Small bowel diagnostics: current place of small bowel endoscopy

Ileal adenocarcinoma in a young pregnant woman: A rare case report

Primary intestinal malignancies account for only 1%-3% of all malignant gastrointestinal tumors. Adenocarcinomas are uncommonly located in the ileum. Ileal adenocarcinoma (IA) is rare and difficult to diagnose because of its location. IA is common in older men and rare in young pregnant women. A 23-year-old pregnant woman was hospitalized several times for repeated vomiting and abdominal pain. Her symptoms were relieved after symptomatic treatment. She exhibited no typical manifestations of intestinal obstruction, such as abdominal distension, difficulty passing gas and defecation. Unfortunately, she was misdiagnosed with acute gastroenteritis. On the second day after delivery, the patient stopped passing gas and computed tomography (CT) revealed an intestinal obstruction. She was treated as paralytic ileus. However, in view of failed conservative management, she was decided for an exploratory laparotomy. A malignant ileal tumor 5cm from the ileocecal valve was found incidentally and was surgically excised accompanied with End-to-side anastomosis of ileal and transverse colon. The operation lasted 195 minutes. Pathological examination revealed an IA. Pregnant woman who experience symptoms of intestinal obstruction should be alert to the possibility of malignancy in the small intestine. IA is an insidious tumor in pregnant women. An "IA triad" can be defined as refractory vomiting, vague abdominal pain, and weight loss (or inadequate weight gain in pregnant women). Pregnant women with an IA triad should undergo investigation with endoscopy or, if necessary, magnetic resonance imaging (MRI).

Noninvasive detection and interpretation of gastrointestinal diseases by collaborative serum metabolite and magnetically controlled capsule endoscopy

Gastrointestinal diseases are complex diseases that occur in the gastrointestinal tract. Common gastrointestinal diseases include chronic gastritis, peptic ulcers, inflammatory bowel disease, and gastrointestinal tumors. These diseases may manifest a long course, difficult treatment, and repeated attacks.

Gastroscopy and mucosal biopsy are the gold standard methods for diagnosing gastric and duodenal diseases, but they are invasive procedures and carry risks due to the necessity of sedation and anesthesia. Recently, several new approaches have been developed, including serological examination and magnetically controlled capsule endoscopy (MGCE). However, serological markers lack lesion information, while MGCE images lack molecular information.

This study proposes combining these two technologies in a collaborative noninvasive diagnostic scheme as an alternative to the standard procedures. We introduce an interpretable framework for the clinical diagnosis of gastrointestinal diseases. Based on collected blood samples and MGCE records of patients with gastrointestinal diseases and comparisons with normal individuals, we selected serum metabolite signatures by bioinformatic analysis, captured image embedding signatures by convolutional neural networks, and inferred the location-specific associations between these signatures.

Our study successfully identified five key metabolite signatures with functional relevance to gastrointestinal disease. The combined signatures achieved discrimination AUC of 0.88. Meanwhile, the image embedding signatures showed different levels of validation and testing accuracy ranging from 0.7 to 0.9 according to different locations in the gastrointestinal tract as explained by their specific associations with metabolite signatures. Overall, our work provides a new collaborative noninvasive identification pipeline and candidate metabolite biomarkers for image auxiliary diagnosis. This method should be valuable for the noninvasive detection and interpretation of gastrointestinal and other complex diseases.

Risk factors for small-intestinal mucosal breaks beyond aspirin

BACKGROUND AND AIM

There remains lots of unknowns for small intestinal mucosal breaks (SIMBs). The application of magnetic controlled capsule endoscope (MCCE) may provide a better understanding of SIMBs. The aim of our study was to investigate the prevalence and characteristics of SIMBs in the general population as well as risk factors for SIMBs other than aspirin.

METHODS

Clinical data on individuals who visited our institute between January 2019 and February 2021 for MCCE examination as a health check were collected and analyzed retrospectively. All study participants must have completed the small bowel inspection. Multivariate analysis was employed to reveal the independent risk factors for SIMBs.

