Influence of Artificial Intelligence on the Adenoma Detection Rate throughout the Day.

BACKGROUND: Artificial intelligence systems recently demonstrated an increase in polyp and adenoma detection rate. Over the daytime, the adenoma detection rate decreases as tiredness leads to a lack of attention. It is not clear if a polyp detection system with artificial intelligence leads to constant adenoma detection over the day. METHODS: We performed a database analysis of screening and surveillance colonoscopies with and without the use of AI. In both groups, patients were investigated with the same endoscopy equipment and by the same endoscopists. Only patients with good bowel preparation (BBPS >6) were included. We correlated the daytime, the investigational time, day of the week, and the adenoma and polyp detection. RESULTS: A total of 303 colonoscopies were analyzed. 163 endoscopies in the AI+ group and 140 procedures in the AI- group were included. In both groups, the total adenoma detection rate was equal (AI+ 0.39 vs. AI- 0.43). The adenoma detection rate throughout the day had a significant decreasing trend in the group without the use of AI (p = 0.015), whereas this trend was not present in the investigations that have been performed with AI (p = 0.65). The duration of investigation did not show a significant difference between the groups (8.9 min in both groups). No relevant effect was noticed in adenoma detection between single days of the working week with or without the use of AI. CONCLUSION: AI helps overcome the decay in adenoma detection over the daytime. This may be attributed to a constant awareness caused by the use of the AI system.

Whipple's Disease - delay of diagnosis by immunosuppressive therapy; a case-series report.

BACKGROUND: Risk factors for the development of Whipple's disease (WD) are largely unknown. Case reports, case series, and reviews suggest immunosuppressive therapy as a potential triggering factor in WD. The low incidence of WD and non-specific symptoms at disease onset contribute to the frequent delay of diagnosis. We describe our centre´s experience on differences in the clinical presentation of patients with classic WD compared to patients with "masked" WD because of immunosuppressive therapy. METHODS: In this retrospective case series, 8 patients were included. Diagnosis of WD was confirmed by histological staining of duodenal biopsies revealing T. whipplei within foamy macrophages or by PCR- based detection of specific T. whipplei DNA. Clinical manifestations, laboratory data, and medication have been recorded over a period of 19 years. Subgroup analyses for the two different variants of WD were performed. RESULTS: Seven of eight patients were initially diagnosed with rheumatic disease (polyarthritis, polymyalgia rheumatica). One patient was correctly diagnosed at the beginning without any medication. Three patients were on immunosuppressive therapy and being treated with disease-modifying drugs (DMARDs), three patients were receiving low-dose cortisone in combination with non-steroidal anti- inflammatory drugs (NSAIDs), and one patient was receiving NSAIDs only. All patients presented with increased parameters of inflammation and with clinical and/or laboratory signs of a malabsorption. From the onset of first symptoms, diagnosis of WD took a median of 36 months (range: 6-120 months). The time between onset of joint complaints and onset of gastrointestinal symptoms was 36 months (range: 0-117 months). WD patients receiving immunosuppressive therapy, compared to those not receiving it, had a longer duration of gastrointestinal symptoms (12 months versus 6 months) and reported a greater weight loss (20,3 kg versus 7,8 kg) up to diagnosis of WD. CONCLUSIONS: Immunosuppressive drugs may delay the diagnosis of WD and prolong the course of T. whipplei infection with deterioration of clinical symptoms. If a patient with rheumatic complaints develops gastrointestinal symptoms, diagnosis of WD should be considered and proper diagnostic investigation carried out.

Performance of a new integrated computer-assisted system (CADe/CADx) for detection and characterization of colorectal neoplasia.

