[Digital documentation of complications in visceral surgery: possibilities and evaluation of an instrument for quality management]. / Digitale Komplikationserfassung in der Viszeralchirurgie: Möglichkeiten und Evaluation eines Instrumentes für das Qualitätsmanagement.

Against the background of the growing economization of clinical medicine, in the last decades the topics of risk and complication management have also become more important in surgical disciplines. The standardization and reproducible documentation of outcome and complication data play a key role for valid quality control. In this article a digital system implemented at the surgical clinic of the Charité University Medicine in Berlin is analyzed with respect to its practicability for perioperative and postoperative monitoring of complications within the framework of quality assurance.

Hepatocyte Transplantation to the Liver via the Splenic Artery in a Juvenile Large Animal Model.

Hepatocyte transplantation (HcTx) is a promising approach for the treatment of metabolic diseases in newborns and children. The most common application route is the portal vein, which is difficult to access in the newborn. Transfemoral access to the splenic artery for HcTx has been evaluated in adults, with trials suggesting hepatocyte translocation from the spleen to the liver with a reduced risk for thromboembolic complications. Using juvenile Göttingen minipigs, we aimed to evaluate feasibility of hepatocyte transplantation by transfemoral splenic artery catheterization, while providing insight on engraftment, translocation, viability, and thromboembolic complications. Four Göttingen Minipigs weighing 5.6 kg to 12.6 kg were infused with human hepatocytes (two infusions per cycle, 1.00E08 cells per kg body weight). Immunosuppression consisted of tacrolimus and prednisolone. The animals were sacrificed directly after cell infusion (n=2), 2 days (n=1), or 14 days after infusion (n=1). The splenic and portal venous blood flow was controlled via color-coded Doppler sonography. Computed tomography was performed on days 6 and 18 after the first infusion. Tissue samples were stained in search of human hepatocytes. Catheter placement was feasible in all cases without procedure-associated complications. Repetitive cell transplantations were possible without serious adverse effects associated with hepatocyte transplantation. Immunohistochemical staining has proven cell relocation to the portal venous system and liver parenchyma. However, cells were neither present in the liver nor the spleen 18 days after HcTx. Immunological analyses showed a response of the adaptive immune system to the human cells. We show that interventional cell application via the femoral artery is feasible in a juvenile large animal model of HcTx. Moreover, cells are able to pass through the spleen to relocate in the liver after splenic artery infusion. Further studies are necessary to compare this approach with umbilical or transhepatic hepatocyte administration.

Impact of Percoll purification on isolation of primary human hepatocytes.

Research and therapeutic applications create a high demand for primary human hepatocytes. The limiting factor for their utilization is the availability of metabolically active hepatocytes in large quantities. Centrifugation through Percoll, which is commonly performed during hepatocyte isolation, has so far not been systematically evaluated in the scientific literature. 27 hepatocyte isolations were performed using a two-step perfusion technique on tissue obtained from partial liver resections. Cells were seeded with or without having undergone the centrifugation step through 25% Percoll. Cell yield, function, purity, viability and rate of bacterial contamination were assessed over a period of 6 days. Viable yield without Percoll purification was 42.4 × 106 (SEM ± 4.6 × 106) cells/g tissue. An average of 59% of cells were recovered after Percoll treatment. There were neither significant differences in the functional performance of cells, nor regarding presence of non-parenchymal liver cells. In five cases with initial viability of <80%, viability was significantly increased by Percoll purification (71.6 to 87.7%, p = 0.03). Considering our data and the massive cell loss due to Percoll purification, we suggest that this step can be omitted if the initial viability is high, whereas low viabilities can be improved by Percoll centrifugation.

[High donor age for liver transplantation : Tackling organ scarcity in Germany]. / Hohes Spenderalter bei Lebertransplantation : Wie begegnen wir dem Organmangel in Deutschland?

