INTRODUCTION:The identification of risk factors for precursor lesions of colorectal cancer (CRC) holds great promise in the context of prevention. With this study, we aimed to identify patient characteristics associated with colorectal polyps (CPs) and polyp features of potential malignant progression. Furthermore, a potential association with gut microbiota in this context was investigated. METHODS:In this single-center study, a total of 162 patients with CPs and 91 control patients were included. Multiple variables including information on lifestyle, diet, serum parameters, and gut microbiota, analyzed by 16S-rRNA gene amplicon sequencing and functional imputations (Picrust2), were related to different aspects of CPs. RESULTS:We observed that elevated serum alkaline phosphatase (AP) levels were significantly associated with the presence of high-grade dysplastic polyps. This association was further seen for patients with CRC. Thereby, AP correlated with other parameters of liver function. We did not observe significant changes in the gut microbiota between patients with CP and their respective controls. However, a trend toward a lower alpha-diversity was seen in patients with CRC. Interestingly, AP was identified as a possible clinical effect modifier of stool sample beta diversity. DISCUSSION:We show for the first time an increased AP in premalignant CP. Furthermore, AP showed a significant influence on the microbial composition of the intestine. Relatively elevated liver enzymes, especially AP, may contribute to the detection of precancerous dysplastic or neoplastic changes in colorectal lesions. The association between elevated AP, premalignant CP, and the microbiome merits further study.

Background:While artificial intelligence (AI) shows high potential in decision support for diagnostic gastrointestinal endoscopy, its role in therapeutic endoscopy remains unclear. Third-space endoscopic procedures pose the risk of intraprocedural bleeding. Therefore, we aimed to develop an AI algorithm for intraprocedural blood vessel detection. Methods:Using a test dataset of 101 standardized video clips containing 200 predefined submucosal blood vessels, 19 endoscopists were evaluated for vessel detection rate (VDR) and time (VDT) with and without support of an AI algorithm. Endoscopists were grouped according to experience in endoscopic submucosal dissection. Results:With AI support, endoscopist VDR increased from 56.4% (95%CI CI 54.1–58.6) to 72.4% (95%CI CI 70.3–74.4). Endoscopist VDT dropped from 6.7 seconds (95%CI 6.2–7.1) to 5.2 seconds (95%CI 4.8–5.7). False-positive readings appeared in 4.5% of frames and were marked for a significantly shorter time than true positives (0.7 seconds [95%CI 0.55–0.87] vs. 6.0 seconds [95%CI 5.28–6.70]). Conclusions:AI improved the VDR and VDT of endoscopists during third-space endoscopy. While these data need to be corroborated by clinical trials, AI may prove to be an invaluable tool for improving safety and speed of endoscopic interventions.

Background and study aims: While artificial intelligence (AI) shows high potential in decision support for diagnostic gastrointestinal endoscopy, its role in therapeutic endoscopy remains unclear. Third space endoscopic procedures pose the risk of intraprocedural bleeding. Therefore, we aimed to develop an AI algorithm for intraprocedural blood vessel detection. Patients and Methods: Using a test dataset with 101 standardized video clips containing 200 predefined submucosal blood vessels, 19 endoscopists were evaluated for the vessel detection rate (VDR) and time (VDT) with and without support of an AI algorithm. Test subjects were grouped according to experience in ESD. Results: With AI support, endoscopists VDR increased from 56.4% [CI 54.1–58.6] to 72.4% [CI 70.3–74.4]. Endoscopists‘ VDT dropped from 6.7sec [CI 6.2-7.1] to 5.2sec [CI 4.8-5.7]. False positive (FP) readings appeared in 4.5% of frames and were marked significantly shorter than true positives (6.0sec [CI 5.28-6.70] vs. 0.7sec [CI 0.55-0.87]). Conclusions: AI improved the vessel detection rate and time of endoscopists during third space endoscopy. While these data need to be corroborated by clinical trials, AI may prove to be an invaluable tool for the improvement of endoscopic interventions.