RESULTS

A total of 1599 participants, 103 of whom were aspirin users, were finally included. The prevalence of SIMBs was 8.3% (132/1599) in all participants, with 36.9% (38/103) in aspirin users and 6.3% (94/1496) in non-aspirin users. The multivariate analysis showed that in addition to aspirin (OR: 6.17, 95% CI: 3.25-11.58), obesity (OR: 2.30, 95% CI: 1.38-3.92) and smoking (OR: 1.85, 95% CI: 1.56-3.20) were also independent risk factors for SIMBs. Jejunum involvement was more common in aspirin users (20/38, 52.6%), while ilium involvement was more common in non-aspirin users (58/94, 61.7%). Moderate SIMBs (erosions) were more common in aspirin users (17/38, 44.7%), while severe SIMBs (large erosions/ulcers) were more common in non-aspirin users (17/94, 18.1%).

CONCLUSIONS

The risk factors for SIMBs include aspirin as well as smoking and obesity, and the severity and distributive features of SIMBs differ between aspirin users and non-aspirin users.

Efficacy of a comprehensive binary classification model using a deep convolutional neural network for wireless capsule endoscopy

The manual reading of capsule endoscopy (CE) videos in small bowel disease diagnosis is time-intensive. Algorithms introduced to automate this process are premature for real clinical applications, and multi-diagnosis using these methods has not been sufficiently validated. Therefore, we developed a practical binary classification model, which selectively identifies clinically meaningful images including inflamed mucosa, atypical vascularity or bleeding, and tested it with unseen cases. Four hundred thousand CE images were randomly selected from 84 cases in which 240,000 images were used to train the algorithm to categorize images binarily. The remaining images were utilized for validation and internal testing. The algorithm was externally tested with 256,591 unseen images. The diagnostic accuracy of the trained model applied to the validation set was 98.067%. In contrast, the accuracy of the model when applied to a dataset provided by an independent hospital that did not participate during training was 85.470%. The area under the curve (AUC) was 0.922. Our model showed excellent internal test results, and the misreadings were slightly increased when the model was tested in unseen external cases while the classified 'insignificant' images contain ambiguous substances. Once this limitation is solved, the proposed CNN-based binary classification will be a promising candidate for developing clinically-ready computer-aided reading methods.

The Detective Value of Magnetically Controlled Robotic Capsule Endoscopy in Patients With Suspected Small Intestinal Disease

Objective: To explore the detective value of magnetically controlled robotic capsule endoscopy (MCRCE) in patients with suspected small intestinal disease.

Patients and Methods: In total, 1,802 patients with suspected small intestinal disease and negative gastroenteroscopy from Shanghai Jiao Tong University Affiliated Sixth People's Hospital were examined with MCRCE, and the data were collected for further analysis.

Results: Among the 1,802 patients who were examined with MCRCE, 974 were diagnosed with small intestinal disease, reaching a positive detection rate of 54.1%. The five most common conditions that were detected include non-specific enteritis in 722 cases (40.1%), small intestinal ulcers in 87 cases (4.8%), abnormal small bowel evacuation in 45 cases (2.5%), small intestinal bleeding in 33 cases (1.8%), and small intestinal yellow spots in 31 cases (1.7%). The running time of the capsules in the small intestine ranged from 85–437 min, with an average of 210.24 ± 89.08 min. No complications, such as intestinal obstruction or capsule retention, were observed in all patients.

Conclusion: MCRCE is a safe and non-invasive endoscopic examination with a highly accurate detection rate for small intestinal diseases.

Evaluation of the diagnostic and therapeutic utility of retrograde through-the-scope balloon enteroscopy and single-balloon enteroscopy

BACKGROUND

Retrograde single balloon enteroscopy (SBE) is a minimally invasive procedure which is less frequently performed compared with antegrade SBE. There are few studies on the retrograde through-the-scope enteroscopy (TTSE), a novel technique for evaluation of the small bowel.

AIM

To compare the clinical utility and safety of retrograde TTSE with retrograde SBE.

METHODS

Clinical data and complications of retrograde TTSE (2014-2018) and retrograde SBE (2011-2018) performed in a community hospital were reviewed and presented as mean ± SD or frequency (%) and compared using proper statistical tests. Technical success was defined as insertion of the enteroscope > 20 cm beyond ileocecal valve.

