Endoluminal radiofrequency ablation in patients with malignant biliary obstruction: a randomised trial.

BACKGROUND: Endoluminal radiofrequency ablation (RFA) has been promoted as palliative treatment for patients with cholangiocarcinoma (CCA) and pancreatic ductal adenocarcinoma (PDAC) in order to improve biliary drainage and eventually prolong survival. No high level evidence is, however, available on this technique. DESIGN: In this randomised controlled study, we compared endoluminal RFA plus stenting with stenting alone (control group) in patients with malignant biliary obstruction; metal stents were primarily placed. Primary outcome was overall survival; secondary outcomes were stent patency, quality of life and adverse events. In a superiority design, survival was assumed to be doubled by RFA as compared with 6.4 months in the control group (n=280). RESULTS: A total of 161 patients (male:female 90:71, mean age 71±9 years) were randomised before recruitment was terminated for futility after an interim analysis. Eighty-five patients had CCA (73 hilar, 12 distal) and 76 had pancreatic cancer. There was no difference in survival in both subgroups: for patients with CCA, median survival was 10.5 months (95% CI 6.7 to 18.3) in the RFA group vs 10.6 months (95% CI 9.0 to 24.8), p=0.58)) in the control group. In the subgroup with pancreatic cancer, median survival was 6.4 months (95% CI 4.3 to 9.7) for the RFA vs 7.7 months (95% CI 5.6 to 11.3), p=0.73) for the control group. No benefit was seen in the RFA group with regard to stent patency (at 12 months 40% vs 36% in CCA and 66% vs 65% in PDAC), and quality of life was unchanged by either treatment and comparable between the groups. Adverse events occurred in seven patients in each groups. CONCLUSION: A combination of endoluminal RFA and stenting was not superior to stenting alone in prolonging survival or improving stent patency in patients with malignant biliary obstruction. TRIAL REGISTRATION NUMBER: NCT03166436.

News in gastroenterology, hepatology and digestive endoscopy.

Gastroenterology, hepatology and digestive endoscopy are rapidly evolving disciplines with significant advances in the diagnostics and treatment in the entire gastrointestinal tract. The aim of our article was to summarize new perspectives on relevant situations in gastroenterology and hepatology like acute pancreatitis, functional dyspepsia, rational indication of proton pump inhibitors, inflammatory bowel diseases (IBD), cholestatic liver diseases, alcohol induced hepatitis, non-alcoholic fatty live disease (NAFLD) and patophysiology of bilirubin and bile acids. Digestive endoscopy represents an interventional part of gastroenterology and key recent topics are mentioned like pancreatic cancer screening, arteficial intelligence, resection of low-risk neoplastic lesions, enteroscopy techniques, cholangio- and pancreatiscopy and extraluminal expansion of endoscopy techniques by means of endoscopic submucosal and transmural dissection, endoscopic myotomy and lumen apposing stents.

Percutaneous endoscopic cecostomy for management of Ogilvie's syndrome: a case series and literature review with an update on current guidelines (with video).

INTRODUCTION: Percutaneous endoscopic cecostomy (PEC) is a viable treatment option for patients with persistent or recurrent acute colonic pseudo-obstruction (ACPO; Ogilvie's syndrome). It should be generally considered in patients that are refractory to pharmacologic and endoscopic decompression, especially those not amenable to surgical intervention due to an increased perioperative risk. Physicians are rather unfamiliar with this approach given the limited number of reports in the literature and paucity of guideline resources, although guidelines concerning ACPO and covering the role of endoscopy were recently published by three major expert societies, all within the last 2 years. PATIENTS AND METHODS: We retrospectively identified three consecutive patients who underwent PEC placement at a Czech tertiary referral center between May 2018 and December 2021: all for recurrent ACPO. In addition, we summarized the current guidelines in order to present the latest knowledge related both to the procedure and management approach in patients with ACPO. RESULTS: The placement of PEC was successful and resulted in clinical improvement in all cases without any adverse events. CONCLUSION: The results of our experience are in line with previous reports and suggest that PEC may become a very useful tool in the armamentarium of modalities utilized to treat ACPO. Furthermore, the availability of guideline resources now offers comprehensive guidance for informed decision-making and the procedural aspects.

