Low incidence of coronary angiography in the evaluation process of the potential heart donor.

INTRODUCTION: We investigated the practice of coronary angiography (CA) on donor hearts. PATIENTS AND METHODS: Between January 1, 2000, and December 31, 2010, all reported organ donors aged <66 years were analyzed retrospectively. Donor charts were evaluated regarding a performed CA, its outcome, the timing of CA during the evaluation process, and reasons for organ refusal. The percentage of positive CA studies in organ donors aged ≥45 years was also evaluated. RESULTS: Of 292 reported organ donors, 152 organ donor hearts were declined (group 1), and 140 hearts (group 2) were transplanted. Of the 152 declined hearts, 91 hearts were found not suitable for organ offer, and 61 were not successfully allocated or were refused by Eurotransplant. CA was conducted in 17 organ donors (5.8%). In 6 donors, a previous CA was reported (all had pathologic findings), and in 11 donors, a donor CA was performed, indicating 4 pathologic and 7 negative findings (54.5% of the hearts evaluated by donor CA were transplanted). No complication or delay of the donation process was reportedly related to donor CA. CONCLUSIONS: Special emphasis and implementation of recommendations for CA to be part of the evaluation of donor organs seem necessary.

Socio-economic effects and cost saving potential of remote patient monitoring (SAVE-HM trial).

OBJECTIVE: In the SAVE-trial we evaluated the safety, reliability and improvements of patient management using the BIOTRONIK Home Monitoring®-System (HM) in pacemaker (PM) and implanted cardioverter defibrillator (ICD) patients. DESIGN: 115 PM (Module A) and 36 ICD-patients (Module B) were recruited 3 months after implantation. PATIENTS: 65 patients in Module A were randomised to HM-OFF and had one scheduled outpatient clinic follow-up(FU) per year, whereas patients randomised to HM-ON were equipped with the mobile transmitter and discharged without any further scheduled in-office FU. In Module B 18 patients were randomised to HM-OFF and followed by standard outpatient clinic controls every 6 months; 18 patients were randomised to HM-ON receiving remote monitoring plus one outpatient clinic visit per year; unscheduled follow-ups were performed when necessary. RESULTS: The average follow-up period was 17.1 ± 9.2 months in Module A and 26.3 ± 8.6 months in Module B. In both modules, the number of FUs per year was significantly reduced (Module A HM-ON 0.29 ± 0.6 FUs/year vs HM-OFF 0.53 ± 0.5 FUs/year; p b 0.001; Module B HM-ON 0.87 ± 0.25 vs HM-OFF 1.73 ± 0.53 FU/year,p b 0.001). Cost analysis was significantly lower in the HM-ON group compared to the HM-OFF group (18.0 ± 41.3 and 22.4 ± 26.9 € respectively; p b 0.003). 93% of the unscheduled visits in Module B were clinically indicated,whereas 55% of the routine FUs were classified as clinically unnecessary. CONCLUSION: Remote home monitoring of pacemaker and ICD devices was safe, reduced overall hospital visits, and detected events that mandated unscheduled visits.

Establishing a brain-death donor model in pigs.

INTRODUCTION: An animal model that imitates human conditions might be useful not only to monitor pathomechanisms of brain death and biochemical cascades but also to investigate novel strategies to ameliorate organ quality and functionality after multiorgan donation. METHODS: Brain death was induced in 15 pigs by inserting a catheter into the intracranial space after trephination of the skull and augmenting intracranial pressure until brain stem herniation. Intracranial pressure was monitored continuously; after 60 minutes, brain death diagnostics were performed by a neurologist including electroencephalogram (EEG) and clinical examinations. Clinical examinations included testing of brain stem reflexes as well as apnoe testing; then intensive donor care was performed according to standard guidelines until 24 hours after confirmation of brain death. Intensive donor care was performed according to standard guidelines for 24 hours after brain death. RESULTS: Sixty minutes after brain-death induction, neurological examination and EEG examination confirmed brain death. Intracranial pressure increased continuously, remaining stable after the occurrence of brain death. All 15 animals showed typical signs of brain death such as diabetes insipidus, hypertensive and hypotensive periods, as well as tachycardia. All symptoms were treated with standard medications. After 24 hours of brain death we performed successful multiorgan retrieval. DISCUSSION: Brain death can be induced in a pig model by inserting a catheter after trephination of the skull. According to standard guidelines the brain-death diagnosis was established by a flat-line EEG, which occurred in all animals at 60 minutes after induction.

