Cold Perfusion Research Articles

Macroscopic assessment of the quality of cold perfusion after deceased-donor kidney procurement: A United Kingdom population-based cohort study.

Concern regarding the quality of cold perfusion (QOP) during macroscopic assessment of procured kidneys is a common reason for discard. In the UK, QOP is routinely graded by both retrieving and implanting teams during back-bench surgery as: 1 (good), 2 (fair), 3 (poor) or 4 (patchy). We evaluated the association of this grading with organ utilization, graft outcomes, and agreement between teams. Data on all deceased-donor kidneys procured between January 2000 and December 2016 were analyzed for discard rates, while association with graft outcomes was studied in single adult transplants. Of 31,167 kidneys procured, 90.6%, 5.7%, 1.7%, and 2.1% were assigned grades 1, 2, 3, and 4, respectively, at retrieval. QOP was an independent risk factor of discard, with the highest rates observed in grade 3 kidneys (41.8%), compared to 6.5% in grade 1 (aOR 7.67, 95% CI 5.44-10.82, p<.001). Grading at retrieval was an independent predictor of delayed graft function (p=.019) and primary non-function (p=.001), but not long-term graft survival (p=.111). Implanting grade was an independent predictor of all three outcomes (p<.001, p<.001, and p=.002, respectively). Consistency of grading between teams was poor (Kappa=0.179). QOP influences utilization and predicts outcomes, but a standardized and validated scoring system is required.

A study of the effect of hot and cold gas perfusion sequence on caloric test results

Objective: To study whether the warm/cold air injection sequence affects the test results in the caloric test, and provide a basis for the specification and quality control of the caloric test. Methods:Video nystagmography and warm and cold air stimulation apparatus were applied for caloric test. Thirty healthy volunteers （60 ears） were divided into two groups of 15 （30 ears） each. The first group was given cold air stimulation followed by warm air stimulation, and the second group was given heat followed by cold. The differences in nystagmus maximal slow phase velocity （SPV）, semicircular canal paresis （CP） and dominant preponderance （DP） were compared between the two groups of subjects under different perfusion sequences of caloric test. Results:The intensity of nystagmus evoked by subjects in group 1 （cold first and then warm） and group 2 （warm first and then cold） were similar. Paired t-test showed that intra-group analysis of the SPV values of the two groups, comparison of the intensity of nystagmus evoked by different temperatures of the same ear or different sides of ear with the same temperature, the difference was not statistically significant （all P>0.05）. Independent samples t-test showed that between-group analysis of SPV values of two groups, the intensity of nystagmus induced by the same and different temperature stimuli in the ipsilateral ear, the difference was not statistically significant （all P>0.05）. Independent samples t-test showed that the CP values of the two groups were analyzed between groups, and the difference was not statistically significant （all P>0.05）. Independent samples t-test showed that DP values of both groups were in the normal range and the difference was not statistically significant （all P>0.05）. Conclusion:Different perfusion sequences of warm and cold air do not affect the results of caloric tests, and the order of warm and cold air stimulation is not the normative and quality control research direction of caloric test.

Surgical strategies in the management of chronic dissection of the thoracoabdominal aorta.

Most operations for dissection of the thoracoabdominal aorta take place in the chronic phase of the disease, because the acutely dissected distal aorta is almost always initially treated non-surgically with aggressive pharmacological anti-impulse therapy. Identifying patients who are no longer responding to medical treatment is the first step in preventing further disease progression and rupture. Symptomatic aneurysms should be promptly repaired. Asymptomatic patients are followed until significant aortic dilation occurs and reaches a threshold of intervention: current guidelines endorse repair once a diameter of 5.5 cm is reached. In patients with heritable thoracic aortic disease (such as Marfan Syndrome), the threshold of intervention is often lowered. Aortic replacement typically centers on the dilatated segment. For all extents of repair, we use passive mild hypothermia, sequential aortic cross-clamping, aggressive reimplantation of intercostal and lumbar arteries, and cold renal perfusion whenever possible. For Crawford extents I and II thoracoabdominal aneurysm repair, we routinely use cerebrospinal fluid drainage, left heart bypass, and selective visceral perfusion. A four-branched graft approach to thoracoabdominal aortic aneurysm repair is frequently used in patients with chronic aortic dissection; this approach facilitates visceral artery perfusion during repair, expedites the distal anastomosis, and prevents subsequent visceral patch aneurysms. Lifelong imaging surveillance is necessary, because the distal aorta often continues to expand; residual aortic dissection commonly remains after repair and may necessitate further repair.

