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Oxygenated machine perfusion of human organs has been shown to improve both preservation quality and time duration when compared to the current gold standard: static cold storage. However, existing machine perfusion devices designed for preservation and transportation of transplantable organs are too complicated and organ-specific to merit use as a solution for all organs. This work presents a novel, portable, and nonelectronic device potentially capable of delivering oxygenated machine perfusion to a variety of organs. An innovative pneumatic circuit system regulates a compressed oxygen source that cyclically inflates and deflates silicone tubes, which function as both the oxygenator and perfusion pump. Different combinations of silicone tubes in single or parallel configurations, with lengths ranging from 1.5 to 15.2 m, were evaluated at varying oxygen pressures from 27.6 to 110.3 kPa. The silicone tubes in parallel configurations produced higher peak perfusion pressures (70% increase), mean flow rates (102% increase), and oxygenation rates (268% increase) than the single silicone tubes that had equivalent total lengths. While pumping against a vascular resistance element that mimicked a kidney, the device achieved perfusion pressures (8.4–131.6 mmHg), flow rates (2.0–40.2 mL min−1), and oxygenation rates (up to 388 μmol min−1) that are consistent with values used in previous kidney preservation studies. The nonelectronic device achieved those perfusion parameters using 4.4 L min−1 of oxygen to operate. These results demonstrate that oxygenated machine perfusion can be successfully achieved without any electronic components. [ABSTRACT FROM AUTHOR]

The advantages of oxygenated perfusion are continuing to be demonstrated by many groups focused on improving the efficacy of tissue preservation for transplant, bioreactors for studies of basic tissue physiology, and closed-loop resuscitation. This work presents a novel and portable device that supplies oxygenated and pulsatile perfusion, both of which are regulated by a single pump-oxygenator component comprised of silicone tubes that are cyclically inflated/deflated with compressed oxygen. In this study, pump variables (oxygen supply pressure and length of a silicone tube) were evaluated against hydraulic elements that mimicked the vascular resistance of kidneys, livers, and hearts. The perfusion pressures, flow rates, and oxygenation rates produced by the device were characterized for all configurations of pump variables, and the pulse rates were tuned to improve performance. The device supplied perfusion pressures ranging from 3.5 to 109 mmHg, flow rates ranging from 1.4 to 71.8 mL min−1, and oxygenation rates up to 316.6 µmol min−1. From those results, it was determined that the device was capable of achieving perfusion parameters used in previous kidney, liver, and heart preservation studies. Ultimately, this research demonstrated the efficacy of a novel device that is designed to supply oxygenated perfusion across a range of applications. [ABSTRACT FROM AUTHOR]

Preservation of human cadaver kidneys for transplantation has been achieved primarily by two methods, hypothermic pulsatile perfusion with cryoprecipitated plasma and cold storage with an electrolyte solution. It has been suggested that pulsatile perfusion results in an increased antigenicity of the transplanted kidney. To investigate the possibility that pulsatile perfusion causes changes which may accelerate allograft rejection, machine preservation was compared with simple cold storage. The kidneys were preserved by either one of the two methods for 6 or 24 hours followed by allotransplantation in nephrectomised dogs. No immunosuppressive drugs were given. Kidneys which were allografted without undergoing any preservation (0 hrs) had a mean survival time of 10.4±1.7 days (n=5). Kidneys preserved by machine perfusion for 6 and 24 hours survived for 9.6±1.4 (n=5) and 10.9±1.3 (n=9) days respectively. The mean suryival time for simple cold storage for 6 and 24 hours was 9.3±1.3 (n=7) and 12.0±1.9 (n=6) days. Our findings suggest that in kidneys exposed to minimal warm ischaemia there is no significant difference between the two methods of preservation on renal allograft survival for the time intervals tested. [ABSTRACT FROM AUTHOR]

Copyright of Langenbecks Archiv fuer Chirurgie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Langenbecks Archiv fuer Chirurgie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Langenbecks Archiv fuer Chirurgie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Twelve surgically removed human kidneys (mainly tumor kidneys) were investigated. The investigations comprised perfusion criteria (perfusion flow, perfusion pressure, perfusion resistance, electrolyte equilibration). During perfusion of the kidneys with HTK solution, the perfusion resistance was nearly three times as high in human kidneys as in canine kidneys perfused under the same conditions in previous studies. Beside possible species differences the raised perfusion resistance may be explained by the greater trauma to the human kidneys due to the surgery, the primary ischemic stress which cannot be avoided clinically and the often nonoptimal initial diuresis. Nevertheless definitive perfusion is possible under clinical conditions although pronounced increases of perfusion resistance may occur. As indicated by the raised perfusion resistance of human kidneys under clinical conditions as compared with canine kidneys in an experimental model, electrolyte equilibration of human kidneys was protracted. For this reason, a duration of perfusion of at least 10 min is necessary in clinical application of HTK solution, i.e., longer than in animal experiments. [ABSTRACT FROM AUTHOR]

