Russell I. Heigh

A Meta-Analysis of the Yield of Capsule Endoscopy Compared to Other Diagnostic Modalities in Patients with Obscure Gastrointestinal Bleeding

OBJECTIVES:Due to its superior ability to examine the entire small bowel mucosa, capsule endoscopy (CE) has broadened the diagnostic evaluation of patients with obscure gastrointestinal bleeding (OGIB). Published studies have revealed a numerically superior performance of CE in determining a source of OGIB compared with other modalities, but due to small sample sizes, the overall magnitude of benefit is unknown. Additionally, the types of lesions more likely to be found by CE versus alternate modalities are also unknown. The aim of this study was to evaluate the yield of small bowel findings with CE in patients with OGIB compared to other modalities using meta-analysis.METHODS:We performed a recursive literature search of prospective studies comparing the yield of CE to other modalities in patients with OGIB. Data on yield and types of lesions identified among various modalities were extracted, pooled, and analyzed. Incremental yield (IY) (yield of CE–yield of comparative modality) and 95% confidence intervals (95% CI) of CE over comparative modalities were calculated.RESULTS:A total of 14 studies (n = 396) compared the yield of CE with push enteroscopy for OGIB. The yield for CE and push enteroscopy was 63% and 28%, respectively (IY = 35%, p < 0.00001, 95% CI = 26–43%) and for clinically significant findings (n = 376) was 56% and 26%, respectively (IY = 30%, p < 0.00001, 95% CI = 21–38%). Three studies (n = 88) compared the yield of CE to small bowel barium radiography. The yield for CE and small bowel barium radiography for any finding was 67% and 8%, respectively (IY = 59%, p < 0.00001, 95% CI = 48–70%) and for clinically significant findings was 42% and 6%, respectively (IY = 36%, p < 0.00001, 95% CI = 25–48%). Number needed to test (NNT) to yield one additional clinically significant finding with CE over either modality was 3 (95% CI = 2–4). One study each compared the yield of significant findings on CE to intraoperative enteroscopy (n = 42, IY = 0%, p = 1.0, 95% CI =−16% to 16%), computed tomography enteroclysis (n = 8, IY = 38%, p = 0.08, 95% CI =−4% to 79%), mesenteric angiogram (n = 17, IY =−6%, p = 0.73, 95% CI =−39% to 28%), and small bowel magnetic resonance imaging (n = 14, IY = 36%, p = 0.007, 95% CI = 10–62%). Ten of the 14 trials comparing CE with push enteroscopy classified the types of lesions found on examination. CE had a 36% yield for vascular lesions versus 20% for push enteroscopy, with an IY of 16% (p < 0.00001, 95% CI = 9–23%). Inflammatory lesions were also found more often in CE (11%) than in push enteroscopy (2%), with an IY of 9% (p = 0.0001, 95% CI = 5–13%). There was no significant difference in the yield of tumors or “other” findings between CE and push enteroscopy.CONCLUSIONS:CE is superior to push enteroscopy and small bowel barium radiography for diagnosing clinically significant small bowel pathology in patients with OGIB. In study populations, the IY of CE over push enteroscopy and small bowel barium radiography for clinically significant findings is ≥30% with an NNT of 3, primarily due to visualization of additional vascular and inflammatory lesions by CE.

A Meta-Analysis of the Yield of Capsule Endoscopy Compared to Other Diagnostic Modalities in Patients with Non-Stricturing Small Bowel Crohn's Disease