Establishing a donation after cardiac death model in pigs.

INTRODUCTION: Due to the lack of human donors, several strategies have sought to expand the organ pool. Efforts to characterize donation after cardiac death (DCD) have included studies of cell viability, histological and immunohistochemical changes, and oxidative stress, which is known to negatively impact graft survival. A large animal model would be useful for these inquiries. Therefore, we sought to establish a DCD animal model in pigs. METHODS: We simulated non-heart-beating donation Maastricht II and III conditions in 24 pigs. Cardiac fibrillation was induced using 9-V direct current. After various times of ventricular fibrillation (1-10 minutes) with no mechanical and/or medical treatment to achieve cardiac output, reanimation was performed for 30 minutes prior to multiorgan donation. Then, a neurological status was performed. Blood samples were obtained at defined times tissue samples were stored in liquid nitrogen and subsequently embedded in paraffin and subjected to further analysis. RESULTS: We established a DCD pig model in our laboratory by inducing cardiac fibrillation. Up to now, only DCD donation according to the Maastricht criteria II and III has been performed, but establishing all Maastricht criteria of DCDs seems to be feasible. CONCLUSION: A DCD model in pigs enables us to characterize organ quality more precisely as well as evaluate amelioration of storage conditions and donor treatments in a large-animal model.

Serum albumin, subjective global assessment, body mass index and the bioimpedance analysis in the assessment of malnutrition in patients up to 15 years after liver transplantation.

BACKGROUND: The subjective global assessment (SGA) or the body mass index (BMI) is used to determine the nutritional state after LTX. Bioelectrical impedance analysis (BIA) is used as tool to determine body composition by nutritional care professionals. METHODS: BIA, SGA, BMI, and serum albumin (SA) levels were performed to assess malnutrition following liver transplantation. BIA measurement was used as reference standard to determine existing malnutrition. A phase angle (PA) <5 was used to define potentially existing chronic disease-related malnutrition as a standard. All other measured parameters were compared with respect to their prognostic accuracy regarding the prediction of malnutrition as compared to the mentioned standard. RESULTS: Seventy-one recipients (51 men, 20 women) were included. Median age was 58, weight 77 kg, BMI 26 kg/m(2) , PA 4.1°, and SA 4.3 g/dL. According to the Nutritional Risk Screening 2002, 9.4% (6/71), to BMI 15.4% (11/71), to SA 30.9% (22/71), and to BIA 36.5% (28/71) of the patients were malnourished. PA did not correlate with BMI or NA, there was a significant correlation with SA (p = 0.001). Univariate analysis revealed SA as independent predictor for malnutrition. ROC analysis for all parameters revealed a significantly (p < 0.05) better area under the receiver operating characteristic curve for SA (0.812) than for BMI (0.603) for the prediction of malnutrition. CONCLUSION: SGA or BMI calculation alone does not suffice to evaluate the nutritional status. SA seems to play a crucial role in the prediction of severe disease-related malnutrition in this special patient cohort.

Case of Paracoccus yeei infection documented in a transplanted heart.

After a successful cardiac transplantation, routine endomyocardial biopsies showed severe infiltrates comparable with myocarditis. Polymerase chain reaction analysis of native myocardial samples revealed infection with Paracoccus yeei, and the clinical condition of the patient deteriorated. After administration of ciprofloxacin, his clinical condition improved, and further biopsies showed no infiltrates in the cardiac specimens. To our knowledge this is the first documented case of P. yeei infection in a heart transplant patient.

Attitude toward xenotransplantation of patients prior and after human organ transplantation.

