Quality Indicators for Small Bowel Capsule Endoscopy

Artificial Intelligence-assisted Analysis of Pan-enteric Capsule Endoscopy in Patients with Suspected Crohn's Disease: A Study on Diagnostic Performance

BACKGROUND AND AIM

Pan-enteric capsule endoscopy [PCE] is a highly sensitive but time-consuming tool for detecting pathology. Artificial intelligence [AI] algorithms might offer a possibility to assist in the review and reduce the analysis time of PCE. This study examines the agreement between PCE assessments aided by AI technology and standard evaluations, in patients suspected of Crohn's disease [CD].

METHOD

PCEs from a prospective, blinded, multicentre study, including patients suspected of CD, were processed by the deep learning solution AXARO® [Augmented Endoscopy, Paris, France]. Based on the image output, two observers classified the patient's PCE as normal or suggestive of CD, ulcerative colitis, or cancer. The primary outcome was per-patient sensitivities and specificities for detecting CD and inflammatory bowel disease [IBD]. Complete reading of PCE served as the reference standard.

RESULTS

A total of 131 patients' PCEs were analysed, with a median recording time of 303 min. The AXARO® framework reduced output to a median of 470 images [2.1%] per patient, and the pooled median review time was 3.2 min per patient. For detecting CD, the observers had a sensitivity of 96% and 92% and a specificity of 93% and 90%, respectively. For the detection of IBD, both observers had a sensitivity of 97% and had a specificity of 91% and 90%, respectively. The negative predictive value was 95% for CD and 97% for IBD.

CONCLUSIONS

Using the AXARO® framework reduced the initial review time substantially while maintaining high diagnostic accuracy-suggesting its use as a rapid tool to rule out IBD in PCEs of patients suspected of Crohn's disease.

Design of a Convolutional Neural Network as a Deep Learning Tool for the Automatic Classification of Small-Bowel Cleansing in Capsule Endoscopy

Background and objectives: Capsule endoscopy (CE) is a non-invasive method to inspect the small bowel that, like other enteroscopy methods, requires adequate small-bowel cleansing to obtain conclusive results. Artificial intelligence (AI) algorithms have been seen to offer important benefits in the field of medical imaging over recent years, particularly through the adaptation of convolutional neural networks (CNNs) to achieve more efficient image analysis. Here, we aimed to develop a deep learning model that uses a CNN to automatically classify the quality of intestinal preparation in CE. Methods: A CNN was designed based on 12,950 CE images obtained at two clinical centers in Porto (Portugal). The quality of the intestinal preparation was classified for each image as: excellent, ≥90% of the image surface with visible mucosa; satisfactory, 50-90% of the mucosa visible; and unsatisfactory, <50% of the mucosa visible. The total set of images was divided in an 80:20 ratio to establish training and validation datasets, respectively. The CNN prediction was compared with the classification established by consensus of a group of three experts in CE, currently considered the gold standard to evaluate cleanliness. Subsequently, how the CNN performed in diagnostic terms was evaluated using an independent validation dataset. Results: Among the images obtained, 3633 were designated as unsatisfactory preparation, 6005 satisfactory preparation, and 3312 with excellent preparation. When differentiating the classes of small-bowel preparation, the algorithm developed here achieved an overall accuracy of 92.1%, with a sensitivity of 88.4%, a specificity of 93.6%, a positive predictive value of 88.5%, and a negative predictive value of 93.4%. The area under the curve for the detection of excellent, satisfactory, and unsatisfactory classes was 0.98, 0.95, and 0.99, respectively. Conclusions: A CNN-based tool was developed to automatically classify small-bowel preparation for CE, and it was seen to accurately classify intestinal preparation for CE. The development of such a system could enhance the reproducibility of the scales used for such purposes.

