Ex vivo gut-hepato-biliary organ perfusion model to characterize oral absorption, gut-wall metabolism, pre-systemic hepatic metabolism and biliary excretion; application to midazolam.

To date, characterization of the first-pass effect of orally administered drugs consisting of local intestinal absorption and metabolism, portal vein transport and hepatobiliary processes remains challenging. Aim of this study was to explore the applicability of a porcine ex-vivo perfusion model to study oral absorption, gut-hepatobiliary metabolism and biliary excretion of midazolam. Slaughterhouse procured porcine en bloc organs (n = 4), were perfused via the aorta and portal vein. After 120 min of perfusion, midazolam, atenolol, antipyrine and FD4 were dosed via the duodenum and samples were taken from the systemic- and portal vein perfusate, intestinal faecal effluent and bile to determine drug and metabolite concentrations. Stable arterial and portal vein flow was obtained and viability of the perfused organs was confirmed. After intraduodenal administration, midazolam was rapidly detected in the portal vein together with 1-OH midazolam (EG-pv of 0.16±0.1) resulting from gut wall metabolism through oxidation. In the intestinal faecal effluent, 1-OH midazolam and 1-OH midazolam glucuronide (EG-intestine 0.051±0.03) was observed resulting from local gut glucuronidation. Biliary elimination of midazolam (0.04±0.01 %) and its glucuronide (0.01±0.01 %) only minimally contributed to the enterohepatic circulation. More extensive hepatic metabolism (FH 0.35±0.07) over intestinal metabolism (FG 0.78±0.11) was shown, resulting in oral bioavailability of 0.27±0.05. Ex vivo perfusion demonstrated to be a novel approach to characterize pre-systemic extraction of midazolam by measuring intestinal as well as hepatic extraction. The model can generate valuable insights into the absorption and metabolism of new drugs.

Prognostic Importance of Increased Right Ventricular Afterload in Orthotopic Liver Transplantation Recipients With Endstage Cirrhosis.

BACKGROUND: Severely increased right ventricular (RV) afterload is considered a contra-indication for orthotopic liver transplantation (OLT). This study assesses the effects of mildly increased RV afterload on long-term outcome after OLT in relation to RV function. METHODS: 139 OLT recipients (53±12years, 76% male) were included. Preoperative RV afterload was assessed invasively or, if not available, echocardiographically and categorised as normal, high-normal (mean pulmonary artery pressure [PAP] 20-25mmHg or echocardiographic systolic PAP 35-40mmHg) or mildly elevated (mean PAP 25-35mmHg or systolic PAP 40-50mmHg). The association between level of RV afterload, echocardiographic RV function and postoperative outcome was assessed. RESULTS: Right ventricular afterload was high-normal in 17% and mildly elevated in 12% of patients. Patients with elevated RV afterload had higher echocardiographic RV dimensions and left ventricular filling pressures. RV functional parameters were within normal range and not associated with RV afterload. Increased RV afterload was associated with a higher incidence of postoperative haemodynamic complications (8%, 17%, and 29% for normal, high-normal and mildly elevated RV afterload, respectively, p=0.03) and worse survival (8-year survival 74%, 41% and 37% respectively, p=0.01). Preoperative RV function was not associated with outcome after OLT. CONCLUSIONS: Increased RV afterload was associated with increased haemodynamic complications and worse long-term survival in OLT recipients. Right ventricular function in patients with increased RV afterload was within normal range and not associated with postoperative outcome.

[Transplantation of islets of Langerhans: procedure, indications and challenges]. / Transplantatie van eilandjes van Langerhans.

Pancreatic islet isolation and transplantation are complicated procedures, indicated for a carefully selected group of patients. After isolation from the pancreas, the islets are infused into the portal vein. Allogeneic islet transplantation is performed in patients with diabetes mellitus, who suffer from severe hypoglycaemic events and/or progressive complications. One or more donor pancreases are used, which necessitates immunosuppressive treatment. In autologous islet transplantation, which is performed in patients in whom the pancreas has to be removed due to a non-malignant disease, the patients' own islets are isolated and reinfused. No immunosuppressive treatment is required. Reconstitution of endogenous insulin production in allogeneic islet transplantation leads to marked improvements in glycaemic regulation, protection against severe hypoglycaemic episodes and fewer diabetes-related complications. Autologous islet transplantation allows for preservation of endogenous insulin production, which prevents (unstable) diabetes from occurring. This article describes the indications, procedure and pitfalls of islet isolation and transplantation, including three representative cases.

['Will I receive a liver transplant in time?'; chance of survival of patients on the liver transplant waiting list]. / 'Komt mijn nieuwe lever wel op tijd?'.