BACKGROUND: Liver transplantation is the only curative treatment option for patients with end-stage liver disease; however, the 40% decline of available organ donors in recent years in Germany necessitates the optimization of available resources and possibly extending the criteria to older donors. MATERIAL AND METHODS: All 2652 livers made available to the Charité Universitätsmedizin Berlin from 2010 to 2016 were retrospectively analyzed and the clinical outcome of 526 liver transplantations during this time frame were evaluated. RESULTS: The median age of donors of transplanted organs increased from 49.3 years in 2010 to 57.3 years in 2016 (p = 0.02). Organs from donors ≥65 years were more frequently discarded than organs from younger donors (n = 344, 18.4% vs. n = 220, 28.1%; p = 0.005). Moreover, the older donors had higher rates of diabetes mellitus and hepatic steatosis. Organs from older donors had a higher donor risk index (2.8 vs. 2.2; p < 0.001) and were transplanted more often in patients with preserved liver function and hepatocellular carcinoma and liver cirrhosis (n = 121, 74.7% of indications). The 3­year survival after liver transplantation from donors ≥65 and ≥80 years old was not significantly reduced in comparison to younger donors; however, there was an increased retransplantation rate (28.6%; p = 0.005) after transplantation of organs from donors ≥80 years old. CONCLUSION: Despite conservative organ acceptance there were higher rates of retransplantation after transplantation from very old donors. In the light of an increasing scarcity of suitable organs this mandates caution and highlights the need for adequate assessment instruments for marginal donor organs before transplantation.

Acute Graft Dysfunction 17 Years After Liver Transplant: A Challenging Clinical and Histologic Manifestation of Hepatitis E.

Acute hepatitis E virus infection after liver transplant is a challenging clinical phenomenon. Due to its unspecific clinical and histological presentation, the diagnosis of acute or chronic hepatitis E virus infection can be difficult in unclear cases of elevated liver enzymes. Here, we report the case of a 56-year-old male patient who presented to our center for 17-year follow-up after liver transplant with α1-antitrypsin deficiency. The patient was asymptomatic but had remarkably increased transaminases and cholestasis parameters. Blood levels for immunosuppressives were in the normal range, and cholestasis and deteriorated liver perfusion were excluded by ultrasonographic examination. A liver biopsy was performed that was histologically interpreted as acute cellular rejection grade I. Accordingly, the patient was treated with 5-day high-dose intravenous steroids and increased doses of the maintenance immunosuppressive agents, resulting in the slow normalization of the liver enzymes. Extended laboratory examinations revealed presence of acute hepatitis E virus infection, and a retrospectively immunohistologic staining of the liver biopsy was positive for hepatitis E virus antigen. Acute hepatitis E virus infection can be a reason for acute allograft dysfunction after liver transplant. This differential diagnosis should be kept in mind, especially when graft dysfunction occurs long after transplant.

Hepatotoxicity following systemic therapy for colorectal liver metastases and the impact of chemotherapy-associated liver injury on outcomes after curative liver resection.

Patients with colorectal liver metastases (CLM) have remarkably benefited from the advances in medical multimodal treatment and surgical techniques over the last two decades leading to significant improvements in long-term survival. More patients are currently undergoing liver resection following neoadjuvant chemotherapy, which has been increasingly established within the framework of curative-indented treatment strategies. However, the use of several cytotoxic agents has been linked to specific liver injuries that not only impair the ability of liver tissue to regenerate but also decrease long-term survival. One of the most common agents included in modern chemotherapy regimens is oxaliplatin, which is considered to induce a parenchymal damage of the liver primarily involving the sinusoids defined as sinusoidal obstruction syndrome (SOS). Administration of bevacizumab, an inhibitor of vascular endothelial growth factor (VEGF), has been reported to improve response of CLM to chemotherapy in clinical studies, concomitantly protecting the liver from the development of SOS. In this review, we aim to summarize current data on multimodal treatment concepts for CLM, give an in-depth overview of liver damage caused by cytostatic agents focusing on oxaliplatin-induced SOS, and evaluate the role of bevacizumab to improve clinical outcomes of patients with CLM and to protect the liver from the development of SOS.

