Scheduled endoscopic treatment of biliary anastomotic and nonanastomotic strictures after orthotopic liver transplantation.

BACKGROUND AND AIMS: Biliary strictures after liver transplantation are associated with significant morbidity and mortality. Although various endoscopic treatment strategies are available, consensus on a particular strategy is lacking. Moreover, the influence of endoscopic therapy on overall survival has not been studied. This retrospective study aimed to evaluate the impact of scheduled endoscopic dilatation of biliary strictures after orthotopic liver transplantation on therapeutic success, adverse events, and survival. METHODS: Between 2000 and 2016, patients with post-transplant anastomotic and nonanastomotic strictures were treated with balloon dilatation at defined intervals until morphologic resolution and clinical improvement. The primary clinical endpoint was overall survival, whereas secondary outcomes were technical and sustained clinical success, adverse events, treatment failure, and recurrence. RESULTS: Overall, 165 patients with a mean follow-up of 8 years were included; anastomotic and nonanastomotic strictures were diagnosed in 110 and 55 patients, respectively. Overall survival was significantly higher in patients with anastomotic strictures than in those with nonanastomotic strictures (median, 17.6 vs 13.9 years; log-rank: P < .05). Sustained clinical success could be achieved significantly more frequently in patients with anastomotic strictures (79.1% vs 54.5%, P < .001), and such patients showed significantly superior overall survival (19.7 vs 7.7 years; log-rank: P < .001). Sustained clinical success and the presence of nonanastomotic strictures were independently associated with better and worse outcomes (P < .05), respectively. CONCLUSIONS: Scheduled endoscopic treatment of biliary anastomotic and nonanastomotic strictures after liver transplantation is effective and safe, with high success rates. The implementation of this strategy controls symptoms and significantly improves survival.

Simultaneous, High-Precision Measurements of δ2H and δ13C in Nanomole Quantities of Acetate Using Electrospray Ionization-Quadrupole-Orbitrap Mass Spectrometry.

Stable hydrogen isotope compositions (2H/1H ratios) have been an invaluable tool for studying biogeochemical processes in nature, but the diversity of molecular targets amenable to such analysis is limited. Here, we demonstrate a new technique for measuring δ2H of biomolecules via Orbitrap mass spectrometry (MS) using acetate as a model analyte. Acetate was chosen as a target molecule because its production and consumption are central to microbial carbon cycling, yet the mechanisms behind acetate turnover remain poorly understood. δ2H of acetate could provide a useful constraint on these processes; however, it remains uncharacterized in nature due to analytical challenges. Electrospray ionization (ESI)-Orbitrap MS circumvents these challenges and delivers methyl-specific H-isotope compositions of acetate with nanomole sensitivity, enough to enable analyses of environmental samples. This approach quantifies the methyl-specific δ2H and molecular-average δ13C of acetate simultaneously while achieving <3 and <0.5‰ uncertainty, respectively. Using optimized ionization and Orbitrap parameters, this level of precision is obtained within 15 min using only 15 nmol of acetate. As a demonstration of our analytical approach, we cultured three acetogenic bacteria and found a large 2H-fractionation between acetate and water (>310‰ depletion) associated with the Wood-Ljungdahl pathway, while fermentation expressed a muted (∼80‰) fractionation. With its high precision and sensitivity, Orbitrap MS is a promising tool for investigating these signals in nature after offline purification. Furthermore, the ESI-Orbitrap method presented here could be applied to other molecules amenable to ESI, including central metabolites and sugars, greatly expanding the molecular targets used in hydrogen isotope biogeochemistry.

Impact of endobiliary radiofrequency ablation on biliary drainage in patients with malignant biliary strictures treated with uncovered self-expandable metal stents: a randomized controlled multicenter trial.

