[Transplant Surgeon Meets Nephrologist: Important Nephrological Aspects Before and After Kidney or Liver Transplantation]. / Abdominalchirurgie trifft Nephrologie: Wichtige nephrologische Aspekte vor und nach Nieren- bzw. Lebertransplantation.

In cases of chronic renal insufficiency, successful kidney transplantation is the method of choice to restore patients' health, well-being and physical fitness. The interdisciplinary collaboration of nephrologists and transplant surgeons has always been a prerequisite for the successful pre-, peri- and post-transplant care of renal transplant patients. The same holds true for liver transplant patients. Here the nephrologist is often involved in cases requiring pre- or post-transplant dialysis as well as in decision making for combined liver-kidney transplantation. This review focuses on nephrological aspects in patient care before and after kidney and liver transplantation.

Five-year outcomes in kidney transplant patients converted from cyclosporine to everolimus: the randomized ZEUS study.

ZEUS study was an open-label, 12-month, multicenter study in which 300 de novo kidney transplant recipients were randomized to continue receiving cyclosporine (CsA) or convert to everolimus at 4.5 months posttransplant. Five-year follow-up data were available for 245/269 patients (91.1%) who completed the core 12-month study (123 everolimus, 109 CsA). At 5 years, adjusted estimated GFR was 66.2 mL/min/1.73 m(2) with everolimus versus 60.9 mL/min/1.73 m(2) with CsA; the mean difference was 5.3 mL/min/1.73 m(2) in favor of everolimus (95% CI 2.4, 8.3; p < 0.001 [intent-to-treat population]). In a post hoc analysis of patients remaining on study drug at 5 years (everolimus 77, CsA 86), mean difference was 8.2 mL/min/1.73 m(2) (95% CI 4.3, 12.1; p < 0.001) in favor of everolimus. The cumulative incidence of biopsy-proven acute rejection postrandomization was 13.6% with everolimus versus 7.5% with CsA (p = 0.095), largely accounted for by grade I rejection (16/21 patients and 7/11 patients, respectively). Postrandomization, graft loss, mortality, serious adverse events and neoplasms were similar in both arms. In conclusion, conversion of kidney transplant patients to everolimus at 4.5 months posttransplant is associated with a significant improvement in renal function that is maintained to at least 5 years. The increase in early mild acute rejection did not affect long-term graft function.

A case of successful renal transplantation for hydatid disease after surgical treatment of disseminated cysts.

Hydatid disease is a systemic disorder affecting especially the liver and lungs. Although it is not endemic in Europe, it can be seen sporadically, particularly because of travel and immigration. Severe, multiple organ involvement is quite rare. A 39-year-old Kurdish male patient presented with the previous diagnosis of hydatid disease and disseminated cysts in the liver, lung, and left kidney, leading to renal failure and the need for hemodialysis. Following multiple operations, complete eradication of infectious cysts was achieved, and kidney transplantation was performed. After 4 years of follow-up, the patient is in good condition, especially with normal renal function and no sign of recurrent hydatid disease.

Everolimus and early calcineurin inhibitor withdrawal: 3-year results from a randomized trial in liver transplantation.

The feasibility of de novo everolimus without calcineurin inhibitor (CNI) therapy following liver transplantation was assessed in a multicenter, prospective, open-label trial. Liver transplant patients were randomized at 4 weeks to start everolimus and discontinue CNI, or continue their current CNI-based regimen. The primary endpoint was adjusted estimated GFR (eGFR; Cockcroft-Gault) at month 11 post randomization. A 24-month extension phase followed 81/114 (71.1%) of eligible patients to month 35 post randomization. The adjusted mean eGFR benefit from randomization to month 35 was 10.1 mL/min (95% confidence interval [CI] -1.3, 21.5 mL/min, p = 0.082) in favor of CNI-free versus CNI using Cockcroft-Gault, 9.4 mL/min/1.73 m(2) (95% CI -0.4, 18.9, p = 0.053) with Modification of Diet in Renal Disease (four-variable) and 9.5 mL/min/1.73 m(2) (95% CI -1.1, 17.9, p = 0.028) using Nankivell. The difference in favor of the CNI-free regimen increased gradually over time due to a small progressive decline in eGFR in the CNI cohort despite a reduction in CNI exposure. Biopsy-proven acute rejection, graft loss and death were similar between groups. Adverse events led to study drug discontinuation in five CNI-free patients and five CNI patients (12.2% vs. 12.5%, p = 1.000) during the extension phase. Everolimus-based CNI-free immunosuppression is feasible following liver transplantation and patients benefit from sustained preservation of renal function versus patients on CNI for at least 3 years.