RESULTS

Data obtained from 54 retrograde SBE in 49 patients and 27 retrograde TTSE in 26 patients were studied. The most common indication for retrograde enteroscopy was iron deficiency anemia (41 patients) followed by gastrointestinal bleeding (37 patients), and chronic diarrhea (7 patients). The duration of retrograde SBE procedure (91.9 ± 34.2 min) was significantly longer compared with retrograde TTSE (70.5 ± 30.7 min) (P = 0.04). Technical success was comparable in TTSE [23/27 (85.2%)] and SBE [41/54 (75.9%) (P = 0.33)]. The mean depth of insertion beyond the ileocecal valve in retrograde SBE (92.5 ± 70.0 cm) tended to be longer compared with retrograde TTSE (64.6 ± 49.0 cm) (P = 0.08). No complication was observed in this study.

CONCLUSION

Both retrograde TTSE and retrograde SBE are feasible and safe. Retrograde TTSE takes a shorter time and has a comparable technical success with SBE. TTSE has a lower capacity of small bowel insertion.

A Gratifying Step forward for the Application of Artificial Intelligence in the Field of Endoscopy: A Narrative Review

Endoscopy is the optimal choice of diagnosis of gastrointestinal (GI) diseases. Following the advancements made in medical technology, different kinds of novel endoscopy-methods have emerged. Although the significant progress in the penetration of endoscopic tools that have markedly improved the diagnostic rate of GI diseases, there are still some limitations, including instability of human diagnostic performance caused by intensive labor burden and high missed diagnosis rate of subtle lesions. Recently, artificial intelligence (AI) has been applied gradually to assist endoscopists in addressing these issues.

Rewiring of Microbiota Networks in Erosive Inflammation of the Stomach and Small Bowel

The development of non-invasive, inexpensive, and effective early diagnosis tests for gastric and small-bowel lesions is an urgent requirement. The introduction of magnetically guided capsule endoscopy (MGCE) has aided examination of the small bowel for diagnoses. However, the distribution of the fecal microbiome in abnormal erosions of the stomach and small bowel remains unclear. Herein, alternations in the fecal microbiome in three groups [normal, small-bowel inflammation, and chronic gastritis (CG)] were analyzed by metagenomics and our well-developed method [individual-specific edge-network analysis (iENA)]. In addition to the dominant microbiota identified by the conventional differential analysis, iENA could recognize novel network biomarkers of microbiome communities, such as the genus Bacteroide in CG and small-bowel inflammation. Combined with differential network analysis, the network-hub microbiota within rewired microbiota networks revealed high-ranked iENA microbiota markers, which were disease specific and had particular pathogenic functions. Our findings illuminate the components of the fecal microbiome and the importance of specific bacteria in CG and small-bowel erosions, and could be employed to develop preventive and non-invasive therapeutic strategies.

Predictors for finding lesions in the small bowel by enteroscopy after a positive capsule endoscopy

INTRODUCTION

studies have examined the agreement between capsule endoscopy and double-balloon enteroscopy, with varying results. The aim of this study was to identify factors that predict the visualization of lesions in the small bowel by double-balloon enteroscopy after a positive capsule endoscopy.

METHODS

a retrospective, observational and comparative study was performed that evaluated patients that underwent double-balloon enteroscopy after a positive capsule endoscopy, between January 2017 and August 2019. The data studied included demographics, indications, comorbidities and the results of capsule endoscopy and double-balloon enteroscopy, which were evaluated by multiple logistic regression.

RESULTS

91 patients were included (age 58 ± 16.5 years, 53 female). Sixty-two double-balloon enteroscopy (68.1 %) found the same lesions as capsule endoscopy. Predictive factors for a positive double-balloon enteroscopy were multiple lesions (OR 8.10, 1.50-43.78; p = 0.015) and < 15 days between both studies (OR 5.31, 1.19-23.66; p=0.029). In the subgroup of patients with small bowel bleeding (70 patients), the results of 46 double-balloon enteroscopies (65.7 %) agreed with the capsule endoscopy. Predictive factors in this group were multiple lesions (OR 13.51, 1.78-102.22; p = 0.012), < 15 days between both studies (OR 13.51, 1.78-102.22; p = 0.012), > 60 years of age (OR 7.45, 1.51-36.75; p = 0.014) and ulcers (OR 4.67, 1.08-20.22; p = 0.039).

