Capsule endoscopy: the voyage is fantastic--will it change what we do?

Optimizing lesion detection in small-bowel capsule endoscopy: from present problems to future solutions

This review presents issues pertaining to lesion detection in small-bowel capsule endoscopy (SBCE). The use of prokinetics, chromoendoscopy, diagnostic yield indicators, localization issues and the use of 3D reconstruction are presented. The authors also review the current status (and future expectations) in automatic lesion detection software development. Automatic lesion detection and reporting, and development of an accurate lesion localization system are the main software challenges of our time. The 'smart', selective and judicious use (before as well as during SBCE) of prokinetics in combination with other modalities (such as real time and/or purge) improves the completion rate of SBCE. The tracking of the capsule within the body is important for the localization of abnormal findings and planning of further therapeutic interventions. Currently, localization is based on transit time. Recently proposed software and hardware solutions are proposed herein. Moreover, the feasibility of software-based 3D representation (attempt for 3D reconstruction) is examined.

Urgent capsule endoscopy is useful in severe obscure-overt gastrointestinal bleeding

AIM

With capsule endoscopy (CE) it is possible to examine the entire small bowel. The present study assessed the diagnostic yield of CE in severe obscure-overt gastrointestinal bleeding (OOGIB).

METHODS

During a 3-year period, 15 capsule examinations (4.5% of all CE in a single institution) were carried out in 15 patients (11 men; mean age 69.9 +/- 20.1 years) with severe ongoing bleeding, defined as persistent melena and/or hematochezia, with hemodynamic instability and the need for significant red blood cell transfusion. CE was carried out after non-diagnostic standard upper and lower endoscopy. The mean time from admission until CE was 4.1 +/- 4.4 days (0-15 days).

RESULTS

CE revealed active bleeding in seven patients and signs of recent bleeding in four. Etiology of bleeding was correctly diagnosed in 11 patients (73.3%) (portal hypertension enteropathy, three patients; subepithelial ulcerated lesion, two patients; angiodysplasia, two patients; jejunal ulcer with visible vessel, one patient; multiple small bowel ulcers, one patient; jejunal tumor, one patient; jejunal mucosa irregularity with adherent clot, one patient). One patient (6.7%) had active bleeding but no visible lesion. As a consequence of the capsule findings, specific therapeutic measures were undertaken in 11 patients (73.3%) with five managed conservatively, four endoscopically and two surgically. Two patients experienced bleeding recurrence. One of them, with a probable small bowel tumor, refused any other interventions.

CONCLUSIONS

CE is useful in patients with severe OOGIB by providing positive findings in the majority of patients, with subsequent impact on therapeutic procedures.

Reproducibility of wireless capsule endoscopy in the investigation of chronic obscure gastrointestinal bleeding

BACKGROUND

Capsule endoscopy (CE) is a valuable tool in the diagnostic evaluation of obscure gastrointestinal bleeding, but limited information is available on the reproducibility of CE findings.

OBJECTIVE

To compare two successive CE studies with push enteroscopy (PE) in patients presenting with chronic obscure gastrointestinal bleeding.

METHODS

A prospective study was conducted. Ten patients (seven men and three women) with chronic obscure gastrointestinal bleeding and no contraindications for CE were eligible and completed the trial. For each patient, the first capsule was administered on day 1, the second capsule was administered on day 2 and PE was performed on day 3. Endoscopists were blinded to the capsule findings. Capsule findings were assessed independently by two investigators blinded to PE findings.

RESULTS

A potential small intestinal bleeding source was found in 60% of the patients when all the studies were combined. A bleeding source was found in four patients in both CE studies. The second CE also identified a bleeding source in a fifth patient. Interobserver agreement by kappa analysis was 0.642 to 1.000 (P < or 05) for the CE studies. PE identified a potential small bowel bleeding site in four patients, including one patient who had negative CE studies.

CONCLUSIONS

This study confirmed the reproducibility of CE findings on successive studies. Some patients did not have a source of bleeding in the small intestine, and all studies found this.

A prospective study of the utility of abdominal radiographs after capsule endoscopy for the diagnosis of capsule retention

BACKGROUND

Capsule retention is a rare but serious complication of capsule endoscopy (CE). The utility of routine abdominal radiographs after CE for the diagnosis of capsule retention is not established.

OBJECTIVE

To establish the utility of abdominal radiographs in the diagnosis of capsule retention in patients undergoing CE.

DESIGN

Prospective cohort study.

PATIENTS

Consecutive patients undergoing CE.

SETTING

Mayo Clinic Scottsdale, Arizona, a multispecialty academic medical center.

INTERVENTION

Abdominal radiographs were performed on days 3, 7, and 14 after CE. If the patient visualized passage of the capsule, the subsequent abdominal radiograph was cancelled.

MAIN OUTCOME AND MEASUREMENTS

Capsule retention, defined as the capsule endoscope seen on the day-14 abdominal radiograph.

