Impact of Endoscopic Treatment in Severe Duodenal Polyposis: A National Study in Familial Adenomatous Polyposis Patients.

BACKGROUND & AIMS: The majority of patients with familial adenomatous polyposis (FAP) develop duodenal adenomas with a risk of progression to duodenal cancer. Endoscopic management of FAP duodenal adenomas has been proposed as a less-invasive option than surgery, but available data still are limited. Our aims were to assess the feasibility and safety of endoscopic treatment in duodenal polyposis and to evaluate its long-term efficacy in terms of recurrence and malignant degeneration. METHODS: FAP patients with stage IV duodenal polyposis were enrolled in 5 French centers as part of a national cohort and followed up for a median period of 5.66 years (interquartile range, 6.39 y). Primary outcomes were duodenal surgery-free and cancer-free survival. Two groups of patients were identified according to endoscopic procedures: group 1: resection and or destruction (by argon plasma coagulation) of duodenal polyps, and group 2: papillectomy. RESULTS: Fifty-eight patients were enrolled (29 men; median age, 44 y). Endoscopic therapy was performed in 37 patients in group 1 and in 19 patients in group 2. Duodenal cancer-free and surgery-free survival were 95.8% at 5 years and 92.6% at 10 years. Four patients required surgery and 2 patients developed cancers. In the 58 patients, the calculated Spigelman score decreased from 9.24 points at entry to 6.35 at 5 years and then plateaued. Complications (mostly bleeding and perforation) occurred in 20 patients. CONCLUSIONS: In this long-term cohort follow-up evaluation, endoscopic treatment of patients with severe duodenal polyposis appears relatively safe and effective as an alternative to surgery for the prevention of cancer.

Factors associated with early failure of peroral endoscopic myotomy in achalasia.

BACKGROUND AND AIMS: Achalasia can be treated very effectively with peroral endoscopic myotomy (POEM), but factors associated with early failure remain to be determined, especially in European cohorts. METHODS: All consecutive adult patients who underwent a first POEM to treat primary achalasia were included in this multicenter retrospective study. Early failure was defined by an Eckardt score (ES) >3 at 3 months after POEM. When evaluating factors predictive of early failure, 2 cohorts were considered: one consisted of the total population, for whom only basic variables were collected, and the other a cohort built for a case-control study that included matched early-failure and early-success patients (ratio, 1:2). RESULTS: Among 746 patients, the early failure rate was 9.4%. Predictive factors were age ≤45 years (P = .019), achalasia types I and III (P < .001), and the development of a severe adverse event during the procedure (P = .023). In the case-control study, the only additional independent risk factor for early failure was a high pre-POEM ES (P = .001). Only the retrosternal pain subscore was significantly associated with the early failure rate. CONCLUSION: The early failure rate of POEM used to treat primary achalasia is <10%. Younger age, type I/III achalasia, and a high pre-POEM ES were significantly associated with failure.

Impact of linked color imaging on the proximal adenoma miss rate: a multicenter tandem randomized controlled trial (the COCORICO trial).

BACKGROUND: Missed lesions are common during standard colonoscopy and are correlated with post-colonoscopy colorectal cancer. Contrast-enhanced technologies have recently been developed to improve polyp detection. We aimed to evaluate the impact of linked color imaging (LCI) on the proximal adenoma miss rate in routine colonoscopy. METHODS: This national, multicenter, tandem, randomized trial compared the outcomes of colonoscopy with white-light imaging (WLI) versus LCI for polyp detection in the right colon. Two consecutive examinations of the right colon (upstream of the hepatic flexure) were made with WLI and LCI by the same operator. First-pass examination by WLI or LCI was randomized 1:1 after cecal intubation. According to statistical calculations, 10 endoscopy units had to include approximately 700 patients. The primary outcome was proximal adenoma miss rate. Secondary outcomes were the proximal miss rates for sessile serrated lesions (SSL), advanced adenomas, and polyps. RESULTS: 764 patients were included from 1 January 2020 to 22 December 2022, and 686 patients were randomized (345 WLI first vs. 341 LCI first). Both groups were comparable in terms of demographics and indications. The proximal adenoma miss rate was not significantly higher in the WLI-first group (36.7%) vs. the LCI-first group (31.8%) (estimated mean absolute difference: 4.9% [95%CI -5.2% to 15.0%], P = 0.34). There was also no significant difference in miss rates for SSLs, advanced adenomas, and polyps in the proximal colon. CONCLUSIONS: In contrast to previous data, this study does not support the benefit of LCI to the proximal adenoma miss rate in routine colonoscopy.