CONCLUSIONS

predictive factors for a positive double-balloon enteroscopy after a positive capsule endoscopy were multiple lesions and < 15 days between both procedures. In patients with small bowel bleeding, age over 60 years and the presence of ulcers were also predictive factors.

Gastroenterologist-Level Identification of Small-Bowel Diseases and Normal Variants by Capsule Endoscopy Using a Deep-Learning Model

BACKGROUND & AIMS

Capsule endoscopy has revolutionized investigation of the small bowel. However, this technique produces a video that is 8-10 hours long, so analysis is time consuming for gastroenterologists. Deep convolutional neural networks (CNNs) can recognize specific images among a large variety. We aimed to develop a CNN-based algorithm to assist in the evaluation of small bowel capsule endoscopy (SB-CE) images.

METHODS

We collected 113,426,569 images from 6970 patients who had SB-CE at 77 medical centers from July 2016 through July 2018. A CNN-based auxiliary reading model was trained to differentiate abnormal from normal images using 158,235 SB-CE images from 1970 patients. Images were categorized as normal, inflammation, ulcer, polyps, lymphangiectasia, bleeding, vascular disease, protruding lesion, lymphatic follicular hyperplasia, diverticulum, parasite, and other. The model was further validated in 5000 patients (no patient was overlap with the 1970 patients in the training set); the same patients were evaluated by conventional analysis and CNN-based auxiliary analysis by 20 gastroenterologists. If there was agreement in image categorization between the conventional analysis and CNN model, no further evaluation was performed. If there was disagreement between the conventional analysis and CNN model, the gastroenterologists re-evaluated the image to confirm or reject the CNN categorization.

RESULTS

In the SB-CE images from the validation set, 4206 abnormalities in 3280 patients were identified after final consensus evaluation. The CNN-based auxiliary model identified abnormalities with 99.88% sensitivity in the per-patient analysis (95% CI, 99.67-99.96) and 99.90% sensitivity in the per-lesion analysis (95% CI, 99.74-99.97). Conventional reading by the gastroenterologists identified abnormalities with 74.57% sensitivity (95% CI, 73.05-76.03) in the per-patient analysis and 76.89% in the per-lesion analysis (95% CI, 75.58-78.15). The mean reading time per patient was 96.6 ± 22.53 minutes by conventional reading and 5.9 ± 2.23 minutes by CNN-based auxiliary reading (P < .001).

CONCLUSIONS

We validated the ability of a CNN-based algorithm to identify abnormalities in SB-CE images. The CNN-based auxiliary model identified abnormalities with higher levels of sensitivity and significantly shorter reading times than conventional analysis by gastroenterologists. This algorithm provides an important tool to help gastroenterologists analyze SB-CE images more efficiently and more accurately.

Molecular endoscopic imaging: the future is bright

The prediction and final survival rate of gastrointestinal cancers are dependent on the stage of disease. The ideal would be to detect those gastrointestinal lesions at early stage or even premalignant forms which are difficult to detect by conventional endoscopy with white light optical imaging as they show minimum or no changes in morphological characteristics and are thus left untreated. The introduction of molecular imaging has greatly changed the pattern for detecting gastrointestinal lesions from purely macroscopic structural imaging to the molecular level. It allows microscopic examination of the gastrointestinal mucosa with endoscopy after the topical or systemic application of molecular probes. In recent years, major advancements in endoscopic instruments and specific molecular probes have been achieved. This review focuses on the current status of endoscopic imaging and highlights the application of molecular imaging in gastrointestinal and hepatic disease in the context of diagnosis and therapy based on recently published literature in this field. We also discuss the challenges of molecular endoscopic imaging, its future directions and potential that could have a tremendous impact on endoscopic research and clinical practice in future.