Small Bowel Capsule Endoscopy within 6 Hours Following Bowel Preparation with Polyethylene Glycol Shows Improved Small Bowel Visibility

Although bowel preparation influences small bowel visibility for small bowel capsule endoscopy (SBCE), the optimal timing for bowel preparation has not been established yet. Thus, the aim of the study was to evaluate the optimal timing of polyethylene glycol (PEG) for small bowel preparation before SBCE. This multicenter prospective observational study was conducted on patients who underwent SBCE following bowel preparation with polyethylene glycol (PEG). Patients were categorized into three groups according to the time used for completing PEG ingestion: group A, within 6 h; group B, 6-12 h; and group C, over 12 h. The percentage of unclean segment in small bowel (unclean image duration / small bowel transit time × 100) and small bowel visibility quality (SBVQ) were evaluated according to the time interval between the last ingestion of PEG and swallowing of small bowel capsule endoscope. A total of 90 patients were enrolled and categorized into group A (n = 40), group B (n = 27), and group C (n = 23). The percentage of unclean segment in the entire small bowel increased gradually from group A to C (6.6 ± 7.6% in group A, 11.3 ± 11.8% in group B, and 16.2 ± 10.7% in group C, p = 0.001), especially in the distal small bowel (11.4 ± 13.6% in group A, 20.7 ± 18.7% in group B, and 29.5 ± 16.4% in group C, p < 0.001). The proportion of patients with adequate SBVQ in group A was significantly (p < 0.001) higher (30/40, 75.0%) than that in group B (17/27, 63.0%) or group C (5/23, 21.7%). In multivariate analysis, group A was associated with an increased likelihood of adequate SBVQ compared with group C (odds ratio [OR]: 13.05; 95% confidence interval [CI]: 3.53-48.30, p < 0.001). Completing PEG ingestion within 6 h prior to SBCE could enhance small bowel visibility.

[Use of Device-Assisted Enteroscopy in Small Bowel Disease: An Expert Consensus Statement by the Korean Association for the Study of Intestinal Diseases]

The introduction of device-assisted enteroscopy (DAE) in the beginning of the 21st century has revolutionized the diagnosis and treatment of diseases of the small intestine. In contrast to capsule endoscopy, the other main diagnostic modality of small bowel diseases, DAE has the unique advantages of allowing the observation of the region of interest in detail and enabling tissue acquisition and therapeutic intervention. As DAE becomes an essential procedure in daily clinical practice, there is an increasing need for correct guidelines on when and how it is to be performed and what technical factors should be taken into consideration. In response to these needs, the Korean Association for the Study of Intestinal Diseases has developed an expert consensus statement on the performance of DAE by reviewing current evidence. This expert consensus statement particularly focuses on the indications, choice of insertion route, therapeutic intervention, complications, and relevant technical points.

Use of device-assisted enteroscopy in small bowel disease: an expert consensus statement by the Korean Association for the Study of Intestinal Diseases

The introduction of device-assisted enteroscopy (DAE) in the beginning of 21st century has revolutionized the diagnosis and treatment of diseases of the small intestine. In contrast to capsule endoscopy, the other main diagnostic modality of the small bowel diseases, DAE has the unique advantages of observing the region of interest in detail and enabling tissue acquisition and therapeutic intervention. As DAE becomes an essential procedure in daily clinical practice, there is an increasing need for correct guidelines on when and how to perform it and what technical factors should be considered. In response to these needs, the Korean Association for the Study of Intestinal Diseases developed an expert consensus statement on the performance of DAE by reviewing the current evidence. This expert consensus statement particularly focuses on the indications, choice of insertion route, therapeutic intervention, complications, and relevant technical points.

Quality indicators for capsule endoscopy and deep enteroscopy

BACKGROUND AND AIMS

Capsule endoscopy (CE) and deep enteroscopy (DE) can be useful for diagnosing and treating suspected small-bowel disease. Guidelines and detailed recommendations exist for the use of CE/DE, but comprehensive quality indicators are lacking. The goal of this task force was to develop quality indicators for appropriate use of CE/DE by using a modified RAND/UCLA Appropriateness Method.