BACKGROUND:Prophylactic application of a haemostatic gel to the resection field may be an easy way to prevent delayed bleeding, a frequent complication after endoscopic mucosal resection (EMR). OBJECTIVE:We aimed to evaluate if the prophylactic application of a haemostatic gel to the resection field directly after EMR can reduce the rate of clinically significant delayed bleeding events. DESIGN:We conducted a prospective randomised trial of patients undergoing hot-snare EMR of flat lesions in the duodenum (≥10 mm) and colorectum (≥20 mm) at 15 German centres. Prophylactic clip closure was not allowed, but selective clipping or coagulation could be used prior to randomisation to treat intraprocedural bleeding or for prophylactic closure of visible vessels. Patients were randomised to haemostatic gel application or no prophylaxis. The primary endpoint was delayed bleeding within 30 days. RESULTS:The trial was stopped early due to futility after an interim analysis. The primary endpoint was analysed in 232 patients (208 colorectal, 26 duodenal). Both groups were comparable in age, sex, comorbidities and lesion characteristics. Preventive measures, such as selective clipping or coagulation, were applied prior to randomisation in 51.9% of cases, with no difference between groups. Delayed bleeding occurred in 14 cases (11.7%; 95% CI 7.1% to 18.6%) after Purastat and in 7 cases (6.3%; 95% CI 3.1% to 12.3%) in the control group (p=0.227), with no difference between colorectal and duodenal subgroups. CONCLUSION:The application of a haemostatic gel following EMR of large flat lesions in the duodenum and colorectum does not reduce the rate of delayed bleeding.

Aims Endoscopic submucosal dissection (ESD) carries the risk of delayed bleeding. A novel self-assembling peptide (SAP) for hemostasis has shown promising results in reducing this risk after endoscopic resection, but there is only little data for the use after ESD. This retrospective trial aimed to compare the delayed bleeding rate (DBR) after ESD with and without application of a novel self-assembling peptide.

Background and AimsEndosonographic-guided gastroenterostomy (EUS-GE) is a novel technique to manage symptoms of gastric outlet obstruction. Major challenges are the high mobility of intestinal loops and the transient loss of endosonographic visibility during the puncture. This can lead to stent-misdeployment, which can be associated with potentially fatal adverse events. By injecting contrast medium through the guidewire-channel of the lumen apposing metal stent (LAMS) application system under fluoroscopic guidance, a positive enterogram can confirm the position of the stent inside the intestinal lumen before its deployment. The aim of this study was to describe this novel technique and to assess its feasibility.MethodsThe data of 39 consecutive patients undergoing EUS-GE with “through-stent-enterography” between July 2020 and March 2022 were retrospectively collected and analyzed. Primary endpoint was to assess the technical success. Secondary endpoints were to assess adverse events, rate of reinterventions and clinical success.ResultsTechnical success was achieved in all cases (n=39). In two cases a second puncture was required to place the stent successfully. In one case, misdeployment could be avoided after a negative enterogram. In the other case, misdeployment occurred despite a positive enterogram a reintervention was needed. Clinical success was achieved in 92.3% (n=36). No major adverse events or mortalities were encountered.Conclusions“Through-stent-enterography” after the puncture to confirm the correct position of the stent in the small bowel is a novel and simple technique, which can potentially reduce the risk of misdepolyment of the stent.

Background and study aims The prognosis for pancreatic cancer remains poor. Molecular diagnostics and customized therapies are becoming increasingly important in clinical routine. Patient-derived, predictive model systems such as organoids have the potential to substantially increase the depth of information from biopsy material by functional and molecular characterization. We compared the extent to which the use of fine-needle aspiration needles (FNA, 22G) or fine-needle biopsy needles (FNB, 22G) influences the generation of pancreatic cancer patient-derived organoids (PDOs) to establish endoscopic standards of organoid technology. Patients and methods Endoscopic ultrasound (EUS)-guided punctures by EUS-FNA and EUS-FNB of pancreatic masses highly suspicious for adenocarcinoma (detected by computed tomography and/or magnetic resonance imaging) were prospectively evaluated. Consecutive patients received EUS-FNA and EUS-FNB in a randomized order without the need to exchange the needle shaft (only the inner needle type (FNA/-B) was exchanged) between the passes. With each needle type, the specimens for histological analysis and for PDOs were obtained separately. Results Fifty patients were enrolled in the study. Histology revealed malignancy in 42 of 50 cases (84%). In total PDOs were generated from 17 patients (34%). Of these, nine were established by FNB only, two by FNA only, and six by both FNA and FNB. Histology revealed malignancy in 13 of 17 PDO cases (76%). In two histologically false-negative cases, PDOs could be established. Conclusions EUS-FNB was superior to EUS-FNA in terms of successful generation of PDOs, although it failed to show statistical significance.

