Lumen apposing metal stents vs. double pigtail plastic stents for the drainage of pancreatic walled-off necrosis

BACKGROUND

Few studies compared lumen-apposing metal stents (LAMS) and standard double pigtail plastic stents (PS) for the endoscopic drainage of pancreatic walled-off necrosis (WON). Albeit sometimes large, previously described cohorts display considerable heterogeneity and often pooled together data from several centers, involving multiple operators and techniques. Moreover, they often lack a control group for the comparison of outcomes. The aim of this study was to compare clinical efficacy and safety of PS versus LAMS for the endoscopic drainage of infected WON.

METHODS

Thirty patients were enrolled between 2011 and 2017. The present study is a single-center, 1:1 case-control study. We compared patients undergoing endoscopic drainages of infected WON through LAMS (cases) or PS (controls). The primary endpoint was the clinical efficacy (resolution of the WON/sepsis), the secondary endpoint was safety (procedure-related complications).

RESULTS

Cases and controls were homogeneous in terms of etiology and clinical characteristics: 93% of cases and 86.7% of controls were clinically successfully treated, with no significant differences in rates of postoperative infections, bleedings, and stent migrations (respectively 13.3% vs. 21.4%; P=0.65; 13.3% vs. 0%; P=0.48; 13.3% vs. 7.1%; P=1.00). No difference was shown regarding the need for additional percutaneous or surgical treatments (33.3% vs. 13.3%; P=0.39). Cases, however, displayed a significantly prolonged mean hospital stay (90.2 days vs. 18.5 days; P<0.01) and a higher mean number of endoscopic procedures per patient (4.8 vs. 1.5; P<0.01).

CONCLUSIONS

PS might be not inferior to LAMS for the treatment WONs. Further prospective RCT is needed to compare clinical efficacy and safety in the two groups.

A novel pancreatic tumour and stellate cell 3D co-culture spheroid model

BACKGROUND

Pancreatic ductal adenocarcinoma is a devastating disease with poor outcome, generally characterized by an excessive stroma component. The purpose of this study was to develop a simple and reproducible in vitro 3D-assay employing the main constituents of pancreatic ductal adenocarcinoma, namely pancreatic stellate and cancer cells.

METHOD

A spheroid assay, directly co-culturing human pancreatic stellate cells with human pancreatic tumour cells in 3D was established and characterized by electron microscopy, immunohistochemistry and real-time RT-PCR. In order to facilitate the cell type-specific crosstalk analysis by real-time RT-PCR, we developed a novel in vitro 3D co-culture model, where the participating cell types were from different species, human and mouse, respectively. Using species-specific PCR primers, we were able to investigate the crosstalk between stromal and cancer cells without previous cell separation and sorting.

RESULTS

We found clear evidence for mutual influence, such as increased proliferation and a shift towards a more mesenchymal phenotype in cancer cells and an activation of pancreatic stellate cells towards the myofibroblast phenotype. Using a heterospecies approach, which we coined virtual sorting, confirmed the findings we made initially in the human-human spheroids.

CONCLUSIONS

We developed and characterized different easy to set up 3D models to investigate the crosstalk between cancer and stroma cells for pancreatic cancer.

Fibroblast drug scavenging increases intratumoural gemcitabine accumulation in murine pancreas cancer

OBJECTIVE

Desmoplasia and hypovascularity are thought to impede drug delivery in pancreatic ductal adenocarcinoma (PDAC). However, stromal depletion approaches have failed to show clinical responses in patients. Here, we aimed to revisit the role of the tumour microenvironment as a physical barrier for gemcitabine delivery.

DESIGN

Gemcitabine metabolites were analysed in LSL-KrasG12D/+ ; LSL-Trp53R172H/+ ; Pdx-1-Cre (KPC) murine tumours and matched liver metastases, primary tumour cell lines, cancer-associated fibroblasts (CAFs) and pancreatic stellate cells (PSCs) by liquid chromatography-mass spectrometry/mass spectrometry. Functional and preclinical experiments, as well as expression analysis of stromal markers and gemcitabine metabolism pathways were performed in murine and human specimen to investigate the preclinical implications and the mechanism of gemcitabine accumulation.