A history of open thoracoabdominal aortic aneurysm repair: perspective from Houston.

As late as the early 1950s, ligation, cellophane wrapping, endoluminal wiring, endoaneurysmorrhaphy, and other techniques were well-accepted treatments for aneurysm. Techniques aimed at repair of syphilitic and saccular aneurysms of the proximal aorta were largely unsuitable for the larger, fusiform atherosclerotic aneurysms of the thoracoabdominal aorta. The earliest replacements of the thoracoabdominal aorta relied on the use of donor homografts. Repair of thoracoabdominal aortic aneurysms (TAAAs) necessitated exposing the thoracic aorta above the diaphragm and the abdominal aorta below the diaphragm. Furthermore, these repairs were complicated by incorporating the branching visceral arteries, as well as the risk of life-threatening distal ischemia during repair. Although many of the early centers for aortic surgery were able to quickly develop aortic banks to prepare and store homografts, in time, it became clear that homografts were not ideal for aortic replacement. The ideal aortic replacement would be nontoxic, hypoallergenic, durable, elastic, pliable, and readily available in multiple sizes and shapes. Although Vinyon-N and other materials were explored as synthetic aortic substitutes, ultimately Dacron (Dacron, Kennesaw, GA, USA) was determined to be the most suitable material for aortic graft replacement. The success of Dacron ushered in extra-anatomic approach to TAAA repair, which remained popular for 2 decades. In time, the graft inclusion technique (which followed an anatomical approach) was adopted, which facilitated shorter repair times and improved outcomes for patients. rotective adjuncts-such as left heart bypass, cerebrospinal fluid drainage, and cold renal perfusion-were incorporated into surgical repair; the historical context of these adjuncts is explored in depth. The success of TAAA repair depends on the contributions of many individuals. The history of TAAA repair continues to evolve and remains indebted to the pioneering heroes, without whom, successful repair would not be possible.

Research Highlights.

Research Highlights.

Functional and oncologic outcomes of robot-assisted simple enucleation with and without renal arterial cold perfusion in complex renal tumors: a propensity score-matched analysis

BackgroundTo compare robot-assisted simple enucleation with renal arterial cold perfusion (RACP-RASE) and RASE alone in complex renal tumors with regard to perioperative, functional and oncologic outcomes by propensity score-matched analysis.MethodsData from 351 patients who underwent RACP-RASE or RASE for complex renal tumors were recorded between September 2014 and December 2017. Propensity score-matched analysis was performed on age, sex, BMI, ECOG score, tumor side and size, preoperative estimated glomerular filtration rate (eGFR), RENAL score and PADUA score.ResultsThe study included 31 RACP-RASE and 320 RASE procedures. RENAL score and PADUA score were higher and tumor diameter was greater under RACP-RASE than RASE. After matching, the two groups were similar in estimated blood loss (208.3 vs 230.7 ml; p = 0.696) and ischemic time (34.8 vs 32.8 min; p = 0.342). The RACP-RASE group had significantly longer operative time than the RASE group (264.1 ± 55.7 vs 206.9 ± 64.0 min, p = 0.001). There was no difference in the incidence of postoperative complications between the two groups (13.8% vs 24.1%; p = 0.315), as was the overall incidence of positive surgical margins (3.4 vs 0%; p = 1.000). The changes in eGFR significantly differed between the two groups at 3 months (p = 0.018) and 12 months (p = 0.038). More patients in the RASE group were CKD upstaged (p = 0.043). At multivariable analysis, preoperative eGFR and the type of procedure were significant predictive factors for a change of more than 10% in eGFR at 3 months postoperatively. There was no local recurrence or distant metastasis during follow-up.ConclusionsRACP-RASE is an effective and safe technique for complex renal tumors that can provide appropriate temporary arterial occlusion and renal hypothermic perfusion. Renal arterial cold perfusion may be helpful in protecting renal function in RASE as compared with warm ischemia.