OBJECTIVES:Capsule endoscopy (CE) allows for direct evaluation of the small bowel mucosa in patients with Crohns disease (CD). A number of studies have revealed significantly improved yield for CE over other modalities for the diagnosis of CD, but as sample sizes have been small, the true degree of benefit is uncertain. Additionally, it is not clear whether patients with a suspected initial presentation of CD and those with suspected recurrent disease are equally likely to benefit from CE. The aim of this study was to evaluate the yield of CE compared with other modalities in symptomatic patients with suspected or established CD using meta-analysis.METHODS:We performed a recursive literature search of prospective studies comparing the yield of CE to other modalities in patients with suspected or established CD. Data on yield among various modalities were extracted, pooled, and analyzed. Incremental yield (IY) (yield of CE − yield of comparative modality) and 95% confidence intervals (95% CI) of CE over comparative modalities were calculated. Subanalyses of patients with a suspected initial presentation of CD and those with suspected recurrent disease were also performed.RESULTS:Nine studies (n = 250) compared the yield of CE with small bowel barium radiography for the diagnosis of CD. The yield for CE versus barium radiography for all patients was 63% and 23%, respectively (IY = 40%, p < 0.001, 95% CI = 28–51%). Four trials compared the yield of CE to colonoscopy with ileoscopy (n = 114). The yield for CE versus ileoscopy for all patients was 61% and 46%, respectively (IY = 15%, p= 0.02, 95% CI = 2–27%). Three studies compared the yield of CE to computed tomography (CT) enterography/CT enteroclysis (n = 93). The yield for CE versus CT for all patients was 69% and 30%, respectively (IY = 38%, p= 0.001, 95% CI = 15–60%). Two trials compared CE to push enteroscopy (IY = 38%, p < 0.001, 95% CI = 26–50%) and one trial compared CE to small bowel magnetic resonance imaging (MRI) (IY = 22%, p= 0.16, 95% CI =−9% to 53%). Subanalysis of patients with a suspected initial presentation of CD showed no statistically significant difference between the yield of CE and barium radiography (p= 0.09), colonoscopy with ileoscopy (p= 0.48), CT enterography (p= 0.07), or push enteroscopy (p= 0.51). Subanalysis of patients with established CD with suspected small bowel recurrence revealed a statistically significant difference in yield in favor of CE compared with all other modalities (barium radiography (p < 0.001), colonoscopy with ileoscopy (p= 0.002), CT enterography (p < 0.001), and push enteroscopy (p < 0.001)).CONCLUSIONS:In study populations, CE is superior to all other modalities for diagnosing non-stricturing small bowel CD, with a number needed to test (NNT) of 3 to yield one additional diagnosis of CD over small bowel barium radiography and NNT = 7 over colonoscopy with ileoscopy. These results are due to a highly significant IY with CE over all other modalities in patients with established non-stricturing CD being evaluated for a small bowel recurrence. While there was no significant difference seen between CE and alternate modalities for diagnosing small bowel CD in patients with a suspected initial presentation of CD, the trend toward significance for a number of modalities suggests the possibility of a type II error. Larger studies are needed to better establish the role of CE for diagnosing small bowel CD in patients with a suspected initial presentation of CD.

Capsule endoscopy has a significantly higher diagnostic yield in patients with suspected and established small-bowel Crohn's disease: a meta-analysis

OBJECTIVES:Capsule endoscopy (CE) has demonstrated superior performance compared with other modalities in its ability to detect early small-bowel (SB) Crohns disease (CD), especially when ileoscopy is negative or unsuccessful. The aim of this study was to evaluate the diagnostic yield of CE compared with other modalities in patients with suspected and established CD using a meta-analysis.METHODS:A thorough literature search for prospective studies comparing the diagnostic yield of CE with other modalities in patients with CD was undertaken. Other modalities included push enteroscopy (PE), colonoscopy with ileoscopy (C+IL), SB radiography (SBR), computed tomography enterography (CTE), and magnetic resonance enterography (MRE). Data on diagnostic yield among various modalities were extracted, pooled, and analyzed. Data on patients with suspected and established CD were analyzed separately. Weighted incremental yield (IYW) (diagnostic yield of CE−diagnostic yield of comparative modality) and 95% confidence intervals (CIs) of CE over comparative modalities were calculated.RESULTS:A total of 12 trials (n=428) compared the yield of CE with SBR in patients with CD. Eight trials (n=236) compared CE with C+IL, four trials (n=119) compared CE with CTE, two trials (n=102) compared CE with PE, and four trials (n=123) compared CE with MRE. For the suspected CD subgroup, several comparisons met statistical significance. Yields in this subgroup were CE vs. SBR: 52 vs. 16% (IYw=32%, P<0.0001, 95% CI=16–48%), CE vs. CTE: 68 vs. 21% (IYw=47%, P<0.00001, 95% CI=31–63%), and CE vs. C+IL: 47 vs. 25% (IYw=22%, P=0.009, 95% CI=5–39%). Statistically significant yields for CE vs. an alternate diagnostic modality in established CD patients were seen in CE vs. PE: 66 vs. 9% (IYw=57%, P<0.00001, 95% CI=43–71%), CE vs. SBR: 71 vs. 36% (IYw=38%, P<0.00001, 95% CI=22–54%), and in CE vs. CTE: 71 vs. 39% (IYw=32%, P=<0.0001, 95% CI=16–47%).CONCLUSIONS:Our meta-analysis demonstrates that CE is superior to SBR, CTE, and C+IL in the evaluation of suspected CD patients. CE is also a more effective diagnostic tool in established CD patients compared with SBR, CTE, and PE.