METHODS

An expert panel of 7 gastroenterologists with diverse practice experience was assembled to identify quality indicators. A literature review was conducted to develop a list of proposed quality indicators applicable to preprocedure, intraprocedure, and postprocedure periods. The panelists reviewed the literature; identified and modified proposed quality indicators; rated them on the basis of scientific evidence, validity, and necessity; and determined proposed performance targets. Agreement and consensus with the proposed indicators were verified using the RAND/UCLA Appropriateness Method.

RESULTS

The voting procedure to prioritize metrics emphasized selecting measures to improve quality and overall patient care. Panelists rated indicators on the perceived appropriateness and necessity for clinical practice. After voting and discussion, 2 quality indicators ranked as inappropriate or uncertain were excluded. Each quality indicator was categorized by measure type, performance target, and summary of evidence. The task force identified 13 quality indicators for CE and DE.

CONCLUSIONS

Comprehensive quality indicators have not existed for CE or DE. The task force identified quality indicators that can be incorporated into clinical practice. The panel also addressed existing knowledge gaps and posed research questions to better inform future research and quality guidelines for these procedures.

Quality Indicators for Capsule Endoscopy and Deep Enteroscopy

INTRODUCTION

Capsule endoscopy (CE) and deep enteroscopy (DE) can be useful for diagnosing and treating suspected small-bowel disease. Guidelines and detailed recommendations exist for the use of CE/DE, but comprehensive quality indicators are lacking. The goal of this task force was to develop quality indicators for appropriate use of CE/DE by using a modified RAND/UCLA Appropriateness Method.

METHODS

An expert panel of 7 gastroenterologists with diverse practice experience was assembled to identify quality indicators. A literature review was conducted to develop a list of proposed quality indicators applicable to preprocedure, intraprocedure, and postprocedure periods. The panelists reviewed the literature; identified and modified proposed quality indicators; rated them on the basis of scientific evidence, validity, and necessity; and determined proposed performance targets. Agreement and consensus with the proposed indicators were verified using the RAND/UCLA Appropriateness Method.

RESULTS

The voting procedure to prioritize metrics emphasized selecting measures to improve quality and overall patient care. Panelists rated indicators on the perceived appropriateness and necessity for clinical practice. After voting and discussion, 2 quality indicators ranked as inappropriate or uncertain were excluded. Each quality indicator was categorized by measure type, performance target, and summary of evidence. The task force identified 13 quality indicators for CE and DE.

DISCUSSION

Comprehensive quality indicators have not existed for CE or DE. The task force identified quality indicators that can be incorporated into clinical practice. The panel also addressed existing knowledge gaps and posed research questions to better inform future research and quality guidelines for these procedures.

Clinical Outcomes between P1 and P0 Lesions for Obscure Gastrointestinal Bleeding with Negative Computed Tomography and Capsule Endoscopy

BACKGROUND

A simple classification for the relevance of lesions (P0, P1, and P2; no bleeding potential, less likely to bleed, and more likely to bleed, respectively) based on capsule endoscopy (CE) findings has been used. This study aimed at investigating rebleeding rates and predictive factors of P0 and P1 lesions after obtaining negative findings in both, CE and computed tomography (CT), for patients with obscure gastrointestinal bleeding (OGIB).

METHODS

Among 193 patients resulted in negative CE findings defined as P0 or P1 lesions, 84 patients with negative results on CT images were enrolled in this study. The rebleeding rates and predictive factors were assessed in the P0 and P1 groups.