Abstract Background Development of esophageal strictures is common after the total laryngectomy of head and neck cancer patients. While endoscopic techniques like dilatation by balloon or Salvary bougies are well established, risk factors and pathophysiology for development of refractory strictures are less well understood. Objective To evaluate risk factors associated with occurrence and recurrence of total-laryngectomy-associated esophageal strictures in head and neck cancer patients. Methods We analyzed retrospectively a cohort of 170 head and neck squamous cell carcinoma patients, who underwent total laryngectomy between 2007 and 2017. The outcome measure was laryngectomy-associated proximal esophageal stricture needing an endoscopic dilatation by using a balloon or Savary dilators. Results Of the 170 patients in the cohort, 32 (18.8%) developed strictures. Mean time between surgery and first endoscopic intervention was 24.4 months. Significant predictive factors were age ≥ 65 (p=0.017), nodal status N> 1 (p=0.003), continued alcohol abuse after surgery (p=0.005) and diabetes mellitus (p=0.005). In a subgroup, 17 of 32 patients developed refractory strictures and needed more than three dilatations to relieve dysphagia. Postoperative mean (p=0.016) and maximum (p=0.015) C-reactive protein (CRP) were predictive for refractory strictures. Conclusion Symptomatic strictures occurred in 18.8% of the cases. Age, nodal status N>1, continued alcohol abuse and diabetes mellitus were predictive factors. For refractory stenosis (>3 dilatations needed) mean and maximum postoperative CRP were predictive. This may indicate that systemic inflammatory response post-surgery is involved in the stricture formation process.

Background Risk stratification and recommendation for surgery for intraductal papillary mucinous neoplasm (IPMN) are currently based on consensus guidelines. Risk stratification from presurgery histology is only potentially decisive owing to the low sensitivity of fine-needle aspiration. In this study, we developed and validated a deep learning-based method to distinguish between IPMN with low grade dysplasia and IPMN with high grade dysplasia/invasive carcinoma using endoscopic ultrasound (EUS) images. Methods For model training, we acquired a total of 3355 EUS images from 43 patients who underwent pancreatectomy from March 2015 to August 2021. All patients had histologically proven IPMN. We used transfer learning to fine-tune a convolutional neural network and to classify “low grade IPMN” from “high grade IPMN/invasive carcinoma.” Our test set consisted of 1823 images from 27 patients, recruiting 11 patients retrospectively, 7 patients prospectively, and 9 patients externally. We compared our results with the prediction based on international consensus guidelines. Results Our approach could classify low grade from high grade/invasive carcinoma in the test set with an accuracy of 99.6 % (95 %CI 99.5 %–99.9 %). Our deep learning model achieved superior accuracy in prediction of the histological outcome compared with any individual guideline, which have accuracies between 51.8 % (95 %CI 31.9 %–71.3 %) and 70.4 % (95 %CI 49.8–86.2). Conclusion This pilot study demonstrated that deep learning in IPMN-EUS images can predict the histological outcome with high accuracy.

Introduction: Cold snare polypectomy (CSP) is a safe and effective procedure for small colorectal polyps ≤9 mm. There are only limited data regarding CSP of larger neoplastic lesions. This study evaluated the efficacy and safety of CSP for polyps between 10 and 15 mm in size. Methods: In this prospective single-arm observational pilot study, patients with a least one polyp 10–15 mm were included. These polyps were preferably removed by CSP using a dedicated hybrid snare. The primary outcome was the histological complete resection rate (CRR) determined by pathologically negative margins of the specimen and no neoplastic tissue obtained from biopsies of the resection site margin. Secondary outcomes were en bloc resection rate, failure of CSP, and incidence of adverse events. Results: A total of 61 neoplastic polyps were removed from 39 patients. Overall CRR was 80.3% (49/61). CSP was feasible in 78.7% (48/61) of polyps and the CRR in this group was 85.4% (41/48). When CSP failed (13/61; 21.3%), lesions were successfully resected by immediate HSP using the same snare with a CRR of 61.5% (8/13) in this group. One patient presented delayed hemorrhage after HSP of a polyp but successful hemostasis was achieved with two hemoclips. No other adverse events occurred. No recurrence was seen on follow-up colonoscopy in cases with incomplete resected polyps. Conclusion: CSP seems to be efficient and safe in removing colorectal polyps up to 15 mm. A hybrid snare seems to be particularly advantageous for these polyps as it allows immediate conversion to HSP if CSP might fail in larger polyps. This trial is registered at ClinicalTrials.gov (NCT04464837).

