More Training Needed for Wireless Capsule Endoscopy

A recent study (NM Hijaz et al. JPGN 2015; 61: 421-23) shows that there is little formal training in wireless capsule endoscopy.  Though this study was merely a 5-item questionnaire sent to program directors (adult and pediatric), it showed that only 4% of pediatric program respondents had a formal training module and only 27% have a hands-on course.  These results were based on a 39% pediatric program response (25/64).

My take: Despite the low response rate to the questionnaire, given the increasing use of WCE as an evaluation tool, better training is needed.

Related blog posts:

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Head-to-Head: Capsule Endoscopy versus Colonoscopy

A recent study shows how useful capsule endoscopy (CE) can be in diagnosing Crohn disease (Clin Gastroenterol Hepatol 2014; 12: 609-15).  Congratulations to one of my partners, Dr. Stan Cohen, who is one of the authors.

This prospective study examined 80 patients with signs and/or symptoms of small-bowel Crohn disease (age, 10-65 years) who underwent CE, small-bowel follow-through (SBFT), and colonoscopy.

Presenting suggestive features included the following:

  • Diarrhea >6 weeks but less than 3 years
  • Abdominal pain >6 weeks but less than 3 years
  • Extraintestinal IBD manifestations: pyoderma gangrenosum, erythema nodosum, perianal disease, arthritis, aphthous stomatitis, and uveitis
  • Along with abnormal laboratory/clinical finding:
  1. positive inflammatory marker: sedimentation rate, C-reactive protein, calprotectin/lactoferrin
  2. unexplained iron deficiency
  3. hypoalbuminemia
  4. positive IBD serology (eg. anti-Saccharomyces cerevisiae antibodies)
  5. or other clinical findings: recurrent fevers, GI bleeding, growth failure, abnormal radiologic study

Results:

  • CE/colonoscopy in combination detected 107 of 110 inflammatory lesions (97.3%)
  • SBFT/colonoscopy detected 63 lesions (57.3%)
  • “The diagnostic yield of CE compared with colonoscopy was not different.”
  • Of the 80 patients with suspected Crohn disease, 25 (31.3%) had the diagnosis confirmed. 9 patients had diagnostic findings on at least 2 of the 3 modalities.  11 were diagnosed with CE alone and 5 by colonoscopy alone.

The authors conclude that colonoscopy remains the initial diagnostic test of choice.  However, “CE is safe and can establish the diagnosis of Crohn’s disease in patients when ileocolonoscopy results are negative or the terminal ileum cannot be evaluated.”

Take-home message: in patients with symptoms suggestive of Crohn disease, a negative colonoscopy is not sufficient to exclude the disease.  Other modalities like CE or MRE may be needed.

Related post:

Pediatric Capsule Endoscopy Experience

Pediatric capsule endoscopy experience

Capsule endoscopy (CE) in pediatric gastroenterology has become a routine procedure.   The experience of our group is noted in a recent study (JPGN 2012; 54: 409-13).  In this study, our single pediatric center reviewed 284 CE procedures (277 patients) over a five-year period.  The youngest patient to swallow a capsule was 4.6 years old.  Twenty capsules were placed endoscopically, with the youngest & smallest patient being 3 years old (13.5kg).  A patency capsule was used in 23 patients.

Overall, the yield with CE was high. 205 (72%) had positive findings; 154 (54%) had small bowel findings.  The study also compared its data to pediatric and adult meta-analysis.  Similar to other pediatric studies, Crohn disease was the most common indication; in adult studies, CE is used mostly for occult GI bleeding and anemia.  CE procedures did not reach the colon in 65 (21%); 36 of these incomplete procedures had positive findings.

Capsule retention occurred in seven patients (2.4%) which is similar to the meta-analysis studies as well.  Six of the seven had surgery due to capsule retention, though one surgical procedure had been planned and capsule helped identify stricture site.  In addition, one of the seven was retrieved through a tight ileostomy.

Additional references:

  • -Gastroenteology 2010; 139: 1468. Predictions for upcoming advances.
  • -Gastroenterology 2009; 137: 1197. Strongest indication -obscure bleeding.
  • -JPGN 2009; 49: 196. Capsule retention in 5.2% in known IBD. overall 3 of 207 studies (1.4%) To date, >170,000 capsule studies worldwide.
  • -Gastrointest Endosc 2008; 68: 255-66. Authors recommend using CT/colonoscopy as primary investigations & reserving capsule only if negative initial evaluation. 17% of pts had asymptomatic partial small bowel obstruction -contraindicating use of capsule.
  • -Endoscopy 2008; 40: 30-35 & -IBD 2008; 14: 1287. Consider wireless capsule before IPAA in UC.
  • -IBD 2008; 14: 1219. Correlation of capsule & MRI enterolysis. Capsule detected more mucosal lesions.
  • -JPGN 2008; 47: 31. Capsule endoscopy may reclassify pediatric IBD
  • Speed matters.  Additional references listed on this previous blog entry.

Speed matters

Capsule endoscopy is cool.  Like any technology, it has certain advantages and some shortcomings.  Understanding that this technology has limited sensitivity and specificity is an important matter in clinical practice.