Peroral endoscopic myotomy: is it better to perform it in naive patients or as second-line therapy? Results of an open-label-controlled study in 105 patients.

BACKGROUND: Whether Peroral Endoscopic Myotomy (POEM) can be proposed as a second-line treatment in patients with achalasia remains to be confirmed in real-life series. OBJECTIVE: This study aimed to compare the efficacy, feasibility and safety of POEM between treatment-naïve patients and patients who had prior endoscopic or surgical therapies for achalasia. METHODS: All consecutive patients who underwent a POEM procedure for achalasia in our centre from June 2015 to September 2018 were included in this retrospective study. They were classified into treatment-naïve patients (POEM1) and patients who had at least one previous endoscopic and/or surgical treatment for achalasia (POEM2). RESULTS: A total of 105 patients were included, 52 in the POEM1 group and 53 in the POEM2 group. Clinical success (defined as an Eckardt score ≤ 3) at 6 months was observed in 93% of POEM1 patients and 84% of POEM2 patients (p = 0.18). Technical success rate was not significantly different between the two groups (100% vs 96%, respectively; p = 0.50). No significant difference was noted in terms of adverse event rate (19% vs 19%, respectively; p = 1.00). Post-procedure pain occurred in 12% of treatment-naive and 9% of non-naïve patients (p = 0.76). The median length of hospital stay was 3 days in both groups (p = 0.17). Symptomatic gastroesophageal reflux occurred in 25% of POEM1 patients and 16% of POEM2 patients (p = 0.24). CONCLUSION: Efficacy, feasibility and safety of POEM are not different between treatment-naïve and non-naïve patients. POEM is a valuable second-line approach in patients with persistent symptoms of achalasia after surgical or endoscopic treatments.

Risk factors of anastomosis-related difficult endoscopic retrograde cholangiopancreatography following endoscopic ultrasound-guided gastro-gastrostomy using a standardized protocol (with video).

OBJECTIVES: Little is known about how to perform the endoscopic ultrasound (EUS)-directed transgastric endoscopic retrograde cholangiopancreatography (ERCP; EDGE) in patients with gastric bypass using lumen-apposing metal stents (LAMS). The aim was to assess the risk factors of anastomosis-related difficult ERCP. METHODS: Observational single-center study. All patients who underwent an EDGE procedure in 2020-2022 following a standardized protocol were included. Risk factors for difficult ERCP, defined as the need of >5 min LAMS dilation or failure to pass a duodenoscope in the second duodenum, were assessed. RESULTS: Forty-five ERCPs were performed in 31 patients (57.4 ± 8.2 years old, 38.7% male). The EUS procedure was done using a wire-guided technique (n = 28, 90.3%) for biliary stones (n = 22, 71%) in most cases. The location of the anastomosis was gastro-gastric (n = 24, 77.4%) and mainly in the middle-excluded stomach (n = 21, 67.7%) with an oblique axis (n = 22, 71%). The ERCP technical success was 96.8%. There were 10 difficult ERCPs (32.3%) due to timing (n = 8), anastomotic dilation (n = 8), or failure to pass (n = 3). By multivariable analysis adjusted by two-stage procedures, the risk factors for a difficult ERCP were the jejuno-gastric route (85.7% vs. 16.7%; odds ratio [ORa ] 31.875; 95% confidence interval [CI] 1.649-616.155; P = 0.022), and the anastomosis to the proximal/distal excluded stomach (70% vs. 14.3%; ORa 22.667; 95% CI 1.676-306.570; P = 0.019). There was only one complication (3.2%) and one persistent gastro-gastric fistula (3.2%) in a median follow-up of 4 months (2-18 months), with no weight regain (P = 0.465). CONCLUSIONS: The jejunogastric route and the anastomosis with the proximal/distal excluded stomach during the EDGE procedure increase the difficulty of ERCP.

