Validation of hypermethylated DNA regions found in colorectal cancers as potential aging-independent biomarkers of precancerous colorectal lesions.

BACKGROUND: We previously identified 16,772 colorectal cancer-associated hypermethylated DNA regions that were also detectable in precancerous colorectal lesions (preCRCs) and unrelated to normal mucosal aging. We have now conducted a study to validate 990 of these differentially methylated DNA regions (DMRs) in a new series of preCRCs. METHODS: We used targeted bisulfite sequencing to validate these 990 potential biomarkers in 59 preCRC tissue samples (41 conventional adenomas, 18 sessile serrated lesions), each with a patient-matched normal mucosal sample. Based on differential DNA methylation tests, a panel of candidate DMRs was chosen on a subset of our cohort and then validated on the remaining part of our cohort and two publicly available datasets with respect to their stratifying potential between preCRCs and normal mucosa. RESULTS: Strong statistical significance for the difference in methylation levels was observed across the full set of 990 investigated DMRs. From these, a selected candidate panel of 30 DMRs correctly identified 58/59 tumors (area under the receiver operating curve: 0.998). CONCLUSIONS: These validated DNA hypermethylation markers can be exploited to develop more accurate noninvasive colorectal tumor screening assays.

Routine Endoscopy Prior to Surgical Ostomy Closure: An Obsolete Concept.

BACKGROUND: Closure of temporary diverting ostomies is commonly preceded by an endoscopic study of the colonic mucosa and anastomosis, despite lacking evidence of its relevance and impact on subsequent operative management. AIM: We sought to determine the incidence of pathological findings and therefore evaluate the clinical benefit of routine pre-operative endoscopy in asymptomatic patients, hypothesizing sole evaluation of the anastomotic integrity to be sufficient in these cases. METHODS: We retrospectively identified all adult patients with ostomy installations who were followed up for potential reversal surgery between 2002 and 2020 at the University Hospital of Zurich, Switzerland. Main outcome measures were the incidence of endoscopically identified pathological findings in the asymptomatic case cohort and their impact on the subsequent course of treatment. RESULTS: Pre-procedural endoscopic data of 187 cases evaluated for ostomy closure were evaluated. Relevant mucosal findings in the asymptomatic cohort were documented in 26.3% and findings at the anastomotic site detected in 8.7%. A change in subsequent surgical management was noted in 10 patients of the entire cohort (5.3%) and in 9 (5.1%) of all asymptomatic cases. Upon multivariate analyses, the age range of 51 to 60 years old was found to be significantly linked to the presence of endoscopic findings entailing a change in patient management. CONCLUSION: Our findings strongly suggest ostomy closure surgery without previous assessment of the bowel mucosa by means of endoscopy to be acceptable in asymptomatic patients. However, we found it to be indicated in all patients meeting the screening criteria for colorectal carcinoma.

Systematic review on groove pancreatitis: management of a rare disease.

BACKGROUND: Groove pancreatitis is a focal form of chronic pancreatitis affecting the area of the paraduodenal groove. The aim of this systematic review was to assess the clinical presentation, diagnosis and treatment of patients with groove pancreatitis. METHODS: Medical literature databases (Embase, Medline via PubMed and Cochrane Central Register of Controlled Trials) were systematically searched for data recorded between 1 January 1990 and 31 August 2022 regarding patient characteristics, diagnosis, surgical treatment and outcomes. The following inclusion criteria were applied: RCTs, observational studies (cohort and case-control studies) and case studies with >3 cases including patients with groove pancreatitis undergoing medical, endoscopic or surgical treatment with available clinical and diagnostic data. Fisher's exact test for binary data and Mann-Whitney U test or Student t-test for continuous data were adopted for statistical analysis. RESULTS: Of 649 studies, 44 were included, involving reports on 1404 patients with a mean age of 49 years. In 41 of the 44 studies in which patient gender was described, 86 per cent (N = 1023) of patients were male. Information on the risk factors of alcohol and nicotine was available in 37 and 23 studies, respectively. Seventy-nine per cent (N = 886) of patients had a history of excessive alcohol consumption and 83 per cent (N = 595) were smokers. Information on clinical symptoms was available in 37 of the 44 included studies and 78.5 per cent (N = 870) presented with abdominal pain. Some 27 studies comprising 920 groove pancreatitis patients were treatment oriented. Seventy-four per cent (N = 682) of patients were treated conservatively, 26.4 per cent (N = 134) underwent endoscopic treatment and 54.7 per cent (N = 503) required surgery. There was complete relief of symptoms in 35.6 per cent (N = 243) after conservative treatment, 55.2 per cent (N = 74) after endoscopic treatment and 69.6 per cent (N = 350) after surgical treatment. The median follow-up time was 42 months (range, 1-161 months). CONCLUSION: Groove pancreatitis shows on imaging a typical triad: cystic lesions in the pancreatic duct or duodenal wall, calcifications, and thickenings of the duodenal wall. Surgery appears to be the most effective treatment modality.