Hepatitis C virus core antigen testing in liver and kidney transplant recipients.

HCV RNA levels correlate with the long-term outcome of hepatitis C in liver transplant recipients. Nucleic acid testing (NAT) is usually used to confirm HCV reinfection and to examine viral loads after liver transplantation. HCV core antigen (HCVcoreAg) testing could be an alternative to NAT with some potential advantages including very low intra- and interassay variabilities and lower costs. The performance of HCVcoreAg testing in organ transplant recipients is unknown. We prospectively studied 1011 sera for HCV RNA and HCVcoreAg in a routine real-world setting including 222 samples obtained from patients after liver or kidney transplantation. HCV RNA and HCVcoreAg test results showed a consistency of 98% with a very good correlation in transplanted patients (r > 0.85). The correlation between HCV RNA and HCVcoreAg was higher in sera with high viral loads and in samples from patients with low biochemical disease. Patients treated with tacrolimus showed a better correlation between both parameters than individuals receiving cyclosporine A. HCV RNA/HCVcoreAg ratios did not differ between transplanted and nontransplanted patients, and HCV RNA and HCVcoreAg kinetics were almost identical during the first days after liver transplantation. HCVcoreAg testing can be used to monitor HCV viral loads in patients after organ transplantation. However, the assay is not recommended to monitor antiviral therapies.

Clinical value and safety of liver biopsies in patients transplanted for hepatitis C virus-related end-stage liver disease.

BACKGROUND: Hepatitis C is the leading indication for liver transplantation. Differentiation between recurrent graft hepatitis C (RGH-C) and graft rejection (GR) is challenging. Liver biopsy is standard to diagnose both conditions; however, little information is available regarding this procedure in hepatitis C virus (HCV)-infected liver transplant recipients. METHODS: Liver biopsies (n = 211) from all consecutive patients (n = 138) transplanted for hepatitis C at Hannover Medical School between January 2000 and October 2011 were screened, and a final cohort of 96 patients with 196 biopsies was included. Indications, histopathological findings, and biopsy-related complications were documented. Modifications in the treatment based on the biopsy result and the biochemical outcome were analyzed. RESULTS: Most biopsies (196/211, 93%) were representative. Five patients (2.5%) developed non-fatal biopsy-related complications. Biopsy results were GR (35%), RGH-C (31%), and other diagnoses (34%). GR was independently associated with lower albumin (P = 0.025) and higher bilirubin levels (P = 0.011). Treatment was modified based on the biopsy result in 25% of cases. Alanine aminotransferase (ALT), gamma-glutamyl transferase (GGT), and bilirubin levels improved in 41%, 25%, and 31% of cases 4 weeks post biopsy respectively. ALT improvements were more significant in patients with GR than in those with RGH-C. CONCLUSION: Liver biopsy in HCV-infected liver transplant recipients is safe and representative in >90% of cases. GR is independently associated with lower albumin and higher bilirubin levels.

The impact of abdominal complications on the outcome after thoracic transplantation--a single center experience.

BACKGROUND: Abdominal complications after thoracic transplantation (Tx) are potentially associated with an increased risk of mortality. We recently reported about the severe outcome after bowel perforation in patients following lung transplantation (LuTx). The aim of the present study was to likewise identify the risk factors with an impact on patient survival following heart transplantation (HTx). METHODS: A retrospective analysis for the frequency and outcome of abdominal interventions following HTx was performed in 342 patients, and these data thereafter compared to a re-evaluated pool of 1,074 patients following LuTx. All patients were transplanted at Hanover Medical School, Germany, between January 2000 and October 2011. RESULTS: The incidence for abdominal surgery was comparable between patients following HTx (n = 33; 9.6 %) and LuTx (n = 90; 8.4 %). Elective operations were more frequently performed in patients after HTx (8.5 vs. 5.1 %). In contrast, the incidence of emergency interventions was higher after LuTx (5.3 %) than that following HTx (2.3 %). Herewith associated was the mortality observed in these transplant recipients (15.3 and 9.9 % for LuTx and HTx, respectively). Leading diagnosis for emergency surgery was bowel perforation (n = 18, regarding all cases). In 11 of these patients, perforation occurred within the first 6 months after Tx and eight of them died in the course of this complication (one patient after HTx and seven patients after LuTx). CONCLUSIONS: Abdominal complications after HTx are less frequently than after LuTx but equally correlate with a high mortality rate. In finding or even reasonable suspicion of an acute abdomen after thoracic Tx, a broad practice for extended diagnostics and a low barrier for an early explorative laparotomy thus are recommended.