PERcutaneous transhepatic CHOLangioscopy using a new single-operator short cholangioscope (PERCHOL): European feasibility study.

OBJECTIVES: A new short device for percutaneous endoscopic cholangioscopy was recently developed. However, feasibility and safety has not yet been evaluated. The aim of this study was to assess clinical success, technical success, and adverse events (AEs). METHODS: This observational multicenter retrospective study included all patients who underwent percutaneous cholangioscopy using a short cholangioscope between 2020 and 2022. The clinical success, defined as the complete duct clearance or obtaining at least one cholangioscopy-guided biopsy, was assessed. The histopathological accuracy, technical success, and the AE rate were also evaluated. RESULTS: Fifty-one patients (60 ± 15 years, 45.1% male) were included. The majority of patients had altered anatomy (n = 40, 78.4%), and biliary stones (n = 34, 66.7%) was the commonest indication. The technique was predominantly wire-guided (n = 44, 86.3%) through a percutaneous sheath (n = 36, 70.6%) following a median interval of 8.5 days from percutaneous drainage. Cholangioscopy-guided electrohydraulic lithotripsy was performed in 29 cases (56.9%), combined with a retrieval basket in eight cases (27.6%). The clinical success was 96.6%, requiring a median of one session (range 1-3). Seventeen patients (33.3%) underwent cholangioscopy-guided biopsies. There were four (7.8%) cholangioscopy-related AEs (cholangitis and peritonitis). Overall, the technical success and AE rates were 100% and 19.6%, respectively, in a median follow-up of 7 months. CONCLUSION: Percutaneous endoscopic cholangioscopy with a new short device is effective and safe, requiring a low number of sessions to achieve duct clearance or accurate histopathological diagnosis.

Feasibility and Safety of Tethered Capsule Endomicroscopy in Patients With Barrett's Esophagus in a Multi-Center Study.

BACKGROUND & AIMS: Tethered capsule endomicroscopy (TCE) involves swallowing a small tethered pill that implements optical coherence tomography (OCT) imaging, procuring high resolution images of the whole esophagus. Here, we demonstrate and evaluate the feasibility and safety of TCE and a portable OCT imaging system in patients with Barrett's esophagus (BE) in a multi-center (5-site) clinical study. METHODS: Untreated patients with BE as per endoscopic biopsy diagnosis were eligible to participate in the study. TCE procedures were performed in unsedated patients by either doctors or nurses. After the capsule was swallowed, the device continuously obtained 10-µm-resolution cross-sectional images as it traversed the esophagus. Following imaging, the device was withdrawn through mouth, and disinfected for subsequent reuse. BE lengths were compared to endoscopy findings when available. OCT-TCE images were compared to volumetric laser endomicroscopy (VLE) images from a patient who had undergone VLE on the same day as TCE. RESULTS: 147 patients with BE were enrolled across all sites. 116 swallowed the capsule (79%), 95/114 (83.3%) men and 21/33 (63.6%) women (P = .01). High-quality OCT images were obtained in 104/111 swallowers (93.7%) who completed the procedure. The average imaging duration was 5.55 ± 1.92 minutes. The mean length of esophagus imaged per patient was 21.69 ± 5.90 cm. A blinded comparison of maximum extent of BE measured by OCT-TCE and EGD showed a strong correlation (r = 0.77-0.79). OCT-TCE images were of similar quality to those obtained by OCT-VLE. CONCLUSIONS: The capabilities of TCE to be used across multiple sites, be administered to unsedated patients by either physicians or nurses who are not expert in OCT-TCE, and to rapidly and safely evaluate the microscopic structure of the esophagus make it an emerging tool for screening and surveillance of BE patients. Clinical trial registry website and trial number: NCT02994693 and NCT03459339.