Impact of donor kidney weight to recipient body weight ratio on long-term graft outcomes in live donor kidney transplantation

Background: Kidney weight has been suggested as a surrogate marker for nephron numbers and renal function. Small donor kid ney sizes relative to recipient body size is an important contributor to short-term graft renal function, but the impact of size mis matching on long-term graft outcomes remains unknown. This study is aimed to evaluate the impact of the donor kidney weight to recipient body weight ratio (KW/BW) on long-term graft survival in live donor kidney transplantation. Methods: We performed a longitudinal cohort study in 1,397 patients who underwent live donor kidney transplantation between 2000 and 2016 at Severance Hospital. Following cold perfusion and back table surgery, the kidney was weighted on the same electronic weighting scale by the surgeon. Patients were grouped into four groups according to KW/BW quartiles. Results: During a median follow-up period of 127 months, 245 graft losses occurred (172 graft failures and 73 patient deaths). The 10-year death-censored graft survival rates were 86.9% in the lowest quartile, 90.4% in the second quartile, 90.5% in the third quartile, and 92.4% in the highest quartile (P=0.002). Multivariable analysis revealed that the lowest KW/BW (hazard ratio [HR], 2.16; 95% confidence interval [CI], 1.33-3.48; P=0.002) and second lowest KW/BW (HR, 1.69; 95% CI, 1.06-2.70; P=0.029) groups were significantly associated with death-censored graft failure compared with the highest KW/BW group. Patients with lower KW/BW exhibited consistently lower estimated glomerular filtration rates than those with higher KW/BW. Conclusions: Low KW/BW ratio is significantly associated with long-term graft outcome in live donor kidney transplantation.

Oxygenated versus standard cold perfusion preservation in kidney transplantation (COMPARE): a randomised, double-blind, paired, phase 3 trial

Deceased donor kidneys are preserved in cold hypoxic conditions. Providing oxygen during preservation might improve post-transplant outcomes, particularly for kidneys subjected to greater degrees of preservation injury. This study aimed to investigate whether supplemental oxygen during hypothermic machine perfusion (HMP) could improve the outcome of kidneys donated after circulatory death. This randomised, double-blind, paired, phase 3 trial was done in 19 European transplant centres. Kidney pairs from donors aged 50 years or older, donated after circulatory death, were eligible if both kidneys were transplanted into two different recipients. One kidney from each donor was randomly assigned using permuted blocks to oxygenated hypothermic machine perfusion (HMPO2), the other to HMP without oxygenation. Perfusion was maintained from organ retrieval to implantation. The primary outcome was 12-month estimated glomerular filtration rate (eGFR) using the Chronic Kidney Disease Epidemiology Collaboration equation in pairs of donated kidneys in which both transplanted kidneys were functioning at the end of follow-up. Safety outcomes were reported for all transplanted kidneys. Intention-to-treat analyses were done. This trial is registered with the ISRCTN Registry, ISRCTN32967929, and is now closed. Between March 15, 2015, and April 11, 2017, 197 kidney pairs were randomised with 106 pairs transplanted into eligible recipients. 23 kidney pairs were excluded from the primary analysis because of kidney failure or patient death. Mean eGFR at 12 months was 50·5 mL/min per 1·73 m2 (SD 19·3) in the HMPO2 group versus 46·7 mL/min per 1·73m2 (17·1) in HMP (mean difference 3·7 mL/min per 1·73m2, 95% CI -1·0 to 8·4; p=0·12). Fewer severe complications (Clavien-Dindo grade IIIb or more) were reported in the HMPO2 group (46 of 417, 11%, 95% CI 8% to 14%) than in the HMP group (76 of 474, 16%, 13% to 20%; p=0·032). Graft failure was lower with HMPO2 (three [3%] of 106) compared with HMP (11 [10%] of 106; hazard ratio 0·27, 95% CI 0·07 to 0·95; p=0·028). HMPO2 of kidneys donated after circulatory death is safe and reduces post-transplant complications (grade IIIb or more). The 12-month difference in eGFR between the HMPO2 and HMP groups was not significant when both kidneys from the same donor were still functioning 1-year post-transplant, but potential beneficial effects of HMPO2 were suggested by analysis of secondary outcomes. European Commission 7th Framework Programme.