Repeat liver resection for colorectal metastases.

BACKGROUND: Following resection of colorectal liver metastases (CLMs) up to 75 per cent of patients develop recurrent liver metastases. Although repeat resection remains the only curative therapy, data evaluating the outcome are deficient. This study analysed postoperative morbidity, mortality and independent predictors of survival following repeat resection of CLMs. METHODS: Data on surgical treatment of primary and recurrent CLMs between 1994 and 2010 were collected retrospectively, and compared with those for single hepatic resections carried out during the same period. Independent predictors of survival were evaluated by means of univariable and multivariable Cox regression models. RESULTS: In this interval 1026 primary resections of CLMs were performed and 94 patients underwent repeat CLM excision. Overall postoperative morbidity and mortality rates were low (15·8 and 1·3 per cent respectively), with no statistical difference in patients undergoing repeat surgery (P = 0·072). Compared with single liver resections, overall survival was improved in repeat resections (P = 0·003). Multivariable analysis revealed that size of primary CLM over 50 mm was an independent predictor of survival (hazard ratio (HR) 2·61; P = 0·008). Only major hepatic resection was associated with poorer outcome following repeat surgery (HR 2·62; P = 0·009). International Union Against Cancer stage, number of CLMs, age at surgery and need for intraoperative transfusion had no impact on survival after repeat resection. CONCLUSION: Recurrent CLM surgery is feasible with similar morbidity and mortality rates to those of initial or single CLM resections.

[Secondary sclerosing cholangitis following liver transplantation: a rare cause for graft failure]. / Sekundär sklerosierende Cholangitis nach Lebertransplantation: Eine seltene Ursache für ein Transplantatversagen.

We report on a 25-year-old female patient who presented with recurrent cholestasis following liver transplantation due to primary sclerosing cholangitis. Abdominal ultrasound and computed tomography showed intrahepatic bile duct dilatation and stenosis of the common hepatic artery with flow acceleration and decreased resistance index. The patient developed a severe secondary sclerosing cholangitis (SSC) with biliary casts - despite interventional stent placement of the common hepatic artery - thus requiring retransplantation. After prolonged intensive care unit treatment the patient was discharged in a good general condition. This case report describes SSC as a rare cause for graft failure. In unclear cholestasis after liver transplantation SSC has to be considered as the underlying cause.

[Diagnosis of and therapy for hepatocellular carcinoma]. / Diagnostik und Therapie des hepatozellulären Karzinoms.

The interdisciplinary guidelines at the S3 level on the diagnosis of and therapy for hepatocellular carcinoma (HCC) constitute an evidence- and consensus-based instrument that is aimed at improving the diagnosis of and therapy for HCC since these are very challenging tasks. The purpose of the guidelines is to offer the patient (with suspected or confirmed HCC) adequate, scientifically based and up-to-date procedures in diagnosis, therapy and rehabilitation. This holds not only for locally limited or focally advanced disease but also for the existence of recurrences or distant metastases. Besides making a contribution to an appropriate health-care service, the guidelines should also provide the foundation for an individually adapted, high-quality therapy. The explanatory background texts should also enable non-specialist but responsible colleagues to give sound advice to their patients concerning specialist procedures, side effects and results. In the medium and long-term this should reduce the morbidity and mortality of patients with HCC and improve their quality of life.

Storylines for unprecedented heatwaves based on ensemble boosting.

Recent temperature extremes have shattered previously observed records, reaching intensities that were inconceivable before the events. Could the possibility of an event with such unprecedented intensity as the 2021 Pacific Northwest heatwave have been foreseen, based on climate model information available before the event? Could the scientific community have quantified its potential intensity based on the current generation of climate models? Here, we demonstrate how an ensemble boosting approach can be used to generate physically plausible storylines of a heatwave hotter than observed in the Pacific Northwest. We also show that heatwaves of much greater intensities than ever observed are possible in other locations like the Greater Chicago and Paris regions. In order to establish confidence in storylines of 'black swan'-type events, different lines of evidence need to be combined along with process understanding to make this information robust and actionable for stakeholders.

