Small bowel enteroscopy

Patterned enteroscopy balloon design factors influence tissue anchoring

Balloon-assisted enteroscopy procedures allow visualization and intervention in the small intestine. These balloons anchor an endoscope and/or overtube to the small intestine, allowing endoscopists to plicate the small intestine over the overtube. This procedure can extend examination deeper into the small intestine than the length of the endoscope would allow with direct examination. However, procedures are often prolonged or incomplete due to balloon slippage. Enteroscopy balloons are pressure-limited to ensure patient safety and thus, improving anchoring without increasing pressure is essential. Patterning balloon exteriors with discrete features may enhance anchoring at the tissue-balloon interface. Here, the pattern design space is explored to determine factors that influence tissue anchoring. The anchoring ability of smooth versus balloons with patterned features is investigated by experimentally measuring a peak force required to induce slippage of an inflated balloon inside ex-vivo porcine small intestine. Stiffer materials, low aspect-ratio features, and pattern area/location on the balloons significantly increase peak force compared to smooth silicone balloons. Smooth latex balloons, used for standard enteroscopy, have the lowest peak force. This work demonstrates both a method to pattern curved surfaces and that a balloon with patterned features improves anchoring against a deformable, lubricated tissue interface.

Ultrasound vs Endoscopy, Surgery, or Pathology for the Diagnosis of Small Bowel Crohn's Disease and its Complications

BACKGROUND

In patients with inflammatory bowel disease, we strive to achieve mucosal healing, as this has been shown to decrease the risk of disease flares, hospitalization, and surgery. For this reason, we must use objective measures of mucosal healing to inform our clinical decision-making and can no longer rely on patient symptoms alone. Assessment of small bowel Crohn's disease (SBCD) is particularly challenging given its lack of accessibility via standard endoscopic techniques. Ultrasound (US) represents a readily available, cost-effective, minimally invasive, radiation-free alternative for the assessment of small bowel disease. In this study, we performed a systematic review to determine the accuracy of ultrasound in diagnosing SBCD and its complications as compared with endoscopic visualization, surgery, and/or pathology.

METHODS

We searched MEDLINE, EMBASE, and CENTRAL. Prospective cohort studies published up to March 2017 were reviewed. References meeting all eligibility criteria were assessed at the full-text level by 2 independent reviewers. Sensitivity and specificity were collected where available.

RESULTS

A total of 2817 unique references were identified. Twenty-two studies were included. All studies were at low-moderate risk of bias based on the Quality Assessment of Diagnostic Accuracy Studies criteria. Transabdominal US (TAUS) yielded moderately high sensitivity and specificity for the diagnosis of SBCD and its postoperative recurrence. Detection was more accurate for severe postoperative recurrence. The diagnostic accuracy of US in stricture and abscess detection was high. Contrast enhancement improved the detection of abscess. Diagnostic detection of fistulas was of moderate accuracy. Entero-enteric fistulization and entero-mesenteric fistulization were most clearly identified.

CONCLUSIONS

Ultrasound can be used to diagnose SBCD in those with known or suspected Crohn's disease. It can be used to detect postoperative recurrence and can accurately identify abscesses and fistulas, especially with the aid of contrast enhancement.

Intelligent magnetic manipulation for gastrointestinal ultrasound

Diagnostic endoscopy in the gastrointestinal tract has remained largely unchanged for decades and is limited to the visualization of the tissue surface, the collection of biopsy samples for diagnoses, and minor interventions such as clipping or tissue removal. In this work, we present the autonomous servoing of a magnetic capsule robot for in-situ, subsurface diagnostics of microanatomy. We investigated and showed the feasibility of closed-loop magnetic control using digitized microultrasound (μUS) feedback; this is crucial for obtaining robust imaging in an unknown and unconstrained environment. We demonstrated the functionality of an autonomous servoing algorithm that uses μUS feedback, both on benchtop trials as well as in-vivo in a porcine model. We have validated this magnetic-μUS servoing in instances of autonomous linear probe motion and were able to locate markers in an agar phantom with 1.0 ± 0.9 mm position accuracy using a fusion of robot localization and μUS image information. This work demonstrates the feasibility of closed-loop robotic μUS imaging in the bowel without the need for either a rigid physical link between the transducer and extracorporeal tools or complex manual manipulation.