Motorized spiral enteroscopy - a prospective analysis of 82 procedures at a single tertiary center.

INTRODUCTION: Motorized spiral enteroscopy (MSE) is a promising novel deep enteroscopy technique. The purpose of our study was to evaluate efficiency and safety of MSE in a single tertiary endoscopy center. METHODS: We prospectively evaluated all consecutive patients undergoing MSE in our endoscopy unit from June 2019 through June 2022. Main outcomes were technical success rate, proportion of procedures with sufficient depth of insertion, success rate of total enteroscopy, diagnostic yield and complication rate. RESULTS: A total of 82 examinations in 62 patients (56% males, mean age 58 ± 18 years) were performed, 56 from antegrade and 26 from retrograde approach. Technical success rate was 94% (77/82) and in 89% (72/82) of cases, depth of insertion was considered sufficient. Total enteroscopy was indicated in 19 patients and it was achieved in 16 of them (84%), either by antegrade in 4 or by combined approach in 12 cases. Diagnostic yield was 81%. Lesion of the small bowel was found in 43 of patients. Mean insertion time was 40 for antegrade and 44 min for retrograde procedures, respectively. Complications occurred in 3% (2/62) of patients. One patient suffered from mild acute pancreatitis after total enteroscopy and there was one intussusception of the sigmoid during endoscope withdrawal resolved by parallel colonoscope insertion. CONCLUSION: In our series of 82 procedures in 62 patients examined by MSE during a three-year period, we show high technical success rate (94%), diagnostic yield (81%) and low complication rate (3%).

Administration of maximum dose of mucolytic solution before upper endoscopy - a double-blind, randomized trial.

OBJECTIVE: The aim of the study was to demonstrate that an administration of mucolytic solution with a maximum dose of simethicone and n -acetylcysteine before upper endoscopy improves mucosal visibility compared to a group without administration of mucolytic solution or water. METHODS: This study was a double-blind, randomized controlled trial. Patients were randomized into four groups, with the administration of 100 ml of water + 600 mg n -acetylcysteine + 400 mg simethicone, 100 ml of water + 400 mg n -acetylcysteine + 20 mg simethicone, 100 ml of water, and without any water or mucolytic solution. During the examination, a total of 10 images were taken in the defined areas. The overall visibility score was given by the sum of the 0-5 scores of the five areas and was assessed by the endoscopist performing the procedure and the blinded endoscopists using static images. RESULTS: A total of 129 patients were randomized. The group of patients did not differ in age, sex distribution, and indications significantly. The overall visibility score as assessed by the endoscopist performing the procedure was significantly higher in the group with the maximum dose of mucolytic solution compared to the group without solution or water (18.9 ±â€…2.9 vs. 16.6 ±â€…3.3, P  = 0.023). This difference was not evident by the blinded evaluation of static photographs. CONCLUSION: Administration of mucolytic solution with a maximum dose of n -acetylcysteine and simethicone before upper endoscopy improved mucosal visibility in the upper gastrointestinal tract compared with the group without any preparation while evaluated by performing endoscopist.

Fluorescence In Situ Hybridization in Primary Diagnosis of Biliary Strictures: A Single-Center Prospective Interventional Study.

Background and aims: Diagnosis of the biliary stricture remains a challenge. In view of the low sensitivity of brush cytology (BC), fluorescence in situ hybridization (FISH) has been reported as a useful adjunctive test in patients with biliary strictures. We aimed to determine performance characteristics of BC and FISH individually and in combination (BC + FISH) in the primary diagnosis of biliary strictures. Methods: This single-center prospective study was conducted between April 2019 and January 2021. Consecutive patients with unsampled biliary strictures undergoing first endoscopic retrograde cholangiopancreatography in our institution were included. Tissue specimens from two standardized transpapillary brushings from the strictures were examined by routine cytology and FISH. Histopathological confirmation after surgery or 12-month follow-up was regarded as the reference standard for final diagnosis. Results: Of 109 enrolled patients, six were excluded and one lost from the final analysis. In the remaining 102 patients (60.8% males, mean age 67.4, range 25-92 years), the proportions of benign and malignant strictures were 28 (27.5%) and 74 (72.5%), respectively. The proportions of proximal and distal strictures were 26 (25.5%) and 76 (74.5%), respectively. In comparison to BC alone, FISH increased the sensitivity from 36.1% to 50.7% (p = 0.076) while maintaining similar specificity (p = 0.311). Conclusions: Dual-modality tissue evaluation using BC + FISH showed an improving trend in sensitivity for the primary diagnosis of biliary strictures when compared with BC alone.