Xenotransplantation is a potential strategy to overcome the shortage of human donor organs. As this technique has a major medical and psychological impact on patients and their family and friends, the attitude of patients currently waiting for organ transplantation is important. Therefore, we conducted a survey on the attitude toward xenotransplantation of patients on the waiting list and already transplanted patients. Patients received detailed information before being asked to fill in the questionnaire. We found that 65% would accept xenotransplantation, irrespective of gender, education level or if the patients were on the waiting list or already transplanted. The most common concern was transmission of diseases or genetic material, followed by psychological concerns and ethical issues. More patients had a positive attitude toward accepting cell or tissue transplantation when compared to whole organs. Pig pancreas islet cell transplantation is generally well accepted, patients with diabetes mellitus show even higher acceptance rates than patients without diabetes. In conclusion, xenotransplantation seems to be well accepted in patients who are potential future candidates for organ transplantation. Informing patients about the current status of research tended to decrease acceptance rates slightly.

Isoprostanes as markers of oxidative stress-induced cell damage in porcine islet cell isolation.

INTRODUCTION: Mechanical stress and reagents used during the isolation and purification process as well as digestion time and temperature can alter the success of porcine islet cell (PIC) isolation. This study aimed to characterize the occurrence of isoprostanes during PIC isolation using a modified automated Ricordi method and to evaluate their influence on PIC isolation outcome. METHODS: Porcine pancreatic tissue was harvested at the local slaughter house, and 10 PIC isolations were performed using a modified automated Ricordi method. As positive controls for tissue damage-associated oxidative stress, six consecutive PIC isolations were performed in the presence of 1 mug lipopolysaccharide (LPS). PIC were purified by density gradient centrifugation using the Lymphoprep density gradient. Isoprostane measurement was performed using enzyme-linked immunosorbent assay. RESULTS: The final yield of viable and pure PICs in the experimental group was 3479 +/- 542 IEQ/g pancreas, and the LPS group yielded lower cell numbers compared to the experimental group. Isoprostane levels were significantly elevated in the LPS group as compared to the experimental group at all time points during the isolation from the beginning of the digestion process. DISCUSSION: PIC isolation and purification results significantly differed in the two experimental groups, underlining the negative effects of oxidative stress on PIC viability and purity, which impact negatively on PIC transplantation success.

Preoxygenation of different preservation solutions for porcine pancreas preservation.

INTRODUCTION: Organ preservation quality impacts porcine islet cell isolation and transplantation success. Among several preservation methods, the two-layer method is promising, but technically demanding and fails to deliver sufficient oxygen. The use of hyperbaric oxygenation may be an easier, more effective method to supply high partial pressure of oxygen (pO(2)) for organ storage. Therefore, the aim of this study was to test the capability of preoxygenation of various preservation solutions with HBO to maintain high pO(2) levels. METHODS: University of Wisconsin (UW), Custodiol, Perfadex, or Celsior solutions were preoxygenated in a pressure chamber. NaCl served as the control. pO(2) levels were measured at defined times. The oxygen storage capability was evaluated by leaving the storage bottles open for 2 minutes. RESULTS: It was feasible to preoxygenate preservation solutions. The best solution to maintain high pO(2) tensions was Perfadex, followed by Celsior, and UW. DISCUSSION: The greater the amount of oxygen in the preservation solution, the more oxygen can be delivered to the preserved pancreas. Further studies on the influence of preoxygenated preservation solutions on the porcine pancreas are warranted to improve organ quality, porcine islet cell isolation, and transplantation success.

Ductal injection of University of Wisconsin solution prior to pancreas preservation prevents oxidative cell damage.

INTRODUCTION: Several studies have been carried out investigating different preservation methods and preservation solutions for the pancreata of various species. Attention has to be drawn to the extreme vulnerability of porcine pancreata (PP) to oxidative stress due to the lack of endogenous antioxidants. This study sought to evaluate the influence of cannulation and infusion of different volumes of University of Wisconsin (UW) solution immediately after organ retrieval on PP organ quality. METHODS: PP from 24 slaughterhouse pigs were harvested with immediate cannulation of the pancreatic duct for infusion of 10 mL, 20 mL, 50 mL, or 100 mL UW solution. The organs were stored in cold UW solution. Control organs were only stored in UW. After 6 hours of cold ischemia, tissue and supernate samples were analyzed for markers of oxidative cell damage, adenosine triphosphate (ATP) levels, and occurrence of apoptosis. RESULTS: The fewest apoptotic cells were detected in the PP infused with 50 mL UW via the pancreatic duct (PP 50) as compared with all other groups. Oxidative cell damage was lowest and ATP levels were highest in the PP 50 group. DISCUSSION: Because PP 50 showed significantly better results when compared with all other groups, we suggest that infusion of 50 mL UW via the pancreatic duct immediately after organ retrieval may be useful to minimize oxidative cell damage and cell death in PP.