Evaluation of hyperbranched polyglycerol for cold perfusion and storage of donor kidneys in a pig model of kidney autotransplantation.

Hyperbranched polyglycerol (HPG) is a biocompatible polyether polymer that is a potential colloid component in a preservation solution for suppressing interstitial edema during cold storage of a donor organ. This study evaluated the outcomes of kidney transplants after cold perfusion and storage with a HPG‐based preservation solution (HPGS) in a pig model of kidney autotransplantation. The left kidneys of farm pigs (weighing 35–45 kg) were perfused with and stored in either cold HPGS or standard UW solution (UWS), followed by transplantation to the right side after right nephrectomy. The survival and function of transplants were determined by the urine output, and serum creatinine (SCr) and blood urea nitrogen (BUN) of recipients. Transplant injury was examined by histological analysis. Here, we showed that there was no significant difference between HPGS and UWS in the prevention of tissue edema, but HPGS was more effective than UWS for initial blood washout of kidney perfusion and for the prevention of cold ischemia injury during cold storage. After autotransplantation, the kidneys preserved with HPGS (HPG group) had better functional recovery than those with UWS (UW group), indicated by significantly more urine output and lower levels of SCr and BUN. The survived grafts in HPG group had less tissue damage than those in UW group. In conclusion, as compared to the UWS the HPGS has less negative impact on kidney cold ischemia during cold storage, resulting in improving immediate functional recovery after transplantation, suggesting that HPG is a promising colloid for donor kidney preservation.

Ex vivo delivery of Mirococept: A dose-finding study in pig kidney after showing a low dose is insufficient to reduce delayed graft function in human kidney.

The complement system plays a pivotal role in the pathogenesis of ischemia-reperfusion injury in solid organ transplantation. Mirococept is a potent membrane-localizing complement inhibitor that can be administered ex vivo to the donor kidney prior to transplantation. To evaluate the efficacy of Mirococept in reducing delayed graft function (DGF) in deceased donor renal transplantation, we undertook the efficacy of mirococept (APT070) for preventing ischaemia-reperfusion injury in the kidney allograft (EMPIRIKAL) trial (ISRCTN49958194). A dose range of 5-25mg would be tested, starting with 10mg in cohort 1. No significant difference between Mirococept at 10mg and control was detected; hence the study was stopped to enable a further dose saturation study in a porcine kidney model. The optimal dose of Mirococept in pig kidney was 80mg. This dose did not induce any additional histological damage compared to controls or after a subsequent 3hours of normothermic machine perfusion. The amount of unbound Mirococept postperfusion was found to be within the systemic dose range considered safe in the Phase I trial. The ex vivo administration of Mirococept is a safe and feasible approach to treat DGF in deceased donor kidney transplantation. The porcine kidney study identified an optimal dose of 80mg (equivalent to 120mg in human kidney) that provides a basis for further clinical development.

Basal and cold-induced fatty acid uptake of human brown adipose tissue is impaired in obesity

Fatty acids (FA) are important substrates for brown adipose tissue (BAT) metabolism, however, it remains unclear whether there exists a difference in FA metabolism of BAT between lean and obese healthy humans. In this study we evaluated supraclavicular BAT fatty acid uptake (FAU) along with blood perfusion in lean and obese subjects during cold exposure and at room temperature using positron emission tomography (PET)/computed tomography (CT). Additionally, tissue samples were taken from supraclavicular region (typical BAT region) from a subset of subjects to evaluate histological presence of BAT. Non-shivering cold stress elevated FAU and perfusion of BAT in lean, but not in obese subjects. Lean subjects had greater FAU in BAT compared to obese subjects during cold exposure and interestingly also at room temperature. The higher BAT FAU was related to younger age and several indicators of superior systemic metabolic health. The subjects who manifested BAT histologically had several folds higher BAT FAU compared to subjects with no such histological manifestation. Together, obese subjects have less active tissue in supraclavicular region both in basal and cold-activated state and the FA metabolism of BAT is blunted in obesity.