OBJECTIVE: To calculate the chance of receiving a liver transplant for patients on the liver transplant waiting list in the Netherlands. DESIGN: Retrospective cohort research. METHOD: Data of all patients in the Netherlands on the waiting list for liver transplantation, from the introduction of the model of end-stage liver disease score on 16th December 2006 through to 31st December 2013 were collected. Survival analysis was computed with competing risk analyses. RESULTS: A total of 851 patients were listed, of whom 236 patients with hepatocellular carcinoma, 147 patients with primary sclerosing cholangitis, 142 patients with post-alcoholic liver disease, 93 patients with metabolic liver disease, 78 with viral hepatitis and 155 patients listed for other indications. The median waiting time till transplantation was 196 days. The chance to be transplanted at two years from listing was 65% and the risk of death was 17%. Patients with metabolic liver disease had the highest chance of undergoing liver transplantation. Patients with viral hepatitis were at highest risk of death while on the list, as well as having the lowest chance of undergoing liver transplantation. CONCLUSION: Our study shows a 65% chance of getting transplanted in time after a median waiting time of 6 months in the Netherlands. Sadly, 1 in 6 patients die before liver transplantation can be performed, with the highest risk of death occurring in patients with viral hepatitis.

Islet alloautotransplantation: Allogeneic pancreas transplantation followed by transplant pancreatectomy and islet transplantation.

Simultaneous pancreas-kidney (SPK) transplantation is an important treatment option for patients with type 1 diabetes (T1D) and end-stage renal disease (ESRD). Due to complications, in up to 10% of patients, allograft pancreatectomy is necessary shortly after transplantation. Usually the donor pancreas is discarded. Here, we report on a novel procedure to rescue endocrine tissue after allograft pancreatectomy. A 39-year-old woman with T1D and ESRD who had undergone SPK transplantation required emergency allograft pancreatectomy due to bleeding at the vascular anastomosis. Islets were isolated from the removed pancreas allograft, and almost 480 000 islet equivalents were infused into the portal vein. The patient recovered fully. After 3 months, near-normal mixed meal test (fasting glucose 7.0 mmol/L, 2-hour glucose 7.5 mmol/L, maximal stimulated C-peptide 3.25 nmol/L, without insulin use in the preceding 36 hours) was achieved. Glycated hemoglobin while taking a low dose of long-acting insulin was 32.7 mmol/mol hemoglobin (5.3%). When a donor pancreas is lost after transplantation, rescue ß cell therapy by islet alloautotransplantation enables optimal use of scarce donor pancreata to optimize glycemic control without additional HLA alloantigen exposure.

Glycemic Stability Through Islet-After-Kidney Transplantation Using an Alemtuzumab-Based Induction Regimen and Long-Term Triple-Maintenance Immunosuppression.

Pancreatic islet transplantation is performed in a select group of patients with type 1 diabetes mellitus. Immunosuppressive regimens play an important role in long-term islet function. We aimed to investigate the efficacy of islet transplantation in patients with type 1 diabetes and a previous kidney transplantation using an alemtuzumab-based induction regimen and triple maintenance immunosuppression. Patients with type 1 diabetes, who had received a kidney transplant previously, were treated with alemtuzumab as induction therapy for their first islet transplantation and basiliximab induction therapy for subsequent islet transplantations. Maintenance immunosuppression consisted of triple immunosuppression (tacrolimus, mycophenolate mofetil, and prednisolone). Thirteen patients (age 50.9 ± 9.2 years, duration of diabetes 35 ± 9 years) received a total of 22 islet transplantations. One- and 2-year insulin independence was 62% and 42%, respectively; graft function was 100% and 92%, respectively. HbA1c dropped from 57.2 ± 13.1 (7.4 ± 1.2%) to 44.5 ± 11.8 mmol/molHb (6.2 ± 0.9%) (p = 0.003) after 2 years. Six of 13 patients suffered from severe hypoglycemia before islet transplantation. After transplantation, severe hypoglycemia was restricted to the only patient who lost graft function. Creatinine clearance was unchanged. Islet-after-kidney transplantation in patients with type 1 diabetes using an alemtuzumab-based induction regimen leads to considerable islet allograft function and improvement in glycemic control.

Acute cellular rejection is associated with matrix metalloproteinase-2 genotype chimerism after orthotopic liver transplantation.

PURPOSE: Chimerism in transplantation medicine refers to the coexistence of cells of donor and recipient origin. Their existence in relation to possible pathological mechanisms remains largely unknown. We used donor-recipient mismatches for matrix metalloproteinases (MMP) gene polymorphisms in liver biopsies and in blood as a marker for chimerism after orthotopic liver transplantation (OLT). The second aim of this study was to evaluate these polymorphisms in relation to clinical outcome such as ischemia-reperfusion injury (IRI) and acute cellular rejection (ACR). METHODS: MMP-2 and MMP-9 promoter polymorphism donor-recipient mismatches were determined in 147 OLT patients. The relationship between these MMP polymorphism mismatches in donor and recipient DNA with the development of IRI and ACR after OLT was evaluated. Liver biopsy specimens and peripheral blood samples were subsequently evaluated for the presence of chimerism, also in relation to these complications. RESULTS: MMP polymorphism donor-recipient mismatches were found in 53.7% (MMP-2) and 35.5% (MMP-9) of the OLT patients but no relation was observed with IRI or ACR. Chimerism in liver biopsy specimens was found to be present in 28.8% (MMP-2) and 16.2% (MMP-9) of the cases. Liver chimerism in MMP-2 was found to be significantly associated with ACR after OLT (χ(2) 6.4, P = .01). Multivariate analysis revealed MMP-2 chimerism to be an independent risk factor for ACR after OLT even adjusted for Model for End-stage Liver Disease score (hazard ratio = 3.83, P = .03). In addition, evidence of donor chimerism was found in peripheral blood samples of the recipients in some cases. CONCLUSION: Chimerism after OLT can be found in liver biopsy specimens and in peripheral blood. MMP donor-recipient polymorphism mismatches are good markers for assessing chimerism after OLT. In the multivariate analysis, liver chimerism in MMP-2 was found to be significantly associated with the development of ACR after OLT.