Sensitive serum parameters for hepatocellular carcinoma recurrence monitoring after liver transplantation: a case report.

Liver cell malignancy can be seen as one of the most common indications for hepatic transplantation, but the recurrence potential of the disease significantly limits its beneficial effects. Hepatic factors influencing the recurrence rate, such as nodule size and criteria wherein transplantations are expedited, are still investigated. Pretransplant intraarterial or percutaneous treatment seem to be predictive for recurrence-free patient survival. Early detection of malignancies via serum parameters as a prognostic factor seems promising. This article reports a special case, where despite an elevated, sensitive, serum marker profile, no HCC recurrence was detected over a 2-year follow-up.

Lessons learned with noninvasive cardiac monitoring for acute rejection.

INTRODUCTION: Computerized Heart Allograft Rejection Monitoring (CHARM), used for noninvasive rejection monitoring in heart transplant recipients, is based on the analysis of ventricular evoked response (VER) signals. This study evaluated the prognostic validity of the TslewC, a parameter extrapolated from the VER. METHODS: During orthotopic heart transplantation (OHT) 2 unipolar, fractally coated, screw-in leads implanted epimyocardially were connected to a telemetric pacemaker. Recordings of IEGMs were performed routinely at hospital and at outpatient visits. Data processing yielded trend curves. TslewC was calculated from the tangent of VER. One hundred five patients divided into survivors and nonsurvivors, were compared using a two-tailed Student's t test. RESULTS: In the final follow-up a significant lower TslewC was observed among patients in the nonsurvivor compared with the other group (P<.001). Tests to find an optimal prognostic threshold of the TslewC yielded the value of 26 mV. CONCLUSION: TslewC functioned as a prognostic factor after OHT. Further studies must provide a prognostic threshold to avoid patient visits all 4 weeks. Patients would only have to be admitted to the hospital if the TslewC was under this prognostic threshold.

Cryopreservation of freshly isolated porcine islet cells.

INTRODUCTION: The use of xenogenic islet cells may be a possibility to overcome the shortage of human donor organs to treat diabetes. Microencapsulation seems to be a promising method for immunoprotection. Since isolation, purification, encapsulation, and transplantation of islet cells are labor intensive, cryopreservation has emerged as an attractive system of islet banking. The aim of this study was to determine the influence of three different freezing media (FM) on viability of freshly isolated porcine islet cells (FIPIC). METHODS: FIPIC were isolated using a modified Ricordi method and purification performed using a Lymphoprep density gradient. Viability of FIPIC prior to freezing and after thawing was determined using the MTT-based Cell Growth Determination Kit. Insulin production was detected using enzyme-linked immunosorbent assay. Three different FM containing dimethylsulfoxide (DMSO) or glycerol and sucrose were used for cryoprotection of FIPIC. RESULTS: Isolation and purification of FIPIC resulted in 95% +/- 1.3% viability and 97% +/- 1.4% purity. Cryopreservation with FM I (containing DMEM, FCS, DMSO) yielded 98.4% and FM III (containing DMEM, FCS, glycerol) 93.1% viability, whereas only 85.6% were alive when cryoprotection is performed with FM II (containing DMSO, BM). Glucose stimulation revealed a loss of 2.8% and 1.9% of insulin secretion per microgram DNA when working with FM I and FM III, but a decrease in glucose-dependent insulin secretion of 7.8% (P < .05) when FIPIC were stored in FM II. DISCUSSION: Low concentrations of DMSO or the use of glycerol and sucrose seem to be equivalent to cryopreserve FIPIC.

Cryopreservation of insulin-producing cells microencapsulated in sodium cellulose sulfate.