Engineering an endocrine Neo-Pancreas by repopulation of a decellularized rat pancreas with islets of Langerhans.

Decellularization of pancreata and repopulation of these non-immunogenic matrices with islets and endothelial cells could provide transplantable, endocrine Neo- Pancreata. In this study, rat pancreata were perfusion decellularized and repopulated with intact islets, comparing three perfusion routes (Artery, Portal Vein, Pancreatic Duct). Decellularization effectively removed all cellular components but conserved the pancreas specific extracellular matrix. Digital subtraction angiography of the matrices showed a conserved integrity of the decellularized vascular system but a contrast emersion into the parenchyma via the decellularized pancreatic duct. Islets infused via the pancreatic duct leaked from the ductular system into the peri-ductular decellularized space despite their magnitude. TUNEL staining and Glucose stimulated insulin secretion revealed that islets were viable and functional after the process. We present the first available protocol for perfusion decellularization of rat pancreata via three different perfusion routes. Furthermore, we provide first proof-of-concept for the repopulation of the decellularized rat pancreata with functional islets of Langerhans. The presented technique can serve as a bioengineering platform to generate implantable and functional endocrine Neo-Pancreata.

Computed tomography-based survey of the vascular anatomy of the juvenile Göttingen minipig.

Over the past 50 years, image-guided procedures have been established for a wide range of applications. The development and clinical translation of new treatment regimens necessitate the availability of suitable animal models. The juvenile Göttingen minipig presents a favourable profile as a model for human infants. However, no information can be found regarding the vascular system of juvenile minipigs in the literature. Such information is imperative for planning the accessibility of target structures by catheterization. We present here a complete mapping of the arterial system of the juvenile minipig based on contrast-enhanced computed tomography. Four female animals weighing 6.13 ± 0.72 kg were used for the analyses. Imaging was performed under anaesthesia, and the measurement of the vascular structures was performed independently by four investigators. Our dataset forms a basis for future interventional studies in juvenile minipigs, and enables planning and refinement of future experiments according to the 3R (replacement, reduction and refinement) principles of animal research.

[The Impact of Tumor Cell Proliferation on Occult Micrometastases, Tumor Recurrence and Patient Outcome Following Resection for Liver Malignancies]. / Stellenwert des Proliferationsreizes auf die okkulte Mikrometastasierung sowie Rezidivhäufigkeit und Prognose nach Resektion von Lebermalignomen.

Liver resection is currently considered to be essential part of the curative treatment of primary and secondary liver malignancies. However, long-term survival in these patients is limited by the high incidence of tumor recurrence. Recent clinical and experimental studies have indicated that cellular and molecular mechanisms associated with liver regeneration after partial hepatectomy may have a proliferative effect on occult micrometastases and circulating tumor cells and are thus responsible for recurrent disease. Growth factors and cytokines involved in liver regeneration have also been shown to influence tumour growth and metastasis. However, the underlying mechanisms explaining the interactions between regenerating liver tissue and tumour cell proliferation remain unclear. The development of modern agents specifically targeting these processes may improve disease-free and overall survival rates after oncological hepatectomy.

Elevated hepatic chemerin mRNA expression in human non-alcoholic fatty liver disease.