Comparison of the Efficacy and Safety of Single- versus Double-Balloon Enteroscopy Performed by Endoscopist Experts in Single-Balloon Enteroscopy: A Single-Center Experience and Meta-Analysis

Background/Aims

Studies concerning the efficacy and safety of single-balloon enteroscopy (SBE) compared with that of double-balloon enteroscopy (DBE) often appear to be conflicting. However, previous studies were performed by endoscopists who were less experienced in SBE compared with DBE.

Methods

We performed a retrospective analysis of SBE and DBE data performed by a single enteroscopist, with expertise in SBE, using a prospective balloon-assisted enteroscopy registry from 2013 to 2015. Furthermore, we performed a comprehensive literature search and meta-analysis of available studies, including the current study, to clarify the efficacy and safety of SBE versus DBE.

Results

A total of 65 procedures in 44 patients with SBE and 74 procedures in 69 patients with DBE were analyzed. There were no significant differences in diagnostic yield (61.1% vs 77.3%, respectively, p=0.397), therapeutic yield (39.1% vs 31.8%, respectively, p=0.548), and complication rate (4.4% vs 2.3%, p=1.000). In the meta-analysis, which included four randomized controlled trials and three observational studies, there were no significant differences in the pooled relative risk and odds ratio for diagnostic and therapeutic yield and complications of SBE compared with those of DBE.

Conclusions

The performance of SBE appears to be similar to that of DBE in terms of diagnostic and therapeutic yield and complications.

The Use of Balloon-assisted Enteroscopy at a Large Volume Centre: A Retrospective Analysis

Objectives

Balloon-assisted enteroscopy (BAE) is increasingly used for the evaluation of small bowel disorders. We quantified local diagnostic and therapeutic yields of BAE in patients with suspected small bowel diseases.

Methods

Adult patients undergoing BAE between January 2010 and July 2015 at McGill University Health Centre were included. Procedures were identified using a prospectively maintained database. Patients were excluded if procedure report was unavailable. Electronic medical records were reviewed. Analyses were restricted to patients who did not have a previous BAE.

Results

BAE was performed in 453 patients, including 421 anterograde cases. Patients had a mean age of 61.0 ± 17.5 years. Most common indications for referral were obscure gastrointestinal bleeding (OGIB) (n=207, 45.7%), abnormal imaging (n=88, 19.4%), suspected small bowel neoplasia (SBN) (n=39, 8.6%) and Crohn’s disease (CD) (n=31, 6.8%). A diagnosis was established in 216 procedures (47.7%). A pre-endoscopic indication of CD (odds ratio [OR]: 3.78; 95% Confidence Interval [CI], 1.60–8.90), OGIB (OR: 3.69, 95% CI, 2.03–6.71), suspected SBN (OR: 2.45; 95% CI, 1.06–5.65) and previous VCE (OR: 9.33; 95% CI, 3.24–26.90) were associated with abnormal findings. A therapeutic procedure was performed in 126 cases (28.3%). OGIB (OR: 7.00; 95% CI, 3.83–12.81), previous video capsule endoscopy (VCE) (OR: 7.86; 95% CI, 2.93–21.04) and suspected SBN (OR: 6.30; 95% CI, 2.58–21.04) were associated with performance of a therapeutic intervention. Complication rate was 1.6%, with bleeding in seven cases and one perforation.

Conclusions

In carefully selected patients, such as those with OGIB, Crohn’s disease and previous VCE, BAE was a safe procedure that led to the identification of abnormal findings and therapeutic interventions.

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.

Spiral Enteroscopy Utilizing Capsule Location Index for Achieving High Diagnostic and Therapeutic Yield

Background and Aim. Spiral enteroscopy (SE) is a new small bowel endoscopic technique. Our aim is to review the diagnostic and therapeutic yield, safety of SE, and the predictive role of prior capsule endoscopy (CE) at an academic center. Methods. A retrospective review of patients undergoing SE after prior CE between 2008 and 2013 was performed. Capsule location index (CLI) was defined as the fraction of total small bowel transit time when the lesion was seen on CE. Results. A total of 174 SEs were performed: antegrade (147) and retrograde (27). Abnormalities on SE were detected in 65% patients. The procedure was safe in patients with surgically altered bowel anatomy (n = 12). The diagnostic yield of antegrade SE decreased with increasing CLI range. The diagnostic yield of retrograde SE decreased on decreasing CLI range. A CLI cutoff of 0.6 was derived that determined the initial route of SE. Vascular ectasias seen on CE were detected in 83% cases on SE; p < 0.01. Conclusions. SE is safe with a high diagnostic and therapeutic yield. CLI is predictive of the success of SE and determines the best route of SE. The type of small bowel pathology targeted by SE may affect its utility and yield.