BACKGROUND: Use of artificial intelligence may increase detection of colorectal neoplasia at colonoscopy by improving lesion recognition (CADe) and reduce pathology costs by improving optical diagnosis (CADx). METHODS: A multicenter library of ≥ 200 000 images from 1572 polyps was used to train a combined CADe/CADx system. System testing was performed on two independent image sets (CADe: 446 with polyps, 234 without; CADx: 267) from 234 polyps, which were also evaluated by six endoscopists (three experts, three non-experts). RESULTS: CADe showed sensitivity, specificity, and accuracy of 92.9 %, 90.6 %, and 91.7 %, respectively. Experts showed significantly higher accuracy and specificity, and similar sensitivity, while non-experts + CADe showed comparable sensitivity but lower specificity and accuracy than CADe and experts. CADx showed sensitivity, specificity, and accuracy of 85.0 %, 79.4 %, and 83.6 %, respectively. Experts showed comparable performance, whereas non-experts + CADx showed comparable accuracy but lower specificity than CADx and experts. CONCLUSIONS: The high accuracy shown by CADe and CADx was similar to that of experts, supporting further evaluation in a clinical setting. When using CAD, non-experts achieved a similar performance to experts, with suboptimal specificity.

Can a Polyp Detection and Characterization System Predict Complete Resection?

INTRODUCTION: Artificial Intelligence (AI) is one of the most evolving fields in endoscopy. We aimed to test if a system for polyp detection and polyp characterization can be used to predict complete endoscopic resection of colon adenomas. METHODS: We used the CAD-Eye AI system (Fujifilm Europe) in consecutive patients who received polypectomy using a cold snare. After resection, the submucosal space was flushed with water using an irrigation pump. Images were obtained using the CAD Eye system, and the characterization of the system was noted and afterward compared to histology of the removed specimen. RESULTS: In total, 17 polypectomies were observed, and in no case the AI was able to give information about resection status. First, the resection plane itself was classified as being adenomatous in all cases, while, second, all adenomas were resected completely, thus harboring no potential for overlying misinterpretations in the images. CONCLUSION: An AI system trained to characterize polyps in healthy surrounding colorectal mucosa cannot predict the state of resection after removal of the adenoma. This is explained by the training and programming. Endoscopists using AI from now on should learn about the basics of AI and the pitfalls in interpreting results from AI.

Biopsy Sampling in Upper Gastrointestinal Endoscopy: A Survey from 10 Tertiary Referral Centres Across Europe.

BACKGROUND: Guidelines give robust recommendations on which biopsies should be taken when there is endoscopic suggestion of gastric inflammation. Adherence to these guidelines often seems arbitrary. This study aimed to give an overview on current practice in tertiary referral centres across Europe. METHODS: Data were collected at 10 tertiary referral centres. Demographic data, the indication for each procedure, endoscopic findings, and the number and sampling site of biopsies were recorded. Findings were compared between centres, and factors influencing the decision to take biopsies were explored. RESULTS: Biopsies were taken in 56.6% of 9,425 procedures, with significant variation between centres (p < 0.001). Gastric biopsies were taken in 43.8% of all procedures. Sampling location varied with the procedure indication (p < 0.001) without consistent pattern across the centres. Fewer biopsies were taken in centres which routinely applied the updated Sydney classification for gastritis assessment (46.0%), compared to centres where this was done only upon request (75.3%, p < 0.001). This was the same for centres stratifying patients according to the OLGA system (51.8 vs. 73.0%, p < 0.001). More biopsies were taken in centres following the MAPS guidelines on stomach surveillance (68.1 vs. 37.1%, p < 0.001). Biopsy sampling was more likely in younger patients in 8 centres (p < 0.05), but this was not true for the whole cohort (p = 0.537). The percentage of procedures with biopsies correlated directly with additional costs charged in case of biopsies (r = 0.709, p = 0.022). CONCLUSION: Adherence to guideline recommendations for biopsy sampling at gastroscopy was inconsistent across the participating centres. Our data suggest that centre-specific policies are applied instead.

Blue Light Imaging and Linked Color Imaging for the Characterization of Mucosal Changes in Chronic Gastritis: A Clinicians View and Brief Technical Report.