Determinants of Advanced Liver Fibrosis in Adult Patients After Fontan Palliation: Usefulness of Ultrasound Transient Elastography.

BACKGROUND: Fontan-associated liver disease is an increasing concern. Our aim was to assess prevalence and predictors of advanced liver fibrosis with a specific focus on utility of liver stiffness measurement by ultrasound transient elastography. METHODS: A total of 97 adult Fontan patients (55% male, median age: 23.1 years, interquartile range [IQR]: 18.7-30.6); 92 (95%) were evaluated with transient elastography, and 50 (52%) underwent transjugular liver biopsy. Advanced liver fibrosis was defined as congestive hepatic fibrosis score 3 or 4. RESULTS: Only 4 patients (4%) had liver stiffness values < 10 kilopascal (kPa). Liver-stiffness measurements correlated weakly with peak oxygen uptake on exercise testing and Fontan pressure but not with Model for End-Stage Liver Disease excluding INR (MELD-XI) score or spleen size. Serial follow-up liver stiffness measurements in 73 clinically stable patients showed large variability among individual patients. Advanced liver fibrosis was present in 35 of 50 (70%) patients on liver biopsy and was associated to MELD-XI-Score ≥ 11 and splenomegaly but not to liver-stiffness measurements. Advanced liver fibrosis was not associated with patient age or time since Fontan operation but with younger age at completion of Fontan (3.7 years, IQR: 2.3-6.3 vs 6.8 years; IQR: 3.5-12.1; P = 0.037). CONCLUSIONS: In our cohort, advanced liver fibrosis was present in the majority of adult Fontan patients. Liver stiffness as measured by transient elastography was not associated with the degree of liver fibrosis. Because of its high variability on serial measurements, it seems not to be useful for clinical decision making. The unexpected finding that younger age at completion of Fontan was associated with advanced liver fibrosis merits further evaluation.

Prospective clinical cohort study: low incidence of Barrett esophagus but high rate of reflux disease at 5-year follow-up after sleeve gastrectomy versus Roux-en-Y gastric bypass.