RESULTS

Overall rebleeding rate in patients with negative CT and CE was 17.9%; 18.4% in the P0 group; 17.4% in the P1 group within a median follow-up duration of 18.5 months. In the P0 and P1 groups, the cumulative rebleeding rates were 9.2%, 25.4%, and 25.4%, and 6.9%, 11.8%, and 18.6% at 12, 24, and 60 months, respectively (p = 0.97). There were no independent rebleeding associated factors in the P0 group, whereas Charlson comorbidity index (CCI) (hazard ratio (HR) = 2.019, 95% confidence interval (CI): 1.158-3.519, p = 0.013), and initial low hemoglobin (Hb) level (<8 g/dL) (HR = 15.085, 95% CI: 1.182-192.514, p = 0.037) were independent predictive factors responsible for rebleeding in the P1 group.

CONCLUSIONS

Despite having negative findings on CT and CE, patients with OGIB have a significant potential rebleeding risk. Although there was no significant difference in rebleeding rates between the P0 and P1 groups on CE, the P1 group, with CCI or low initial Hb level, should be cautiously observed after the first bleeding episode.

Double-headed small-bowel capsule endoscopy: Real-world experience from a multi-centre British study

INTRODUCTION

Capsule endoscopy (CE) is well established the investigation of small-bowel (SB) pathology. We compared the use of double-headed (DH) capsules, to conventional single-headed (SH), in a real-world patient cohort in the first multicentre British study.

METHODS

Over 9 months, patients referred for routine SBCE at 4 tertiary referral centres in the UK underwent DH CE instead of conventional SH using MiroCam^Ⓡ MC2000 as per local protocols. One head (L/R) was chosen at random and reported by an expert reviewer. The DH recordings, anonymised and randomised, reported by another expert or re-read after a 4-week interval. For each CE, numbers and types of findings and overall conclusion/diagnosis were compared between SH and DH examinations.

RESULTS

211 CEs were performed. 7 failed to reach the SB; 204 analysed. Indications were: SB bleeding (n = 94); ?SB inflammation or reassessment of known inflammatory bowel disease (IBD) (n = 84); ?SB neoplasia including suspicious radiological imaging (n = 15); and, others e.g. ?celiac disease (n = 11). For SB bleeding: 27/94 (28.7%) examinations reported differences between SH and DH readings. In 17 (18.1%) the findings were clinically significant. SH CE missed angiectasias (5 pts), SB inflammation (7 pts), oesophagitis (2 pts) and SB masses (2 pts). In 1 patient, the extent of angiectasias seen was greater on the DH reading. For IBD: findings differed in 30/84 (35.7%) of CEs; 11 (13.1%) were clinically significant. In 5, signs of active inflammation were missed by the SH reading. In 6, assessment of extent/severity differed. For?SB neoplasia findings differed in 2/15 (13.3%) of examinations. Both were clinically significant. For others: 1/11 (9.1%) examinations differed; however, not deemed clinically significant. Overall, use of DH CE impacted the diagnosis in 30/204 (14.7%).

CONCLUSIONS

The use of DH CE provides more information with the potential to change clinical diagnosis and therefore management. Therefore, the routine adoption of DH CE in SB assessment should be considered.

Capsule endoscopy in inflammatory bowel disease: when and how

Capsule endoscopy (CE) is emerging as an important investigation in inflammatory bowel disease (IBD); common types include the standard small bowel CE and colon CE. More recently, the pan-enteric CE was developed to assess the large and small bowel in patients with Crohn’s disease (CD). Emerging indications include noninvasive assessment for mucosal healing (both in the small bowel and the colon) and detection of postoperative recurrence in patients with CD. Given the increasing adoption, several CE scoring systems have been specifically developed for IBD. The greatest concern with performing CE, particularly in CD, is capsule retention, but this can be overcome by performing cross-sectional imaging such as magnetic resonance enterography and using patency capsules before performing the procedure. The development of software for automated detection of mucosal abnormalities typically seen in IBD may further increase its adoption.