BACKGROUND: Blue light imaging (BLI) and linked color imaging (LCI) are new imaging modalities for the endoscopic evaluation of mucosal changes within the digestive tract. There is little experience with these modalities in the characterization of chronic gastritis (CG) intestinal metaplasia (IM) and atrophy in the stomach. AIMS AND METHODS: In a single-center observational pilot study, we correlated endoscopic findings with histology in selected patients. RESULTS: Findings from 29 patients were included in the analysis. Six patients had macroscopically normal gastric mucosa at endoscopy, and this was confirmed histologically in 5 of them. At endoscopy, 15 patients had the presence of IM in the antrum predicted, and this was confirmed histologically in 11 (73%). In the corpus, we predicted the presence of IM in 14 patients, and this was confirmed in 11 (78%) at histology. Eleven patients had the endoscopic suspicion of atrophy in antrum, which was confirmed in 9 patients (82%). In total, 14 patients had endoscopic suspicion of atrophy in corpus mucosa at endoscopy, but only 10 were confirmed in histology (71%). The concordance of endoscopic classification and histology was 93% for antrum and 88% for corpus. The positive predictive value and negative predictive value for IM were 0.74 and 0.83 and for atrophy 0.63 and 0.97, respectively. CONCLUSIONS: LCI and BLI are helpful in characterization of mucosal changes in CG. The ability to rule out premalignant conditions by endoscopy only reflects the clinical use and harbors significant clinical implications.

Combined Gastric and Colorectal Cancer Screening-A New Strategy.

BACKGROUND: Our aim was to evaluate the feasibility of a serological assessment of gastric cancer risk in patients undergoing colonoscopy in countries with low-to-moderate incidence rates. METHODS: Serum samples were prospectively collected from 453 patients (>50 years old) undergoing colonoscopies. Of these, 279 (61.6%) also underwent gastroscopy to correlate the results for serum pepsinogen I and II (sPG-I and sPG-II), sPG-I/II ratio, and anti-H. pylori antibodies with gastric histopathology findings (graded according to the updated Sydney classification and the Operative Link of Gastritis Assessment (OLGA) and the Operative Link for Gastric Intestinal Metaplasia assessment (OLGIM) systems). RESULTS: H. pylori was found in 85 patients (30.5%). Chronic atrophic gastritis was diagnosed in 89 (31.9%) patients. High-risk OLGA (III⁻IV) stages were present in 24 patients, and high-risk OLGIM stages were present in 14 patients. There was an inverse correlation of sPG-I with the degree of atrophy and intestinal metaplasia (IM), as well as with the respective OLGA (r = -0.425; p < 0.001) and OLGIM (r = -0.303; p < 0.001) stages. A pathological sPG-I result was associated with a relative risk (RR) of 12.2 (95% confidence interval: 6.29⁻23.54; p < 0.001) for gastric preneoplastic changes. CONCLUSIONS: The assessment of serum pepsinogen allows the identification of patients at increased risk of gastric cancer. A prevention strategy of combining a screening colonoscopy with a serological screening for preneoplastic gastric changes should be considered in the general population.

Correlation of High-Resolution Manometric Findings with Symptoms of Dysphagia and Endoscopic Features in Adults with Eosinophilic Esophagitis.

BACKGROUND: Eosinophilic esophagitis (EoE) presents with dysphagia, but data about motility patterns using high-resolution manometry (HRM) are rare. We aimed at evaluating esophageal motility patterns in EoE and their correlation to endoscopic and dysphagia scores. METHODS: Twenty-six EoE patients and 23 controls were included after 4 weeks of treatment with proton pump inhibitors. Dysphagia and endoscopic scores were evaluated before performing HRM. EoE patients were classified to have fibrostenotic (FS) or inflammatory (IF) type. HRM analysis was performed according to the Chicago classification (CC) system. RESULTS: According to the CC, the HRM findings in EoE and controls were normal in 11 (42%) and 20 (88.5%), p < 0.0001. Weak and failed peristaltic integrity was only seen in EoE patients (failed 1/2.7%, weak 7/26.9%, p = 0.004). Of the EoE patients, 17 had IF and 9 presented with FS type. HRM parameters showed no differences according to the EoE subtype. The endoscopic score in the FS subtype was significantly higher than in EoE with IF subtype (5.33 vs. 3.58, p = 0.001). No significant difference was seen in dysphagia scores in EoE subtypes. DISCUSSION: HRM findings in EoE are often diagnostic, but they are non-specific and do not correlate with the severity of dysphagia or endoscopic appearance. The clinical impact of HRM in EoE needs further evaluation.

Recurrent diffuse gastric bleeding as a leading symptom of gastrointestinal AL amyloidosis.