Cold non-ischemic heart preservation with continuous perfusion prevents early graft failure in orthotopic pig-to-baboon xenotransplantation.

Successful preclinical transplantations of porcine hearts into baboon recipients are required before commencing clinical trials. Despite years of research, over half of the orthotopic cardiac xenografts were lost during the first 48hours after transplantation, primarily caused by perioperative cardiac xenograft dysfunction (PCXD). To decrease the rate of PCXD, we adopted a preservation technique of cold non-ischemic perfusion for our ongoing pig-to-baboon cardiac xenotransplantation project. Fourteen orthotopic cardiac xenotransplantation experiments were carried out with genetically modified juvenile pigs (GGTA1- KO/hCD46/hTBM) as donors and captive-bred baboons as recipients. Organ preservation was compared according to the two techniques applied: cold static ischemic cardioplegia (IC; n=5) and cold non-ischemic continuous perfusion (CP; n=9) with an oxygenated albumin-containing hyperoncotic cardioplegic solution containing nutrients, erythrocytes and hormones. Prior to surgery, we measured serum levels of preformed anti-non-Gal-antibodies. During surgery, hemodynamic parameters were monitored with transpulmonary thermodilution. Central venous blood gas analyses were taken at regular intervals to estimate oxygen extraction, as well as lactate production. After surgery, we measured troponine T and serum parameters of the recipient's kidney, liver and coagulation functions. In porcine grafts preserved with IC, we found significantly depressed systolic cardiac function after transplantation which did not recover despite increasing inotropic support. Postoperative oxygen extraction and lactate production were significantly increased. Troponin T, creatinine, aspartate aminotransferase levels were pathologically high, whereas prothrombin ratios were abnormally low. In three of five IC experiments, PCXD developed within 24 hours. By contrast, all nine hearts preserved with CP retained fully preserved systolic function, none showed any signs of PCXD. Oxygen extraction was within normal ranges; serum lactate as well as parameters of organ functions were only mildly elevated. Preformed anti-non-Gal-antibodies were similar in recipients receiving grafts from either IC or CP preservation. While standard ischemic cardioplegia solutions have been used with great success in human allotransplantation over many years, our data indicate that they are insufficient for preservation of porcine hearts transplanted into baboons: Ischemic storage caused severe impairment of cardiac function and decreased tissue oxygen supply, leading to multi-organ failure in more than half of the xenotransplantation experiments. In contrast, cold non-ischemic heart preservation with continuous perfusion reliably prevented early graft failure. Consistent survival in the perioperative phase is a prerequisite for preclinical long-term results after cardiac xenotransplantation.

Neuroprotective effects of combination therapy of regional cold perfusion and hemoglobin-based oxygen carrier administration on rat transient cerebral ischemia

Regional cold perfusion and hemoglobin-based oxygen carrier administration both exert neuroprotective effects against cerebral ischemia reperfusion injury. We herein investigated whether the combination of these two therapies leads to stronger neuroprotective effects. Combination therapy was performed with the regional perfusion of cold HemoAct, a core-shell structured hemoglobin-albumin cluster, in a rat transient middle cerebral artery occlusion model. The effects of combination therapy, the intra-arterial administration of 10 °C HemoAct (10H) initiated at the onset of reperfusion, were compared with those of monotherapies, the intra-arterial administration of 10 °C saline (10S) and 37 °C HemoAct (37H), and an untreated control under the condition of 2-hour ischemia/24-hour reperfusion. The durability of therapeutic effects and the therapeutic time window of combination therapy were assessed based on comparisons with the 10H and control groups. Significantly better neurological findings and smaller infarct volumes were observed in the three treated (10S, 37H, and 10H) groups than in the control group. Among the 3 treated groups, only the 10H group showed significant improvements over the control group in the other items examined, including cerebral blood flow reduction, brain edema, and protein extravasation. The significant therapeutic effects of combination therapy on neurological disabilities and infarct volumes were confirmed at least until 7 days after reperfusion. Furthermore, combination therapy ameliorated neurological disabilities and hemorrhagic transformation in rats subjected to 4- and 5-hour ischemia/24-hour reperfusion. Since therapeutic effects may be expected until at least 5 h of complete ischemia and reperfusion, this combination therapy is a promising neuroprotective strategy against severe ischemic stroke.