OBJECTIVE: Adipose tissue-derived factors link non-alcoholic fatty liver disease (NAFLD) with obesity, which has also been reported for circulating chemerin. On the other hand, hepatic chemerin and chemokine-like receptor 1 (CMKLR1) mRNA expression has not yet been studied in an extensively characterized patient collective. DESIGN: This study was cross-sectional and experimental in design. METHODS: Liver tissue samples were harvested from 47 subjects and histologically examined according to the NAFLD activity score (NAS). The concentrations of chemerin and CMKLR1 were measured using semi-quantitative real-time PCR, and the concentration of serum chemerin was measured using ELISA. To evaluate potential effects of chemerin and CMKLR1, cultured primary human hepatocytes (PHHs) were exposed to selected metabolites known to play a role in NAFLD (insulin, glucagon, palmitoic acid, and interleukin-6 (IL6)). RESULTS: Chemerin and CMKLR1 mRNA levels were elevated in the human liver. Their expression was correlated with the NAS (R(2)=0.543; P<0.001 and R(2)=0.355; P=0.014 respectively) and was significantly elevated in patients with definite non-alcoholic steatohepatitis (NASH) (P<0.05 respectively). Linear regression analysis confirmed an independent association of liver fibrosis, steatosis, inflammation, and hepatocyte ballooning with hepatic chemerin mRNA expression (P<0.05 respectively). The expression of hepatic chemerin and CMKLR1 was correlated with the measures of obesity (P<0.05). The incubation of PHHs with IL6 significantly increased the expression of CMKLR1 mRNA (P=0.027), while that of chemerin remained unaffected (P>0.05). None of the other metabolites showed an influence (P>0.05). CONCLUSION: This is the first study to show that chemerin mRNA expression is significantly elevated in the liver of NASH patients and that CMKLR1 expression is upregulated in liver inflammation, whereby IL6 could play a causal role.

APACHE III score is superior to King's College Hospital criteria, MELD score and APACHE II score to predict outcomes after liver transplantation for acute liver failure.

OBJECTIVES: The Model for End-Stage Liver Disease score and King's College Hospital (KCH) criteria are accepted prognostic models acute liver failure (ALF), while the use of (APACHE) scores predict to outcomes of emergency liver transplantation is rare. MATERIALS AND METHODS: The present study included 87 patients with ALF who underwent liver transplantation. We calculated (KCH) criteria, as well as MELD, APACHE II, and APACHE III scores at the listing date for comparison with 3-month outcomes. RESULTS: According to the Youden-Index, the best cut-off value for the APACHE II score was 8.5 with 100% sensitivity, 49% specificity, 24% positive predictive value (PPV), and 100% negative predictive value (NPV). Patients with <8.5 points had a significantly higher survival rate (P < .05). The proposed APACHE III cut-off was 80. The APACHE III score demonstrated the highest specificity and PPV (90% specificity, 50% PPV). The NPV was 92%. With a 90-point threshold the specificity increased to 98% with 75% PPV and 89% NPV. Only 1 of 4 patients with a score >90 survived transplantation (P = .001). MELD score and KCH criteria were not significant (P > .05). According to the Hosmer-Lemeshow test, only the APACHE III score adequately describe the data. CONCLUSIONS: The APACHE III score was superior to KCH criteria, MELD score, and APACHE II score to predict outcomes after transplantation for ALF. It is a valuable parameter for pretransplantation patient selection.

A novel cannulation technique for isolation of human hepatocytes from explanted diseased whole livers.

Diseased human organs explanted during liver transplantation can be used as a cell source for basic research and future therapeutic applications in regenerative medicine. Enzymatic digestion using the perfusion technique has become the gold standard in liver cell isolation. Usually the portal vein is used as a vascular access for liver cell isolation from explanted livers, that were rejected from whole organ transplantation. No special techniques are required for cannulation; the cannulas are simply introduced into the vessels and a ligature is then thrown around the vessel to secure the cannulation. This method is not applicable to organs explanted during liver transplant surgery, because as much of the vessels as possible has to be kept in situ, to facilitate anastomosis of the new organ. Therefore, when perfusing the explanted organ, normal perfusion catheters are easily displaced and a more complex "vascular reconstruction" must be performed to secure hold of the catheters. We established a novel cannulation technique using commercially available Foley catheters for liver cell isolation from diseased whole organs explanted during transplant surgery. We evaluated this technique in 15 diseased organs. 5 were isolated in the conventional setting and 10 were cannulated using Foley catheters. The average cannulation time was significantly shortened using Foley catheters compared with the conventional approach (12 ± 5.2 min vs 40 ± 14.1 min; P = .0001). Foley catheter cannulation is fast, simple, and efficient. It appears to be favorable for hepatocyte isolation from diseased whole livers or from explanted organs with technically difficult vascular access.