Effect of Different Modalities of Purgative Preparation on the Diagnostic Yield of Small Bowel Capsule for the Exploration of Suspected Small Bowel Bleeding: A Multicenter Randomized Controlled Trial.

INTRODUCTION: The aim of our study was to compare clear liquid diet with 2 different polyethylene glycol (PEG)-based bowel preparation methods regarding diagnostic yield of small bowel capsule endoscopy (SBCE) in patients with suspected small bowel bleeding (SBB). METHODS: In this prospective multicenter randomized controlled trial, consecutive patients undergoing SBCE for suspected SBB between September 2010 and February 2016 were considered. Patients were randomly assigned to standard regimen, that is, clear fluids only (prep 1), standard regimen plus 500 mL PEG after SBCE ingestion (prep 2), or standard regimen plus 2 L PEG plus 500 mL PEG after SBCE ingestion (prep 3). The primary outcome was the detection of at least one clinically significant lesion in the small bowel. The quality of small bowel cleansing was assessed. A questionnaire on the clinical tolerance was filled by the patients. RESULTS: We analyzed 834 patients. No significant difference was observed for detection of P1 or P2 small bowel lesions between prep1 group (40.5%), prep 2 group (40.2%), and prep 3 group (38.5%). Small bowel cleansing was improved in prep 2 and 3 groups compared with that in prep 1 group. Compliance to the preparation and tolerance was better in prep 2 group than in prep 3 group. DISCUSSION: Small bowel purgative before SBCE allowed better quality of cleansing. However, it did not improve diagnostic yield of SBCE for suspected SBB.

Endoscopic sigmoidopexy for recurrent sigmoid volvulus in inoperable patients: a retrospective series of 15 patients.

BACKGROUND: Recurrent sigmoid volvulus is frequent and sometimes occurs in frail patients with contraindications to surgical sigmoidectomy. Percutaneous endoscopic sigmoidopexy (PES) has recently been proposed as an alternative to elective sigmoidectomy. We aimed to describe the efficacy and safety of PES. METHODS: All consecutive patients who underwent PES for recurrent sigmoid volvulus at two French centers between January 2017 and March 2021 were included in this retrospective case series. Recurrent sigmoid volvulus was defined as at least two symptomatic episodes treated by endoscopic decompression. Under endoscopic guidance, anchors were placed to attach the sigmoid to the anterior abdominal wall, allowing the placement of pigtail Chait catheters. RESULTS: 15 patients (60 % female; median age 74 years [range 49-96]) were included. Median number of previous sigmoid volvulus episodes was 3 (range 2-6). Procedures were technically successful with no intraprocedural adverse events for 14 patients (93 %). Peritonitis occurred at Day 2 in one patient (serious adverse event rate 7 %). Median follow-up time was 10 months (range 1-30). No sigmoid volvulus recurrence occurred during follow-up. CONCLUSION: PES using Chait catheters was feasible and effective for recurrent sigmoid volvulus and should be considered as an alternative to sigmoidectomy in inoperable patients.

Full-field optical coherence tomography: novel imaging technique for extemporaneous high-resolution analysis of mucosal architecture in human gut biopsies.