Double-Balloon Endoscopy in Overt and Occult Small Bowel Bleeding: Results, Complications, and Correlation with Prior Videocapsule Endoscopy in a Tertiary Referral Center

Background/Aims

Videocapsule endoscopy (VCE) and double-balloon endoscopy (DBE) allow deep exploration in patients with suspected small bowel pathology. VCE is often performed as an initial small bowel examination to explore whether an intervention by DBE is indicated and to determine insertion route. The study aim was to evaluate the correlation between DBE and VCE in patients with obscure or overt bleeding or anemia, as well as intervention frequency, and complications.

Methods

Retrospective observational study.

Results

DBE procedures (n=205) showed small bowel lesions in 64% cases. Antegrade DBE showed positive results in 79% cases, mostly angiodysplasias (63%). Retrograde DBE showed positive results in 22% cases. An intervention was performed in 64% of DBE procedures. The major complication rate was 0.5%, which was one case of perforation. Pancreatitis did not occur. The overall diagnostic agreement was 66% among the 134 DBEs with preceded VCE.

Conclusions

In cases of overt or occult bleeding or anemia, DBE was positive in 64%, with only a few complications. Positive correlation was 66% among initially performed VCEs and DBEs. Owing to the time-consuming and invasive character of DBE, performing VCE before DBE might still be clinically relevant.

Oral distension methods for small bowel MRI: comparison of different agents to optimize bowel distension

Background Different methods for bowel distension prior to magnetic resonance imaging (MRI) examinations were described in recent years. Purpose To compare orally administered psyllium or locust bean gum / mannitol (LBM) with tylose administered through a duodenal catheter for bowel distension in patients undergoing MRI examination of the small bowel. Material and Methods Three different methods of bowel distension prior to MRI were compared: tylose applied through a duodenal catheter and orally administered psyllium and LBM in three groups with 15 patients each. Datasets were blinded and reviewed independently by two experienced radiologists, who assessed the diagnostic value and the maximum luminal diameter. Results Tylose was superior to psyllium and LBM in the examination of the duodenum and proximal jejunum. LBM was superior to the other methods for distension of the ileum and terminal ileum. The greatest luminal diameter of the duodenum was achieved after tylose and distension of the terminal ileum was the best in patients receiving LBM. The psyllium group was inferior to the other two groups in all segments. Conclusion By using LBM as an oral method of bowel distension, many patients can avoid the unpleasant placement of a duodenal catheter without compromising the diagnostic value of the examination.

Timing of single balloon enteroscopy: significant or not?

BACKGROUND

The development of balloon assisted enteroscopy (BAE) has revolutionized diagnostic and therapeutic modalities for small-bowel disorders. Although the role of emergent esophagogastroduodenoscopy and colonoscopy for upper and lower gastrointestinal bleeding is well defined, there is scarce data with regard to emergent BAE for gastrointestinal bleeding.

STUDY

We performed a retrospective cohort study including 110 hospitalized patients with obscure gastrointestinal bleeding who underwent single balloon enteroscopy (SBE) between January 2010 and August 2013. Patients were divided into two groups based on procedures performed emergently (within 24 hours) versus non-emergently (greater than 24 hours). Data on patient demographics, hemodynamic characteristics, type of obscure bleed, lesions identified, location of lesions, endoscopic intervention performed, need for further surgical or radiological intervention, diagnostic and therapeutic yield, and adverse events were compared between groups. Independent samples t test and Fisher's exact test were used to assess the association between dependent and independent variables. For continuous data, the results were summarized as mean difference and 95 % confidence intervals (CI), and for binary as odds ratio and 95 %CI.

RESULTS

Although patients in the group where enteroscopy was performed within 24 hours had a significantly higher incidence of radiological intervention (10.0 % vs. 0.0 %, P = 0.019), the diagnostic and therapeutic yields between the two groups were not significantly different. Additionally, there were no statistically significant differences between the groups for overt and occult bleeding, transfusion requirements, type and location of lesions, endoscopic intervention performed, or adverse events. Hospital stay was shorter in the patients who had SBE within 24 hours of admission (6.2 vs. 11.3 days, P < 0.001).

CONCLUSIONS

Although the diagnostic and therapeutic yields of SBE were not significantly different between patients having the procedure within 24 hours and those having it later, the early SBE group required more interventional radiology procedures. While endoscopists may not necessarily have to perform emergent assessment within 24 hours in patients with obscure gastrointestinal bleeding (OGIB) for greater diagnostic or therapeutic yield, early intervention may allow for earlier stabilization and thus shorter hospital stays. Prospective studies further evaluating these findings are indicated.

