Role of extracellular matrix structural components and tissue mechanics in the development of postoperative pancreatic fistula.

Radical resection remains the only curative treatment option in pancreatic cancer. Postoperative pancreatic fistulas (POPF) occur in up to 30% of patients leading to prolonged hospital-stay, increased cost of care and morbidity and mortality. Mechanical properties of the pancreas are associated with POPF. The aim of this study is to analyze the role of extracellular matrix (ECM) and tissue mechanics in the risk of POPF. Biopsies of 41 patients receiving a partial pancreas-resection are analyzed. Clinical data, ECM components and mechanical properties are correlated with POPF. Preoperative cholestasis is correlated with reduced risk of POPF, which comes along with a dilatation of the pancreatic duct and significantly higher content of collagen I. Patients developing POPF exhibited a degenerated tissue integrity, with significantly lower content of fibronectin and a trend for lower collagen I, III, IV and hyaluronic acid. This correlated with a soft tactile sensation of the surgeon during the intervention. However, this was not reflected with tissue mechanics evaluated by ex vivo uniaxial compression testing, where a significantly higher elastic modulus and no effect on the stress relaxation time were found. In conclusion, patients with cholestasis seem to have a lower risk for POPF, and an increase in collagen I. A degenerated matrix with lower content of structural ECM components correlates with increased risk of POPF. However, ex vivo uniaxial compression testing failed to clearly explain the link of ECM properties and POPF.

Cancer Associated Fibroblasts Derived from Pancreatic Adenocarcinoma and Their Role in Cell Migration.

BACKGROUND/AIM: Pancreatic ductal adenocarcinoma (PDAC) shows poor survival and early systemic dissemination. Cancer associated fibroblasts (CAFs) enhance migration and invasion of cancer cells. We aimed to investigate the role of CAFs in cell migration and their underlying paracrine effects. MATERIALS AND METHODS: Using Transwell® migration assays, PDAC cells (PANC-1) and three distinct types of fibroblasts were analyzed: CAFs, genetically transformed human foreskin-fibroblasts (BJeLR), and non-transformed human foreskin-fibroblasts (VH7). IL6 in the culture supernatant was measured to investigate paracrine communication in monocultures and direct/indirect cocultures. RESULTS: CAFs showed a significantly higher capacity to migrate in vitro when compared to benign fibroblasts (p=0.009). They also facilitated the migration of PDAC cells in coculture (p=0.001). Neither BJeLR, nor VH7 displayed such features. This was accompanied by a significant increase in IL-6 when CAFs were cocultured with PANC-1 (p=0.009). CONCLUSION: CAFs are a key element of intra-tumoral migration and should be further investigated as a potential therapeutic target.

Speckle Tracking Analysis Reveals Altered Left Atrial and Ventricular Myocardial Deformation in Patients with End-Stage Liver Disease.

BACKGROUND: Cardiac function can be influenced by liver cirrhosis and should be thoroughly evaluated before liver transplantation. We investigated left ventricular (LV) and, for the first time, left atrial (LA) strain and strain rate in end-stage liver cirrhosis patients of different etiologies. METHODS: This retrospective, cross-sectional study evaluated left heart function in 80 cirrhosis patients and 30 controls using standardized echocardiographic techniques and speckle tracking technology (STE) analysis. Serum markers of liver function were used for correlation analysis. RESULTS: While conventional parameters demonstrated no alteration in systolic function, speckle tracking analysis showed a significant increase in LV longitudinal strain throughout all cardiac layers, with significant correlation to model of end-stage liver disease (MELD) score. LA reservoir and conduit strain as well as LA strain rate in all phases were significantly reduced in end-stage liver disease (ESLD) patients compared to control. STE for the evaluation of LA phasic function seemed to be more sensitive than volumetric methods. Kaplan-Meier curves showed a trend towards reduced post-transplant survival in patients with a reduced LA reservoir and conduit strain. CONCLUSION: STE analysis detected increased LV and decreased LA deformation in cirrhosis patients, thus proving to be highly sensitive to cardiac changes and useful for more precise cardiac evaluation.