Full-field optical coherence tomography (FFOCT) is an imaging technique of biological tissue based on tissue light reflectance analysis. We evaluated the feasibility of imaging fresh digestive mucosal biopsies after a quick mounting procedure (5 min) using two distinct modalities of FFOCT. In static FFOCT mode, we gained high-resolution images of general gut tissue-specific architecture, such as oesophageal papillae, gastric pits, duodenal villi and colonic crypts. In dynamic FFOCT mode, we imaged individual epithelial cells of the mucosal lining with a cellular or subcellular resolution and identified cellular components of the lamina propria. FFOCT represents a promising dye-free imaging tool for on-site analysis of gut tissue remodelling.

Prognostic factors for stage III colon cancer in patients 80 years of age and older.

PURPOSE: Oncological strategies in the elderly population are debated. The objective of this study was to assess the factors predictive of poor prognosis in elderly patients with stage III colon cancer. METHODS: A retrospective review of demographic, pathologic, treatment, and outcome data from 308 patients with stage III colon adenocarcinoma who had undergone surgery between 2007 and 2014 was conducted. A proportional hazards model was used to assess the association of prognostic factors with disease-free survival (DFS) and overall survival (OS). RESULTS: The 5-year survival rate was 34.4% (95% CI 27.1-39.8%) and Charlson comorbidity index was a significant predictor of death (p < 0.01). The presence of perineural invasion (p = 0.03) and incomplete resection (p < 0.001) were significantly correlated with OS. The postoperative (30 days) mortality rate was 11.7%. Adjuvant chemotherapy was significantly associated with better OS (p < 0.001) independently of the regimens. Disease-free survival was significantly correlated with adjuvant chemotherapy (HR 0.63, 95% CI: 0.42-0.97, p = 0.034), Charlson comorbidity index (CCI 5; HR 1.61, 95% CI: 1.05-2.48, p = 0.029), and venous and/or perineural invasion (HR 1.54, 95% CI: 1.03-2.29, p = 0.035). CONCLUSION: Age, comorbidities, tumor histology, and adjuvant chemotherapy were independent predictors of prognosis in patients with stage III colon cancer. These data can be used to identify elderly patients with poor prognosis and to design future tailored randomized clinical trials. TRIAL REGISTRATION: ClinicalTrial.gov No. NCT04526314. Date of registration 25 August 2020.

Prevalence, Characteristics and Endoscopic Management of Gastric Premalignant Lesions in France.

INTRODUCTION: Surveillance of gastric precancerous lesions (GPL) is recommended, but the data on their clinical and endoscopic management in a "real-life" practice are limited. Our aim was to study the modalities of endoscopic management of patients with GPL in France. DESIGN: All the patients diagnosed with GPL in our center between 2000 and 2015 were grouped and analyzed according to the most severe GPL found, in the following order: atrophic gastritis only (AG), intestinal metaplasia (IM), low grade dysplasia (LGD), high grade dysplasia (HGD). RESULTS: Out of 16,764 patients having undergone upper endoscopy with gastric biopsies, 507 were identified with GPL (detection rate 3.2%). Overall, Helicobacter pylori infection was found in 41% of patients. IM was by far the most frequently found lesion (79%), followed by LGD (17%), HGD (2%), and AG only (2%). H. pylori infection rate was decreasing, while the age of the patients was increasing, together with the increasing severity of GPL (p = 0.005). Only 28% of the patients had at least one follow-up endoscopy. No correlation was found between the endoscopist's appreciation of the mucosa and histological results. CONCLUSION: In France, GPL can be expected in about 3% of patients undergoing upper endoscopy with gastric biopsies for any reason. The correlation between the endoscopic evaluation and histology is poor. Spreading of published guidelines should improve the management of patients with GPL in the future.

Quantitative assessment of mucosal architecture using computer-based analysis of confocal laser endomicroscopy in inflammatory bowel diseases.