RESULTS

Gemcitabine accumulation was significantly enhanced in fibroblast-rich tumours compared with liver metastases and normal liver. In vitro, significantly increased concentrations of activated 2',2'-difluorodeoxycytidine-5'-triphosphate (dFdCTP) and greatly reduced amounts of the inactive gemcitabine metabolite 2',2'-difluorodeoxyuridine were detected in PSCs and CAFs. Mechanistically, key metabolic enzymes involved in gemcitabine inactivation such as hydrolytic cytosolic 5'-nucleotidases (Nt5c1A, Nt5c3) were expressed at low levels in CAFs in vitro and in vivo, and recombinant expression of Nt5c1A resulted in decreased intracellular dFdCTP concentrations in vitro. Moreover, gemcitabine treatment in KPC mice reduced the number of liver metastases by >50%.

CONCLUSIONS

Our findings suggest that fibroblast drug scavenging may contribute to the clinical failure of gemcitabine in desmoplastic PDAC. Metabolic targeting of CAFs may thus be a promising strategy to enhance the antiproliferative effects of gemcitabine.

Endoscopic classification of the papilla of Vater. Results of an inter- and intraobserver agreement study

BACKGROUND

Many endoscopists acknowledge that the appearance of the papilla of Vater seems to affect biliary cannulation. To assess the association between the macroscopic appearance of the papilla and biliary cannulation and other related clinical issues, a system is needed to define the appearance of the papilla.

OBJECTIVE

The purpose of this study was to validate an endoscopic classification of the papilla of Vater by assessing the interobserver and intraobserver agreements among endoscopist with varying experience.

METHODS

An endoscopic classification, based on pictures captured from 140 different papillae, containing four types of papillae was proposed. The four types are (a) Type 1: regular papilla, no distinctive features, 'classic appearance'; (b) Type 2: small papilla, often flat, with a diameter ≤ 3 mm (approximately 9 Fr); (c) Type 3: protruding or pendulous papilla, a papilla that is standing out, protruding or bulging into the duodenal lumen or sometimes hanging down, pendulous with the orifice oriented caudally; and (d) Type 4: creased or ridged papilla, where the ductal mucosa seems to extend distally, rather out of the papillary orifice, either on a ridge or in a crease. To assess the level of interobserver agreement, a web-based survey was sent out to 18 endoscopists, containing 50 sets of still images of the papilla, distributed between the four different types. Three months later a follow-up survey, with images from the first survey was sent to the same endoscopists.

RESULTS

Interobserver agreement was substantial (κ = 0.62, 95% confidence interval (CI) 0.58-0.65) and were similar for both experts and non-experts. The intraobserver agreement assessed with the second survey was also substantial (κ = 0.66, 95% CI 0.59-0.72).

CONCLUSION

The proposed endoscopic classification of the papilla of Vater seems to be easy to use, irrespective of the level of experience of the endoscopist. It carries a substantial inter- and intraobserver agreement and now the clinical relevance of the four different papilla types awaits to be determined.

Cationic liposomal paclitaxel plus gemcitabine or gemcitabine alone in patients with advanced pancreatic cancer: a randomized controlled phase II trial

BACKGROUND

Paclitaxel embedded in cationic liposomes (EndoTAG™-1; ET) is an innovative agent targeting tumor endothelial cells. This randomized controlled phase II trial evaluated the safety and efficacy of ET in combination with gemcitabine (GEM) in advanced pancreatic cancer (PDAC).

PATIENTS AND METHODS

Chemotherapy-naive patients with locally advanced or metastatic disease were randomly assigned to receive weekly GEM 1000 mg/m(2) or GEM plus twice-weekly ET 11, 22 or 44 mg/m(2) for 7 weeks. After a safety run-in of 100 patients, a second cohort continued treatment. End points included overall survival (OS), progression-free survival (PFS), tumor response and safety.