EUS-guided transluminal drainage using lumen-apposing metal stents with or without coaxial plastic stents for treatment of walled-off necrotizing pancreatitis: a prospective bicentric randomized controlled trial.

BACKGROUND AND AIMS: Lumen-apposing metal stents (LAMSs) have proven to be effective for drainage of pancreatic walled-off necrosis (WON), although associated adverse events (AEs) have been reported. Anchoring coaxial double-pigtail plastic stents (DPSs) within LAMSs have been proposed to prevent LAMS-related AEs but have not been assessed in prospective studies. We aimed to evaluate the utility of such measures with a randomized controlled trial. METHODS: We randomly assigned consecutive patients with WON indications for drainage to EUS-guided transluminal drainage using LAMSs with (group A) or without (group B) DPSs. All LAMSs were to be removed after 3 weeks had elapsed from the index procedure with a preceding CT to decide whether additional steps needed to be taken (eg, transluminal necrosectomy or placing transluminal plastic stents in patients with incomplete resolution of WON). The main outcomes were failure of the index method, defined as necessity of reintervention (endoscopic, percutaneous, or surgical) before LAMS removal because of LAMS-related AEs and/or clinical deterioration; AE rates; and mortality with the LAMS in place. Variables were evaluated using the Mann-Whitney U test, χ2 test, or Fisher exact test as appropriate. P < .05 was considered significant. RESULTS: Sixty-seven patients (37.3% women; mean age, 54 ± 14.4 years) underwent LAMS placement with (n = 34) or without (n = 33) DPS placement in 2 tertiary centers. Baseline characteristics including demographics, etiology, comorbidity, and clinical presentation (sterile vs infected necrosis) were comparable between both groups. The technical success rate in placing LAMSs and DPSs was 100%. The global rate of AEs was significantly lower in group A versus group B (20.7% vs 51.5%, respectively; P = .008). Stent occlusion was the most frequently observed AE (14.7% vs 36.3%, P = .042). Failure of the index method was lower in group A versus group B (29.4% vs 48.5%, respectively; P = .109); however, the difference did not achieve statistical significance. The same applied to the mortality rate with LAMSs in place (2.9% vs 12.1%, P = .197). CONCLUSIONS: The addition of a coaxial DPS within a LAMS was associated with a significantly lower global rate of AEs and stent occlusion rate in EUS-guided drainage of WON. (Clinical trial registration number: NCT03923686.).

Administration of mucolytic solution before upper endoscopy - double-blind, monocentric, randomized study.

AIMS: Sufficient visibility of the mucosa during upper endoscopy is crucial for successful diagnosis, especially for early neoplastic lesions. Data documenting the effect of administration of mucolytic solution prior to gastroscopy in order to improve mucosal visibility are limited in Europe. The aim of the study was to assess the score of mucosal visibility in the upper gastrointestinal tract after administration of the mucolytic solution defined by us. PATIENTS AND METHODS: This is a monocentric, double-blind, randomized study involving 134 patients indicated for diagnostic upper endoscopy. Patients were randomly assigned to one of three arms, with mucolytic solution (100 mL water + 400 mg N-acetylcysteine + 20 mg simethicone), without the solution , and with 100 mL pure water. During the examination, 11 photographs were taken in defined areas. The visibility score was given by the sum of the score 0-5 from 5 defined localities evaluated by a blinded endoscopist and subsequently by two blinded endoscopists. Other parameters monitored were examination time and a semiquantitative evaluation of residual gastric fluid. RESULTS: The basic characteristics of the group (sex, age, indications for examination) were comparable between arms. The visibility score was similar in all arms - 17.4 ± 1.9 vs. 17.0 ± 2.0 vs. 17.6 ± 1.8 (P=0.32). The examination time and the amount of residual fluid in the stomach were comparable in all arms. CONCLUSIONS: Administration of the mucolytic solution in our study did not increase the mucosal visibility score in the esophagus, stomach and duodenum. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02967094.

