the extracellular type

The consequences of preservation by solution of extracellular composition were examined in 24 renal autografts. Nine animals survived for indefinite period. In the reimplanted kidneys of the animals which had died in the acute phase (1st to 7th day) gross oedema, haemorrhages, lesions of tubular epithelium and glomerular congestion were prevalent. In later stages (23rd to 43rd day) the renal structure was well preserved in some places and there were extensive fibrous peritubular areas. In the kidneys of the long-term survivors the fibrous tissue resulting from irreversible destruction was confined to small areas. It is concluded that, though some degree of tissue destruction is inevitable, it is possible to minimize it by using appropriate preserving solutions.     

Vascular function in kidneys preserved by simple cold storage in Sacks' or Collins' solutions.

Vascular resistance was determined in 40 kidneys after preservation in Collins' or Sacks' solution for 24 and 48 hours. Kidneys without warm ischaemia and kidneys with up to 60 min of warm ischaemia prior to preservation were investigated, vascular resistance was determined during short time perfusion with Tis-U-Sol at 4 degrees. The experiments showed that cold preservation of kidneys with no warm ischaemia or 15 min of warm ischaemia gave a small increase in vascular resistance, independent of the solution used. 30 and 60 min of warm ischaemia gave a considerable increase in vascular resistance, but less increase was found in kidneys preserved in Sacks' solution. Determination of the weights and thereby formation of oedema showed slight dehydration in kidneys preserved in Sacks' solution. Kidneys preserved in Collins' solution showed small increase in weight. No correlation was, however, found between the vascular resistance and degree of oedema.     

Evidence of free-radical-induced damage in rabbit kidneys after simple hypothermic preservation and autotransplantation

Rabbit kidneys were stored for 24 or 48 hr at 0 degree C after single-passage vascular flush with 30 ml of cold hypertonic citrate solution or 0.9% isotonic sodium chloride solution. They were then subjected to in vitro biochemical assay for evidence of free-radical damage immediately after storage or after they had been orthotopically autotransplanted and reperfused with blood in vivo for 60 min. Kidney homogenates were incubated at 37 degrees C and assayed for fluorescent conjugated Schiff bases as indicators of lipid peroxidation, as well as for superoxide dismutase activity and reduced and oxidized glutathione. In kidneys flushed with hypertonic citrate, no evidence of peroxidation could be detected immediately after storage for 24 or 48 hr. However, after in vivo reperfusion significantly more peroxidation (P less than 0.01) was evident. Storage in isotonic saline solution produced still higher levels of peroxidation damage whether reperfused or not (P less than 0.001). Schiff base formation was inversely proportional to the reduced and oxidized glutathione levels measured. No changes in superoxide dismutase levels could be detected. It is concluded that lipid peroxidation is important during cold ischemia but most damage occurs during the 60-min of reperfusion in vivo immediately after transplantation.     

Increased urinary excretion of endothelin during hypothermic perfusion preservation in kidneys subjected to preretrieval warm ischemic injury

The purpose of the study was two-fold: 1) to determine whether endothelin (ET) levels could be detected in the ureteral effluent during hypothermic perfusion preservation (HPP) and; 2) to determine whether preretrieval warm ischemic (WI) injury is associated with increased ureteral excretion of ET. In situ pre-WI injury was induced in Lewis rats (n=10) by a 30-min extrinsic occlusion of the suprarenal aorta. The left kidney underwent 16 hr of HPP, and ureteral effluent (UE) from ischemic and control kidneys (n=10) was collected over 16 hr of HPP. The UE ET concentration and total ET excretion over 16 hr of HPP were significantly higher in kidneys subjected to pre-WI injury compared with nonischemic controls. Kidneys subjected to pre-WI injury can be distinguished from nonischemic control kidneys during HPP by a significantly higher concentration of ET in the UE and a higher overall excretion of ET during HPP.     

Effects of hypothermic perfusion in isolated pig kidneys after warm ischemia

An experimental study in pigs was designed to evaluate the consequences of normothermic ischemia in hypothermic isolated renal perfusion (HP). We perfused 16 kidneys after 45 minutes of vascular occlusion. Another 16 kidneys were perfused without previous warm ischemia. The ureter was catheterized in all procedures and the output collected during HP. Creatinine was added to the perfusion solution initially in order to determine creatinine clearance (CrCl). HP hydrodynamics were recorded in real time through a computerized system. According to the results, renal vascular resistance as well as CrCl were higher in ischemic kidneys. Both facts, along with minimal differences in the microscopic study, suggested an increased vascular tone of the efferent postglomerular arteriole during HP. HP was proven to be an optimal technique to minimize the histological consequences of ischemia. Microvascular and biochemical changes produced during HP may be essentially related to dynamic causes.