The suboptimal sensitivity is apparent in a recent study (Am J Gastroenterology, (10 January 2012) | doi:10.1038/ajg.2011.461).  In this study titled, “Detection of Lesions During Capsule Endoscopy: Physician Performance Is Disappointing,” the authors compare the performance of 17 capsule endoscopists in reading clips from 24 capsule procedures.  18 of these clips were abnormal but only abnormal in <0.1% of frames.  They compared different reading modes, speeds and the experience of the physicians.  By using clips, they were able to truncate the sessions to a similar length as an individual capsule procedure.

Their findings showed detection rates of 69% for angioectasias, 38% for ulcers/erosions, 46% for masses/polyps, and 17% for blood.  For all categories the detection rate was ~45% for SingleView15, QuadView20, and QuadView30; however, SingleView25 had a 25% detection rate.  One surprising finding was how little experience mattered; there was no significant advantage in having more experience.  In fact, the best performer who correctly identified 78% of the abnormalities had read only 45 capsule studies previously; the worst performer with a 17% score had read more than 11,000 previously.

In a typical capsule study, 40,000-60,000 images are generated.  If there is not a diffuse disease, then the lesion may go undetected.  The findings of these studies, though limited by the small number of interpreting physicians, confirm problems with sensitivity from other studies.  One aspect of this study that deserves emphasis is that speed matters.  As with colonoscopy, additional time reviewing the study does increase the likelihood of identifying abnormalities.  Ultimately, technological innovation may improve the results with capsule endoscopy.  With newer versions of the software,  “suspected blood indicator” (SBI) quickly identified six of the 18 lesions and “QuickView” identified 11 of the 18 lesions.  As with any test, though, if the clinical suspicion is high, having another physician review the study or using an alternative imaging tool may be necessary.

Another problem to keep in mind with capsule endoscopy (or wireless capsule endoscopy -WCE) is that especially in adults there is a significant background abnormality rate that may be clinically unrelated (Clin Gastro & Hepatol 2005; 3: 133-141. n=413. 13.8% with baseline mucosal injury).

Additional references:

  • -IBD 2008; 14: 1219. Correlation of capsule & MRI enteroclysis. Capsule detected more mucosal lesions.
  • -JPGN 2008; 47: 31. Capsule endoscopy may reclassify pediatric IBD.
  • -Dig Liver Dis 2008; 40: 216-223. Study comparing capsule vs EGD in detecting varices.
  • -JPGN 2008; 46:4. Review.
  • -Gastroenterology 2007; 132: 855. Capsule outperforms push enteroscopy.
  • -IBD 2007; 13: 331. Role of WCE in IBD.
  • -Pediatrics 2006; 118: e904. Use of capsule endoscopy for HSP
  • -Clin Gastro & Hep 2005; 3: 959. WCE should be 2nd step in obscure bleed, p egd/col.
  • -Clin Gastro & Hep 2005; 3: 772. WCE outperforms enteroclysis in identifying Crohn’s sm bwl dz.
  • -Gastroenterology 2005; 128: 1172. NSAID injury witnessed in 68% of healthy volunteers p 2 week course; 75% c increased fecal calprotectin.
  • -Clin Gastro & Hepatol 2005; 3: 411. Practical applications & review.
  • -Clin Gastro & Hepatol 2005; 3: 264-70. Study of 30 children; helpful in diagnosing obscure bleeding.
  • -Endoscopy 2005; 37: 960-65. Results of capsule endoscopy trials
  • -Clin Gastro & Hepatol 2005; 3: 133-141. WCE to assess NSAID injury, n=413. 13.8% with baseline mucosal injury. Celebrex with fewer lesions than Naproxen plus omeprazole.
  • -Gortzak Y, Lantsberg L, Odes HS. Video capsule entrapped in a Meckel’s diverticulum. J Clin Gastro 2003; 37: 270-271.
  • -Clin Gastro & Hep 2005; 3: 55. visible lesions c NSAIDs
  • -IBD 2004;10: 278-285. WCE for Crohn’s (review) Capsule can help differentiate UC from Crohn’s.
  • -Clin Gastro & Hepatology 2004; 2:xx. Dx of Peutz-Jeghers w WCE.
  • -Gastro 2004; 126: 643-653. WCE performs well for occult bleeding, especially active bleeding (87% detection rate)
  • -Clinical Gastro & Hepatology 2004; 2: 14-15, 31-40.
  • -Gastroenterology 2003; 124 (suppl 1) A37. abnl small bowel findings common in healthy subjects.
  • -JPGN 2003; 37: 332 (18A), n=58. Crohn’s, polyposis, occult bleeding
  • -Gastroenterology  2003; 124: suppl 1, A-37 (284) 22% of normal pts c abnl wireless findings
  • -Gastroenterology  2002; 123: 999-1005, 1385-88. capsule is superior to radiographs for suspected small bowel dz.
  • -Gastro Endosc 2002; 56: 452-456. Algorithm suggests using this modality if negative upper & lower endoscopy & no acute overt bleeding. If capsule endoscopy is negative & patient is stable, observation appropriate.
  • -Gastro Endosc 2002; 56: 621-24. ASGE guidelines.