INTRODUCTION: Diabetes mellitus may be treated with pancreatic islet cell transplantation. The use of xenogenic islet cells may overcome the shortage of human donor organs. Microencapsulation seems to be a promising method for immunoprotection. Since isolation, purification, encapsulation, and transplantation of islet cells are labor-intensive, cryopreservation has emerged as an attractive system for islet banking. In this study sodium cellulose sulfate (NaCS), a novel method for microencapsulation of islet cells, was tested for its capability to protect cells during cryopreservation. METHODS: HIT-T15 cells were microencapsulated in NaCS. Cells were frozen and thawed using three different media containing varying amounts of dimethylsulfoxide (DMSO) and glycerol. Cell viability and cell growth were monitored using 3-(-4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide before freezing and 1 week after thawing. RESULTS: NaCS did not show any negative impact on the growth rates of encapsulated HIT-T15 cells compared with nonencapsulated controls. Nonencapsulated cells were adequately cryopreserved by both DMSO- and glycerol-containing freezing media. DMSO was not suitable for cryopreservation of encapsulated HIT-T15 cells, whereas glycerol seemed to produce no considerable cell loss during freezing and thawing. DISCUSSION: Islet banking of cells encapsulated in NaCS was feasible. Microencapsulation did not harm islet cell recovery. As NaCS is less immunogenic and more biocompatible than other materials used for microencapsulation, it may be a promising method for immunoisolation of islet cells to replace the endocrine pancreas in a physiological way.

Morphological and functional characterization of a pancreatic beta-cell line microencapsulated in sodium cellulose sulfate/poly(diallyldimethylammonium chloride).

BACKGROUND: Late diabetic complications cannot be prevented totally by current antidiabetic strategies. Therefore, new therapeutic concepts of insulin replacement such as pancreas transplantation are evolving. Due to the shortage of human donor organs, transplantation of microencapsulated xenogeneic pancreatic islet cells has attracted considerable attention. Sodium cellulose sulfate/poly(diallyldimethylammonium chloride) (NaCS/PDADMAC) is a material with favorable biogenic properties that has been used for microencapsulation of various cell types. However, there are no data on the suitability of NaCS/PDADMAC for microencapsulation of pancreatic beta-cells. MATERIAL AND METHODS: Cell growth and viability of NaCS/PDADMAC-microencapsulated HIT-T15 cells, an immortalized hamster pancreatic beta-cell line, were assessed using a dimethylthiazol-diphenyltetrazoliumbromide (MTT)-based cell growth determination kit and apoptosis was detected by antibodies against activated caspase 3. Glucose-dependent insulin secretion was assessed with ELISA and the uptake of glucose was measured using fluorescence-labeled glucose. RESULTS: Statistical analysis revealed no differences in glucose-dependent cell proliferation, insulin secretion and glucose uptake between non-microencapsulated and microencapsulated HIT-T15 cells. Stimulation of HIT-T15 cells with glucose (100 mg/ml) resulted in a biphasic insulin secretion response. CONCLUSION: Microencapsulation of HIT-T15 cells in NaCS/PDADMAC does not influence cell proliferation, insulin secretion and glucose uptake. Our results indicate that NaCS/PDADMAC is well suited for microencapsulation of pancreatic beta-cells.

The impact of overweight on the development of diabetes after heart transplantation.

BACKGROUND: Overweight is defined with a body mass index (BMI) >25. A BMI >25 is known as an independent risk factor for increased morbidity and mortality. The influence of an increased BMI on the development of diabetes and on survival after heart transplantation (HTX) was investigated. METHODS: A total of 137 patients (116 men, 21 women), who underwent HTX at our Department from 1986 to 2002, were included in the study. For group stratification, the pre-operative BMI values were taken (group I: BMI 25). Groups were compared for primary disease, age and sex, development of renal failure, development of diabetes, and survival. The probability of survival and the freedom-from-diabetes interval were calculated by the use of Kaplan-Meier method. RESULTS: No significant differences between groups I and II were found concerning primary disease, age and sex, and occurrence of renal failure. There was a tendency towards increased survival (p = 0.18) in group I. Patients of group II developed diabetes after HTX more frequently than those of group I (p < 0.001). Cox regression revealed that pre-operative BMI >25 is a highly significant independent risk factor for post-operative development of diabetes mellitus (DM) (p < 0.001). CONCLUSION: Overweight prior to HTX appears to negatively influence long-term survival after HTX, although this difference did not reach statistical significance. Pre-operative overweight is a significant and independent risk factor for the development of post-transplant diabetes.