Endoscopic treatment of early colorectal cancer.

Early colorectal neoplasia is a localized precancerous lesion of the large intestine associated with negligible risk of lymphatic or systemic dissemination. Early neoplasia consists of adenoma with low- and high-grade dysplasia, intramucosal carcinoma and superficially invasive cancer without other high-risk features. In the majority of cases, early neoplastic lesions are detected by colonoscopy and treated by means of endoscopy resection replacing surgical treatment. Risk of invasive cancer should be stratified during diagnostic colonoscopy using morphological classifications and then, appropriate resection technique (endoscopic polypectomy, endoscopic mucosal resection, endoscopic submucosal dissection or full-thickness resection) is used. Success of endoscopic resection is assessed by histological examination of the resected specimen and in some cases, additional surgical resection with lymphadenectomy should be performed. Colonoscopic surveillance is needed due to the risk of local recurrence and metachronous lesions.

Current Screening Strategies for Pancreatic Cancer.

Pancreatic ductal adenocarcinoma (PDAC) is a dreaded malignancy with a dismal 5-year survival rate despite maximal efforts on optimizing treatment strategies. Radical surgery is the only potential curative procedure. Unfortunately, the majority of patients are diagnosed with locally advanced or metastatic disease, which renders them ineligible for curative resection. Early detection of PDAC is thus considered to be the most effective way to improve survival. In this regard, pancreatic screening has been proposed to improve results by detecting asymptomatic stages of PDAC and its precursors. There is now evidence of benefits of systematic surveillance in high-risk individuals, and the current guidelines emphasize the potential of screening to affect overall survival in individuals with genetic susceptibility syndromes or familial occurrence of PDAC. Here we aim to summarize the current knowledge about screening strategies for PDAC, including the latest epidemiological data, risk factors, associated hereditary syndromes, available screening modalities, benefits, limitations, as well as management implications.

A cirrhotic patient in an internal medicine ward.

Liver cirrhosis represents a common condition with substantial mortality. Manifestation and progression of ascites, hepatic encephalopathy or gastrointestinal bleeding are among main reasons for hospital admission. Infections represent another specific area in cirrhotic patients. Timely and correct diagnosis and therapy of these conditions are the mainstay of optimal outcome. Manifestation of complications of liver cirrhosis significantly deteriorates prognosis of the patient. Ascites in portal hypertension develops as a result of sodium and consequently water retention. Therapy comprises of restriction of sodium intake, diuretic therapy with combination of spironolactone and furosemide, alternatively large-volume paracentesis. Hepatic encephalopathy comprises a spectrum of neuropsychiatric abnormalities from subtle changes to overt desorientation and asterixis to hepatic coma. Treatment includes correcting of predisposing conditions, administering of non-absorbable disaccharides or rifaximin. The most common cause of bleeding in a cirrhotic patient is oesophageal bleeding. Therapy is complex including hemodynamic stabilisation, antibiotic prophylaxis, vasoactive and endoscopic treatment. Infections are common causes of decompensation and occurrence of complications of advanced chronic liver disease. Their unfavourable outcome is a result of a complex immune disorder in cirrhotic patients. Specific type of infection in cirrhosis is spontaneous bacterial peritonitis, which has to be always excluded with diagnostic paracentesis. The mainstay of successful therapy of infections is timely and vigorous broad spectrum antibiotic therapy which can significantly improve otherwise unfavourable outcome of these patients.

Surgical treatment of duodenal adenocarcinoma: ampullary vs. non-ampullary, short- and long-term outcomes.