BACKGROUND: Gastroesophageal reflux disease seems more frequent after laparoscopic sleeve gastrectomy (LSG) than Roux-en-Y gastric bypass (LRYGB). Retrospective case series have raised concerns about a high incidence of Barrett esophagus (BE) after LSG. OBJECTIVE: This prospective clinical cohort study compared the incidence of BE ≥5 years after LSG and LRYGB. SETTING: St. Clara Hospital, Basel, and University Hospital, Zürich, Switzerland. METHODS: Patients were recruited from 2 bariatric centers where preoperative gastroscopy is standard practice and LRYGB is preferred for patients with preexisting gastroesophageal reflux disease. At follow-up ≥5 years after surgery, patients underwent gastroscopy with quadrantic biopsies from the squamocolumnar junction and metaplastic segment. Symptoms were assessed using validated questionnaires. Wireless pH measurement assessed esophageal acid exposure. RESULTS: A total of 169 patients were included, with a median 7.0 ± 1.5 years after surgery. In the LSG group (n = 83), 3 patients had endoscopically and histologically confirmed de novo BE; in the LRYGB group (n = 86), there were 2 patients with BE, 1 de novo and 1 preexisting (de novo BE, 3.6% versus 1.2%; P = .362). At follow-up, reflux symptoms were reported more frequently by the LSG group than by the LRYGB group (51.9% versus 10.5%). Similarly, moderate-to-severe reflux esophagitis (Los Angeles grade B-D) was more common (27.7% versus 5.8%) despite greater use of proton pump inhibitors (49.4% versus 19.7%), and pathologic acid exposure was more frequent in patients who underwent LSG than in patients who underwent LRYGB. CONCLUSIONS: After at least 5 years of follow-up, a higher incidence of reflux symptoms, reflux esophagitis, and pathologic esophageal acid exposure was found in patients who underwent LSG compared with patients who underwent LRYGB. However, the incidence of BE after LSG was low and not significantly different between the 2 groups.

Performance of two-dimensional shear wave elastography and transient elastography compared to liver biopsy for staging of liver fibrosis.

BACKGROUND: Staging of liver fibrosis traditionally relied on liver histology; however, transient elastography (TE) and more recently two-dimensional shear wave elastography (2D-SWE) evolved to noninvasive alternatives. Hence, we evaluated the diagnostic accuracy of 2D-SWE assessed by the Canon Aplio i800 ultrasound system using liver biopsy as reference and compared the performance to TE. METHODS: In total, 108 adult patients with chronic liver disease undergoing liver biopsy, 2D-SWE and TE were enrolled prospectively at the University Hospital Zurich. Diagnostic accuracies were evaluated using the area under the receiver operating characteristic (AUROC) analysis, and optimal cut-off values by Youden's index. RESULTS: Diagnostic accuracy of 2D-SWE was good for significant (≥F2; AUROC 85.2%, 95% confidence interval (95%CI):76.2-91.2%) as well as severe fibrosis (≥F3; AUROC 86.8%, 95%CI: 78.1-92.4%) and excellent for cirrhosis (AUROC 95.6%, 95%CI: 89.9-98.1%), compared to histology. TE performed equally well (significant fibrosis: 87.5%, 95%CI: 77.7-93.3%; severe fibrosis: 89.7%, 95%CI: 82.0-94.3%; cirrhosis: 96%, 95%CI: 90.4-98.4%), and accuracy was not statistically different to 2D-SWE. 2D-SWE optimal cut-off values were 6.5, 9.8 and 13.1 kPa for significant fibrosis, severe fibrosis and cirrhosis, respectively. CONCLUSIONS: Performance of 2D-SWE was good to excellent and well comparable with TE, supporting the application of this 2D-SWE system in the diagnostic workup of chronic liver disease.

Sustained weight loss after duodenal-jejunal bypass liner treatment in patients with body mass index below, but not above 35 kg/m2 : A retrospective cohort study.

Previous data from short term studies have shown an efficacy of the duodenal-jejunal bypass liner (DJBL) for weight loss. However, less data is available regarding weight change after device removal and possible predictors for weight loss. This is a retrospective chart review of all patients who had DJBL inserted at the University Hospital Zurich between December 2012 and June 2015. A total of 27 patients had DJBL insertion. The median BMI at baseline was 38.5 (34.0-42.2) kg/m2 . In the 24 patients with DJBL treatment >3 months (failed implantation or early removal due to side effects in 3 patients), the mean duration of implantation was 42.9 ± 13.1 weeks. During the treatment, the mean total body weight loss (%TBWL) was 15.0 ± 8.3%. Fifteen patients had long-term follow-up data available (mean duration of follow-up 4.0 ± 0.9 years). The mean weight change was 12.7 ± 12.8 kg, corresponding with a mean % weight regain of 13.3 ± 13.3%. Five patients (33.3%) subsequently underwent bariatric surgery. In patients with class I obesity (BMI <35 kg/m2 at baseline), 4 out of 6 (66.7%) had a stable weight or only a weight regain <7%. In contrast, no patient with BMI >35 kg/m2 at baseline was able to keep weight regain below 7%. DJBL is an effective treatment for obesity, but substantial weight regain occurs during long-term follow up after the device removal, in particular in patients with BMI > 35 kg/m2 .