BACKGROUND AND AIMS: Endobiliary radiofrequency ablation (RFA), usually combined with endoscopic stent insertion, is a simple procedure with the potential to improve stent patency and patient survival for malignant biliary obstruction. We conducted this randomized multicenter trial to evaluate the impact of RFA on stent patency. METHODS: Eighty-six patients with malignant biliary obstruction and nonresectable tumors (pancreatic carcinoma, cholangiocarcinoma, or metastases) were included and randomly assigned to receive a self-expandable metal stent (SEMS) only (n = 44) or RFA followed by SEMS insertion (RFA+SEMS, n = 42). The primary outcome measure was stent patency after 3 and 6 months; secondary outcome measures were patient survival and early adverse events within 30 days. RESULTS: Technical success rates for RFA and stent insertion were 100% and 98.8%, respectively. Stent patency after 3 and 6 months did not differ significantly between groups (RFA+SEMS group, 73.1% and 33.3%, respectively; SEMS-only group, 81.8% and 52.4%, respectively; P = .6). Similarly, the addition of RFA did not impact overall survival (hazard ratio, .72; P = .389 for RFA+SEMS). The adverse event rate in the RFA+SEMS group was 10.5% compared with 2.3% in the SEMS-only group, without a statistically significant difference (P = .18). CONCLUSIONS: RFA as an addition to SEMS implantation had no positive impact on patency rate or survival. (Clinical trial registration number: DRKS00018993.).

Effect of endoscopic treatment in patients with secondary sclerosing cholangitis.

BACKGROUND AND AIM: Secondary sclerosing cholangitis (SSC) is a progressive disease with high mortality and characterized by chronic inflammation and biliary obstruction. Therapeutic options are limited. The aim of this retrospective study was to evaluate the effects of endoscopic treatment in patients with SSC, the outcome, and association with potential risk factors. METHODS: Data from all patients with SSC from 1996 to April 2021 were included. RESULTS: Eighty patients with SSC were included. Seventy-five patients (93.8%) underwent diagnostic endoscopic retrograde cholangiography; 46 patients (57.5%) could be treated endoscopically. Endoscopic treatment comprised removal of biliary casts (n = 36/75), dilatation of bile ducts (n = 17/75), and intermittent stenting (n = 11/75). Twenty patients underwent orthotopic liver transplantation (25%); 27 patients died (33.8%). Transplantation-free survival was affected neither by endoscopic treatment nor by presence of biliary strictures, but bacteria positive bile culture was associated with better and increased levels of serum alkaline phosphatase and bilirubin levels with poor outcome. CONCLUSIONS: Secondary sclerosing cholangitis is a progressive disease with poor long-term prognosis. Endoscopic treatment options seem to be limited regarding transplantation-free survival but might improve quality of life and prevent local complications such as cholangitis. The observed limited effect of endoscopic treatment might be attributed to the rapid progression of this disease.

Self-Expanding Metal Stents for Anastomotic Leaks After Upper Gastrointestinal Cancer Surgery.

BACKGROUND: Anastomotic leakage (AL) is a common and severe complication after upper gastrointestinal (UGI) surgery. Although evidence is scarce, endoscopic deployed self-expanding metal stents (SEMS) are well-established for the management of AL in UGI surgery. The present study aimed to evaluate the feasibility, effectiveness, and safety of SEMS in terms of success, mortality, and morbidity in patients with AL after UGI cancer surgery. MATERIALS AND METHODS: Patients with AL after primary UGI cancer surgery were retrospectively analyzed with regard to demographics, disease, surgical and endoscopic procedures, and complications. Stent treatment success was divided into technical, primary (within 72 hours of stent deployment), sustained (after 72 hours of stent deployment), and sealing success. RESULTS: In a total of 63 patients, 74 stents were used and 11 were deployed in endoscopic reinterventions. Stent deployment was successful in all patients. Primary and sustained success rates were 68.3% (n = 43) and 65.1% (n = 41), respectively. Of the primarily successfully treated patients, 87.8% remained successfully treated. If primary treatment was unsuccessful, it remained unsuccessful in 66.6% of the patients (P = 0.002). Final sealing of the leakage was observed in 65.1% of patients (n = 41). Longer stent shafts and wider stent end widths were correlated with successful stent treatment (P < 0.05). CONCLUSION: SEMS are a safe and sufficient tool in the treatment of AL after UGI cancer surgery. Treatment success is improved with longer stent shafts and wider stent end widths. Switching to alternative treatments is strongly suggested if signs of persistent leakage are present beyond 72 hours after stent placement, as this is highly indicative of sustained stent failure.