100 - Functional and oncologic outcomes of robot-assisted simple enucleation with and without renal arterial cold perfusion in complex renal tumors: A propensity score-matched analysis

100 - Functional and oncologic outcomes of robot-assisted simple enucleation with and without renal arterial cold perfusion in complex renal tumors: A propensity score-matched analysis

Novel delivery of cellular therapy to reduce ischemia reperfusion injury in kidney transplantation.

Ex vivo normothermic machine perfusion (NMP) of donor kidneys prior to transplantation provides a platform for direct delivery of cellular therapeutics to optimize organ quality prior to transplantation. Multipotent Adult Progenitor Cells (MAPC® ) possess potent immunomodulatory properties that could minimize ischemia reperfusion injury. We investigated the potential capability of MAPC cells in kidney NMP. Pairs (5) of human kidneys, from the same donor, were simultaneously perfused for 7 hours. Kidneys were randomly allocated to receive MAPC treatment or control. Serial samples of perfusate, urine, and tissue biopsies were taken for comparison. MAPC-treated kidneys demonstrated improved urine output (P=.009), decreased expression of injury biomarker NGAL (P=.012), improved microvascular perfusion on contrast-enhanced ultrasound (cortex P=.019, medulla P=.001), downregulation of interleukin (IL)-1β (P=.050), and upregulation of IL-10 (P<.047) and Indolamine-2, 3-dioxygenase (P=.050). A chemotaxis model demonstrated decreased neutrophil recruitment when stimulated with perfusate from MAPC-treated kidneys (P<.001). Immunofluorescence revealed prelabeled MAPC cells in the perivascular space of kidneys during NMP. We report the first successful delivery of cellular therapy to a human kidney during NMP. Kidneys treated with MAPC cells demonstrate improvement in clinically relevant parameters and injury biomarkers. This novel method of cell therapy delivery provides an exciting opportunity to recondition organs prior to transplantation.

Protection of the transplant kidney during cold perfusion with doxycycline: proteomic analysis in a rat model

BackgroundIt has been previously shown that doxycycline (Doxy) protects the kidney from preservation injury by inhibition of matrix metalloproteinase. However, the precise molecular mechanism involved in this protection from injury is not known. We used a pharmaco-proteomics approach to identify potential molecular targets associated with kidney preservation injury.MethodsRat kidneys were cold perfused with or without doxycycline (Doxy) for 22 h. Kidneys perfusates were analyzed for the presence of injury markers such as lactate dehydrogenase (LDH), and neutrophil-gelatinase associated lipocalin (NGAL). Proteins extracted from kidney tissue were analyzed by 2-dimensional gel electrophoresis. Proteins of interest were identified by mass spectrometry.ResultsTriosephosphate isomerase, PGM, dihydropteridine reductase-2, pyridine nucleotide-disulfide oxidoreductase, phosphotriesterase-related protein, and aminoacylase-1A were not affected by cold perfusion. Perfusion with Doxy increased their levels. N(G),N(G)-dimethylarginine dimethylaminohydrolase and phosphoglycerate kinase 1 were decreased after cold perfusion. Perfusion with Doxy led to an increase in their levels.ConclusionsThis study revealed specific metabolic enzymes involved in preservation injury and in the mechanism whereby Doxy protects the kidney against injury during cold perfusion.