Notch Signaling Pathway in Pancreatobiliary Tumors.

Background and objectives: The Notch signaling pathway plays an important role both in the development of the ductal systems of the pancreas and the bile ducts as well as in cancer development and progression. The aim of this study was to examine the expression of central proteins of the Notch signaling pathway in pancreatobiliary tumors and its influence on patient survival. Materials and Methods: We compared the receptors (Notch1, Notch4), activating splicing factors (ADAM17), and target genes (HES1) of the Notch pathway and progenitor cell markers with relevance for the Notch signaling pathway (CD44, MSI1) between pancreatic adenocarcinomas (PDAC, n = 14), intrahepatic cholangiocarcinoma (iCC, n = 24), and extrahepatic cholangiocarcinoma (eCC, n = 22) cholangiocarcinomas via immunohistochemistry and ImageJ software-assisted analysis. An Immunohistochemistry (IHC)-score was determined by the percentage and intensity of stained (positive) cells (scale 0-7) and normal and malignant tissue was compared. In the IHC results, patients' (gender, age) and tumor (TNM Classification of Malignant Tumors, Union Internationale contre le Cancer (UICC) stages, grading, and lymphangitic carcinomatosa) characteristics were correlated to patient survival. Results: For eCC, the expression of CD44 (p = 0.043, IHC-score 3.94 vs. 3.54) and for iCC, the expression of CD44 (p = 0.026, IHC-score 4.04 vs. 3.48) and Notch1 (p < 0.001, IHC-score 2.87 vs. 1.78) was significantly higher in the tumor compared to non-malignant tissue. For PDAC, the expression of ADAM17 (p = 0.008, IHC-score 3.43 vs. 1.73), CD44 (p = 0.012, IHC-score 3.64 vs. 2.27), Notch1 (p = 0.012, IHC-score 2.21 vs. 0.64), and Notch4 (p = 0.008, IHC-score 2.86 vs. 0.91) was significantly higher in the tumor tissue. However, none of the analyzed Notch-signaling related components showed an association to patient survival. Conclusion: A significant overexpression of almost all studied components of the Notch signaling pathway can be found in the tumor tissue, however, without a significant influence on patient survival. Therefore, further studies are warranted to draw conclusions on Notch pathway's relevance for patient survival.

Characterization of Pancreatic and Biliary Cancer Stem Cells in Patient-derived Tissue.

BACKGROUND/AIM: Pancreatic ductal adenocarcinoma (PDAC) and extrahepatic cholangio-carcinoma (eCC) represent two cancer entities with devastating prognoses. Despite recent progress in research and treatment, therapy remains challenging. Cancer stem cells (CSCs) have been shown to play an important role in metastasis and chemoresistance. Therefore, CSCs may play a promising role as a potential therapeutic target. MATERIALS AND METHODS: A total of 31 patients (23 PDAC, 8 eCC) were included in the study. CSCs were analyzed in a single-cell suspension of tumor samples via fluorescence-activated cell scanning (FACS) with a functional Hoechst 33342 staining as well as a cell surface marker staining of the CSC-panel (CD24, CD44 and EpCAM) and markers to identify fibroblasts, leukocytes and components of the notch signaling pathway. Furthermore, the potential presence of CSCs among primary cancer-associated fibroblasts (CAFs) was assessed using the same FACS-panel. RESULTS: We showed that CSCs are present in patient-derived dissociated tumor tissue. The functional and surface marker profile of CSC-detection did in fact correlate. The amount of CSCs was significantly correlated with tumor characteristics such as a higher UICC stadium and nodal invasion. CSCs were not restricted to the epithelial cell fraction in tumor tissues, which has been verified in independent analysis of primary cell cultures of CAFs. CONCLUSION: Our study confirms the in vivo presence of CSCs in PDAC and eCC, stating a clinical significance thereof and thus their plausibility as therapeutic targets. In addition, stem-like cells also seem to constitute a part of the CAFs.