Feasibility, effectiveness, and safety of endoscopic vacuum therapy for intrathoracic anastomotic leakage following transthoracic esophageal resection.

BACKGROUND: Anastomotic leakage (AL) in the upper gastrointestinal (GI) tract is associated with high morbidity and mortality rates. Especially intrathoracic anastomotic leakage leads to life-threatening complications. Endoscopic vacuum therapy (EVT) for anastomotic leakage after transthoracic esophageal resection represents a novel concept. However, sound clinical data are still scarce. This retrospective, single-center study aimed to evaluate the feasibility, effectiveness, and safety of EVT for intrathoracic anastomotic leakage following abdomino-thoracic esophageal resection. METHODS: From March 2014 to September 2019 259 consecutive patients underwent elective transthoracic esophageal resection. 72 patients (27.8%) suffered from AL. The overall collective in-hospital mortality rate was 3.9% (n = 10). Data from those who underwent treatment with EVT were included. RESULTS: Fifty-five patients were treated with EVT. Successful closure was achieved in 89.1% (n = 49) by EVT only. The EVT-associated complication rate was 5.4% (n = 3): bleeding occurred in one patient, while minor sedation-related complications were observed in two patients. The median number of EVT procedures per patient was 3. The procedures were performed at intervals of 3-5 days, with a 14-day median duration of therapy. The mortality rate of patients with AL was 7.2% (n = 4). Despite successfully terminated EVT, three patients died because of multiple organ failure, acute respiratory distress syndrome, and urosepsis (5.4%). One patient (1.8%) died during EVT due to cardiac arrest. CONCLUSIONS: EVT is a safe and effective approach for intrathoracic anastomotic leakages following abdomino-thoracic esophageal resections. It offers a high leakage-closure rate and the potential to lower leakage-related mortalities. TRIAL REGISTRATION: This trial was registered and approved by the Institutional Ethics Committee of the University of Heidelberg on 16.04.2014 (Registration Number: S-635/2013).

Evaluation of two functional CD24 polymorphisms in primary sclerosing cholangitis.

Background: Primary sclerosing cholangitis (PSC) is a progressive liver disease and characterized by chronic inflammation, sclerosis and strictures of bile ducts. Several genetic risk factors might contribute to pathogenesis. Functional single nucleotide polymorphisms (SNPs) in the CD24 gene have been associated with the development of autoimmune and autoinflammatory diseases and might contribute to the susceptibility for inflammatory bowel disease (IBD).Aim: This retrospective study aimed to evaluate the impact of two functional CD24 SNPs on clinical features and disease progression in patients with PSC.Methods: A C to T coding polymorphism (rs8734) and a TG deletion in the 3´- untranslated region (rs3838646) were genotyped. The study cohort comprises of 359 PSC patients for rs3838646 genotype and 335 PSC patients for rs8734 genotype. Clinical and laboratory parameters were collected by chart review.Results: For the rs8734 genotype, 175 patients (52.2%) were found to be homozygous wildtype ('Ala/Ala'), 127 (37.9%) patients were heterozygous ('Ala/Val') and 33 patients (9.9%) were homozygous mutant ('Val/Val'). The rs8734genotype was associated with a decreased risk for dominant strictures at first diagnosis of PSC (p = .04). For the rs3838646 genotype, 322 patients (89.7%) were found to be homozygous wildtype ('TG/TG'); 37 showed the 'TG/del' genotype (10.3%). The 'TG/del'genotype was associated with alower risk of IBD (p = .01).There was no influence of both CD24 SNPs with clinical end points or transplantation-free survival in our PSC cohort.Conclusion: Our results suggest a mild association of the rs8734 CD24 genotype with dominant strictures at first diagnosis of PSC. The rs3838646 CD24 genotype is associated with a lower rate of IBD. Both SNPs seem to modulate the clinical phenotype without major pathogenetic importance for disease progression in PSC.