Assessment of hepatic fibrosis and inflammation with look-locker T1 mapping and magnetic resonance elastography with histopathology as reference standard.

PURPOSE: To compare the diagnostic performance of T1 mapping and MR elastography (MRE) for staging of hepatic fibrosis and grading inflammation with histopathology as standard of reference. METHODS: 68 patients with various liver diseases undergoing liver biopsy for suspected fibrosis or with an established diagnosis of cirrhosis prospectively underwent look-locker inversion recovery T1 mapping and MRE. T1 relaxation time and liver stiffness (LS) were measured by two readers. Hepatic fibrosis and inflammation were histopathologically staged according to a standardized fibrosis (F0-F4) and inflammation (A0-A2) score. For statistical analysis, independent t test, and Mann-Whitney U test and ROC analysis were performed, the latter to determine the performance of T1 mapping and MRE for fibrosis staging and inflammation grading, as compared to histopathology. RESULTS: Histopathological analysis diagnosed 9 patients with F0 (13.2%), 21 with F1 (30.9%), 11 with F2 (16.2%), 10 with F3 (14.7%), and 17 with F4 (25.0%). Both T1 mapping and MRE showed significantly higher values for patients with significant fibrosis (F0-1 vs. F2-4; T1 mapping p < 0.0001, MRE p < 0.0001) as well as for patients with severe fibrosis or cirrhosis (F0-2 vs. F3-4; T1 mapping p < 0.0001, MRE p < 0.0001). T1 values and MRE LS were significantly higher in patients with inflammation (A0 vs. A1-2, both p = 0.01). T1 mapping showed a tendency toward lower diagnostic performance without statistical significance for significant fibrosis (F2-4) (AUC 0.79 vs. 0.91, p = 0.06) and with a significant difference compared to MRE for severe fibrosis (F3-4) (AUC 0.79 vs. 0.94, p = 0.03). For both T1 mapping and MRE, diagnostic performance for diagnosing hepatic inflammation (A1-2) was low (AUC 0.72 vs. 0.71, respectively). CONCLUSION: T1 mapping is able to diagnose hepatic fibrosis, however, with a tendency toward lower diagnostic performance compared to MRE and thus may be used as an alternative to MRE for diagnosing hepatic fibrosis, whenever MRE is not available or likely to fail due to intrinsic factors of the patient. Both T1 mapping and MRE are probably not sufficient as standalone methods to diagnose hepatic inflammation with relatively low diagnostic accuracy.

Permanent Tunneled Drainage of Ascites in Palliative Patients: Timing Needs Evaluation.

Background: Treatment of refractory ascites remains challenging. We evaluated the safety and efficacy of permanent tunneled peritoneal catheters (PTPC) in this condition. Methods: We retrospectively analyzed consecutive patients in palliative situations in a tertiary referral center. Safety parameters, symptom relief, and survival were assessed. Results: Seventy patients were included from February 2012 to January 2021. Ninety percent had ascites due to malignancy, 10% due to end-stage liver disease. The technical procedure was successful in all cases; no deaths occurred. Procedure-related infections were rare and only observed in patients without peri-interventional antibiotics. Most patients experienced symptom relief (76%) and were satisfied with the device (83%). Survival after PTPC was relatively short (median 19 days). Discussion: PTPC is a safe option for refractory ascites in palliative settings with symptom relief in the majority of patients and should be considered early after onset of ascites. Periprocedural antibiotic prophylaxis may be considered to avoid procedure-related infections.

Clinical parameters associated with gastric portal hypertensive polyps.