Double-balloon enteroscopy for retrieving retained small-bowel video capsule endoscopes: a systematic review

Background and aim: Capsule retention is the most common adverse event associated with video capsule endoscopy. The use of double-balloon enteroscopy-assisted capsule endoscope retrieval has been increasingly reported in recent years. However, evidence is limited regarding its success rate, associated factors, and subsequent clinical outcomes.Methods: A systematic review of relevant studies published before January 2019 was performed. Successful retrieval rate and associated factors, rate of endoscopic balloon dilation, and outcomes after double-balloon enteroscopy were summarized and pooled.Results: Within 154 associated original articles, 12 including 150 cases of capsule retrieval by double-balloon enteroscopy were included. The estimated pooled successful retrieval rate was 86.5% (95% confidence interval, 75.6-95.1%). Anterograde approach and capsules retained in the jejunum or trapped by malignant strictures were associated with a higher successful retrieval rate than the retrograde approach (62/83 [74.7%] vs. 10/38 [26.3%], p < .001) and capsules retained in the ileum (41/41 [100.0%] vs. 43/58 [74.1%], p < .001) or trapped by benign strictures (21/21 [100.0%] vs. 65/83 [78.3%], p = .043). Endoscopic balloon dilation was performed in 38.8% (95% confidence interval, 22.3-56.3%) of patients with benign strictures. Two perforations (1.3%) were reported as severe adverse events after double-balloon enteroscopy. A significantly lower surgery rate was found among cases with successful video capsule removal compared with unsuccessful cases (7.2% vs. 38.5%, p = .002).Conclusions: Double-balloon enteroscopy is feasible and safe for removing retained video capsule endoscopes, and its use could decrease the need for surgery in patients with benign strictures and facilitate subsequent surgery in patients with malignant strictures.

Outcomes and Management Strategies for Capsule Retention: A Korean Capsule Endoscopy Nationwide Database Registry Study

BACKGROUND

The most concerning complication of capsule endoscopy (CE) is capsule retention (CR) in the gastrointestinal (GI) tract; however, the clinical outcomes and management of patients with CR are still uncertain.

AIMS

This study aimed to investigate the clinical outcomes and management of CR.

METHODS

The outcomes of CR in multiple centers between October 2002 and June 2018 were retrospectively reviewed. Data on CE indication, findings, and management details were analyzed.

RESULTS

A total of 2705 consecutive small-bowel CE procedures were performed. CR was detected in 20 cases (0.7%). The most common site of CR was the small bowel (19 cases), followed by the esophagus (one case). In patients who underwent CE, CR was detected in nine (0.6%) of 1397 patients with obscure GI bleeding. Further, CR occurred in 11 (6.5%) of 169 patients with Crohn's disease based on the final diagnoses after CE. Capsule retrieval was safely performed surgically in nine cases and endoscopically in six cases. The retained capsules dislodged after steroid treatment in two cases, whereas three cases of CR resolved without any intervention. In multivariate analysis, the development of abdominal symptoms after CR was a significant predictive factor for requiring endoscopic or surgical interventions for capsule extraction.

CONCLUSIONS

This large multicenter study shows that CR is a rare complication with favorable clinical outcomes. Three-fourths of the patients with CR were managed with endoscopic or surgical intervention, which was required particularly in patients with abdominal symptoms after CR.

Analysis of small bowel angioectasia in asymptomatic individuals depending on patients' age and gender

Objectives: Small bowel angioectasia (SBA) plays an important role in the etiologies of obscure gastrointestinal haemorrhage. But the exact prevalence of the disease is unknown, especially in asymptomatic populations. Therefore, we aimed to evaluate the prevalence of asymptomatic angioectasia in the small bowel (SB) with magnetically controlled capsule gastroscopy (MCCG).Methods: We retrospectively collected a multicentre clinical data of 508 asymptomatic patients who underwent MCCG from June 2018 to May 2019. Bowel cleanliness was rated as four grades according to the criteria, and the excellent or good preparation was classified as the adequate group. The detection rates of small bowel lesions were analysed according to the ages, genders and bowel preparations.Results: A total of 508 individuals have completed the examination. There were 316 men and 192 women with an average age of 44.5 years old. The prevalence of SBA was 11.8% (95% CI: 9.0-14.6%). 70.0% of them were over 40 years old and 73.3% were male although there was no obvious disparity found in age and gender for the SBA. Most findings were located in the proximal small bowel (jejunum). The incidence of small bowel lesions was not related to bowel preparations (p > .05).Conclusions: SBA is not uncommon in asymptomatic individuals. Age and gender may be risk factors for bleeding of angioectasia in the small bowel, but they seem to have little to do with the occurrence of it. MCCG showed no difference in ages, genders or bowel preparations of small bowel lesions among our study population.