Sedation-related complications during anesthesiologist-administered sedation for endoscopic retrograde cholangiopancreatography: a prospective study.

BACKGROUND: Patients undergoing endoscopic retrograde cholangiopancreatography (ERCP) require adequate sedation or general anesthesia. To date, there is lack of consensus regarding who should administer sedation in these patients. Several studies have investigated the safety and efficacy of non-anesthesiologist-administered sedation for ERCP; however, data regarding anesthesiologist-administered sedation remain limited. This prospective single-center study investigated the safety and efficacy of anesthesiologist-administered sedation and the rate of successful performed ERCP procedures. METHODS: The study included 200 patients who underwent ERCP following anesthesiologist-administered sedation with propofol and remifentanil. Procedural data, oxygen saturation, systolic blood pressure (SBP), heart rate, recovery score, patient and endoscopist satisfaction, as well as 30-day mortality and morbidity data were analyzed. RESULTS: Sedation-related complications occurred in 36 of 200 patients (18%) and included hypotension (SBP < 90 mmHg) and hypoxemia (O2 saturation < 90%) in 18 patients (9%) each. Most events were minor and did not necessitate discontinuation of the procedure. However, ERCP was terminated in 2 patients (1%) secondary to sedation-related complications. Successful cannulation was performed in all patients. The mean duration of the examination was 25 ± 16 min. Mean recovery time was 14 ± 10 min, and high post-procedural satisfaction was observed in both, patients (mean visual analogue scale [VAS] 9.6 ± 0.8) and endoscopists (mean VAS 9.3 ± 1.3). CONCLUSION: This study suggests that anesthesiologist-administered sedation is safe in patients undergoing ERCP and is associated with a high rate of successful ERCP, shorter procedure time, and more rapid post-anesthesia recovery, with high patient and endoscopist satisfaction.

Prognostic value of inflammatory markers for detecting anastomotic leakage after esophageal resection.

BACKGROUND: Early diagnosis of anastomotic leakage (AL) after esophageal resection is crucial for the successful management of this complication. Inflammatory serological markers are indicators of complications during the postoperative course. The aim of the present study was to evaluate the prognostic value of routine inflammatory markers to predict anastomotic leakage after transthoracic esophageal resection. METHODS: Data from all consecutive patients undergoing transthoracic esophageal resection between January 2010 and December 2016 were analyzed from a prospective database. Besides clinicodemographic parameters, C-reactive protein, white blood cell count and albumin were analyzed and the Noble/Underwood (NUn) score was calculated to evaluate their predictive value for postoperative anastomotic leakage. Diagnostic accuracy was measured by sensitivity, specificity, and negative and positive predictive values using area under the receiver operator characteristics curve. RESULTS: Overall, 233 patients with transthoracic esophageal resection were analyzed, 30-day mortality in this group was 3.4%. 57 patients (24.5%) suffered from AL, 176 patients were in the AL negative group. We found significant differences in WBCC, CRP and NUn scores between patients with and without AL, but the analyzed markers did not show an independent relevant prognostic value. For CRP levels below 155 mg/dl from POD3 to POD 7 the negative predictive value for absence of AI was > 80%. Highest diagnostic accuracy was detected for CRP levels on 4th POD with a cut-off value of 145 mg/l reaching negative predictive value of 87%. CONCLUSIONS: In contrast to their prognostic value in other surgical procedures, CRP, WBCC and NUn score cannot be recommended as independent markers for the prediction of anastomotic leakage after transthoracic esophageal resection. CRP is an accurate negative predictive marker and discrimination of AL and no-AL may be helpful for postoperative clinical management. Trial registration The study was approved by the local ethical committee (S635-2013).

Effect of scheduled endoscopic dilatation of dominant strictures on outcome in patients with primary sclerosing cholangitis.