RESULTS

Two hundred and twelve patients were randomly allocated to the study and 200 were treated (80% metastatic, 20% locally advanced). Adverse events were manageable and reversible. Transient thrombocytopenia and infusion reactions with chills and pyrexia mostly grade 1 or 2 occurred in the ET groups. Disease control rate after the first treatment cycle was 43% with GEM and 60%, 65% and 52% in the GEM + ET cohorts. Median PFS reached 2.7 compared with 4.1, 4.6 and 4.4 months, respectively. Median OS was 6.8 compared with 8.1, 8.7 and 9.3 months, respectively.

CONCLUSIONS

Treatment of advanced PDAC with GEM + ET was generally well tolerated. GEM + ET showed beneficial survival and efficacy. A randomized phase III trial should confirm this positive trend.

[Autoimmune pancreatitis]

Autoimmune pancreatitis has been established as a special entity of pancreatitis. It is an enigmatic disease since it is adding an autoimmune etiology to the existing causes of pancreatitis. Morphological hallmarks of the disease are narrowing of the pancreatic duct system and the bile duct by periductal lymphoplasmocytic inflammation. This results in many cases in obstructive jaundice due to a mass-forming lesion in the pancreatic head mimicking pancreatic ductal adenocarcinoma. Therefore, patients will frequently undergo surgery. Histopathologically, the disease can be diagnosed by IgG4-positive plasma cells. Serologically, patients may present with elevated serum IgG and IgG4 levels. Other autoantibodies are also described. Association with other autoimmune manifestations in a wide range of organs is frequent. Autoimmune pancreatitis will respond to steroid treatment, which is of specific importance because pancreatic cancer is one of its clinical differential diagnoses. It is important to positively diagnose autoimmune pancreatitis, especially if the bile ducts are affected, since cholangitis may be or become a prominent problem before or after surgery.

[Proteome analysis--basis for individualized pancreatic carcinoma therapy?]

Ductal pancreatic adenocarcinoma is a dismal disease, having the worst prognosis of all solid tumors. While genomics and transcriptomics have provided a wealth of data, no contribution has been made to clinical medicine in terms of diagnostic or prognostic markers. Hope lies in yet another novel technology, proteomics. Conceptually, proteomics bears the advantage of incorporating both posttranslational modifications as well as host factors. This is thought to be important in factors influencing survival such as chemoresistance. This tutorial review discusses the state of the art in pancreatic cancer proteomics in light of technical developments. At this moment, proteomics is still at the beginning in clinical application. First results, however, suggest some hope for the development of a new understanding of the molecular biology in pancreatic cancer yielding into very specific markers of disease or allowing a rational and individualized therapy.

[The diagnostic validity of non-invasive pancreatic function tests--a meta-analysis]

BACKGROUND

The paper discusses the non-invasive (tubeless) pancreatic function tests used to diagnose exocrine pancreatic insufficiency (EI). Studies evaluating the diagnostic validity of these tests are integrated into a meta-analysis, provided that they comply with the following criteria: The sensitivity (Ss) of a test has to be calculated by comparing it with an invasive function test which is accepted as the gold standard of pancreatic function diagnostics. Furthermore, the test must differentiate between slight (sl), moderate (md) and severe (sv) EI. For assessment of the specificity (Sp), the control group should not contain healthy persons but rather patients with other gastrointestinal diseases and a normal pancreatic function. In the statistical evaluation, each study was weighted according to the number of persons included.