Right Heart Remodeling in Patients with End-Stage Alcoholic Liver Cirrhosis: Speckle Tracking Point of View.

BACKGROUND: Data regarding cardiac remodeling in patients with alcoholic liver cirrhosis are scarce. We sought to investigate right atrial (RA) and right ventricular (RV) structure, function, and mechanics in patients with alcoholic liver cirrhosis. METHODS: This retrospective cross-sectional investigation included 67 end-stage cirrhotic patients, who were referred for evaluation for liver transplantation and 36 healthy controls. All participants underwent echocardiographic examination including strain analysis, which was performed offline. RESULTS: RV basal diameter and RV thickness were significantly higher in patients with cirrhosis. Conventional parameters of the RV systolic function were similar between the observed groups. Global, endocardial, and epicardial RV longitudinal strains were significantly lower in patients with cirrhosis. Active RA function was significantly higher in cirrhotic patients than in controls. The RA reservoir and conduit strains were significantly lower in cirrhotic patients, while there was no difference in the RA contractile strain. Early diastolic and systolic RA strain rates were significantly lower in cirrhotic patients than in controls, whereas there was no difference in the RA late diastolic strain rate between the two groups. Transaminases and bilirubin correlated negatively with RV global longitudinal strain and RV-free wall strain in patients with end-stage liver cirrhosis. The Model for End-stage Liver Disease (MELD) score, predictor of 3-month mortality, correlated with parameters of RV structure and systolic function, and RA active function in patients with end-stage liver cirrhosis. CONCLUSIONS: RA and RV remodeling is present in patients with end-stage liver cirrhosis even though RV systolic function is preserved. Liver enzymes, bilirubin, and the MELD score correlated with RV and RA remodeling.

The role of hepatectomy for synchronous liver metastases from pancreatic adenocarcinoma.

BACKGROUND: The role of hepatectomy for patients with liver metastases from ductal adenocarcinoma of the pancreas (PLM) remains controversial. Therefore, the aim of our study was to examine the postoperative morbidity, mortality, and long-term survivals after liver resection for synchronous PLM. METHODS: Clinicopathological data of patients who underwent hepatectomy for PLM between 1993 and 2015 were assessed. Major endpoint of this study was to identify predictors of overall survival (OS). RESULTS: During the study period, 76 patients underwent resection for pancreatic cancer and concomitant hepatectomy for synchronous PLM. Pancreatoduodenectomy, distal pancreatectomy, and total pancreatectomy were performed in 67%, 25%, and 8% of the patients, respectively. The median PLM size was 1 (1-13) cm and 36% of patients had multiple PLM. The majority of patients (96%) underwent a minor liver resection. After a median follow-up time of 130 months, 1-, 3-, and 5-year OS rates were 41%, 13%, and 7%, respectively. Postoperative morbidity and mortality rates were 50% and 5%, respectively. Preoperative and postoperative chemotherapy was administered to 5% and 72% of patients, respectively. In univariate analysis, type of pancreatic procedure (P = .020), resection and reconstruction of the superior mesenteric artery (P = .016), T4 stage (P = .086), R1 margin status at liver resection (P = .001), lymph node metastases (P = .016), poorly differentiated cancer (G3) (P = .037), no preoperative chemotherapy (P = .013), and no postoperative chemotherapy (P = .005) were significantly associated with worse OS. In the multivariate analysis, poorly differentiated cancer (G3) (hazard ratio [HR] = 1.87; 95% confidence interval [CI] = 1.08-3.24; P = .026), R1 margin status at liver resection (HR = 4.97; 95% CI = 1.46-16.86; P = .010), no preoperative chemotherapy (HR = 4.07; 95% CI = 1.40-11.83; P = .010), and no postoperative chemotherapy (HR = 1.88; 95% CI = 1.06-3.29; P = .030) independently predicted worse OS. CONCLUSIONS: Liver resection for PLM is feasible and safe and may be recommended within the framework of an individualized cancer therapy. Multimodal treatment strategy including perioperative chemotherapy and hepatectomy may provide prolonged survival in selected patients with metastatic pancreatic cancer.