Renal comorbidity after solid organ and stem cell transplantation.

After transplantation of solid organs or hematopoietic stem cells, a significant acute decrease in renal function occurs in the majority of patients. Depending on the degree of kidney injury, a large number of patients develop chronic kidney disease (CKD) and some develop end-stage renal disease requiring renal replacement therapy. The incidence varies depending on the transplanted organ, but important risk factors for the development of CKD are preexisting renal disease, hepatitis C, diabetes, hypertension, age, sex, posttransplant acute kidney injury and thrombotic microangiopathy. This review article focuses on the risk factors of posttransplant chronic kidney disease after organ transplantation, considering the current literature and integrates the incidence and the associated mortality rates of acute and chronic kidney disease. Furthermore, we introduce the RECAST (REnal Comorbidity After Solid organ and hematopoietic stem cell Transplantation) registry.

Enrichment of regulatory T cells in acutely rejected human liver allografts.

Acute cellular rejection (ACR) occurs frequently after liver transplantation and can usually be controlled. Triggering of allospecific immune responses and lack of immunoregulation are currently suggested as a cause of ACR, but there are no investigations of intrahepatic immune responses during ACR. Therefore we prospectively analyzed the intrahepatic T cell infiltration pattern in correlation to the severity of ACR in a cohort of patients with graft hepatitis (n = 151). While CD4(+) cells dominated the portal infiltrates in mild-moderate ACR, CD8(+) cells prevailed in severe ACR. Furthermore portal CD8(+) and not CD4(+) infiltration correlated with serum transaminases and with the likelihood of subsequent ACRs. Surprisingly, the rise of portal effector T cells density during ACR was surpassed by the increase in portal infiltration of regulatory T cells by a factor of two. Thus ACRs rather showed an increase and not a lack of regulation, as was suggested by analysis of peripheral blood mononuclear cells. Despite the pattern of enhanced immunoregulation, patients with severe ACR had a higher risk for subsequent rejections and showed a trend to a reduced survival. Thus, patients with severe rejections might need a modification of their immunosuppression to improve prognosis.

Conversion from cyclosporine to everolimus at 4.5 months posttransplant: 3-year results from the randomized ZEUS study.

The long-term effect of conversion from calcineurin inhibitor (CNI) therapy to an mTOR inhibitor requires clarification. Following completion of the 12-month, open-label, multicenter ZEUS study, in which 300 kidney transplant recipients were randomized to continue cyclosporine (CsA) or convert to everolimus at 4.5 months posttransplant, outcomes were assessed at month 36 (n = 284; 94.7%). CNI therapy was reintroduced in 28.4% of everolimus patients by month 36. The primary efficacy endpoint, estimated glomerular filtration rate (Nankivell, ANCOVA) was significantly higher with everolimus versus the CsA group at month 24 (7.6 mL/min/1.73 m(2) , 95%CI 4.3, 11.0 mL/min/1.73 m(2) ; p < 0.001) and month 36 (7.5 mL/min/1.73 m(2) , 95%CI 3.6, 11.4 mL/min/1.73 m(2) ; p < 0.001). The incidence of biopsy-proven acute rejection from randomization to month 36 was 13.0% in the everolimus arm and 4.8% in the CsA arm (p = 0.015). Patient and graft survival, as well as incidences of malignancy, severe infections and hospitalization, were similar between groups. Kidney transplant patients who are converted from CsA to everolimus at month 4.5 and who remain on everolimus thereafter may achieve a significant improvement in renal function that is maintained to 3 years. There was a significantly higher rate of rejection in the everolimus arm but this did not exert a deleterious effect by 3 years posttransplant.

A randomized, controlled study to assess the conversion from calcineurin-inhibitors to everolimus after liver transplantation--PROTECT.