A single-center experience of 260 consecutive patients undergoing capsule endoscopy for obscure gastrointestinal bleeding.

OBJECTIVES:Capsule endoscopy (CE) has revolutionized the evaluation of obscure gastrointestinal bleeding (OGIB) but published literature is limited to small series with heterogeneous indications. The aim of this study was to determine the findings and the diagnostic yield of CE in a large series of patients with overt and occult OGIB.METHODS:Data on 260 patients who underwent CE for overt (N = 126) or occult (N = 134) OGIB were obtained by retrospective chart review and review of an internal database of CE patients and findings.RESULTS:Visualization of the entire small bowel was achieved in 74%. The majority of exams (66%) were rated as having a good or excellent prep. Clinically significant positive findings occurred in 53%. The yield of CE in the obscure-overt group was greater than in the obscure-occult group (60% vs 46%, P = 0.03). Small bowel angioectasias were the most common finding, comprising over 60% of clinically significant lesions. The mean follow-up was 9.6 months, and there were significant reductions in hospitalizations, additional tests/procedures, and units of blood transfused after CE. Both before and after CE, patients in the overt group had more significant GI bleeding than patients in the occult group. Complications occurred in five (1.9%) cases: nonnatural excretion (four) and CE impaction at cricopharyngeus (one).CONCLUSIONS:The yield of clinically important findings on CE in patients with OGIB is 53% and is greater in patients with obscure-overt than obscure-occult GI bleeding. Angioectasias account for the majority of significant lesions in both groups. Compared with pre-CE, patients had clinical improvement post-CE in medical interventions for OGIB. Complications of CE occur in less than 2% of cases.

Retention of the capsule endoscope: a single-center experience of 1000 capsule endoscopy procedures

BACKGROUNDnRetention of the video capsule is the most significant complication associated with capsule endoscopy (CE). There are limited data on incidence, risk factors, and outcomes of capsule retention.nnnOBJECTIVEnWe aimed to determine the incidence of capsule retention and to investigate the causes and clinical outcomes of capsule retention.nnnSETTINGnSingle tertiary referral medical center.nnnPATIENTSnAll patients who underwent CE for suspected small bowel disease from June 2002 to March 2006.nnnMETHODSnRetrospective case series.nnnRESULTSnCapsule retention occurred in 1.4% of our patients (14/1000). Eleven patients failed to pass the capsule because of nonsteroidal anti-inflammatory drug (NSAID) enteropathy (diaphragm disease). One patient had capsule retention from an obstructing carcinoid tumor. Metastatic ovarian cancer with invasion of the ileum was the cause of retention in another patient. One patient who did not have surgical removal of the capsule because of loss of follow-up had retention caused by a small-bowel tumor suspicious for carcinoid tumor on CT enterography. All patients remained asymptomatic from the retained capsules. Thirteen patients underwent elective partial small-bowel resection and capsule removal. No deaths were associated with these surgeries. Eleven patients recovered promptly, whereas 2 patients had mild postoperative ileus.nnnLIMITATIONnRetrospective study.nnnCONCLUSIONnRetention of the capsule endoscope appears to be infrequent. The most common cause is diaphragm disease resulting from NSAIDs in this study population. In most cases, capsule retention is asymptomatic, and it usually leads to surgical removal, which appears safe and also identifies and treats the underlying small-bowel condition.