BACKGROUND: The aim of this study was to evaluate symptoms, diagnostic methods, short- and long-term outcomes of surgical treatment in patients with duodenal adenocarcinoma. PATIENTS AND METHODS: A single center, retrospective, observational study of 52 consecutive patients with duodenal adenocarcinoma operated on with curative intent between 2006 - 2019. Duodenectomy as part of a hemipancreatoduodenectomy or total pancreatectomy procedure was performed for ADAC (ampullary duodenal/intestinal adenocarcinoma) or NADAC (non-ampullary duodenal adenocarcinoma). RESULTS: Prevailing symptoms were obstructive jaundice in the ADAC group (P<0.0001) and bleeding in the NADAC group (P=0.005), with larger tumor size in patients with NADAC (P=0.001). Complication rate, morbidity and mortality were comparable. Primary total pancreatoduodenectomy predominated in the NADAC group, 16.6% vs. 2.9%, and salvage completion pancreatectomy in the ADAC group, 6% vs. 0%. Significant prognostic factors for OS were perineural invasion (P=0.006) and adjuvant chemotherapy (P=0.045) in the ADAC group, and for DFS the total number of resected lymph nodes (P=0.042) and lymph node ratio (P=0.031) in the NADAC group. Median OS is 21 months and 5-year survival 27.3% in the NADAC group and 41.5 months and 52% in the ADAC group. CONCLUSION: Ampullary duodenal/intestinal adenocarcinomas are smaller than non-ampullary at diagnosis, with a higher rate of lymph node metastases, but with a better prognosis and long-term outcome in the presented cohort. Oral localisation of NADAC prevailed in the present cohort. Perineural invasion and postoperative oncological therapy are significant prognostic factors for OS in ADAC, but the total number of lymph nodes and lymph node ratio are significant prognostic factors for DFS in NADAC.

Endoscopic full-thickness resection versus endoscopic submucosal dissection in the treatment of colonic neoplastic lesions ≤ 30 mm-a single-center experience.

Endoscopic full-thickness resection (FTR) is a novel technique of endoscopic treatment of colorectal neoplastic lesions not suitable for endoscopic polypectomy or mucosal resection. FTR appears to be a reasonable alternative to technically demanding endoscopic submucosal dissection (ESD) for lesions ≤ 30 mm. However, comparison between FTR and ESD has not been published yet and their mutual positioning in the treatment algorithm is still unclear. The purpose of the analysis was to evaluate efficacy and safety of FTR in the treatment of colorectal lesions ≤ 30 mm by comparing prospectively followed FTR cohort to retrospective ESD cohort in the setting of single tertiary endoscopy center. Primary outcomes were technical success rate, R0 resection and curative resection rate, and complication rate. A total of 52 patients in FTR and 50 patients in ESD group were treated between 2015 and 2018. Technical success rate was significantly higher in FTR group (92 vs. 74%, P = 0.01) as well as R0 resection rate (85 vs. 62%, P = 0.01) and curative resection rate (75 vs. 56%, P = 0.01). Complications occurred more frequently in ESD group (40 vs. 13%, P = 0.002), mainly due to high incidence of electrocoagulation syndrome (24 vs. 0%). Total procedure time was substantially shorter in FTR group (26.4 ± 11.0 min vs. estimated 90-240 min). Local residual neoplastic lesions were detected numerically more often in FTR group (12 vs. 5%, P = 0.12). No patient died during follow-up. Compared to ESD, FTR proved significantly higher technical success rate, higher R0 and curative resection rate, and shorter procedure time. In the FTR group, there were significantly less complications but higher incidence of local residual neoplasia. Further research including randomized trials is needed to compare both resection techniques.

Routine SARS-CoV-2 RT-PCR testing before digestive endoscopy during the peak of the pandemic - a single tertiary center experience.