Posttransplant immunosuppression with calcineurin inhibitors (CNIs) is associated with impaired renal function, while mTor inhibitors such as everolimus may provide a renal-sparing alternative. In this randomized 1-year study in patients with liver transplantation (LTx), we sought to assess the effects of everolimus on glomerular filtration rate (GFR) after conversion from CNIs compared to continued CNI treatment. Eligible study patients received basiliximab induction, CNI with/without corticosteroids for 4 weeks post-LTx, and were then randomized (if GFR > 50 mL/min) to continued CNIs (N = 102) or subsequent conversion to EVR (N = 101). Mean calculated GFR 11 months postrandomization (ITT population) revealed no significant difference between treatments using the Cockcroft-Gault formula (-2.9 mL/min in favor of EVR, 95%-CI: [-10.659; 4.814], p = 0.46), whereas use of the MDRD formula showed superiority for EVR (-7.8 mL/min, 95%-CI: [-14.366; -1.191], p = 0.021). Rates of mortality (EVR: 4.2% vs. CNI: 4.1%), biopsy-proven acute rejection (17.7% vs. 15.3%), and efficacy failure (20.8% vs. 20.4%) were similar. Infections, leukocytopenia, hyperlipidemia and treatment discontinuations occurred more frequently in the EVR group. No hepatic artery thrombosis and no excess of wound healing impairment were noted. Conversion from CNI-based to EVR-based immunosuppression proved to be a safe alternative post-LTx that deserves further investigation in terms of nephroprotection.

Diffusion tensor imaging and tractography for assessment of renal allograft dysfunction-initial results.

OBJECTIVES: To evaluate MR diffusion tensor imaging (DTI) as non-invasive diagnostic tool for detection of acute and chronic allograft dysfunction and changes of organ microstructure. METHODS: 15 kidney transplanted patients with allograft dysfunction and 14 healthy volunteers were examined using a fat-saturated echo-planar DTI-sequence at 1.5 T (6 diffusion directions, b = 0, 600 s/mm²). Mean apparent diffusion coefficient (ADC) and mean fractional anisotropy (FA) were calculated separately for the cortex and for the medulla and compared between healthy and transplanted kidneys. Furthermore, the correlation between diffusion parameters and estimated GFR was determined. RESULTS: The ADC in the cortex and in the medulla were lower in transplanted than in healthy kidneys (p < 0.01). Differences were more distinct for FA, especially in the renal medulla, with a significant reduction in allografts (p < 0.001). Furthermore, in transplanted patients a correlation between mean FA in the medulla and estimated GFR was observed (r = 0.72, p < 0.01). Tractography visualized changes in renal microstructure in patients with impaired allograft function. CONCLUSIONS: Changes in allograft function and microstructure can be detected and quantified using DTI. However, to prove the value of DTI for standard clinical application especially correlation of imaging findings and biopsy results is necessary.

Liver resection of colorectal liver metastases in elderly patients.

BACKGROUND: The percentage of elderly patients with colorectal liver metastases (CLM) has increased. Liver resection remains the only curative therapy; data evaluating the outcome in this age group is limited. Aim of the present study was to determine if postoperative morbidity, mortality, and other independent predictors influence survival in patients ≥ 70 years undergoing liver resection for CLM. METHODS: Clinical data on primary tumor and metastases of 939 patients after liver resection for CLM between 1994 and 2008 were retrospectively collected and subdivided in three age-groups (≥ 70, 40-69, <40). Independent predictors of survival were evaluated with overall and age-specific univariate and multivariate Cox regression models. RESULTS: A total of 939 patients underwent liver resection for CLM, 20.3% aged ≥ 70 years. Overall postoperative mortality and morbidity were 1.08 and 14.82%, revealing no age-related differences. With 5-year survival of 31.8% in the elderly and 37.5% in the mid-age population, age ≥ 70 years was linked with decreased survival (Hazard Ratio [HR] = 1.305; P = 0.0186). Multivariate overall analyses showed size of CLM > 50 mm (HR = 1.376; P = 0.0060), a high amount of transfusion during surgery (HR = 1.676; P = 0.0110), duration of surgery >210 min (HR = 1.241; P = 0.0322), primary UICC (International Union Against Cancer) stage IV (HR = 2.297; P < 0.0001), and performance of repeat resections (HR = 0.652; P = 0.0107) as independent predictors of survival. In the elderly group, effects of UICC IV (HR = 3.260; P = 0.0148) and high numbers of transfusions (HR = 3.647; P = 0.0129) were confirmed; the others did not show statistical significance. CONCLUSIONS: Resection of CLM at older age is feasible with morbidity and mortality rates similar to those in younger patients. Although age ≥ 70 was shown to be associated with poorer overall outcome, reasonable 5-year survival was observed.