Tracking of primary human hepatocytes with clinical MRI: initial results with Tat-peptide modified superparamagnetic iron oxide particles.

The transplantation of primary human hepatocytes is a promising approach in the treatment of specific liver diseases. However, little is known about the fate of the cells following application. Magnetic resonance imaging (MRI) could enable real-time tracking and long-term detection of transplanted hepatocytes. The use of superparamagnetic iron oxide particles as cellular contrast agents should allow for the non-invasive detection of labelled cells on high-resolution magnetic resonance images. Experiments were performed on primary human hepatocytes to transfer the method of detecting labelled cells via clinical MRI into human hepatocyte transplantation. For labelling, Tat-peptide modified nano-sized superparamagnetic MagForce particles were used. Cells were investigated via a clinical MR scanner at 3.0 Tesla and the particle uptake within single hepatocytes was estimated using microscopic examinations. The labelled primary human hepatocytes were clearly detectable by MRI, proving the feasibility of this new concept. Therefore, this method is a useful tool to investigate the effects of human hepatocyte transplantation and to improve safety aspects of this method.

In vitro comparison of two bioartificial liver support systems: MELS CellModule and AMC-BAL.

Clinically applied bioartificial liver (BAL) support systems are difficult to compare with regard to overall hepatocyte-specific function and clinical outcome. We compared two clinically applied BAL systems, the Modular Extracorporeal Liver Support (MELS) CellModule and the AMC-bioartificial liver (AMC-BAL) in an in vitro set-up. Both BAL systems were loaded with 10 billion freshly isolated porcine hepatocytes, cultured for 7 days and tested on days 1, 2, 4 and 7. Average decrease in hepatocyte-specific functions over 7 days was 9.7%. Three parameters differed between both bioreactors: lidocaine elimination at days 1 and 2 was significantly higher in the AMCBAL, ammonia elimination showed a significantly higher trend for the AMC-BAL over 7 days and LDH release was significantly lower at day 7 for the MELS CellModule. In conclusion, this first in vitro comparison of two clinically applied BAL systems shows comparable functional capacity over a period of 7 days.

[Clinical results of intestinal and multivisceral transplantation at the Charité, Berlin. A case series]. / Klinische Ergebnisse der Dünndarm- und Multiviszeraltransplantation an der Berliner Charité - Eine Fallserie -

BACKGROUND AND OBJECTIVE: Intestinal transplantation (ITx) is the only causal therapy of short bowel syndrome (SBS). Long-term survival after ITx has been improved significantly during the last years. The experience with ITx at the Charite, Campus Virchow Klinikum, are described and discussed. PATIENTS AND METHODS: Twelve isolated ITx and one multivisceral transplantation (including stomach, pancreatodudenal complex, small intestine, liver, ascending colon, right kidney, and adrenal gland) were performed. Mean recipient age was 37.7+/-10.6 yrs (median: 35 yrs; range: 27 - 58 yrs; M:F = 8:5). All patients had irreversible SBS (0 - 30 cm residual bowel length; mean: 11.8+/-11.4 cm; median: 13 cm). RESULTS: 6-months and 1-year patient and graft survival were 85 % (11/13) and 77 % (10/13), respectively. Reasons for graft loss and patient death were necrotizing enterocolitis, severe, muromonab-resistent, acute rejection, and graft ischemia due to complex coagulopathy. All other patients had good long-term outcome. They received enteral nutrition at six hours after operation and were persistently off total parenteral nutrition (TPN) by week two after ITx. CONCLUSION: ITx as established in our centre, with 1-year-patient and graft survival rates of 77 %, reflects current international standard. ITx is complementary to conservative and other operative methods of treating SBS. Referral and indication criteria need wider dissemination to prevent life-threatening complications of TPN.

Bioartificial liver: current status.