OBJECTIVE: Scheduled endoscopic dilatation of dominant strictures (DS) in primary sclerosing cholangitis (PSC) might improve outcome relative to endoscopic treatment on demand, but evidence is limited. Since randomisation is difficult in clinical practice, we present a large retrospective study comparing scheduled versus on-demand endoscopic retrograde cholangiopancreatography (ERCP) based on patient preferences. DESIGN: Between 1987 and 2017, all new patients with PSC had been offered scheduled ERCP with dilatation of a DS if diagnosed; the latter was repeated at defined intervals until morphological resolution, independent of clinical symptoms (treatment group). Patients who refused participation were clinically evaluated annually and received endoscopic treatment only on demand (control group). The primary clinical endpoint was transplantation-free survival. Secondary outcomes were overall survival, bacterial cholangitis episodes, hepatic decompensation of liver cirrhosis and endoscopy-related adverse events. RESULTS: The final study included 286 patients, 133 (46.5%) receiving scheduled ERCP and 153 (53.5%) receiving on-demand ERCP. After a mean follow-up of 9.9 years, the rate of transplantation-free survival was higher in patients receiving scheduled ERCP (51% vs 29.3%; p<0.001), as was transplantation-free survival time (median: 17.9 vs 15.2 years; log-rank: p=0.008). However, the benefit of scheduled ERCP was significant only in patients with the initial (17.1%) or later (45.5%) diagnosis of a DS (17.8 vs 11.1 years; log-rank: p<0.001). IBD (p=0.03), DS (p=0.006), higher Mayo Risk Score (p=0.02) and non-adherence to scheduled endoscopy (p=0.005) were independently associated with transplantation-free survival. CONCLUSION: In our large retrospective study, regular ERCP with endoscopic balloon dilatation significantly benefits patients with PSC with DS, diagnosed both at initial presentation and during surveillance, even if asymptomatic. Further studies have to find out how to best identify stricture patients non-invasively.

Linking variation in intrinsic water-use efficiency to isohydricity: a comparison at multiple spatiotemporal scales.

Species-specific responses of plant intrinsic water-use efficiency (iWUE) to multiple environmental drivers associated with climate change, including soil moisture (θ), vapor pressure deficit (D), and atmospheric CO2 concentration (ca ), are poorly understood. We assessed how the iWUE and growth of several species of deciduous trees that span a gradient of isohydric to anisohydric water-use strategies respond to key environmental drivers (θ, D and ca ). iWUE was calculated for individual tree species using leaf-level gas exchange and tree-ring δ13 C in wood measurements, and for the whole forest using the eddy covariance method. The iWUE of the isohydric species was generally more sensitive to environmental change than the anisohydric species was, and increased significantly with rising D during the periods of water stress. At longer timescales, the influence of ca was pronounced for isohydric tulip poplar but not for others. Trees' physiological responses to changing environmental drivers can be interpreted differently depending on the observational scale. Care should be also taken in interpreting observed or modeled trends in iWUE that do not explicitly account for the influence of D.

Association between serum IgG level and clinical course in primary sclerosing cholangitis.

BACKGROUND: Primary sclerosing cholangitis is a chronic cholestatic liver disease. The pathomechanism is still not fully understood, but there is evidence that immune-mediated processes may contribute to disease progression. METHODS: We studied the prognostic relevance of serum immunoglobulin G (IgG) elevated above the upper limit of normal as a marker for immune activation at initial diagnosis and its influence on transplantation-free survival in a well-defined cohort of PSC patients. RESULTS: The final study cohort comprises of 148 PSC patients. Elevated IgG levels were found in 66 patients (44.6%). Apart from their younger age at first diagnosis, there was no significant difference between patients with or without elevated IgG levels. The presence of a concomitant inflammatory bowel disease, an autoimmune hepatitis or immunosuppressive medication was equally distributed between both groups. Patients with elevated IgG levels reached the combined endpoint (34 (59.6%) vs. 23 (40.4%); p = 0.004) significantly more often and had reduced transplantation-free survival (Log-rank: 24.0 (10.2-37.9) vs. 14.0 (8.5-19.5); p < 0.05). Cox regression analysis including age, gender, presence of IBD, presence of dominant stricture (DS), Mayo Risk Score (MRS), immunosuppression, biochemical response to UDCA and elevated IgG-levels confirmed MRS (p = 0.03), DS (p = 0.04), biochemical response (p = 0.04) and elevated IgG level (p = 0.04) as independent risk factors for reduced transplantation-free survival. CONCLUSION: We identified elevated serum IgG levels at first diagnosis as an independent risk factor for reduced transplant free-survival in patients with PSC.