RESULTS

A total of 115 patients (46% men; mean age 65 years, range 20-88 years) underwent CE, which was performed for obscure GI bleeding in 86%, for suspected Crohn's disease in 5%, and for other indications in 9%. Thirty-four patients (30%) reported spontaneous passage of the capsule by day 3 and an additional 2 patients by day 7. Of the 81 reporting nonpassage by day 3, 66 (82%) underwent abdominal radiographs. Abdominal radiographs in 14 of 66 patients (21%), 3 of 12 (25%), and 2 of 3 (66%) showed a retained capsule on day 3, 7, and 14, respectively. Three patients (2.6%) were diagnosed with capsule retention. Two had serial abdominal radiographs: capsule retention was detected on the day-14 radiographs, and both underwent surgery. Histopathology revealed diaphragm disease of the small intestine in both patients. One patient who did not have serial abdominal radiographs had a small-bowel tumor as the cause of his capsule retention. In all 3 patients, the colon was not visualized on CE.

CONCLUSIONS

Capsule retention is a rare but serious complication of CE. Most patients do not visualize capsule passage. For patients who do not visualize capsule passage and, in whom the colon is not visualized on the video imaging, an abdominal radiograph on day 14 will help identify those with capsule retention.

Clinical application of wireless capsule endoscopy in pediatric patients for suspected small bowel diseases

Capsule endoscopy (CE) has been demonstrated to be safe and well tolerated in adults with suspicion of small intestinal diseases with negative results of gastroscopy and colonoscopy. However, its value in pediatric patients has not yet been well studied. This study aimed to evaluate the results and safety of CE in pediatric patients with suspicion of small bowel disorders. There were 16 consecutive children and adolescents (12 boys, 4 girls) and 15 adults (9 men, 6 women) referred to us for suspected small bowel diseases from August 2002 to September 2005. Among the pediatrics, six patients were less than 10 years old. Technique for capsule placement, gastric transit time, small bowel transit time, excretion time of capsule endoscopy, capsule findings, and complications were recorded. All 16 pediatric patients described that the capsule was easy to swallow except for three children. Finally we delivered the capsule under gastroscopy with overtube for these three children. No capsule retention occurred during our study. Median recording time was 7 h 44 min (range 6 h 51 min-9 h 11 min). Median gastric transit time was 83.5 min (range 4-296 min). Median small bowel transit time was 270 min (range 142-484 min). Median excretion time of capsule was 33.9 h (range 12-96 h). There was no significant difference in excretion time of capsule, gastric transit time and small bowel transit time between pediatric patients and adult patients (P > 0.05). CE was positive in 12 patients, including Crohn's disease (4), hemangioma (2), angiodysplasia (2), Meckel diverticulum (1), polyp (1), aphthous ulcer in ascending colon (1), and cobblestone appearance of ileal mucosa. CE has been performed safely in a small series of pediatric patients after ingestion or endoscopic placement of the capsule. The high yield of abnormal findings was comparable to those of adult patients.

Sensitivity and inter-observer variability for capsule endoscopy image analysis in a cohort of novice readers

AIM: To determine the performance of novice readers (4^th year medical students) for detecting capsule endoscopy findings.

METHODS: Ten capsule endoscopy cases of small bowel lesions were administered to the readers. Gold standard findings were pre-defined by gastroenterologists. Ten gold standard “targets” were identified among the 10 cases. Readers were given a 30-min overview of Rapid Reader software and instructed to mark any potential areas of abnormalities. A software program was developed using SAS to analyze the thumbnailed findings.

RESULTS: The overall sensitivity for detecting the gold standard findings was 80%. As a group, at least 5 out of 10 readers detected each gold standard finding per recording. All the gold standard targets were identified when the readers’ results were combined. Incidental finding/false positive rate ranged between 8.2-59.8 per reader.

CONCLUSION: A panel of medical students with minimal endoscopic experience can achieve high sensitivity in detecting lesions on capsule endoscopy. A group of novice readers can pre-screen recordings to thumbnail potential areas of small bowel lesions for further review. These thumbnails must be reviewed to determine the clinical relevance. Further studies are ongoing to assess other cohorts.

Rectal perforations after barium enema: a review

PURPOSE

Rectal injuries during barium enema are rare but life-threatening complications. The last review about this subject was published more than ten years ago. In the present review, we present an overview on the subject and especially focus on changes in treatment strategies and developments of less risky visualization techniques.

METHODS

A literature search was performed in the PubMed library using the key words-barium enema, complications, peritonitis, and rectal perforation-as well as related articles and other references obtained from these articles.

RESULTS

The most frequent cause of perforation is iatrogenic and catheter-related. Other causes are related to weakness of the colorectal wall or obstruction. Five types of perforations have been described: 1) perforations of the anal canal below the levator; 2) incomplete perforations; 3) perforations into the retroperitoneum; 4) transmural perforations into adjacent viscera; 5) perforations into the free intraperitoneal cavity. Most incomplete perforations and one-half of the retroperitoneal perforations have minimal clinical signs. Intraperitoneal perforations lead to the most catastrophic course, starting with rectal bleeding and mild abdominal complaints. This is rapidly followed by progressive sepsis and peritonitis, and leads to a high mortality rate. Surgery is not always required for intramural or small retroperitoneal perforations. These can be treated conservatively and require surgical debridement only in case of large amounts of extravasation or abscesses. Surgical repair of large rectal mucosal lesions or anal sphincter lesions is advised. Perirectal abscesses require drainage. Intraperitoneal perforations with gross extravasation need immediate aggressive surgical treatment in a critical care setting, because the threat of shock is high. Intraperitoneal perforations, neglected perforations, gross barium extravasation, poorly prepared colon, and venous intravasation of barium are prognostically unfavorable. The severest late complication in intraperitoneal perforations is ileus. Meticulous technical performance of the barium enema is the most important factor in prevention.