Amyloidosis is a rare disease (incidence about 0.8/100 000) characterized by extracellular tissue deposition of fibrils composed of low molecular weight subunits of a variety of serum proteins. Clinical manifestations are largely determined by the type of precursor protein, the tissue distribution and the amount of amyloid deposition. Gastrointestinal (GI) manifestations of amyloidosis are even more uncommon (3 % of all amyloidosis patients). Symptoms of GI amyloidosis are nonspecific, heterogeneous, and include weight loss, GI bleeding, heartburn, early satiety, diarrhea and abdominal pain. The histopathological examination of biopsy specimens from the GI tract leads to the diagnosis.Herein we report the case of a 63-year-old woman with recurrent diffuse gastric bleeding. Endoscopic biopsies revealed distinct amyloid deposits in the mucosa of the stomach. Further histochemical assessment confirmed systemic light chain (AL) amyloidosis with clinically predominant gastrointestinal manifestation. An induction therapy with bortezomib and dexamethasone was initiated.Our report illustrates the importance of the multidisciplinary approach for diagnosis and management of AL amyloidosis. Current treatment of systemic AL amyloidosis is based on cytostatic targeting of immunoglobulin producing plasma cells. Therapeutic options are limited and highly toxic, making the development of novel treatment approaches an urgent need.

Esophageal intraluminal baseline impedance differentiates gastroesophageal reflux disease from functional heartburn.

BACKGROUND & AIMS: Mucosal integrity can be assessed in patients with gastroesophageal reflux disease (GERD) by measuring intraluminal baseline impedance (BI). However, it is not clear whether BI is abnormal in patients with functional heartburn (FH), or can be used to distinguish them from patients with GERD. We compared differences in BI between patients with FH vs GERD. METHODS: We performed a prospective study of 52 patients (16 men; mean age, 55 y; range, 23-78 y) seen at a tertiary university hospital from February 2009 through December 2012. Thirty-five patients had GERD (19 had nonerosive reflux disease [NERD], 16 had erosive reflux disease [ERD]) and 17 had FH. All patients discontinued proton pump inhibitor therapy and then underwent esophagogastroduodenoscopy and multichannel intraluminal impedance and pH monitoring. BI was assessed at 3, 5, 7, 9, 15, and 17 cm proximal to the lower esophageal sphincter in recumbent patients. Biopsy specimens were taken from 3 cm above the gastroesophageal junction; histology analysis was performed to identify and semiquantitatively score (scale, 0-3) dilated intercellular spaces. RESULTS: Baseline impedance in the distal esophagus was significantly lower in patients with NERD or erosive reflux disease (ERD) than FH (P = .0006). At a cut-off value of less than 2100 Ω, BI measurements identified patients with GERD with 78% sensitivity and 71% specificity, with positive and negative predictive values of 75%. Also in the proximal esophagus, reduced levels of BI levels were found only in patients with ERD. There were negative correlations between level of BI and acid exposure time (r = -0.45; P = .0008), number of acidic reflux episodes (r = -0.45; P = .001), and proximal extent (r = -0.40; P = .004). Biopsy specimens from patients with NERD or ERD had significant increases in dilation of intercellular spaces, compared with those from patients with FH; there was an inverse association between dilated intercellular spaces and BI in the distal esophagus (r = -0.28; P = .06). CONCLUSIONS: Measurement of BI in the lower esophagus can differentiate patients with ERD or NERD from patients with FH (78% sensitivity and 71% specificity), and therefore should be considered as a diagnostic tool for patients with proton pump inhibitor-refractory reflux. Low levels of BI are associated with increased exposure to acid and dilation of intercellular spaces, indicating that BI is a marker of mucosal integrity.

Cone-beam computed tomography - adding a new dimension to ERCP.

Six patients with biliary duct pathologies were investigated with three-dimensional endoscopic retrograde cholangiopancreatography (3D-ERCP). The technique of 3D-ERCP consists of c-arm rotation using a flat detector c-arm to acquire a complete set of images for 3 D visualization of the biliary system. Our case series demonstrates a high level of accuracy with regard to the diagnosis of stenosis and biliary leakage. In two patients the diagnosis obtained from conventional ERCP changed significantly after 3D-ERCP. From these early observations we conclude that 3D-ERCP enhances the diagnostic performance of ERCP in a subset of patients with biliary tract disease.