Initial experiences with a telemedicine framework for remote pacemaker follow-up.

According to international guidelines implanted cardiac pacemakers (PM) have to be checked periodically to ensure that they are working correctly. To spare a significant number of patients the burden of traveling to specialized PM clinics a telemedicine framework has been developed prototypically. A mobile, personal digital assistant (PDA) based PM follow-up unit provides the caregiver at the point-of-care with the necessary infrastructure to perform a basic PM follow-up examination remotely. In case of detected malfunction of the PM the patient is ordered to the hospital for further examination. The system has been evaluated in a clinical pilot trial on 44 patients with a total of 23 different PM models from 8 different manufacturers. The initial results indicate the potential of the concept to work as an efficient, manufacturer independent screening method with the ultimate goal to increase the safety, quality and efficiency of PM therapy.

Porcine islet cells microencapsulated in sodium cellulose sulfate.

One hundred fifty million people suffer from diabetes mellitus worldwide. Modern exogenous insulin therapy cannot prevent late complications. Islet cell transplantation could be a sufficient therapeutic option but the shortage of human organs limits this option. The use of xenogeneic porcine islet cells may also be a viable alternative. One way to manage hyperacute rejection is by the protection of xenogeneic cells from the immune system by microencapsulation. In this study sodium cellulose sulfate (NaCS) was evaluated as a material for encapsulation. An insulin-producing cell line (HIT-T15) was established in our laboratory. Glucose-dependent insulin production and cell growth were monitored. Cells were encapsulated with NaCS by Austrianova, Vienna. The insulin production and mitosis rate were examined. Cell growth and insulin production by HIT-T15 cells affected the glucose levels in the nutrient solution. Cell viability and glucose-dependent insulin production were not influenced by NaCS. Encapsulation with NaCS is feasible and it could be shown that the material is permeable to nutrients and metabolic side products. The encapsulated cells are able to detect the glucose concentration in the nutrient solution and to react in a proper way by producing insulin. Encapsulation with NaCS, which is more biocompatible and less immunogenic than other materials, seems to be a promising method for immunoisolation of porcine beta cells for xenotransplantation to replace the endocrine pancreas in a physiologic way.

Late acute cardiac allograft rejection: new therapeutic options?

BACKGROUND: Late acute cellular rejection is associated with decreased survival and the development of CAV. Among new immunosuppressive drugs introduced into clinical practice, everolimus, has been shown to be safe in cardiac transplantation. We report our experience with everolimus in heart transplant recipients who developed late acute cellular cardiac rejection. METHODS: Patients with a history of previous rejection episodes who experienced cardiac rejection were switched to an everolimus, cyclosporine, and steroid immunosuppressive regimen. All patients had already received statins and antihypertensive medications. Everolimus, cyclosporine trough levels, and laboratory values were controlled monthly. Drug administration was adapted to an everolimus trough level between 3 and 8 ng/mL, mean maintenance dosage was 0.25 to 1.5 mg twice a day. Death, safety, side effects, biopsy-proven acute rejection episodes, laboratory values, and blood levels were evaluated retrospectively. RESULTS: Four cardiac allograft recipients (two male, two female), at a median of 1473.25 days post-orthotopic heart transplantation (oHTx) (range = 65 to 3045), received 1 to 1.5 mg everolimus per day. Over a follow-up period of at least 2 month (range = 2 to 10) the mortality was 0%. The drug was well tolerated; no acute cellular rejection greater than grade 1a (ISHLT grading) was observed after 2 months. In one patient increased cholesterol values and in two others, elevated triglyceride levels were seen, but were controlled with increased statin therapy. No obvious increased creatinine values were seen with everolimus. CONCLUSION: In conclusion, conversion to an everolimus-based immunosuppressive regimen after late cardiac rejection is safe and effective; no major side effects were observed.