Liver failure remains a life-threatening syndrome. With the growing disparity between the number of suitable donor organs and the number of patients awaiting transplantation, efforts have been made to optimize the allocation of organs, to find alternatives to cadaveric liver transplantation, and to develop extracorporeal methods to support or replace the function of the failing organ. An extracorporeal liver support system has to provide the main functions of the liver: detoxification, synthesis, and regulation. The understanding that the critical issue of the clinical syndrome in liver failure is the accumulation of toxins not cleared by the failing liver led to the development of artificial filtration and adsorption devices (artificial liver support). Based on this hypothesis, the removal of lipophilic, albumin-bound substances, such as bilirubin, bile acids, metabolites of aromatic amino acids, medium-chain fatty acids, and cytokines, should be beneficial to the clinical course of a patient in liver failure. Artificial detoxification devices currently under clinical evaluation include the Molecular Adsorbent Recirculating System (MARS), Single-Pass Albumin Dialysis (SPAD), and the Prometheus system. The complex tasks of regulation and synthesis remain to be addressed by the use of liver cells (bioartificial liver support). The Extracorporeal Liver Assist Device (ELAD), HepatAssist, Modular Extracorporeal Liver Support system (MELS), and the Amsterdam Medical Center Bioartificial Liver (AMC-BAL) are bioartificial systems. This article gives a brief overview on these artificial and bioartificial devices and discusses remaining obstacles.

Clinical extracorporeal hybrid liver support--phase I study with primary porcine liver cells.

The objective of this study was to evaluate the feasibility and safety of a hybrid liver support system with extracorporeal plasma separation and bioreactor perfusion in patients with acute liver failure (ALF) who had already fulfilled the criteria for high urgency liver transplantation (LTx). Eight patients (one male, seven female) were treated in terms of bridging to transplantation. The mean age was 36.5 yr (range 20 to 58). Etiology of liver failure was drug-related in two patients, hepatitis B infection in three patients, and unknown for three patients. The bioreactors were charged with primary liver cells from specific pathogen-free pigs. Cell viability varied between 91 and 98%. Continuous liver support treatment over a period of 8 to 46 h (mean 27.3 h) was safely performed and well-tolerated by all patients. No complications associated with the therapy were observed during the follow-up period. Thrombocytopenia was considered to be an effect of the plasma separation. Subsequently, all patients were transplanted successfully and were observed over at least 3 yr with an organ and patient survival rate of 100%. Screening of patient's sera for antibodies specific for porcine endogenous retroviruses (PERVs) showed no reactivity--either prior to application of the system, or after extracorporeal treatment. The results encourage us to continue the development of the technology, and further studies appear to be justified. The bioreactor technology has been integrated into a modular extracorporeal liver support (MELS) system, combining biologic liver support with artificial detoxification technology.

Primary human liver cells as source for modular extracorporeal liver support--a preliminary report.

Cell-based extracorporeal liver support is an option to assist or replace the failing organ until regeneration or until transplantation can be performed. The use of porcine cells or tumor cell lines is controversial. Primary human liver cells, obtained from explanted organs found to be unsuitable for transplantation, are a desirable cell source as they perform human metabolism and regulation. The Modular Extracorporeal Liver Support (MELS) concept combines different extracorporeal therapy units, tailored to suit the individual and intra-individual clinical needs of the patient. A multi-compartment bioreactor (CellModule) is loaded with human liver cells obtained by 5-step collagenase liver perfusion. A cell mass of 400 g - 600 g enables the clinical application of a liver lobe equivalent hybrid organ. A detoxification module enables single pass albumin-dialysis via a standard high-flux dialysis filter, and continuous veno-venuous hemodiafiltration may be included if required. Cells from 54 human livers have been isolated (donor age: 56 +/- 13 years, liver weight: 1862 +/- 556 g resulting in a viability of 55.0 +/- 15.9%). These grafts were not suitable for LTx, due to steatosis (54%), cirrhosis (15%), fibrosis (9%), and other reasons (22%). Out of 36 prepared bioreactors, 10 were clinically used to treat 8 patients with liver failure. The overall treatment time was 7-144 hours. No adverse events were observed. Initial clinical applications of the bioreactor evidenced the technical feasibility and safety of the system.