Worldwide First Successful and Reproducable Long-Term Survival up to Half a Year: Completed Preclinical Study with Life-Supporting Orthotopic Pig-to-Baboon Cardiac Xenotransplantation (oXHTx) Fullfilling the ISHLT Prerequisite for Clinical Cardiac Xenotransplantation

Major hurdles in oXHTx are the delayed xenograft rejection, the early perioperative cardiac xenograft dysfunction (PCXD) and the pig heart overgrowth, which were solved in this study with a costimulation blockade, a new non-ischemic cold preservation and a growth inhibition by anti-proliferative drugs. Aim was to achieve a 90-days-survival of minimal 60% (6 of 10 baboons) in this life-supporting orthotopic pig-to-baboon model (oXHTx), because this is the recommendation of the ISHLT to begin a clinical cardiac XT program. We transplanted 8 GalKO/hCD46/hTM transgenic (tg) pig hearts orthotopically into baboons with using a basic immunosuppression consisting of ATG, rituximab, mycophenolate (MMF), cortisone and a costimulation blockade CD40mAb (high dose: 50 mg/kg). To prevent PCXD, we used instead of the crystalloid solution a new non-ischemic 8°C cold perfusion technique with oxygenated erythrocytes. Additional antihypertensive drugs and an mTOR inhibitor (temsirolimus) were applied to inhibit pig xenograft growth and hypertrophy. In comparison to our previous group with crystalloid cardioplegia (Längin et al. Nature. 2018;564:430-433) in this group with cold perfusion preservation (non-ischemic) no PCXD was found. One baboon died of a pancreatitis on day 14, another of sepsis on day 26. By using the antiproliferative therapy, 6 of 8 recipient baboons reached the end of study, were long-term surviving (4 were actively terminated after 90 days according to the guidelines of our government). With special permit two further experiments could be prolonged to half a year and the animals were terminated on day 182 and 195. All baboons lived under excellent physical conditions and no hyperacute rejection or DXR occurred. First time in a life-supporting oXHT of multi-tg pig hearts here was a consistent reproduceable long-term survival of 3 - 6 months achieved, which is a major progress after 25 years of research. This is an essential milestone and breakthrough and meets the prerequisite according to the ISHLT to begin a clinical phase I study with patients in terminal heart failure. This paves the way to clinical cardiac XT in the next 2 to 5 years.

Using intracorporeal hypothermic perfusion in removal of single kidney tumor with spread to the main renal vein

The paper presents the experience of using hypothermic cold perfusion of a kidney in situ when performing complex nephron-sparing surgery for a tumor of a single right kidney with spreading to the main renal vein. The technique of the operation included separate clamping on the renal artery and IVC in the area of the cavorenal segment. Then the renal artery was opened and cannulated, and a vena cava was opened as a longitudinal section. The kidney was washed with a solution of kustadiol cooled to 4 °C. Then we performed standard steps of kidney resection, removal of the arterial cannula and suturing of the renal artery and inferior vena cava (IVC) sections. The patient underwent extrarenal thrombectomy with reconstruction of the renal vein using a flap v. saphena magna. The time of cold ischemia was 76 minutes. The main advantages of this approach are good visibility of the resection zone, bloodless surgical field and the possibility of long-term safe renal ischemia. To assess the effectiveness of perfusion hypothermic kidney protection in situ, further accumulation of experience in conducting these operations is required.

Cold Renal Perfusion During Simulation of Juxtarenal Aortic Aneurysm Repair Reduces Systemic Oxidative Stress and Sigmoid Damage in Rats