Primary hyperparathyroidism caused by parathyroid adenoma requires surgical resection. To confine the extent of surgery to the very minimum and to exclude an atypical adenoma location, preoperative imaging aims at identifying the suspicious gland. For this purpose, Technetium-99m (99mTc)-sestamibi scintigraphy and SPECT have become the international imaging standard, in inconclusive cases also with C-11 methionine and F-18 choline PET/CT. We present a case of surgery for an ectopic retroesophageal adenoma resected under gamma probe guidance after preoperative radioactive targeting. A 73-year-old patient, who was diagnosed with primary hyperparathyroidism, presented to our outpatient clinic. The patient was symptom-free, but during a routine check-up, parathormone levels of 127 pg/ml (normal range 15-65) were detected. Parathyroid MIBI scintigraphy, including SPECT/CT, failed to locate an adenoma. Therefore, a PET/MRI scan with 164 MBq F-18 choline was applied and a single parathyroid adenoma was detected in a very untypical retroesophageal and prevertebral position, respectively. Due to its esophageal proximity and to enable a very confined surgery, endosonography was performed and the adenoma was transesophageally injected with 75 MBq 99mTc-human serum albumin (HSA). The next day gamma probe-guided minimally invasive resection was performed without any intra- or postoperative complications. Minimally invasive resection of parathyroid adenomas should be the standard but may be difficult in deep collar and atypical locations. Marking the adenoma with a radioactive nanocolloid tracer for gamma probe-guided surgery can be considered an innovative approach to maintain minimal invasive therapy for ectopic adenomas.

Background Malignant tumors of the esophagus are the sixth leading cause of cancer-related deaths worldwide. Postoperative leakage of the esophago-gastrostomy leads to mediastinal sepsis, which is still associated with a high morbidity and mortality rate. The aim of this study was to describe the endoscopic view of the different severity grades of an anastomotic leakage. MethodsPatients Between June 2016 and September 2018, 144 patients were operated upon in the Department of Surgery, University of Munich, Germany. Among these patients, 34 (23.6%) presented with a leakage of the anastomosis. EndoscopyIn this retrospective analysis the focus is to describe different patterns of leakage of the anastomosis.Results We studied 34 patients in whom post-esophagectomy leakage of the anastomosis was detected and treated with an endoluminal vacuum sponge system. The leakage healed in 26 of 29 patients (success rate 89.7%). With increasing severity of leakage, the treatment time and the in-hospital mortality correspondingly increased. Furthermore, the incidence of development of a fistula to the tracheobronchial system increased with higher grades of leakage.ConclusionsExact descriptions of leakage are necessary to compare the cases and to prove post-treatment improvement. This is, to our knowledge, the first publication to present a leakage grading score in patients after esophagectomy including reconstruction with a gastric tube. This new grading system needs to be tested in further analyses, with special focus on prospective analysis.

Background and goals Risk stratification for the need for therapeutic endoscopy and prediction of mortality in patients with upper gastrointestinal bleeding (UGIB) can be assessed by several scores. However, current scores are not validated for variceal bleeding and Intensive Care Unit (ICU) patients. The aim of this study was to evaluate potential parameters for the prediction of UGIB and patient outcomes. Patients and study methods In this monocenter retrospective observational study, data from all esophagogastroduodenoscopies (EGD) between November 2014 and February 2020 with suspected hemorrhage in our ICU were evaluated. Results Out of 345 included EGD, 42.3% of UGIB was diagnosed. 51.9% needed endoscopic intervention. Overall, 52.3% of included patients with UGIB died. Logistic regression showed that preceding variceal or non-variceal UGIB (p < .001), serum lactate (p = .001), heart rate (HR) (p = .005), and blood transfusions (p = .001) were significant predictors of UGIB. Previous UGIB (p < .001), male sex (p = .015), known varices (p < .001), serum albumin (p = .19) and use of catecholamines (p = .040) were significant predictors for the need of endoscopic intervention. Higher mortality was significantly associated with the usage of steroids (p < .001), malignant preconditions (p = .021), serum albumin (p = .020) and prolonged PTT (partial thromboplastin time) (p = .001). Conclusions We were able to identify additional parameters that had previously not been included in existing scores to predict the risk of UGIB, the need for therapeutic endoscopy and mortality in ICU patients. Therefore, an extension of these scores is necessary. Further validation of identified parameters in multicenter trials is needed to improve risk scores for ICU patients.