Indications, diagnostic yield, and complication rate of balloon-assisted enteroscopy (BAE) during the first decade of its use in Korea

BACKGROUND AND AIM

Previous studies addressed the outcome of balloon-assisted enteroscopy (BAE) were based on its early experience. This procedure is operator-dependent and requires learning curve. Therefore, the accumulated BAE experience over the last decade might affect its pattern of use and outcome. In order to evaluate the changes of BAE practice over time, we compared the indications, diagnostic yield, and complication rate between the early and late stages of BAE implementation.

METHODS

This multicenter study analyzed BAE-related factors of 1,108 BAE procedures performed in 860 patients and compared the BAEs performed in early stage (Jan. 2004-Aug. 2008, n=543 procedures) to those performed in late stage (Sept. 2008-Feb. 2013, n=565 procedures).

RESULTS

The most common indication for BAE was obscure gastrointestinal bleeding (58.3%). In the early stage, BAE to assess unexplained symptoms/signs was more common (18.8% vs. 9.7%), whereas BAE to confirm abnormal findings of imaging studies was more common in late stage (9.4% vs. 18.8%, P<0.001). Overall diagnostic yield of BAE was 74.6% (95% CI, 72.0%-77.1%). There was no significant difference in the diagnostic yield between the early and late stages (72.2% vs. 77.0%, P=0.073). BAE-associated complications occurred in 12 procedures (1.1%; 95% CI, 0.6%-1.9%). The complication rate decreased significantly in late stage compared to that during early stage (1.8% vs. 0.4%, P=0.020).

CONCLUSIONS

BAE is a safe and useful tool for the diagnosis and management of small bowel disease. With time, the indications for BAE have become more specific and the BAE-associated complication rate has decreased. This article is protected by copyright. All rights reserved.

Randomized controlled trial of cholestyramine and hydrotalcite to eliminate bile for capsule endoscopy

BACKGROUND/AIMS

Bile is the main cause of poor bowel preparation for capsule endoscopy (CE). We aimed to determine whether cholestyramine and hydrotalcite can eliminate bile in the bowel.

PATIENTS AND METHODS

Patients undergoing CE were randomized into two groups. Group A patients (n = 75) received 250 mL 20% mannitol and 1 L 0.9% saline orally at 20:00 hours on the day before and at 05:00 hours on the day of CE and 20 mL simethicone 30 min before CE. Group B patients (n = 73) were treated identically, except for taking oral cholestyramine and hydrotalcite, starting 3 days before CE. Greenish luminal contents were assessed by four tissue color bar segments using Color Area Statistics software. Bowel cleanliness was evaluated by visualized area percentage assessment of cleansing (AAC) score.

RESULT

Bowel cleanliness (82.7% [62/75] vs 46.6% [34/73]; χ2 = 14.596, P = 0.000). and detected greenish luminal contents (20.0% [15/75] vs 8.2% [6/73]; χ2 = 4.217, P = 0.040) were significantly greater in Group A than in Group B. Greenish luminal contents in the two groups differed significantly in the captured small-bowel (t = -13.74, P = 0.000) segments and proximal small-bowel (t = -0.7365, P = 0.000) segments, but not for the distal small-bowel (t = -0.552, P = 0.581) segments.

CONCLUSIONS

Cholestyramine and hydrotalcite were ineffective in eliminating bile and improving small-bowel preparation.

Modern imaging techniques: which--when--why?

Within the last decade, the technological development improved the diagnostic work-up of small bowel diseases. In addition to abdominal ultrasound and radiological methods, the importance of endoscopy is increasing. Nowadays, five nonsurgical flexible endoscopy techniques are available for small bowel endoscopy: push enteroscopy and balloon-guided enteroscopy for evaluation of the proximal small bowel, balloon-assisted enteroscopy using two balloons (double-balloon enteroscopy) or one balloon (single-balloon enteroscopy), and spiral enteroscopy for evaluation of the deep small bowel. Intraoperative enteroscopy has become a reserve method.