BACKGROUND AND AIMS: Confocal laser endomicroscopy (CLE) might discriminate mucosal lesions between Crohn's disease (CD) and ulcerative colitis (UC). However, the analysis of CLE images requires time-consuming methods, a long training time, and potential impediments, such as significant interobserver variability. Therefore, we developed a computer-based method to analyze mucosal architecture from CLE images and discriminate between healthy subjects and patients with inflammatory bowel disease (IBD) as well as between UC and CD patients. METHODS: We retrospectively screened patients who had undergone CLE either for an evaluation of IBD in remission or for colorectal cancer screening (control subjects) between 2009 and 2016. We assessed 14 morphologic and functional parameters in each CLE recording from 23 CD patients, 27 UC patients, and 9 control patients. Next, we constructed 2 scores, 1 for the IBD diagnosis and 1 for the differential diagnosis between UC and CD. RESULTS: In IBD patients, the mean intercrypt distance, wall thickness, and fluorescein leakage through the colonic mucosa were significantly increased compared with control patients by 155%, 188%, and 297%, respectively (P < .05). In UC patients, the same parameters were significantly increased by 109%, 117%, and 174%, respectively (P < .05), compared with CD patients. IBD diagnosis had 100% (95%CI, 93%; 100%) sensitivity and 100% (95%CI, 66%; 100%) specificity. IBD differential diagnosis provided discrimination of UC from CD patients with 92% (95%CI, 75%; 99%) sensitivity and 91% (95%CI, 72%; 99%) specificity. CONCLUSIONS: Confirming these results using prospective validation cohorts can substantiate that computer-based analysis of CLE images may provide new biomarkers for the diagnosis and characterization of IBD.

Anterograde colonic irrigations by percutaneous endoscopic caecostomy in refractory colorectal functional disorders.

PURPOSE: In case reports or small studies, percutaneous endoscopic caecostomy (PEC) has been proposed as an alternative to the Malone intervention to perform antegrade colonic enemas. Our goal was to assess the feasibility, efficacy, and tolerance of PEC in a large group of patients with refractory colorectal functional disorders. METHODS: From September 2006 to April 2014, all patients undergoing PEC for constipation, fecal incontinence, and incontinence after rectal resection in two expert centers were studied. The PEC procedure consisted in anchoring the caecum to the abdominal wall (caecopexy) and placing a specifically designed tube in the colonic lumen to perform antegrade enemas. The quality of life (GIQLI), constipation (Kess), and incontinence (Cleveland) scores were assessed before PEC and at 3, 6, 12, and 24 months. RESULTS: A total of 69 patients were included. GIQLI scores were significantly improved in constipation group (n = 43), incontinence group (n = 19), and rectal resection group (n = 10). In the constipation group, Kess score decreased from 25.9 before PEC to 20.6 at 2 years (p = 0.01). In the incontinence and post-rectal resection groups, Cleveland scores decreased from 14.3 before PEC to 2.7 at 6 months (p = 0.01) and to 10.4 at 2 years (p = 0.04). Overall, PEC was considered successful by patients in 58%, 74%, and 90% of cases, in constipation, incontinence, and rectal resection groups, respectively. Chronic pain (52%) at the catheter site was the most frequent complication. CONCLUSIONS: Percutaneous endoscopic caecostomy for antegrade colonic enemas improves significantly the quality of life of patients with colorectal disorder refractory to medical treatment.

Tethered capsule endomicroscopy for microscopic imaging of the esophagus, stomach, and duodenum without sedation in humans (with video).