OBJECTIVES: Portal hypertensive polyps (PHPs) are incompletely characterized lesions that can be found in the distal stomach of patients with portal hypertension. We aimed to delineate clinical factors associated with the appearance of these rare polyps. MATERIAL AND METHODS: We conducted a cross-sectional study of a cohort with 513 cirrhotic patients comparing patients with and without PHP using descriptive analyses and multivariable logistic regression. To address the problem of missing values, in particular for HVPG and liver stiffness, we used multiple imputation of missing values. RESULTS: The prevalence of macroscopically diagnosed PHP was 3.3% (95% confidence interval 2.0 - 5.4%). In 53% of cases, the correct classification was missed on index gastroscopy. Patients with PHP were older at gastroscopy (65 years vs. 59), had higher hepatic venous pressure gradients (HVPG, 28 mmHg vs. 19 mmHg), higher transient elastography (TE) measurements (50.7 kPa vs. 21.8 kPa) and more often had previous rubber band ligations (RBL, 64.7% vs. 25.8%). The multivariable logistic regression on the outcome macroscopically diagnosed PHP estimated an odds ratio (OR) for HPVG of 1.13 (CI 0.95-1.34), increased liver stiffness of 1.03 (1.00 - 1.07) and previous RBL of 3.84 (1.24 - 11.88), respectively. CONCLUSION: The prevalence of PHPs in the stomach was higher than assumed in previous studies and misclassification was commonly observed. The appearance of these rare polyps is associated with previous RBL and may correlate with severity of PH. Thus, PHPs may be regarded as marker for relevant PH, but clinical significance of these polyps is still uncertain.

Diagnosis of Gastric Cancer in the Excluded Stomach After RYGB by Jejunogastrostomy Using a LAMS.

For patients after bariatric surgery, diagnosis of gastric cancer is a challenge. We present a patient after Roux-en-Y gastric bypass with upper abdominal pain and abnormal computed tomography scan with diffuse wall thickening of the gastric antrum. Various biopsy techniques have been described, with surgical (laparoscopic) exploration being the most common. We were able to successfully diagnose gastric cancer in the excluded stomach by biopsy using a jejunogastrostomy, which proved to be safe and effective.

A systematic review of the perforated duodenal diverticula: lessons learned from the last decade.

BACKGROUND: The perforated duodenal diverticulum remains a rare clinical entity, the optimal management of which has not been well established. Historically, primary surgery has been the preferred treatment modality. This was called into question during the last decade, with the successful application of non-operative therapy in selected patients. The aim of this systematic review is to identify cases of perforated duodenal diverticula published over the past decade and to assess any subsequent evolution in treatment. METHODS: A systematic review of English and non-English articles reporting on perforated duodenal diverticula using MEDLINE (2008-2020) was performed. Only cases of perforated duodenal diverticula in adults (> 18 years) that reported on diagnosis and treatment were included. RESULTS: Some 328 studies were identified, of which 31 articles met the inclusion criteria. These studies included a total of 47 patients with perforated duodenal diverticula. This series suggests a trend towards conservative management with 34% (16/47) of patients managed non-operatively. In 31% (5/16) patients initially managed conservatively, a step-up approach to surgical intervention was required. CONCLUSION: Conservative treatment of perforated duodenal diverticula appears to be an acceptable and safe treatment strategy in stable patients without signs of peritonitis under careful observation. For patients who fail to respond to conservative treatment, a step-up approach to percutaneous drainage or surgery can be applied. If surgery is required, competence in techniques ranging from simple diverticulectomy to Roux-en-Y gastric diversion or even Whipple's procedure may be required depending on tissue friability and diverticular collar size.

ß6-Integrin Serves as a Potential Serum Marker for Diagnosis and Prognosis of Pancreatic Adenocarcinoma.