Clinicopathological Stratification and Long-term Follow-up of Patients with Periampullary Carcinomas.

BACKGROUND: Periampullary carcinomas generally confer a poor outcome. Choosing the most effective treatment regimen for each sub-entity proves challenging and is usually based on experience from pancreatic adenocarcinoma (PDAC). PATIENTS AND METHODS: The long-term follow-up is presented of 472 patients with periampullary tumors [PDAC, distal cholangiocarcinoma (dCC) and ampullary carcinomas (AC)] who underwent radical resection considering clinical characteristics, paraclinical findings and histopathological features in order to define factors of prognostic relevance. RESULTS: Patients with PDACs presented with larger tumor sizes, more frequent R1 resection, higher rate of nodal and perineural invasion, higher tumor stage according to the classification of tumors of the Union Internationale contre le Cancer when compared to those with dCCs and ACs. In a multivariate analysis, age >65 years, postoperative complications and higher grading of the tumor proved to be independent prognostic factors for survival. CONCLUSION: Patients suffering from PDAC have the worst prognosis and greatest benefit from radical resection of all patients with periampullary tumors. More detailed studies are warranted to better distinguish between the different entities.

Incidence and Oncological Implications of Previously Undetected Tumor Multicentricity Following Pancreaticoduodenectomy for Pancreatic Adenocarcinoma in Patients Undergoing Salvage Pancreatectomy.

BACKGROUND: The risk for multicentricity of pancreatic adenocarcinoma remains unclear and the question whether pancreaticoduodenectomy represents sufficient oncological treatment for patients with ductal adenocarcinoma of the head of the pancreas needs further investigation. PATIENTS AND METHODS: Clinicopathological data of patients who underwent pancreaticoduodenectomy for pancreatic adenocarcinoma between 2005 and 2015 were assessed and the incidence of tumor multicentricity among patients who required salvage pancreatectomy within 90 postoperative days was evaluated. RESULTS: Pancreaticoduodenectomy was performed in 1,005 patients. Sixty-two patients (6%) suffered a major postoperative complication (pancreatic fistula/anastomotic leak/bleeding) after resection of the head of the pancreas, requiring salvage pancreatectomy. Histological examination of the pancreatic remnant in patients with ductal adenocarcinoma (n=19) revealed multicentric carcinoma in two patients, resulting in an incidence of 11% for tumor multicentricity. Preoperative cross-sectional imaging failed to identify tumor multicentricity in these patients. Additionally, two patients with pancreatic intraepithelial neoplasia and two with neuroendocrine tumor were identified. CONCLUSION: The incidence of previously undetected multicentric adenocarcinoma among patients undergoing salvage pancreatectomy in our study was surprisingly high. This finding suggests that the role of total pancreatectomy for pancreatic head cancer, as well as the current strategies for postoperative tumor surveillance, should be re-evaluated in order to provide the best oncological approach and prolonged survival for patients with ductal adenocarcinoma.

Impact of Doppler Ultrasound on Diagnosis and Therapy Control of Lienalis Steal Syndrome After Liver Transplantation.

BACKGROUND Lienalis steal syndrome is a rare complication after orthotopic liver transplantation leading to severe complications. Routine duplex sonography allows early and safe detection of lienalis steal syndrome and secondarily helps to monitor the outcome by evaluating the hemodynamics. MATERIAL AND METHODS This analysis included eight patients who after orthotopic liver transplantation needed splenic artery embolization due to lienalis steal syndrome. Lienalis steal syndrome was assumed in case of elevated transaminases, bilirubinemia or persistent ascites, and the absence of further pathologies. Diagnosis was supported by ultrasound, confirmed by digital subtraction angiography, and followed by splenic artery embolization for treatment. We analyzed blood levels and ultrasound findings before and after splenic artery embolization as well as during follow-up and evaluated for incidence of severe biliary complications and survival. RESULTS Arterial resistive index (RI) significantly regularized after splenic artery embolization while the maximum arterial velocity increased. The portal venous flow volume and maximum velocity decrease. Laboratory parameters normalized. Two of eight patients developed ischemic-type biliary disease. Survival rate was 88% over a median follow-up of 33 months. CONCLUSIONS Beside unspecific clinical findings, bedside ultrasound examination enabled a quick verification of the diagnosis and allowed direct treatment to minimize further complications. Furthermore, ultrasound can immediately monitor the therapeutic effect of splenic artery embolization.