Prevalence of human herpesviruses in biliary fluid and their association with biliary complications after liver transplantation.

BACKGROUND: Beta-herpesviruses are common opportunistic pathogens that cause morbidity after liver transplantation (LT). METHODS: Objective of the study was to evaluate the prevalence and correlation of herpesviruses in bile, blood and liver tissue and to investigate their association with biliary complications and retransplantation (re-LT) free survival after LT. The study design is a single-center case-control study. We performed quantative polymerase chain reaction (qPCR) for herpesvirus 1-8 DNA in bile, blood and liver tissue of 73 patients after first LT and analyzed their clinical courses retrospectively. RESULTS: The median follow-up was 48 months (range 2-102), during which a total of 16 patients underwent re-LT and 11 patients died. Of the patients, 46.5% received valganciclovir prophylaxis at the time of bile sample acquisition. Cytomegalovirus (CMV) (18.3%), human herpesvirus 6 (HHV-6) (34.2%), human herpesvirus 7 (HHV-7) (20.5%) and Epstein-Barr virus (EBV) (16.4%) were highly prevalent in bile after LT, while herpes simpex virus 1 and 2 (HSV-1, HSV-2), varicella-zoster virus (VZV) and human herpesvirus 8 (HHV-8) were not or rarely detected in bile. Valganciclovir prophylaxis did not reduce the prevalence of HHV-6 and HHV-7 in bile, but it did reduce the presence of CMV and EBV. The presence of HHV-6 in bile was associated with non-anastomotic biliary strictures (NAS) and acute cellular rejection (ACR). CONCLUSIONS: CMV, EBV, HHV-6 and HHV-7 are more prevalent in biliary fluid than in liver biopsy or blood serum after LT. HHV-6 and HHV-7 might be associated with biliary complications after LT. Biliary fluids might be an attractive target for routine herpesvirus detection.

2 H-fractionations during the biosynthesis of carbohydrates and lipids imprint a metabolic signal on the δ2 H values of plant organic compounds.

Hydrogen (H) isotope ratio (δ2 H) analyses of plant organic compounds have been applied to assess ecohydrological processes in the environment despite a large part of the δ2 H variability observed in plant compounds not being fully elucidated. We present a conceptual biochemical model based on empirical H isotope data that we generated in two complementary experiments that clarifies a large part of the unexplained variability in the δ2 H values of plant organic compounds. The experiments demonstrate that information recorded in the δ2 H values of plant organic compounds goes beyond hydrological signals and can also contain important information on the carbon and energy metabolism of plants. Our model explains where 2 H-fractionations occur in the biosynthesis of plant organic compounds and how these 2 H-fractionations are tightly coupled to a plant's carbon and energy metabolism. Our model also provides a mechanistic basis to introduce H isotopes in plant organic compounds as a new metabolic proxy for the carbon and energy metabolism of plants and ecosystems. Such a new metabolic proxy has the potential to be applied in a broad range of disciplines, including plant and ecosystem physiology, biogeochemistry and palaeoecology.

CD14 is associated with biliary stricture formation.