BACKGROUND AND AIMS: COVID-19 pandemic has impacted on all endoscopy centers in the Czech Republic, that belongs to the most affected countries in the world. The aim of our study was to analyze all procedures following routine RT-PCR testing in our tertiary center during the peak of the pandemic. METHODS: We retrospectively analyzed all procedures performed from October 2020 to January 2021 after a new RT-PCR center had been set up. Main outcomes were type of scheduled procedure, indication, rate of therapeutic interventions and rate of new relevant and malignant findings. Comparison to the same period before the pandemic and SARS-CoV-2 infection in endoscopy staff are also reported. RESULTS: A total of 1,953 procedures were performed. 624 patients were referred with a negative RT-PCR test and the remaining 1,346 patients were tested in the new center. 1,293 negative tests led to 1,329 procedures. A new relevant finding was reported in 589 (44.3%), including new malignancy in 56 (4.2%). 53 patients tested positive (3.9%). There was a reduction by 9% in the number of all procedures compared to the same period before the pandemic and an increase in the number of screening colonoscopies and ERCP procedures. In the study period, 9 of 54 staff members contracted SARS-CoV-2 infection. CONCLUSIONS: Routine RT-PCR testing of patients scheduled for elective endoscopy during the peak of COVID-19 pandemic enabled us to essentially maintain our unit productivity, including activities such as screening colonoscopy, endoscopic resection and pancreatobiliary endoscopy.

Differences in the placental pharmacokinetics of vedolizumab and ustekinumab during pregnancy in women with inflammatory bowel disease: a prospective multicentre study.

BACKGROUND: Vedolizumab demonstrated different placental pharmacokinetics than other immunoglobulin G1 antibodies, leading to lower drug levels in cord blood in contrast to maternal blood at the time of delivery. The placental transfer of ustekinumab seems to have a pattern similar to anti-tumour necrosis factor agents. Current evidence on the placental pharmacokinetics of vedolizumab and ustekinumab is limited. We aimed to assess the placental transfer of ustekinumab and vedolizumab in pregnant patients with inflammatory bowel disease. METHODS: Consecutive women from a prospective observational study who were exposed to ustekinumab or vedolizumab within 2 months prior to conception or during pregnancy were included. Ustekinumab and vedolizumab levels were measured in maternal and cord blood at the time of delivery. RESULTS: Drug levels were available in 31 infant-mother pairs (15 exposed to ustekinumab and 16 to vedolizumab). The median maternal and newborn ustekinumab levels were 5.3 mg/l and 10.3 mg/l, respectively (the median infant-to-maternal ratio was 1.7), while the median maternal and cord vedolizumab levels were 7.3 mg/l and 4.5 mg/l (the median infant-to-maternal ratio was 0.66). The ustekinumab levels in cord blood positively correlated with the maternal levels at delivery (ρ = 0.751, p = 0.001). However, no correlation with the timing of the last drug administration was found. In contrast, the vedolizumab levels in cord blood demonstrated significant positive correlation with the maternal levels (ρ = 0.831, p < 0.001) along with the gestational week of the last infusion (ρ = 0.736, p = 0.001). CONCLUSION: Vedolizumab demonstrated different placental pharmacokinetics, leading to lower drug levels in cord blood compared to maternal blood at delivery; in contrast, the placental transfer of ustekinumab seems to have a pattern similar to anti-tumour necrosis factor (TNF) agents.

Extraintestinal complications of inflammatory bowel diseases.

Inflammatory bowel disease (IBD) includes Crohns disease (CD) and ulcerative colitis (UC). Those are chronic gastrointestinal disorders of inflammatory nature and not fully known etiology. As a result of their immune-mediated mechanism and complex impact on the whole organism other organs than gastrointestinal system may be affected in many ways. These extraintestinal manifestations (EIM) and complications may severely deteriorate prognosis of the patient, cause his morbidity and worsen the quality of life. While classical extraintestinal manifestations, such as enteropathic arthropathy, skin or eye involvement or primary sclerosing cholangitis, share common immunopathological mechanism with IBD, whole range of other disorders may result from various anatomical or metabolic abnormalities caused by IBD or its treatment. This review focus on the most common extraintestinal complications, such as anaemia, metabolic bone disease, biliary and urolithiasis, which we meet in our daily clinical practice.

Life Stressors in Patients with Inflammatory Bowel Disease: Comparison with a Population-Based Healthy Control Group in the Czech Republic.