Investigations were carried out by means of an autologous, heterotopic model for kidney transplantation applied to dogs. Duration of cold ischemia was 48 h. Four experimental groups were arranged. During the first 20 min following revitalization of the transplanted kidney, group 1 (HTK solution/80 cm perfusion height) showed a significant glomerular and tubular malfunction. In group 2 (HTK solution/120 cm perfusion height), only four urinary proteins with molecular weights of 25 kDa, 67 kDa, 100 kDa and >100 kDa were found. The excretion of higher molecular proteins receded over the 20-min period of observation. In both group 3 (HTK/aspartate solution) and group 4 (HTK/tryptophan solution) the quantity of excreted glomerular and tubular protein was well above that of group 2. As opposed to the 'Tryptophan' group, a complete restoration of renal function was observed in the 'Aspartate' group after 4 weeks. In general, the 'standard' HTK protective solution delivered with 120 cm perfusion pressure gave the most favorable results, with the lowest levels of proteinuria and a satisfactory recovery of renal function after revitalization. [ABSTRACT FROM AUTHOR]

Although transplanting rat kidneys is an established microsurgical technique, inulin clearance is abnormally low, due to rejection and/or warm ischemia-induced damage. In the present studies, rejection was avoided by using inbred Brown Norway rats as donors and recipients. Donor kidneys were flushed with ice-cold solutions of various composition (saline, saline + 200 or 400 m M mannitol) and pHs (5.7, 6.4, and 7.4), and the kidneys were kept cold during transplantation into unilaterally nephrectomized recipients. Renal function was assessed by clearance techniques 1 week later. In control rats, with both native kidneys intact, the ratio of inulin clearance, left kidney to right kidney, was 0.99±0.02. In rats with a native right kidney and a transplanted left kidney that had been flushed with saline, the ratio was considerably lower (0.46±0.09). Adding 200 m M mannitol to the saline flush solution increased the ratio (0.89±0.09). In comparison, adding 200 m M mannitol and 5 m M phosphate buffer at pH 7.4 resulted in a somewhat lower ratio (0.80±0.09), whereas adding 200 m M mannitol and 5 m M phosphate buffer at pH 5.7 resulted in a higher ratio, one that was indistinguishable from control (0.97±0.09). Thus, in this latter group, the inulin clearances of the transplanted kidneys were identical to those of the contralateral native kidneys. [ABSTRACT FROM AUTHOR]

In 110 canine kidneys, we examined the time course of energy rich phosphates, lactate, intrarenal ph and renal morphology with Euro-Collins-or with HTK-protection of Bretschneider and compared these findings with unprotected kidneys during complete ischemia at 1 °C and at 25 °C. Both kidney protective solutions prolonged energyrich phosphate-decline by a factor of 3-4 compared with that of unprotected kidneys. The lactate increase was greater in Euro-Collins-protected kidneys than in HTK-protected and in unprotected kidneys, leading to pH values of 6.5 in Euro-Collins and to 6.4 in unprotected kidneys after 24 hours, in contrast to a pH-value of 7.3 with HTK-protection. This may be the reason for structural deterioration seen in unprotected and in Euro-Collins-protected kidneys after 12, and 48 h of ischemia at 1 °C, whereas in HTK-protected kidneys a sufficient preservation of structure can be seen. In one human kidney, protected with Euro-Collins-solution, we were able to show that at 1 °C intrarenal pH and lactate accumulation is similiar to the levels in canine kidneys. In Euro-Collins preserved kidneys lactate accumulation at 25 °C is even greater than at 1 °C, leading to inhibition of energy metabolism and to structural deterioration, whereas HTK-solution, because of its high buffer concentration, is able to maintain ischemic metabolism leading to sufficient protection of intrarenal pH and of adenine nucleotides as well as structural protection at 1 °C and at 25 °C. [ABSTRACT FROM AUTHOR]

Copyright of Klinische Wochenschrift is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Klinische Wochenschrift is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The article discusses research on the use of histidine-tryptophan-ketoglutarate (HTK) solution for the preservation of kidneys. It references the studies "Increased Primary Non-Function in Transplanted Deceased-Donor Kidneys Flushed With Histidine-Tryptophan-Ketoglutarate Solution," by R. B. Stevens et al. and "Histidine-Tryptophan-Ketoglutarate (HTK) Is Associated With Reduced Graft Survival of Deceased Donor Kidney Transplants," by Z. A. Stewart et al., published in a 2009 issue of "American Journal of Transplantation."

Copyright of Langenbecks Archiv fuer Chirurgie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)