INTRODUCTION: Despite enormous efforts during the past decades, pancreatic adenocarcinoma (PAC) remains one of the most deleterious cancer entities. A useful biomarker for early detection or prognosis of PAC does not yet exist. The goal of our study was the characterization of ß6-integrin (ITGB6) as a novel serum tumor marker for refined diagnosis and prognosis of PAC. Serum ITGB6 levels were analyzed in 3 independent PAC cohorts consisting of retrospectively and prospectively collected serum and/or (metastatic) PAC tissue specimens. METHODS: Using 2 independent cohorts, we measured serum ITGB6 concentrations in 10 chronic pancreatitis patients, 10 controls, as well as in 27 (cohort 1) and 24 (cohort 2) patients with PAC, respectively. In these patients, we investigated whether ITGB6 serum levels correlate with known clinical and prognostic markers for PAC and whether they might differ between patients with PAC or benign inflammatory diseases of the pancreas. RESULTS: We found that elevated serum ITGB6 levels (≥0.100 ng/mL) in patients suffering from metastasizing PAC presented an unfavorable prognostic outcome. By correlating the ITGB6 tissue expression in primary and metastatic PAC with clinical parameters, we found that positive ITGB6 expression in the tumor tissue is linked to increased serum ITGB6 levels in nonmetastatic PAC and correlates with carbohydrate antigen 19-9 and clinical outcome. DISCUSSION: Our findings suggest that ITGB6 might serve as a novel serum biomarker for early diagnosis and prognosis of PAC. Given the limited specificity and sensitivity of currently used carbohydrate antigen 19-9-based assays, ITGB6 may have the potential to improve the diagnostic accuracy for PAC.

Preemptive Endoluminal Vacuum Therapy to Reduce Morbidity After Minimally Invasive Ivor Lewis Esophagectomy: Including a Novel Grading System for Postoperative Endoscopic Assessment of GI-Anastomoses.

OBJECTIVE: Preemptive endoluminal vacuum therapy (pEVT) is a novel concept to reduce postoperative morbidity and has the potential to disrupt current treatment paradigms for patients undergoing esophagectomy. SUMMARY OF BACKGROUND DATA: Endoluminal vacuum therapy is an accepted treatment for AL after esophagectomy. METHODS: Retrospective analysis of patients undergoing minimally invasive Ivor Lewis esophagectomy with pEVT between 11/2017 and 10/2020. The sponge was removed endoscopically after 4-6 days, and anastomosis and gastric conduit were assessed according to a novel endoscopic grading system. Further management was customized according to endoscopic appearance and clinical course. Endpoints were postoperative morbidity and AL rate, defined according to the Clavien-Dindo (CD) and International Esodata Study Group classifications. RESULTS: PEVT was performed in 67 consecutive patients, 57 (85%) were high-risk patients with an ASA score >2, WHO/ECOG score >1, age >65 years, or BMI >29 kg/m2. Thirty patients experienced textbook outcome, and overall minor (≤CD IIIa) and major (≥CD IIIb) morbidity was 40.3% and 14.9% respectively. 30-day-mortality was 0%. Forty-nine patients (73%) had uneventful anastomotic healing after pEVT without further endoscopic treatment. The remaining 18 patients (27%) underwent prolonged EVT with uneventful anastomotic healing in 13 patients (19%), contained AL in 4 patients (6%), and 1 uncontained leakage (1.5%) in a case with proximal gastric conduit necrosis, resulting in an overall AL rate of 7.5%. CONCLUSIONS: PEVT is an innovative and safe procedure with a promising potential to reduce postoperative morbidity after minimally invasive Ivor Lewis esophagectomy and may be particularly valuable in highly comorbid cases.

Functional syndromes and symptom-orientated aftercare after esophagectomy.

BACKGROUND: Surgery is the cornerstone of esophageal cancer treatment but remains burdened with significant postoperative changes of gastrointestinal function and quality of life. PURPOSE: The aim of this narrative review is to assess and summarize the current knowledge on postoperative functional syndromes and quality of life after esophagectomy for cancer, and to provide orientation for the reader in the challenging field of functional aftercare. CONCLUSIONS: Post-esophagectomy syndromes include various conditions such as dysphagia, reflux, delayed gastric emptying, dumping syndrome, weight loss, and chronic diarrhea. Clinical pictures and individual expressions are highly variable and may be extremely distressing for those affected. Therefore, in addition to a mostly well-coordinated oncological follow-up, we strongly emphasize the need for regular monitoring of physical well-being and gastrointestinal function. The prerequisite for an effective functional aftercare covering the whole spectrum of postoperative syndromes is a comprehensive knowledge of the pathophysiological background. As functional conditions often require a complex diagnostic workup and long-term therapy, close interdisciplinary cooperation with radiologists, gastroenterologists, oncologists, and specialized nutritional counseling is imperative for successful management.