microRNA signatures in peripheral blood fail to detect acute cellular rejection after liver transplantation.

OBJECTIVE: We investigated whether microRNA signatures in whole blood samples are associated with acute cellular rejection (ACR) after liver transplantation. MATERIALS AND METHODS: Blood samples were collected using Paxgene technology and analyzed by microarrays and quantitative real-time polymerase chain reaction (qRT-PCR). RESULTS: microRNA signatures failed to distinguish between 19 patients with ACR and 16 controls. Let-7b-5p and let-7c were upregulated in a subgroup of patients with ACR during the 6th and 7th postoperative days but failed in an independent validation of 20 patients. CONCLUSION: microRNA signatures in whole blood processed by Paxgene technology are not suited for the detection of ACR after liver transplantation.

Distal bile duct carcinomas and pancreatic ductal adenocarcinomas: postulating a common tumor entity.

The set definition of distal cholangiocarcinomas and adenocarcinomas of the pancreatic head is challenged by their close anatomical relation, similar growth pattern, and corresponding therapeutic outcome. They show a mutual development during embryologic organ formation and share phenotypic characteristics. This review will highlight the similarities with regard to the common origin of their primary organs, histopathological similarities, and modern clinical management. Thus, we propose to subsume those entities under a common superfamily.

Porcine liver decellularization under oscillating pressure conditions: a technical refinement to improve the homogeneity of the decellularization process.

Decellularization and recellularization of parenchymal organs may facilitate the generation of autologous functional liver organoids by repopulation of decellularized porcine liver matrices with induced liver cells. We present an accelerated (7 h overall perfusion time) and effective protocol for human-scale liver decellularization by pressure-controlled perfusion with 1% Triton X-100 and 1% sodium dodecyl sulfate via the hepatic artery (120 mmHg) and portal vein (60 mmHg). In addition, we analyzed the effect of oscillating pressure conditions on pig liver decellularization (n=19). The proprietary perfusion device used to generate these pressure conditions mimics intra-abdominal conditions during respiration to optimize microperfusion within livers and thus optimize the homogeneity of the decellularization process. The efficiency of perfusion decellularization was analyzed by macroscopic observation, histological staining (hematoxylin and eosin [H&E], Sirius red, and alcian blue), immunohistochemical staining (collagen IV, laminin, and fibronectin), and biochemical assessment (DNA, collagen, and glycosaminoglycans) of decellularized liver matrices. The integrity of the extracellular matrix (ECM) postdecellularization was visualized by corrosion casting and three-dimensional computed tomography scanning. We found that livers perfused under oscillating pressure conditions (P(+)) showed a more homogenous course of decellularization and contained less DNA compared with livers perfused without oscillating pressure conditions (P(-)). Microscopically, livers from the (P(-)) group showed remnant cell clusters, while no cells were found in livers from the (P(+)) group. The grade of disruption of the ECM was higher in livers from the (P(-)) group, although the perfusion rates and pressure did not significantly differ. Immunohistochemical staining revealed that important matrix components were still present after decellularization. Corrosion casting showed an intact vascular (portal vein and hepatic artery) and biliary framework. In summary, the presented protocol for pig liver decellularization is quick (7 h) and effective. The application of oscillating pressure conditions improves the homogeneity of perfusion and thus the outcome of the decellularization process.