RESULTS

Tests (n = sum of persons included in all analysed studies): Fecal chymotrypsin: Ss (n = 169) 54 % (sl EI), 53 % (md EI), 89 % (sv EI), Sp (n = 202) 74 %. NBT-PABA test: Ss (n = 394) 49 % (sl EI), 64 % (md EI), 72 % (sv EI), Sp (n = 218) 83 %. Pancreolauryl test: Ss (n = 320) 63 % (sl EI), 76 % (md EI), 94 % (sv EI), Sp (n = 171) 85 %. Fecal elastase-1: Ss (n = 307) 54 % (sl EI), 75 % (md EI), 95 % (sv EI), Sp (n = 347) 79 %. Additional tests discussed but not included in the meta-analysis were fecal fat, (13)C breath tests, amino acid consumption test, serum tests.

CONCLUSION

None of the non-invasive pancreatic function tests is sensitive enough to diagnose reliably a slight to moderate exocrine pancreatic insufficiency.

Low frequency of p53 and ras mutations in bile of patients with hepato-biliary disease: a prospective study in more than 100 patients

The diagnosis of biliary disease, namely malignant disorders, is frequently hampered by the inconclusive cytology. We investigated prospectively the frequency of molecular changes in p53 and ras compared with cytology in patients with primary or secondary hepato-biliary disease. We investigated 118 consecutive patients, aged 24-89 with the following clinical diagnoses: choledocho/cholecystolithiasis (28), cholangiocellular carcinoma (21), gall bladder tumor (8), liver metastasis (3), autoimmune disease (8), chronic pancreatitis (16), pancreatic carcinoma (11), papillary disease (4), hepatic cirrhosis (6), cholangitis (2), anomalies (2), and normal (9). Bile was aspirated during routine endoscopic retrograde cholangio pancreatography (ERCP) or percutaneous transhepatic cholangiography (PTC). DNA was prepared freshly from a native aliquot. p53 mutations were detected by polymerase chain reaction (PCR) for exons 5 through 8 followed by TGGE. PCR for ras mutations was performed as RFLP-PCR with sequencing. In four cases, mutations in p53 could be found in exons 6 and 7. Twenty-two samples showed ras mutations; ras mutations were found in choledocholithiasis (4/28), bile duct (5/21), gall bladder (3/8) and pancreatic (1/11) carcinoma, liver metastasis (3/3), ulcerative colitis (2/3), PSC (1/2), and chronic pancreatitis (1/16). Cytology was clearly positive in seven cases, suspicious in three other, inconclusive in six, and negative in the rest. The molecular analysis resulted in a sensitivity of 33% and specificity of 87%, respectively, for the diagnosis of a malignant condition. PCR for p53 and ras mutations may aid the diagnosis of primary and secondary (metastatic) hepatobiliary disease if a malignant condition of the bile ducts and the liver is suspected and cytology is inconclusive or negative. However, the incidence of p53 and ras mutations in bile seems less frequent than in other malignant conditions of the gastrointestinal tract and the pancreas and lower than in tissue, leaving a poor sensitivity and specificity. Nevertheless, the presence of a p53 and/or ras mutation per se supports a clinical suspicion of malignancy, even when the conventional cytology is negative or inconclusive.

[Palliative therapy of pancreatic adenocarcinoma]

The palliative therapy of pancreatic carcinoma consists of best supportive care (BSC) including nutritional and pain therapy, and antineoplastic remedies. This is complemented by interventional endoscopy aiming to treat obstructive jaundice and/or gastric or duodenal obstruction by implantation of endoprostheses. Pain therapy is standardized for the most part according to the WHO guidelines; nutrition of the cancer patient, however, is sometimes disregarded. For palliative chemotherapy, 5-fluorouracil and gemcitabine can be recommended. Combinations thereof with other cytostatic drugs or radiation are subject to ongoing studies. A variety of novel therapeutic concepts, e.g. immunomodulation or suicide gene therapy, have demonstrated good effects in animal studies. Unfortunately, very few of these have entered clinical studies (phase I and phase II). This will be the focus of future research in this field.