BACKGROUND: Stress has been suggested to play a potential role in inflammatory bowel disease (IBD) pathogenesis, but studies focussing on the occurrence of specific life stress events among IBD patients are scarce. Therefore, the aim of the present study was to explore the association between various life stress events and IBD. METHODS: Patients with IBD (N = 98, mean age: 38.45, 54.1% men) were compared to a group of healthy controls (N = 405, mean age: 36.45, 58.0% men) originating from a health survey conducted on a representative population sample of Czech adults. The Life Stressor Checklist-Revised (LSC-R) was used to assess the stressors. RESULTS: IBD patients had higher odds of reporting life stressors overall (p < 0.001), life stressors before the age of 16 (p < 0.004) and a higher score in traumatic stress (p < 0.005) and interpersonal violence (p < 0.001) when compared to the control group. Gender- and diagnosis-related differences are discussed. CONCLUSION: Reporting life stressors experienced during childhood or adulthood is strongly associated with IBD. This should be considered in illness management, especially in a severe course of IBD.

Water-assisted colonoscopy: an international modified Delphi review on definitions and practice recommendations.

BACKGROUND AND AIMS: Since 2008, a plethora of research studies has compared the efficacy of water-assisted (aided) colonoscopy (WAC) and underwater resection (UWR) of colorectal lesions with standard colonoscopy. We reviewed and graded the research evidence with potential clinical application. We conducted a modified Delphi consensus among experienced colonoscopists on definitions and practice of water immersion (WI), water exchange (WE), and UWR. METHODS: Major databases were searched to obtain research reports that could potentially shape clinical practice related to WAC and UWR. Pertinent references were graded (Grading of Recommendations, Assessment, Development and Evaluation). Extracted data supporting evidence-based statements were tabulated and provided to respondents. We received responses from 55 (85% surveyed) experienced colonoscopists (37 experts and 18 nonexperts in WAC) from 16 countries in 3 rounds. Voting was conducted anonymously in the second and third round, with ≥80% agreement defined as consensus. We aimed to obtain consensus in all statements. RESULTS: In the first and the second modified Delphi rounds, 20 proposed statements were decreased to 14 and then 11 statements. After the third round, the combined responses from all respondents depicted the consensus in 11 statements (S): definitions of WI (S1) and WE (S2), procedural features (S3-S5), impact on bowel cleanliness (S6), adenoma detection (S7), pain score (S8), and UWR (S9-S11). CONCLUSIONS: The most important consensus statements are that WI and WE are not the same in implementation and outcomes. Because studies that could potentially shape clinical practice of WAC and UWR were chosen for review, this modified Delphi consensus supports recommendations for the use of WAC in clinical practice.

Water Exchange (WE) and Quality Improvement-Enhanced Advanced Adenoma Detection: A Pooled Data Analysis of 6 Randomized Controlled Trials.

INTRODUCTION: Advanced adenomas (≥10 mm in diameter, >25% villous, or high-grade dysplasia), a marker of colorectal cancer risk, are used to stratify patients for closer surveillance. Modern accessories, endoscopes, and age-adjusted evaluation have variable impacts on the advanced adenoma detection rate (AADR). In 1 randomized controlled trial (RCT) comparing air insufflation (AI) with water exchange (WE), the right colon AADR was significantly increased by WE. Four network meta-analyses reported that WE significantly increased overall adenoma detection rate (ADR), but the impact on AADR was not addressed. AIM: The aim of this study was to test the hypothesis that WE significantly increased AADR compared with AI. METHOD: Six Clinicaltrial.gov-registered RCTs were reported by a group of WE investigators. Data including AADR (primary outcome) and overall ADR (secondary outcome) were pooled. RESULTS: A total of 5407 patients were randomized to AI (2699) and WE (2708). Compared with AI, WE significantly increased AADR (5.7% vs. 8.3%, P=0.001) and overall ADR (20.9% vs. 27.4%, P=0.001). CONCLUSIONS: In contrast to published reports, which showed variable impacts on AADR, WE was consistent in increasing AADR in 6 reported RCTs. The pooled data confirm that the impact of WE in increasing AADR was significant. The significantly enhanced overall ADR indicated that WE provided a higher quality outcome than AI. The significant improvement in AADR confirmed WE to be clinically relevant and has finally arrived as a timely addition to colorectal cancer prevention programs.