Similar liver transplantation survival with selected cardiac death donors and brain death donors.

BACKGROUND: The outcome of orthotopic liver transplantation (OLT) with controlled graft donation after cardiac death (DCD) is usually inferior to that with graft donation after brain death (DBD). This study compared outcomes from OLT with DBD versus controlled DCD donors with predefined restrictive acceptance criteria. METHODS: All adult recipients in the Netherlands in 2001-2006 with full-size OLT from DCD (n = 55) and DBD (n = 471) donors were included. Kaplan-Meier, log rank and Cox regression analyses were used. RESULTS: One- and 3-year patient survival rates were similar for DCD (85 and 80 per cent) and DBD (86.3 and 80.8 per cent) transplants (P = 0.763), as were graft survival rates (74 and 68 per cent versus 80.4 and 74.5 per cent; P = 0.212). The 3-year cumulative percentage of surviving grafts developing non-anastomotic biliary strictures was 31 per cent after DCD and 9.7 per cent after DBD transplantation (P < 0.001). The retransplantation rate was similar overall (P = 0.081), but that for biliary stricture was higher in the DCD group (P < 0.001). Risk factors for 1-year graft loss after DBD OLT were transplant centre, recipient warm ischaemia time and donor with severe head trauma. After DCD OLT they were transplant centre, donor warm ischaemia time and cold ischaemia time. DCD graft was a risk factor for non-anastomotic biliary stricture. CONCLUSION: OLT using controlled DCD grafts and restrictive criteria can result in patient and graft survival rates similar to those of DBD OLT, despite a higher risk of biliary stricture.

Liver transplantation in a patient with encapsulating peritoneal sclerosis.

Encapsulating peritoneal sclerosis (EPS) is a poorly understood condition in which excess fibrosis results in an encasement of the small bowel, which can clinically result in obstruction. The condition is thought to be related to the persistent expression of transforming growth factor beta on mesothelial cells causing proliferation of subserosal fibroblasts, massive production of extracellular matrix and loss of mesothelial cells. We report a patient with liver cirrhosis in whom the diagnosis of EPS was made. During laparotomy for liver transplantation the complete peritoneum was found to be thickened, consisting of white sheets; liver transplantation was deferred. Histological examination showed peritoneal sclerosing fibrosis. Immunosuppressive medication was started and a difficult but successful liver transplantation followed. If EPS is diagnosed during laparotomy for organ transplantation, adjusted immunosuppression is preferred as calcineurin inhibitors such as cyclosporin and tacrolimus may accelerate EPS while prednisone and some other drugs may stop progression.

Reuse of auxiliary liver grafts in second recipients with chronic liver disease.

We describe the first cases of reuse of auxiliary liver grafts for orthotopic transplantation in chronic liver disease. A reduced liver graft (segments 2, 3, half of 4) was first transplanted auxiliary for acute liver failure using a new technique. After regeneration of both native liver and graft, the auxiliary graft was removed and immunosuppression discontinued in the first recipients. After informed consent of donors and recipients, both auxiliary grafts were then orthotopically transplanted into second recipients. Both grafts function normally. Reuse of auxiliary grafts may help to reduce the shortage or liver grafts available for transplantation.

A novel technique for auxiliary partial liver transplantation with reno-portal anastomosis and avoidance of the hepatoduodenal ligament.

Auxiliary liver transplantation (ALT) is a treatment for acute liver failure when regeneration of the native liver is possible or for metabolic disorders. In selected cases ALT and orthotopic liver transplantation (OLT) have similar survival when ALT is performed in the orthotopic position (auxiliary partial orthotopic liver transplantation, APOLT). Drawback of ALT with portal vein to portal vein anastomosis is the frequent occurrence of thrombosis, compromising both graft and native liver, and the necessity of a significant resection. To avoid division of portal flow we performed ALT with an end-to-end anastomosis between the graft portal vein and the left renal vein of the recipient (reno-portal ALT, REPALT). The hepatic artery was anastomosed to the aorta using an iliac arterial graft conduit. The bile duct was anastomosed to the stomach. In the two cases presented here excellent immediate graft function occurred with rapid regeneration of the graft and without early vascular complications.