Improvement of hepatorenal syndrome with extracorporeal albumin dialysis MARS: results of a prospective, randomized, controlled clinical trial

In hepatorenal syndrome (HRS), renal insufficiency is often progressive, and the prognosis is extremely poor under standard medical therapy. The molecular adsorbent recirculating system (MARS) is a modified dialysis method using an albumin-containing dialysate that is recirculated and perfused online through charcoal and anion-exchanger columns. MARS enables the selective removal of albumin-bound substances. A prospective controlled trial was performed to determine the effect of MARS treatment on 30-day survival in patients with type I HRS at high risk (bilirubin level, > or =15 mg/dL) compared with standard treatment. Thirteen patients with cirrhosis with type I HRS were included from 1997 to 1999. All were Child's class C, with Child-Turcotte-Pugh scores of 12.4 +/- 1. 0, United Network for Organ Sharing status 2A, and total bilirubin values of 25.7 +/- 14.0 mg/dL. Eight patients were treated with the MARS method in addition to hemodiafiltration (HDF) and standard medical therapy, and 5 patients were in the control group (HDF and standard medical treatment alone). None of these patients underwent liver transplantation or received a transjugular intrahepatic portosystemic shunt or vasopressin analogues during the observation period. In the MARS group, 5.2 +/- 3.6 treatments (range, 1 to 10 treatments) were performed for 6 to 8 hours daily per patient. A significant decrease in bilirubin and creatinine levels (P <.01) and increase in serum sodium level and prothrombin activity (P <.01) were observed in the MARS group. Mortality rates were 100% in the control group at day 7 and 62.5% in the MARS group at day 7 and 75% at day 30, respectively (P <.01). We conclude that the removal of albumin-bound substances with the MARS method can contribute to the treatment of type I HRS.

Improvement of hepatorenal syndrome with extracorporeal albumin dialysis MARS: results of a prospective, randomized, controlled clinical trial

In hepatorenal syndrome (HRS), renal insufficiency is often progressive, and the prognosis is extremely poor under standard medical therapy. The molecular adsorbent recirculating system (MARS) is a modified dialysis method using an albumin-containing dialysate that is recirculated and perfused online through charcoal and anion-exchanger columns. MARS enables the selective removal of albumin-bound substances. A prospective controlled trial was performed to determine the effect of MARS treatment on 30-day survival in patients with type I HRS at high risk (bilirubin level, > or =15 mg/dL) compared with standard treatment. Thirteen patients with cirrhosis with type I HRS were included from 1997 to 1999. All were Child's class C, with Child-Turcotte-Pugh scores of 12.4 +/- 1. 0, United Network for Organ Sharing status 2A, and total bilirubin values of 25.7 +/- 14.0 mg/dL. Eight patients were treated with the MARS method in addition to hemodiafiltration (HDF) and standard medical therapy, and 5 patients were in the control group (HDF and standard medical treatment alone). None of these patients underwent liver transplantation or received a transjugular intrahepatic portosystemic shunt or vasopressin analogues during the observation period. In the MARS group, 5.2 +/- 3.6 treatments (range, 1 to 10 treatments) were performed for 6 to 8 hours daily per patient. A significant decrease in bilirubin and creatinine levels (P <.01) and increase in serum sodium level and prothrombin activity (P <.01) were observed in the MARS group. Mortality rates were 100% in the control group at day 7 and 62.5% in the MARS group at day 7 and 75% at day 30, respectively (P <.01). We conclude that the removal of albumin-bound substances with the MARS method can contribute to the treatment of type I HRS.

Does acute ingestion of large amounts of alcohol cause pancreatic injury? A prospective study

The contribution of ethanol to the pathogenesis of acute pancreatitis has been questioned for a long time. The authors asked whether acute ingestion of large amounts of alcohol may lead to pancreatic injury, as assessed by serum amylase levels, clinical picture, and abdominal ultrasound. Therefore, all patients (N = 122) admitted to our medical emergency ward with the diagnosis of alcohol intoxication were evaluated prospectively during a 12-mo period. Of these, 78 (56 M, 22 F; mean age 36 +/- 15) could be evaluated. The other 44 were excluded because of incomplete data (n = 18), mixed intoxications (n = 8), repeated admission (n = 9), incorrect diagnosis on admission (n = 7), and chronic pancreatitis (n = 2). Serum ethanol, amylase, and GOT were measured. Serum ethanol was 246 +/- 122 mg/dL (3-500 mg/dL), amylase 83 +/- 44 U/L (27-361 U/L), and GOT 25 +/- 37 U/L (5-271 U/L) without significant differences among the genders. No correlation between serum ethanol and serum amylase levels could be detected.