Helicobacter pylori but not gastrin is associated with the development of colonic neoplasms.

Recent studies have suggested that Helicobacter pylori (H. pylori) constitutes a risk for the development of colonic neoplasia. Hypergastrinemia can be induced by H. pylori infection, and gastrin can act as putative promoter of colorectal carcinogenesis. Aim of our study was to assess whether H. pylori infection and/or increased serum gastrin levels are associated with the occurrence of colonic neoplasms. For this, we reviewed prospectively collected data of 377 patients with a minimum age of 50 years who underwent colonoscopy. H. pylori and CagA status were determined by serology. Serum gastrin levels were measured in fasting state by commercially available assay. In H. pylori infected patients (n = 138; 36.6%), the overall prevalence of colonic neoplasms was more frequent compared to H. pylori negative patients (n = 239; 63.4%) (OR = 2.73, 95% CI: 1.76-4.24). H. pylori infection occurred more frequently in patients with hyperplastic polyps (OR = 2.66, 95% CI: 1.23-5.74) and adenomas presenting with low grade intraepithelial neoplasia (IEN) (OR = 1.85, 95% CI: 1.14-2.99). Attributable risk for adenomas with high grade IEN and colorectal adenocarcinoma (n = 14) was not assessed due to the low number of cases. The expression of CagA was also associated with an increased risk for colonic neoplasms (OR = 2.25, 95% CI: 1.29-3.94). Hypergastrinemia did not increase the risk for any colonic neoplasms and there was no difference in basal serum gastrin levels between H. pylori positive and negative patients. In conclusion, H. pylori infection, including CagA expression is associated with an increased risk for the development of colonic neoplasm.

A multicenter study on the role of direct retrograde cholangioscopy in patients with inconclusive endoscopic retrograde cholangiography.

BACKGROUND AND STUDY AIMS: Direct retrograde cholangioscopy (DRC) may improve the diagnostic and therapeutic yield of endoscopic retrograde cholangiography (ERC) but safety, feasibility, and outcome are unknown. PATIENTS AND METHODS: All consecutive patients who underwent DRC at three tertiary endoscopy centers for inconclusive findings at ERC were included in this retrospective analysis. Ultraslim endoscopes (FujiFilm EG 530NP; Olympus GIF XP180; GIF N180) were used by the peroral route for intubating all accessible bile ducts. Success rate, usefulness in diagnosis and therapy, and safety of DRC were assessed in terms of technical and clinical parameters and therapeutic vs. diagnostic indication. RESULTS: DRC was performed in 130 cases (89 patients). CO2 insufflation and an anchoring balloon were used in 66.9% and 97.7% of cases, respectively. Intubation of the papilla was successful in 115 of 130 (88.5%) cases, and the aim of the DRC investigation was accomplished in 105 cases (80.8%). DRC-guided biopsies were taken in 53 cases (40.8%), and a therapeutic intervention was performed in 32 cases (24.6%). The initial diagnosis was revised by DRC in 18 of 69 patients (26.1%) with indeterminate biliary stricture. Complications were observed in 10 cases (7.7%), including cholangitis (n=2; 1.5%), bleeding (n=2; 1.5%), and pain, hypoxia, bradyarrhythmia, air embolism, and perforation of an intrahepatic and an extrahepatic bile duct (1 each; 0.8%). There was no mortality associated with DRC. CONCLUSIONS: DRC was successfully performed for the diagnosis and treatment of biliary disease that had eluded diagnosis with conventional ERC. DRC impacted on clinical decision making. The complication rate was low and similar to other cholangioscopy techniques.

GERD assessment including pH metry predicts a high response rate to PPI standard therapy.