Pre-Emptive Endoluminal Negative Pressure Therapy at the Anastomotic Site in Minimally Invasive Transthoracic Esophagectomy (the preSPONGE Trial): Study Protocol for a Multicenter Randomized Controlled Trial.

INTRODUCTION: Anastomotic leakage (AL) accounts for a significant proportion of morbidity following oesophagectomy. Endoluminal negative pressure (ENP) therapy via a specifically designed polyurethane foam (EsoSponge®, B.Braun Medical, Melsungen, Germany) has become the standard of care for AL in many specialized centres. The prophylactic (pENP) application of this technique aims to reduce postoperative morbidity and is a novel approach which has not yet been investigated in a prospective study. The aim of this study is therefore to assess the effect of pENP at the anastomotic site in high-risk patients undergoing minimally invasive transthoracic Ivor Lewis oesophagectomy. METHODS AND ANALYSIS: The study design is a prospective, multi-centre, two-arm, parallel-group, randomised controlled trial and will be conducted in two phases. Phase one is a randomised feasibility and safety pilot trial involving 40 consecutive patients. After definitive sample size calculation, additional patients will be included accordingly during phase two. The primary outcome of the study will be the postoperative length of hospitalization until reaching previously defined "fit for discharge criteria". Secondary outcomes will include postoperative morbidity, mortality and postoperative AL-rates based on 90-day follow-up. A confirmatory analysis based on intention-to-treat will be performed. ETHICS AND DISSEMINATION: The ethics committee of the University of Zurich approved this study (2019-00562), which has been registered with ClinicalTrials.gov on 14.11.2019 (NCT04162860) and the Swiss National Clinical Trials Portal (SNCTP000003524). The results of the study will be published and presented at appropriate conferences.

Long-term immune-related adverse events after discontinuation of immunotherapy.

Immune checkpoint inhibitors have revolutionized the treatment of various cancers but are notorious for their potential to cause severe side effects. While most side effects occur during ongoing therapy, an increasing number of reports of late onset have emerged. It is also not yet clear how long side effects can last. Resolution is achieved under symptomatic therapy, but the side effects may persist latently. We present a patient case with recurrence of colitis after closure of an ileostomy over 1 year after discontinuation of immune checkpoint inhibitor therapy with nivolumab and ipilimumab. To the best of our knowledge, no other case with severe colitis still lasting after more than a year of suspension of therapy has yet been reported.

Lay abstract Checkpoint inhibitors have revolutionized therapy for suitable cancers. However, they can cause side effects that are reminiscent of autoimmune diseases. While most adverse effects occur during ongoing therapy, there are increasing reports of late-onset adverse effects after discontinuation of therapy and of long-lasting adverse effects after discontinuation of treatment, which may remain latent even if symptom relief could be achieved by immunosuppression. We present a patient case with reappearance of a severe inflammation of the large bowel (colitis) after closure of an ostomy over 1 year after withdrawal of immune checkpoint inhibitor therapy. To the best of our knowledge, no other case with severe colitis still lasting after more than a year of suspension of therapy has yet been reported.

Retrospective Analysis of Treatment and Complications of Immune Checkpoint Inhibitor-Associated Colitis: Histological Ulcerations as Potential Predictor for a Steroid-Refractory Disease Course.