Yield of repeat wireless video capsule endoscopy in patients with obscure gastrointestinal bleeding.

PURPOSE:Capsule endoscopy (CE) has been shown to have a high diagnostic yield in patients with obscure gastrointestinal bleeding (OGIB). It is not known if repeating CE improves diagnostic yield or changes patient management when the initial CE is negative or nondiagnostic. The aims of this study are (1) to understand the reasons for repeat CE, (2) to determine the diagnostic yield of repeat CE, and (3) to establish if findings on repeat CE resulted in a change in patient management.METHODS:Between August 2001 and October 2003, we performed 391 capsule studies. Of these, 24 were repeat studies in patients with OGIB. We retrospectively reviewed the charts of these 24 patients.RESULTS:The reasons for repeat CE were: recurrent gastrointestinal bleeding (13), limited visualization on first exam due to poor prep or blood (10), complication (1) (capsule impaction at cricopharyngeus). Eighteen of 24 (75%) repeat capsule studies revealed additional findings (7 arteriovenous malformations, 2 gastropathy, 2 erosions, 2 masses, 1 ulcer, 2 red spots, 1 linear streak, 1 erythema). These findings led to changes in patient management in 15 of the 24 (62.5%) cases.CONCLUSIONS:Indications for repeat CE most commonly include recurrent gastrointestinal bleeding and limited visualization on initial study. Repeat CE results in a high yield of new findings that lead to changes in patient management. Repeat CE should be considered in patients with persistent OGIB when the initial study is negative or inconclusive.

The diagnostic yield of stool pathogen studies during relapses of inflammatory bowel disease

Goals We sought to determine the yield of stool analysis for bacterial culture, ova and parasites, and Clostridium difficile toxin in suspected relapses of inflammatory bowel disease (IBD). Background The diagnostic yield of such stool studies has not been examined recently in the United States. Study The medical records of consecutive IBD patients who underwent stool testing for relapses at our institution between July 1, 2000, and November 25, 2001, were abstracted for demographics, stool test results, recent antibiotic exposure, and hospitalization. Results Fifty-four patients were evaluated during 62 relapses with 99 stool samples. Twelve stool tests were positive. C. difficile accounted for the majority of positive tests (10/12). Of these, 9 (90%) were associated with antibiotic use in the prior month versus 10 (22%) in the C. difficile-negative group (P < 0.001). Hospitalization, prednisone use, or sulfasalazine use did not differ significantly with C. difficile status. Eight C. difficile-positive patients improved clinically with targeted antibiotic therapy. Two bacterial cultures (4%) were positive for Campylobacter jejuni and Plesiomonas shigelloides. Conclusion Stool studies yielded a pathogen, mainly C. difficile, in 20% of the relapsing IBD patients. Antibiotic use was significantly associated with a positive C. difficile toxin. Toxin-positive patients improved clinically with targeted antibiotics.