Background and study aims Endoscopic ultrasound-guided gastroenterostomy (EUS-GE) with lumen-apposing metal stents (LAMS) appears to be a promising intervention in management of gastroduodenal out obstruction (GOO), particularly for patients for whom surgery is high risk or in a palliative setting. This study aimed to evaluate the technical feasibility, procedure-associated adverse events (AEs), and clinical outcome of direct “free hand” EUS-GE. Patients and methods This retrospective two-center study included patients who underwent direct “free hand” EUS-GE (April 2017 to March 2021) investigating technical success (correctly placed LAMS), clinical outcome (successful oral nutrition), and management of procedure-associated AEs. “Free hand” was defined as the use of the electrocautery enhanced stent delivery system alone without additional guidewire-assistance for EUS-GE creation. Results Forty-five patients (58 % women/42 % men; mean age 65 years) with malignant (n = 39), benign (n = 4) or unclear (n = 2) GOO underwent direct “free hand” EUS-GE. The technical success rate was 98 % (44/45). Of the patients, 95% (42/44) had less vomiting and increased ability to tolerate oral food intake after the intervention. In one patient, a second EUS-GE was necessary to achieve sufficient clinical improvement. Procedure-associated AEs were observed in 24 % (11/45) of cases including stent misplacement (n = 7), leakage (n = 1), development of a gastrojejunocolic fistula (n = 1), and bleeding (n = 2), which could be all managed endoscopically. Conclusions Direct EUS-GE has a favorable risk-benefit profile for patients with GOO, showing high technical success rates, manageable AEs, and rapid symptom relief.

Background and Aims: Direct endoscopic necrosectomy (DEN) of walled-off pancreatic necrosis (WOPN) lacks dedicated instruments and requires repetitive and cumbersome procedures. This study evaluated the safety and efficacy of a new powered endoscopic debridement (PED) system designed to simultaneously resect and remove solid debris within WOPN. Methods: This was a single-arm, prospective, multicenter, international device trial conducted from November 2018 to August 2019 at 10 sites. Patients with WOPN >= 6 cm and <= 22 cm and with >30% solid debris were enrolled. The primary endpoint was safety through 21 days after the last DEN procedure. Efficacy outcomes included clearance of necrosis, procedural time, adequacy of debridement, number of procedures until resolution, hospital stay duration, and quality of life. Results: Thirty patients (mean age, 55 years; 60% men) underwent DEN with no device-related adverse events. Of 30 patients, 15 (50%) achieved complete debridement in 1 session and 20 (67%) achieved complete debridement within 2 or fewer sessions. A median of 1.5 interventions (range, 1-7) were required. Median hospital stay was 10 days (interquartile range, 22). There was an overall reduction of 91% in percent necrosis within WOPN from baseline to follow-up and 85% in collection volume. Baseline WOPN volume was positively correlated with the total number of interventions (rho = .363, P = .049). Conclusions: The new PED system seems to be a safe and effective treatment tool for WOPN, resulting in fewer interventions and lower hospital duration when compared with published data on using conventional instruments. Randomized controlled trials comparing the PED system with conventional DEN are needed.

Cold Snare Polypectomy (CSP) has been gaining interest in recent years and is already an integral part of guidelines for polyps <10mm in size. In contrast to hot snare polypectomy (HSP), CSP doesn’t involve electrocautery and less adverse events (AE) with comparable resection rates have been shown. However, little is known about the feasibility of CSP for colorectal polyps of 10 to 15 mm. Therefore, this study evaluates the efficacy and safety of CSP for these polyps.