BACKGROUND: Inadequate response to proton pump inhibitor (PPI) therapy in patients with gastroesophageal reflux disease (GERD) is reported in up to 40%. Patients with non erosive reflux disease (NERD) have lower response rates compared to patients with erosive reflux disease (ERD); pH metry contributes to GERD diagnosis and is critical for proper diagnosis of NERD. Aim of the study was to assess the need for doubling esomeprazole standard dose (40 mg) for 4 weeks in PPI naive patients with typical reflux symptoms and diagnosis of GERD based on endoscopy and 48 hours, wireless pH metry. METHODS: All patients underwent upper GI endoscopy. Symptoms were recorded with a structured questionnaire (RDQ) and acid exposure was determined by 48 hours, wireless pH monitoring (BRAVO). In case of abnormal acid exposure, patients received a short term treatment with esomeprazole 40 mg q.d. for 4 weeks. If symptoms persisted, patients underwent a second pH metry on PPI and the dose was increased to 40 mg b.i.d. RESULTS: 31 consecutive patients with typical reflux symptoms underwent 48 hours pH monitoring. 22 patients (71%) had abnormal acid exposure, 9 patients had normal pH metry (29%). Of the 9 patients with normal pH metry, 2 were found with erosive esophagitis and 7 without endoscopic abnormalities. 24 patients with documented GERD received esomeprazole treatment. 21 patients achieved complete symptom resolution with 40 mg q.d. after 4 weeks (88%). Only 2 patients required doubling the dose of esomeprazole for complete symptom resolution, 1 patient remained with symptoms. CONCLUSIONS: Patients with typical reflux symptoms and abnormal acid exposure have a high response rate to standard dose esomeprazole regardless of whether they have ERD or NERD.

Long-term outcome of self expandable metal stents for biliary obstruction in chronic pancreatitis.

CONTEXT: Insertion of a self-expandable metal stent is still controversial for treatment of benign common bile duct stenosis but can be a valuable alternative to surgical treatment. OBJECTIVE: Aim of our study was to analyze the efficacy of covered and uncovered self-expandable metal stent in patients with chronic pancreatitis and common bile duct stenosis. MATERIAL AND METHODS: Twenty patients with common bile duct stenosis due to alcoholic chronic pancreatitis were retrospective analyzed. All patients had advanced chronic pancreatitis, presenting with calcifications in pancreatic head. Uncovered self-expandable metal stent (uSEMS) were used in 11 patients (3 females, 8 males) while in 9 patients (3 females, 6 males) partially covered self-expandable metal stent (cSEMS) were inserted. All patients treated with self-expandable metal stent had contraindications for surgery. RESULTS: Overall mean follow up time was 155 weeks: 206 (52-412) weeks in uSEMS, and 93 (25-233) weeks in cSEMS, respectively. Stent patency was in mean 118 weeks: 159 (44-412) weeks in uSEMS and 67 (25-150) weeks in cSEMS (P=0.019). In the uSEMS group, reintervention was necessary in 5 patients (45%) due to stent obstruction, whereas in the cSEMS group 4 patients (44%) needed reintervention (2 obstructions, 2 migration). Stent migration is an early complication, compared to obstruction (P<0.05), and in cSEMS obstruction occurred significantly earlier compared to uSEMS (P<0.05). CONCLUSION: Patency of uSEMS was significantly longer compared to partially cSEMS. Available self-expandable metal stent, unfortunately, do not meet the demands on successful treatment of benign common bile duct stenosis.

Influence of the Bile Acid Transporter Genes ABCB4, ABCB8, and ABCB11 and the Farnesoid X Receptor on the Response to Ursodeoxycholic Acid in Patients with Nonalcoholic Steatohepatitis.

The prevalence of NAFLD and NASH is increasing worldwide, and there is no approved medical treatment until now. Evidence has emerged that interfering with bile acid metabolism may lead to improvement in NASH. In this study, 28 patients with elevated cholestatic liver function tests (especially GGT) were screened for bile acid gene polymorphisms and treated with UDCA. All patients had a bile acid gene polymorphism in ABCB4 or ABCB11. Treatment with UDCA for 12 months significantly reduced GGT in all patients and ALT in homozygous patients. No difference in fibrosis was observed using FIb-4, NFS, and transient elastography (TE). PNPLA3 and TM6SF2 were the most common NASH-associated polymorphisms, and patients with TM6SF2 showed a significant reduction in GGT and ALT with the administration of UDCA. In conclusion, NASH patients with elevated GGT should be screened for bile acid gene polymorphisms, as UDCA therapy may improve liver function tests. However, no difference in clinical outcomes, such as progression to cirrhosis, has been observed using non-invasive tests (NITs).