Safety of capsule endoscopy in patients with pacemakers

BACKGROUNDnCapsule endoscopy, a new technology, allows visualization of the entire small intestinal mucosa. The main indication for capsule endoscopy at present is the evaluation of GI bleeding of obscure origin. Studies to date suggest that capsule endoscopy is safe and is associated with few adverse events. One concern, which has not been studied, is the potential effect of the capsule on cardiac pacemakers and other electromedical devices. The primary aims of this study were to evaluate the safety of capsule endoscopy in patients with cardiac pacemakers who are being evaluated for GI bleeding of obscure origin and to determine whether pacemakers have any effect on the images captured by the capsule endoscope.nnnMETHODSnPatients with cardiac pacemakers referred for evaluation of GI bleeding of obscure origin were entered into the study. Before the procedure, an electrocardiogram was obtained, and pacemaker functions were checked. Capsule endoscopy was performed in a hospital setting to allow closer monitoring, instead of the outpatient clinic, which is our routine. Cardiac rhythm was assessed simultaneously during capsule endoscopy with a Holter monitor. Post-procedure pacemaker function was again checked for any disturbance. When the capsule endoscopy studies were reviewed, observations were made with particular reference to technical difficulty or interference with imaging.nnnOBSERVATIONSnFive consecutive patients (4 men, 1 woman; mean age, 73 years, range 56-92 years) with cardiac pacemakers were studied. In all patients, the indication for capsule endoscopy was GI bleeding of obscure origin. A cardiologist and pacemaker nurse specialist reviewed the Holter monitor recordings and evaluated pacemaker function after the procedure for each patient. No arrhythmia or other adverse cardiac event was noted during capsule transmission. No pacemaker-induced interference on the capsule endoscopy images was observed.nnnCONCLUSIONSnCapsule endoscopy appears to be safe in patients with cardiac pacemakers and does not appear to be associated with any significant adverse cardiac event. Pacemakers do not interfere with capsule imaging.

Safety of wireless capsule endoscopy in patients with implantable cardiac defibrillators.

OBJECTIVES:Wireless video capsule endoscopy (CE) is a new technology that allows visualization of the entire small intestinal mucosa. It is indicated for the evaluation of obscure gastrointestinal bleeding (OGIB) and other disorders of the small intestine. Studies to date suggest that CE is safe and associated with few adverse events. A concern, which has not been studied, is the potential effect of CE on implanted cardiac devices such as implantable cardiac defibrillators (ICD) and other electromedical devices. We previously found CE to be safe in patients with cardiac pacemakers. The primary aim of this study was to evaluate the safety of CE in patients with ICDs who were being evaluated for OGIB. In addition, a secondary aim of the study was to determine whether ICDs had any effect on the images captured by CE.METHODS:Patients referred for the evaluation of OGIB and who also had an ICD were enrolled into the study after informed consent. Five consecutive patients (four females and one male; mean age: 72 yr; range: 60–81 yr) with ICDs were studied. All patients had transvenous endocardial ICDs located in the chest. Prior to CE, patients had a baseline electrocardiogram (ECG) and ICD interrogation. Thereafter, CE was performed in a hospital setting with telemetry monitoring performed simultaneously. A post-procedure ICD interrogation was carried out to evaluate changes in programmed parameters. A cardiologist and ICD nurse specialist together reviewed both the telemetry monitor and the post-procedure ICD interrogation on each patient. When CE studies were reviewed, observations pertaining to technical difficulties and interference with video imaging were documented.RESULTS:No arrhythmia or other adverse cardiac events were noted during capsule transmission. No interference by the ICD on the CE video images was seen.CONCLUSIONS:CE was performed safely in these five patients with ICDs, and was not associated with any adverse cardiac events. ICDs also do not appear to interfere with video capsule imaging.

Accuracy of assessment of the extent of examination by experienced colonoscopists

One hundred colonoscopies were done. The colonoscopist noted whether the cecum had been intubated as well as the markers used to make this determination. With the colonoscope in position at maximum penetration, a radiologist independently determined its position using fluoroscopy, with a contrast agent delivered through the colonoscope. The cecum was entered in 86 of 100 cases. The tip of the colonoscope was at the level of the ileocecal valve in nine additional cases; the colonoscopist judged that the cecum was well seen in five of these nine. In one case, the colonoscopist overestimated the extent of the examination when transillumination in the right lower quadrant was the only confirming marker. When the more reliable markers (ileocecal valve, appendiceal orifice, converging indentations of the taenia coli in the cecal pole) were seen, no errors were made. Experienced colonoscopists are accurate in assessing the extent of colonoscopy and fluoroscopic confirmation is not routinely needed. When reliable markers are not seen during the examination, a barium enema, preferably with air contrast, should be done.