Adherence to European Society of Gastrointestinal Endoscopy recommendations of endoscopists performing small bowel capsule endoscopy in Italy

BACKGROUND

The European Society of Gastrointestinal Endoscopy (ESGE) has recently issued a technical review focused on small bowel capsule endoscopy (SBCE).

AIM

To compare SBCE current practice in Italy to ESGE technical recommendations.

MATERIAL AND METHODS

A dedicated per-centre semi-quantitative questionnaire was prepared by a group of SBCE experts. One-hundred-fifty Centres were invited to participate in the data collection concerning SBCEs performed between June 2016 and June 2017. Data were compared with ESGE recommendations.

RESULTS

120 Centres participated in the data collection. Current practices agreed with ESGE recommendations in 56.3% (9/16) of the issues evaluated. Differences between ESGE recommendations and current practice concerned the management of patients with pacemakers or cardiac implantable defibrillators (which was in agreement with ESGE recommendations in 31.7% and 15.8% of Centres, respectively), the SBCE setting (only 51% of SBCEs were performed as outpatients procedures), the assessment of capsule excretion (timing and modality were in agreement with ESGE recommendation in 20.0% of Centres), and in the involvement of trained nurses or fellows in training as pre-readers (7/120; 5.8%).

CONCLUSIONS

Although SBCE is widely used and largely available in Italy, there are still some technical, practical and organizational issues that can be modified to bridge the gap between current practice and ESGE guideline recommendations.

CapsoCam SV-1 Versus PillCam SB 3 in the Detection of Obscure Gastrointestinal Bleeding: Results of a Prospective Randomized Comparative Multicenter Study

BACKGROUND AND STUDY AIM

Newer capsule with a panoramic viewing mode is available and might increase the detection rate of bleeding lesions in patients with obscure gastrointestinal bleeding (OGIB). Furthermore, an improved patient acceptance rate is expected.

MATERIALS AND METHODS

In a randomized prospective comparative multicenter study, patients with OGIB were included and examined either with CapsoCam SV-1 or with PillCam SB 3. Detection of bleeding lesions, transit, and evaluation time and adverse events were evaluated. Physicians were interviewed about their experience with both capsules and the evaluation software. A detailed subject questionnaire analyzed acceptance of each capsule. Follow-up was 3 months.

RESULTS

In total, 181 patients with OGIB were recruited into the study. After exclusion of 28 patients 153 patients were randomized and CapsoCam SV-1 (n=78) or PillCam SB 3 (n=75) was administered. CapsoCam SV-1 detected more cases of bleeding (31/79, diagnostic yield 39.7%) compared with PillCam SB 3 (26/75, diagnostic yield 34.6%, NS). Transit time of both capsules was not different. Evaluation time with PillCam SB 3 was superior to CapsoCam SV-1 (27 vs. 40 min, P=0.01). In total, 95% of the physicians were satisfied with each capsule system and evaluation software. The acceptance rate of the patients to retrieve the CapsoCam SV-1 was high. Adverse events/serious adverse events were 17.9%/1.3% with CapsoCam SV-1 and 16%/0% with PillCam SB 3. Rebleeding rate was 28.75% within 3 months.

CONCLUSIONS

CapsoCam SV-1 detected more lesions; however, relevant bleeding sources were visualized by both capsules. Physician's satisfaction was high with both capsule systems and evaluation software. Patient's acceptance with CapsoCam SV-1 was unexpectedly high. Serious adverse events were 0% with PillCam SB 3 and 1.3% with CapsoCam SV-1.