BACKGROUND AND AIMS: Patients with many different digestive diseases undergo repeated EGDs throughout their lives. Tethered capsule endomicroscopy (TCE) is a less-invasive method for obtaining high-resolution images of the GI mucosa for diagnosis and treatment planning of GI tract diseases. In this article, we present our results from a single-center study aimed at testing the safety and feasibility of TCE for imaging the esophagus, stomach, and duodenum. METHODS: After being swallowed by a participant without sedation, the tethered capsule obtains cross-sectional, 10 µm-resolution, optical coherence tomography images as the device traverses the alimentary tract. After imaging, the device is withdrawn through the mouth, disinfected, and reused. Safety and feasibility of TCE were tested, focusing on imaging the esophagus of healthy volunteers and patients with Barrett's esophagus (BE) and the duodenum of healthy volunteers. Images were compared with endoscopy and histopathology findings when available. RESULTS: Thirty-eight patients were enrolled. No adverse effects were reported. The TCE device swallowing rate was 34 of 38 (89%). The appearance of a physiologic upper GI wall, including its microscopic pathology, was visualized with a tissue coverage of 85.4% ± 14.9% and 90.3% ± 6.8% in the esophagus of BE patients with and without endoscopic evidence of a hiatal hernia, respectively, as well as 84.8% ± 7.4% in the duodenum. A blinded comparison of TCE and endoscopic BE measurements showed a strong to very strong correlation (r = 0.7-0.83; P < .05) for circumferential extent and a strong correlation (r = 0.77-0.78; P < .01) for maximum extent (Prague classification). TCE interobserver correlation was very strong, at r = 0.92 and r = 0.84 (P < .01), for Prague classification circumferential (C) and maximal (M) length measurements, respectively. CONCLUSIONS: TCE is a safe and feasible procedure for obtaining high-resolution microscopic images of the upper GI tract without endoscopic assistance or sedation.

Curative criteria for endoscopic treatment of colorectal cancer.

As endoscopic treatment enables en bloc resection of T1 colorectal cancers, the risk of recurrence, often assimilated to the risk of lymph node metastases, must be assessed in order to offer patients an additional treatment if this risk is deemed significant. The curative criteria currently used by most guidelines are depth of invasion <1 mm, well or moderately differentiated tumour, absence of lympho-vascular invasion, absence of significant budding and tumour-free resection margins. However, these factors must be assessed by qualified pathologists, as they are difficult to evaluate. Moreover, the combination of these factors leads to unnecessary surgery in over 80 % of patients whose tumours are classified as high risk. Refinement of current criteria and research into new tumour and immunological markers are needed to better predict the actual risk of our patients.

Confocal laser endomicroscopy as predictive biomarker of clinical and endoscopic efficacy of vedolizumab in ulcerative colitis: The DETECT study.

AIMS: In patients with ulcerative colitis (UC), no biomarker is available to help the physician to choose the most suitable biotherapy. The primary objective of this pilot study was to assess the feasibility of identification of α4ß7- and TNF-expressing cells, to predict the response to vedolizumab using confocal laser endoscopy (CLE). METHODS: Patients with moderate-to-severe UC, naïve of biotherapy, received vedolizumab. Clinical evaluation was performed at each infusion. Endoscopic evaluation was performed before inclusion and at week 22. Fresh colonic biopsies were stained using FITC-labelled vedolizumab and Alexa fluor-labelled adalimumab and ex vivo dual-band CLE images were acquired. Blood samples were collected to measure trough concentrations of vedolizumab and to determine absolute counts of T and B cells subpopulations, NK cells and monocytes. RESULTS: Nineteen patients were enrolled in the study and received at least one dose of vedolizumab. Clinical remission and endoscopic improvement were observed in 58% of whom 5 patients (45%) had an endoscopic subscore of 0. In terms of clinical response and remission, endoscopic improvement and histologic response, FITC-conjugated vedolizumab staining tended to be higher in responder patients compared to non-responders at week 22. A threshold value of 6 positive FITC-vedolizumab staining areas detected by CLE seemed informative to discriminate the responders and non-responders. The results were similar in terms of clinical remission and endoscopic improvement with a sensitivity of 78% and a specificity of 85% (p = 0.05). Trough concentrations and blood immune cells were not associated with responses to vedolizumab. CONCLUSION: This pilot study demonstrate that dual-band CLE is feasible to detect α4ß7- and TNF-expressing cells. Positive α4ß7 staining seems to be associated with clinical and endoscopic remission in UC patients treated by anti-α4ß7-integrin, subject to validation by larger-scale studies. Clinical-trial.gov: NCT02878083.