UNLABELLED: The pathogenesis of intrahepatic biliary stricture formation in patients with primary sclerosing cholangitis (PSC) or after liver transplantation (LTx) remains elusive. CD14 receptor signaling is a key mediator of the innate immune system; its common genetic variant is associated with alcoholic liver disease. PSC and LTx cohort patients and primary biliary cirrhosis (PBC) control patients were genotyped for the CD14 -260C>T (rs2569190) polymorphism, and genotypes were correlated with long-term clinical outcome. Biliary tissue, bile, and whole blood of PSC patients and healthy controls were screened for markers of the innate immune system and bacterial infection. In 121 PSC patients, the CD14 -260C>T genotype was associated with development of dominant bile duct strictures (P = 0.02). In 365 LTx patients, TT carriers (4.1%) were protected against the formation of nonanastomotic biliary strictures versus CC/CT patients (12.6%; P = 0.01). Chemokine ligand 8 (P = 0.04) and chemokine receptor 6 (P = 0.004) were up-regulated in biliary tissue of PSC patients with the TT versus the CC/CT genotype. Lipopolysaccharide whole-blood stimulation resulted in a significant change in interleukin (IL)-8 (P = 0.05) and IL-12p40 levels (P = 0.04) in healthy control subjects carrying the TT genotype. TT PSC patients were protected against Gram-negative bacterial biliary infection (TT: 0% vs. CC/CT: 22.5%; P = 0.02). Serum-soluble CD14 levels correlated with the CD14 -260C>T genotype (P = 0.02), representing an independent risk indicator of survival in PSC patients (hazard ratio, 0.40; 95% confidence interval, 0.19-0.86; P =0.01). CONCLUSIONS: The function of the innate immune response by CD14 is crucial during biliary infection and stricture formation. The benefits of CD14 signaling modification should be addressed in future studies. (Hepatology 2016;64:843-852).

Laparoscopic transgastric circumferential stapler-assisted vs. endoscopic esophageal mucosectomy in a porcine model.

Background and study aims Extensive endoscopic mucosal resection (EMR) for Barrett's esophagus (BE) may lead to stenosis. Laparoscopic, transgastric, stapler-assisted mucosectomy (SAM) with the retrieval of a circumferential specimen is proposed. Methods SAM was evaluated in two phases. The feasibility of SAM and the quality of specimens were assessed in eight animals. The mucosal healing was evaluated in a 6-week survival experiment comparing SAM (n = 6) with EMR (n = 6). The ratio of the esophageal lumen width (REL) at the resection level measured on fluoroscopy at 6 weeks divided by the width immediately after resection was compared. Results In all animals, a circular mucosectomy specimen was successfully obtained, with a median area of 492 mm2 (interquartile range [IQR] 426 - 573 mm2) and 941 mm2 (IQR 813 - 1209 mm2) using a 21 mm and 25 mm stapler, respectively. In the survival experiments, symptomatic stenosis developed in two animals after EMR and in none after SAM. The REL was 0.27 (0.18 - 0.39) and 0.96 (0.9 - 1.04; P < 0.0001) for EMR and SAM, respectively. Conclusions SAM provides a novel technique for en bloc mucosectomy in BE. In contrast to EMR, mucosal healing after SAM was not associated with stenosis up to 6 weeks after intervention.

Location of a biliary leak after liver resection determines success of endoscopic treatment.

BACKGROUND: Bile leaks after hepatic resection are serious complications associated with substantial morbidity and mortality. The aim of this prospective observational study was to determine the therapeutic success of endoscopic treatment of biliary leakage after liver resection. PATIENTS AND METHODS: Grade B biliary leaks were considered for endoscopic treatment in patients after liver resection between 1/09 and 4/12. Endoscopic treatment (sphincterotomy only, plastic stent distal to leak or bridging) was defined as successful when the patient remained without symptoms after drain removal and without extravasation follow-up ERC 8 weeks later. RESULTS: Overall rate of biliary leak was 7.4 % (61/826). 35 patients with a grade B bile leak were considered for endoscopic treatment. 22 (63 %) had bile leaks that were peripherally located, and 13 (37 %) had bile leaks at central location. In 3 patients, sphincterotomy only was performed; in 19 patients, a stent distal to the leak and in 13 patients, a bridging stent was inserted. The overall success rate was 74 % (26/35 patients). Endoscopic treatment failed in 26 % (9/35), and mortality rate was 11 % (4/35). In all patients with leaks located at the right or left hepatic duct, treatment with the bridging stent was successful. CONCLUSION: Endoscopic therapy for biliary leakage after liver resection is safe and effective and should be considered as a first-line therapy in patients who are suitable for an interventional, non-surgical approach. Patients with a centrally located leak who are treated with a bridging stent are more likely to benefit from endoscopic intervention.