Compression of the common bile duct due to portal-vein thrombosis in polycythemia vera

The case of a 56-yr-old patient with polycythemia vera who was initially seen with jaundice is reported. Compression of the common bile duct by choledochal varices was found to be the cause of the obstructive jaundice. This compression was successfully treated with placement of a plastic endoprosthesis across the stenosis during endoscopic retrograde cholangiopancreatography. The significance of choledochal varices in the evaluation of obstructive jaundice is emphasized.

Detection of cytomegalovirus nucleic acid sequences in pancreas in type 2 diabetes

Nucleic acid sequences specific for human cytomegalovirus (CMV) were found in samples of pancreatic tissue from patients with non-insulin-dependent (type 2) diabetes mellitus. RNA extracted from paraffin-embedded or fresh-frozen specimens from 14 of 32 (44%) diabetic patients but from none of 49 non-diabetic controls reacted with 10 kb (pJN201) or 6.6 kb (pCM3) probes of human CMV immediate-early or late gene products, respectively. The RNA from the 32 diabetic patients did not react with nucleic acid probes for mumps, rubella, or coxsackie B viruses. In-situ nucleic acid hybridisation on tissues from 5 randomly selected human-CMV-positive patients showed that the human CMV signal was localised primarily in the islets of Langerhans and not in exocrine cells. Despite the clear viral nucleic acid signal in tissues of human-CMV-positive patients, there were no morphological injuries to the islets, no inflammatory cells in the islets, and no perivascular inflammatory cell cuffing. These findings suggest a possible association of human CMV with type 2 diabetes in human beings.

Is herpes simplex virus associated with peptic ulcer disease?

To test the hypothesis that herpes simplex virus type 1 (HSV-1) may be associated with peptic ulcer disease, we examined ulcerative lesions of the distal stomach and proximal duodenum for the presence of nucleic acids and antibodies specific for HSV-1. Utilizing in situ hybridization, immunocytochemistry, and polymerase chain reaction with sequencing, gastric or duodenal tissues from 4 of 22 patients (18%) with documented peptic ulcer disease demonstrated the presence of both specific HSV-1 nucleic acid sequences and proteins. HSV-1 was found restricted in clusters of cells near the margin of the ulcer but was absent at sites distal to the lesion. Several of such HSV-1-infected cells also contained cholecystokinin. These cholecystokinin-containing cells are of neuroendocrine origin and receive contact from the vagal nerve. Campylobacter pylori bacteria were not found in three of the four peptic ulcer tissues that harbored HSV-1. Further, none of the stomach or duodenal tissue samples from 33 patients undergoing clinical evaluation, but having no evidence of peptic ulcer disease, had HSV-1 materials. Thus, our data suggest that a subset of peptic ulcer disease may be associated with HSV-1 and raise the possibility that some peptic ulcers may be caused by this virus.

[Experimental investigations of electrolyte metabolism of the myocardium during coronary perfusion of isolated hearts of warm blooded animals with ionic, less ionic, and non-ionic contrast media. Part 5 (author's transl)]

In the isolated guinea pig heart the extracellular metabolism of Sodium, Potassium and Calcium after coronary perfusion of ionic, less ionic and non-ionic contrast media has been examined. Under these conditions there are not significant differences of the extracellular metabolism for these electrolytes. The results are controversial to those gained in the whole-body animal. The causes are being discussed. In clinical treatment better tolerance of the patients after the application of less ionic and non-ionic contrast media was observed during laevocardiography and coronarography.