Recent Development of Computer Vision Technology to Improve Capsule Endoscopy

Capsule endoscopy (CE) is a preferred diagnostic method for analyzing small bowel diseases. However, capsule endoscopes capture a sparse number of images because of their mechanical limitations. Post-procedural management using computational methods can enhance image quality. Additional information, including depth, can be obtained by using recently developed computer vision techniques. It is possible to measure the size of lesions and track the trajectory of capsule endoscopes using the computer vision technology, without requiring additional equipment. Moreover, the computational analysis of CE images can help detect lesions more accurately within a shorter time. Newly introduced deep leaning-based methods have shown more remarkable results over traditional computerized approaches. A large-scale standard dataset should be prepared to develop an optimal algorithms for improving the diagnostic yield of CE. The close collaboration between information technology and medical professionals is needed.

Current Status of Interpretation of Small Bowel Capsule Endoscopy

Capsule endoscopy (CE) has revolutionized direct small bowel imaging and is widely used in clinical practice. Remote visualization of bowel images enables painless, well-tolerated endoscopic examinations. Small bowel CE has a high diagnostic yield and the ability to examine the entire small bowel. The diagnostic yield of CE relies on lesion detection and interpretation. In this review, issues related to lesion detection and interpretation of CE have been addressed, and the current status of automated reading software development has been reviewed. Clinical significance of an external real-time image viewer has also been described.

What defines quality in small bowel capsule endoscopy

Small bowel capsule endoscopy is considered a first-line diagnostic tool for the investigation of small bowel diseases. Gastroenterological and endoscopic societies have proposed and established measures known as quality indicators, quality measures or performance measures for the majority of endoscopic procedures, in order to ensure competence, healthcare quality and define areas requiring improvement. However, there is a paucity of publications describing small bowel capsule endoscopy quality indicators. Hereby, we attempt to identify and describe a number of pre-procedure, intra-procedure and post-procedure quality indicators, regarding process measures in small bowel capsule endoscopy, after a comprehensive review of the literature.

Physical activity during video capsule endoscopy correlates with shorter bowel transit time

BACKGROUND AND STUDY AIM

 Video capsule endoscopy (VCE) is limited by reliance on bowel motility for propulsion, and lack of physical activity has been proposed as a cause of incomplete studies. Our aim was to prospectively investigate the association between physical activity and VCE bowel transit.

PATIENTS AND METHODS

 Ambulatory outpatients receiving VCE were eligible for the study. A pedometer was attached at the time of VCE ingestion and step count was recorded at the end of the procedure. VCE completion was assessed by logistic regression models, which included step count (500 steps as one unit). Total transit time was analyzed by Cox proportional hazards models. The hazard ratios (HR) with 95 % confidence interval (CI) indicated the "hazard" of completion, such that HRs > 1 indicated a reduced transit time.

RESULTS

 A total of 100 patients were included. VCE was completed in 93 patients (93 %). The median step count was 2782 steps. Step count was not significantly associated with VCE completion (odds ratio 1.45, 95 %CI 0.84, 2.49). Pedometer step count was significantly associated with shorter total, gastric, and small-bowel transit times (HR 1.09, 95 %CI 1.03, 1.16; HR 1.05, 95 %CI 1.00, 1.11; HR 1.07, 95 %CI 1.01, 1.14, respectively). Higher body mass index (BMI) was significantly associated with VCE completion (HR 1.87, 95 %CI 1.18, 2.97) and shorter bowel transit times (HR 1.05, 95 %CI 1.02, 1.08).

CONCLUSIONS

 Increased physical activity during outpatient VCE was associated with shorter bowel transit times but not with study completion. In addition, BMI was a previously unreported clinical characteristic associated with VCE completion and should be included as a variable of interest in future studies.