CONCLUSIONS

Rectal perforations after barium enema are rare. The overall mortality rate decreased in recent decades from approximately 50 to 35 percent as the result of advances in supportive and intensive care. Because of these advances, more aggressive surgical strategies were undertaken. With the advent of endoscopy, less barium enemas are performed. Consequently, the absolute incidence of complications has decreased. It is expected that in the future barium enemas will be replaced by more sensitive and less risky techniques, such as CT colonography and magnetic resonance colonography.

Technical modification of the double-balloon endoscopy to access to the proximal side of the stenosis in the distal colon

BACKGROUND

The inability to pass endoscopes beyond strictures is a considerable problem in patients with a colonic stricture.

METHODS

In patients with bowel obstruction, we have modified the insertion method for double-balloon endoscopy with a long, transnasal decompression tube.

OBSERVATIONS

We have succeeded in reaching the proximal side of the stricture from the oral approach across the entire small bowel in a patient.

CONCLUSIONS

This modified double-balloon enteroscopy is useful for patients with bowel obstruction in whom a long decompression tube is already placed.

Clinical outcomes of enteroscopy using the double-balloon method for strictures of the small intestine

AIM: To evaluate the clinical outcome of enteroscopy, using the double-balloon method, focusing on the involvement of neoplasms in strictures of the small intestine.

METHODS: Enteroscopy, using the double-balloon method, was performed between December 1999 and December 2002 at Jichi Medical School Hospital, Japan and strictures of the small intestine were found in 17 out of 62 patients. These 17 consecutive patients were subjected to analysis.

RESULTS: The double-balloon enteroscopy contributed to the diagnosis of small intestinal neoplasms found in 3 out of 17 patients by direct observation of the strictures as well as biopsy sampling. Surgical procedures were chosen for these three patients, while balloon dilation was chosen for the strictures in four patients diagnosed with inflammation without involvement of neoplasm.

CONCLUSION: Double-balloon enteroscopy is a useful method for the diagnosis and treatment of strictures in the small bowel.

Bowel preparation increases the diagnostic yield of capsule endoscopy: a prospective, randomized, controlled study

BACKGROUND

The aim of this study was to determine the value of small-bowel preparation for patients undergoing capsule endoscopy.

METHODS

The study design was prospective, randomized, and controlled. Eighty patients referred for capsule endoscopy were randomized into two equal groups. Patients in Group A (mean age 54.40 [15.65] years) ingested 2 L of a polyethylene glycol/electrolyte solution 16 hours before the test, whereas patients in Group B (mean age 59.85 [14.58] years) prepared for the procedure by taking only clear liquids during the prior day. The primary outcome evaluated was the effect of bowel preparation on the quality of capsule images, as assessed with an objective scoring system in which cleansing was graded as "adequate" or "inadequate" by blinded examiners. A secondary outcome was the effect of bowel preparation on diagnostic yield. For this purpose, the results of capsule endoscopy were classified as positive findings, findings of uncertain significance, and no findings.

RESULTS

Cleansing of the small intestine was considered "adequate" in 36 patients in Group A (90%) vs. 24 patients of Group B (60%) (p = 0.004). A diagnosis was established in 26 patients in Group A (65%) compared with 12 patients in Group B (30%) (p = 0.003).

CONCLUSIONS

Bowel preparation before capsule endoscopy improves visualization of the small intestine, which may lead to an improvement in diagnostic yield.

Simethicone for small bowel preparation for capsule endoscopy: a systematic, single-blinded, controlled study

BACKGROUND

Capsule endoscopy is a new imaging method for visualization of the entire small bowel. However, no standardized protocol for bowel preparation for capsule endoscopy has been evaluated.

METHODS

Capsule endoscopy was performed in 36 consecutive patients, all of whom fasted for 12 hours before ingestion of the capsule. Before capsule endoscopy, 18 patients received 80 mg simethicone and 18 had no supplemental medication for bowel preparation. Two observers, both experienced endoscopists, independently reviewed the examinations in a single-blinded and randomly assigned fashion. Mucosal visibility and intraluminal gas bubbles were assessed and graded by both observers.

RESULTS

Bowel preparation with simethicone resulted in significantly better visibility because of fewer intraluminal bubbles (p<0.01). Interobserver agreement was excellent (r>/=0.8; k 0.78: 95% CI[0.57, 0.98] ). No adverse effect of simethicone was observed.

CONCLUSIONS

Simethicone may be added to the routine preparation for capsule endoscopy to improve the visibility of small bowel mucosa.