BACKGROUND/AIMS: Among the severe immune-related adverse events (irAEs) that occur with immune checkpoint inhibitor (ICI) therapy, colitis is the most frequent one. This study aimed at describing the experience from the largest gastroenterology unit in Switzerland with immune checkpoint inhibitor-associated colitis (ICIAC), its clinical presentation, management, and outcomes. METHODS: We performed a retrospective review of patients who were referred for the evaluation of ICIAC between January 2011 and October 2018 to the Division of Gastroenterology and Hepatology, University Hospital Zurich. RESULTS: Thirty-three patients with immune-related colitis grade 3 or 4 met the inclusion criteria and were analyzed in detail: All patients had diarrhea, 64% had abdominal pain, 42% had bloody stool, 27% had emesis, and 18% developed fever. In total, 33% were successfully treated with corticosteroids alone; 66% were steroid-refractory and treated with infliximab or vedolizumab. Two of these patients developed severe complications requiring surgery. All patients reached complete remission of ICIAC and its symptoms. At colonoscopy, ulcerations were seen in 37% of steroid-refractory versus 63% of steroid-responsive cases. Deep histological ulcerations invading the submucosa were only present in steroid-refractory cases. CONCLUSION: ICIAC is a severe irAE which frequently requires high-dose steroids and a close follow-up due to deleterious complications. The detection of histologically diagnosed deep ulcerations may predict a steroid-refractory course and may warrant early application of infliximab. However, larger studies are required to confirm our findings.

Bouveret's Syndrome - Case Series with Therapeutic Implications.

Bouveret's syndrome is a rare complication resulting from gallstone disease. Both surgical and endoscopical procedures are performed, with the disease to be seen as strictly interdisciplinary. There are no well-established recommendations for this condition. In this paper, we want to describe our experience from 6 cases in 3 Swiss hospitals from 2015 to 2017 with emphasis on the endoscopic technique of electrohydraulic lithotripsy followed by balloon dilatation and propose a treatment algorithm.

Diagnostic accuracy of texture analysis and machine learning for quantification of liver fibrosis in MRI: correlation with MR elastography and histopathology.

OBJECTIVES: To compare the diagnostic accuracy of texture analysis (TA)-derived parameters combined with machine learning (ML) of non-contrast-enhanced T1w and T2w fat-saturated (fs) images with MR elastography (MRE) for liver fibrosis quantification. METHODS: In this IRB-approved prospective study, liver MRIs of participants with suspected chronic liver disease who underwent liver biopsy between August 2015 and May 2018 were analyzed. Two readers blinded to clinical and histopathological findings performed TA. The participants were categorized into no or low-stage (0-2) and high-stage (3-4) fibrosis groups. Confusion matrices were calculated using a support vector machine combined with principal component analysis. The diagnostic accuracy of ML-based TA of liver fibrosis and MRE was assessed by area under the receiver operating characteristic curves (AUC). Histopathology served as reference standard. RESULTS: A total of 62 consecutive participants (40 men; mean age ± standard deviation, 48 ± 13 years) were included. The accuracy of TA and ML on T1w was 85.7% (95% confidence interval [CI] 63.7-97.0) and 61.9% (95% CI 38.4-81.9) on T2w fs for classification of liver fibrosis into low-stage and high-stage fibrosis. The AUC for TA on T1w was similar to MRE (0.82 [95% CI 0.59-0.95] vs. 0.92 [95% CI 0.71-0.99], p = 0.41), while the AUC for T2w fs was significantly lower compared to MRE (0.57 [95% CI 0.34-0.78] vs. 0.92 [95% CI 0.71-0.99], p = 0.008). CONCLUSION: Our results suggest that liver fibrosis can be quantified with TA-derived parameters of T1w when combined with a ML algorithm with similar accuracy compared to MRE. KEY POINTS: • Liver fibrosis can be categorized into low-stage fibrosis (0-2) and high-stage fibrosis (3-4) using texture analysis-derived parameters of T1-weighted images with a machine learning approach. • For the differentiation of low-stage fibrosis and high-stage fibrosis, the diagnostic accuracy of texture analysis on T1-weighted images combined with a machine learning algorithm is similar compared to MR elastography.