Biopsy-diagnosed renal disease in patients after transplantation of other organs and tissues.

Renal function deteriorates in about half of patients undergoing other transplants. We report the results of 105 renal biopsies from 101 nonrenal transplant recipients (bone marrow 14, liver 41, lung 30, heart 20). Biopsy indications were protracted acute renal failure (9%), creatinine increases (83%), heavy proteinuria (22%), or renal insufficiency before re-transplantation (9%). Histological findings other than nonspecific chronic changes, hypertension-related damage, and signs of chronic CNI toxicity included primary glomerular disease (17%), mostly after liver transplantation (21%) or after bone marrow transplantation (29%), and thrombotic microangiopathy (TMA) namely (10%). TMA had the most serious impact on the clinical course. Besides severe hypertension, one TMA patient died of cerebral hemorrhage, 5 had hemolytic-uremic syndrome, and 6 rapidly developed end-stage renal failure. TMA patients had the shortest kidney survival post-biopsy and, together with patients with acute tubular injury, the shortest kidney and patient survival since transplantation. Nine TMA patients had received CNI, 3 of them concomitantly received an mTOR-inhibitor. CNI toxicity is implicated in most patients with renal failure after transplant of other organs and may play a role in the development of TMA, the most serious complication. However, decreased renal function should not be routinely ascribed to CNI.

[Liver resection for non-colorectal, non-neuroendocrine liver metastases--is hepatic resection justified as part of the oncosurgical treatment?]. / Leberresektion bei nicht kolorektalen, nicht neuroendokrinen Lebermetastasen--ist die Resektion im Rahmen des "onko-chirurgischen" Therapiekonzeptes gerechtfertigt?

BACKGROUND: The value of hepatic resection for non-colorectal, non-neuroendocrine liver metastases remains controversial and is still under debate. Although there are numerous reported cases, the results are inconsistent due to the heterogeneity of the enrolled patients. The aim of the present study was to determine the utility of liver resection in the long-term outcome of patients with non-colorectal, non-neuroendocrine liver metastases and to define prognostic factors predicting long-term survivors. METHODS: The records of patients undergoing liver resection for non-colorectal, non-neuroendocrine liver metastases between January 1994 and December 2008 were analysed. Patient demographics, tumour characteristics, type of resection, long-term outcome and prognostic factors were analysed. RESULTS: Between 1994 and December 2008 273 liver resections were performed in 242 patients because of non-colorectal, non-neuroendocrine liver metastases. The morbidity rate was 20.9 % (n = 57), the mortality rate was 2.2 % (n = 6). Patient survival at 1, 3, 5 and 10 years was 76 %, 42 %, 28 % and 13 %, respectively. In multivariate analyses margin status (R0 vs. R2; p = 0.001) and time to metastases (synchronous vs. metachronous) were predictors of survival. Patient's age, type of resection, number and size of metastases did not achieve significance. According to the primary tumour site, patient survival differed. Patients with urological and gynaecological primary tumours fared better whereas patients with liver metastases from gastrointestinal primary tumours did worse without reaching statistical significance. CONCLUSION: Liver resection for non-colorectal, non-neuroendocrine liver metastases is safe and effective. For individual patients with controlled systemic disease, liver resection can offer appropriate survival rates and should be a part of the onco-surgical treatment.

[Pancreas and islet transplantation]. / Pankreas- und Inseltransplantation.

Pancreas transplantation is a successful and effective procedure resulting in tight glucose control. Due to the postoperative morbidity and the need for immunosuppression pancreas transplantation should be considered in patients with type I diabetes at the time of kidney transplantation. Besides this pancreas transplantation alone can be taken into consideration for patients with very poor metabolic control and quality of life despite optimal medical treatment. Recently, islet transplantation became a less invasive alternative to pancreas transplantation. Due to the lack of long-term follow-up and due to the need of multiple donor grafts for one recipient, islet transplantation should be performed under experimental settings in experienced centers. New developments in protecting transplanted islets and in the induction of donor-specific tolerance could increase the indication to perform the procedure. Therefore alternative sources of beta-cells have to be identified.