Juxtarenal aortic surgery induces renal ischaemia reperfusion, which contributes to systemic inflammatory tissue injury and remote organ damage. Renal cooling during suprarenal cross clamping has been shown to reduce renal damage. It is hypothesised that renal cooling during suprarenal cross clamping also has systemic effects and could decrease damage to other organs, like the sigmoid colon. Open juxtarenal aortic aneurysm repair was simulated in 28 male Wistar rats with suprarenal cross clamping for 45 min, followed by 20 min of infrarenal aortic clamping. Four groups were created: sham, no, warm (37 °C saline), and cold (4 °C saline) renal perfusion during suprarenal cross clamping. Primary outcomes were renal damage and sigmoid damage. To assess renal damage, procedure completion serum creatinine rises were measured. Peri-operative microcirculatory flow ratios were determined in the sigmoid using laser Doppler flux. Semi-quantitative immunofluorescence microscopy was used to measure alterations in systemic inflammation parameters, including reactive oxygen species (ROS) production in circulating leukocytes and leukocyte infiltration in the sigmoid. Sigmoid damage was assessed using digestive enzyme (intestinal fatty acid binding protein - I-FABP) leakage, a marker of intestinal integrity. Suprarenal cross clamping caused deterioration of all systemic parameters. Only cold renal perfusion protected against serum creatinine rise: 0.45 mg/dL without renal perfusion, 0.33 mg/dL, and 0.14 mg/dL (p = .009) with warm and cold perfusion, respectively. Microcirculation in the sigmoid was attenuated with warm (p = .002) and cold renal perfusion (p = .002). A smaller increase of ROS production (p = .034) was seen only after cold perfusion, while leukocyte infiltration in the sigmoid colon decreased after warm (p = .006) and cold perfusion (p = .018). Finally, digestive enzyme leakage increased more without (1.5AU) than with warm (1.3AU; p = .007) and cold renal perfusion (1.2AU; p = .002). Renal ischaemia/reperfusion injury after suprarenal cross clamping decreased microcirculatory flow, increased systemic ROS production, leukocyte infiltration, and I-FABP leakage in the sigmoid colon. Cold renal perfusion was superior to warm perfusion and reduced renal damage and had beneficial systemic effects, reducing sigmoid damage in this experimental study.

Cold Renal Perfusion During Simulation of Juxtarenal Aortic Aneurysm Repair Reduces Systemic Oxidative Stress and Sigmoid Damage in Rats

Juxtarenal aortic surgery induces renal ischaemia reperfusion, which contributes to systemic inflammatory tissue injury and remote organ damage. Renal cooling during suprarenal cross clamping has been shown to reduce renal damage. It is hypothesised that renal cooling during suprarenal cross clamping also has systemic effects and could decrease damage to other organs, like the sigmoid colon. Open juxtarenal aortic aneurysm repair was simulated in 28 male Wistar rats with suprarenal cross clamping for 45min, followed by 20min of infrarenal aortic clamping. Four groups were created: sham, no, warm (37°C saline), and cold (4°C saline) renal perfusion during suprarenal cross clamping. Primary outcomes were renal damage and sigmoid damage. To assess renal damage, procedure completion serum creatinine rises were measured. Peri-operative microcirculatory flow ratios were determined in the sigmoid using laser Doppler flux. Semi-quantitative immunofluorescence microscopy was used to measure alterations in systemic inflammation parameters, including reactive oxygen species (ROS) production in circulating leukocytes and leukocyte infiltration in the sigmoid. Sigmoid damage was assessed using digestive enzyme (intestinal fatty acid binding protein - I-FABP) leakage, a marker of intestinal integrity. Suprarenal cross clamping caused deterioration of all systemic parameters. Only cold renal perfusion protected against serum creatinine rise: 0.45mg/dL without renal perfusion, 0.33mg/dL, and 0.14mg/dL (p=.009) with warm and cold perfusion, respectively. Microcirculation in the sigmoid was attenuated with warm (p=.002) and cold renal perfusion (p=.002). A smaller increase of ROS production (p=.034) was seen only after cold perfusion, while leukocyte infiltration in the sigmoid colon decreased after warm (p=.006) and cold perfusion (p=.018). Finally, digestive enzyme leakage increased more without (1.5AU) than with warm (1.3AU; p=.007) and cold renal perfusion (1.2AU; p=.002). Renal ischaemia/reperfusion injury after suprarenal cross clamping decreased microcirculatory flow, increased systemic ROS production, leukocyte infiltration, and I-FABP leakage in the sigmoid colon. Cold renal perfusion was superior to warm perfusion and reduced renal damage and had beneficial systemic effects, reducing sigmoid damage in this experimental study.