Significant decrease of mortality due to anastomotic leaks following esophageal resection: management makes the difference.

PURPOSE: Anastomotic leakage is the most frequent cause of postoperative mortality following esophageal surgery. However, no gold standard for diagnosing and managing leakage has been established. Continuous clinical judgment is extremely important; therefore, to optimize the management of leakage, we established a special group for decision-making in cases of suspected leakage in the early postoperative period. METHODS: Between January 2010 and December 2016, 234 consecutive patients underwent elective esophageal resection with a thoracoabdominal incision. In 2014, we established a group consisting of a surgeon, surgical endoscopist, and anesthesiologist for decision-making in cases of suspected leakage. They discussed emerging problems and decided on further diagnostics or therapy. The data were documented prospectively and compared to the years prior to 2014. RESULTS: Two hundred and thirty-four consecutive patients were enrolled in the study, 110 in the years 2010-2013 (group A), and 124 in the years 2014-2016 (group B). Neither patients' characteristics nor the rate of anastomotic leakage differed significantly between the two study groups. The hospital mortality rate was 10% (11 patients) in group A and 4.8% (six patients) in group B. Most interestingly, mortality due to anastomotic leakage was 35% in group A (9/26), whereas it decreased significantly to 6.5% (2/31 patients) (P < 0.001) in group B. CONCLUSIONS: Our data clearly demonstrated that optimizing the management of anastomotic leakage by making team decisions can lead to a significant decrease in mortality.

Organic Reference Materials for Hydrogen, Carbon, and Nitrogen Stable Isotope-Ratio Measurements: Caffeines, n-Alkanes, Fatty Acid Methyl Esters, Glycines, L-Valines, Polyethylenes, and Oils.

An international project developed, quality-tested, and determined isotope-δ values of 19 new organic reference materials (RMs) for hydrogen, carbon, and nitrogen stable isotope-ratio measurements, in addition to analyzing pre-existing RMs NBS 22 (oil), IAEA-CH-7 (polyethylene foil), and IAEA-600 (caffeine). These new RMs enable users to normalize measurements of samples to isotope-δ scales. The RMs span a range of δ(2)H(VSMOW-SLAP) values from -210.8 to +397.0 mUr or ‰, for δ(13)C(VPDB-LSVEC) from -40.81 to +0.49 mUr and for δ(15)N(Air) from -5.21 to +61.53 mUr. Many of the new RMs are amenable to gas and liquid chromatography. The RMs include triads of isotopically contrasting caffeines, C16 n-alkanes, n-C20-fatty acid methyl esters (FAMEs), glycines, and l-valines, together with polyethylene powder and string, one n-C17-FAME, a vacuum oil (NBS 22a) to replace NBS 22 oil, and a (2)H-enriched vacuum oil. A total of 11 laboratories from 7 countries used multiple analytical approaches and instrumentation for 2-point isotopic normalization against international primary measurement standards. The use of reference waters in silver tubes allowed direct normalization of δ(2)H values of organic materials against isotopic reference waters following the principle of identical treatment. Bayesian statistical analysis yielded the mean values reported here. New RMs are numbered from USGS61 through USGS78, in addition to NBS 22a. Because of exchangeable hydrogen, amino acid RMs currently are recommended only for carbon- and nitrogen-isotope measurements. Some amino acids contain (13)C and carbon-bound organic (2)H-enrichments at different molecular sites to provide RMs for potential site-specific isotopic analysis in future studies.