(Includes new vocabulary and concepts)
Is the PillCam outdated?
Not yet. Not for everyone. Not every where.
But increasingly so.
We love to love the PillCam or capsule endoscopy (CE). After decades of barium swallow small bowel x-rays (aka barium enterography or BE) with the unsavory contrast, radiation exposure and the unreliable results (many missed polyps), we rejoiced during the PillCam era. Instead of contrast, we swallowed a pill. Instead of radiation, images were sent to a recording device worn around the waist. Instead of hours in hospital, we were free to move about for 8 hours as the PillCam made its way through the GI tract. And the results - compared to barium swallow x-rays - pristine, clear and accurate.
But time tells.
Reports from doctors and first-hand reports from patients reveal that the PillCam has missed polyps and, too often, large, problematic polyps. Maybe the problem was technology - not enough shots per minute or the device just slid by the polyp. Maybe operator error contributed - hours of watching the walls of the small intestine, I'd blink too.
Whatever the problem, patients need to be aware that some doctors are moving on from the PillCam to other imaging techniques.
The following entry from the NCBI Bookshelf contains the current reasoning. You can find the movie clips, references and the rest of the PJS chapter at http://www.ncbi.nlm.nih.gov/bookshelf/br.fcgi?book=famcan&part=ch1famcan
“Small intestine polyp and cancer surveillance
“The purpose of small intestine surveillance in PJS is to identify polyps before they serve as the lead point for an intussusception, develop dysplasia, or become too large to remove endoscopically. The current standard for adult PJS patients is to remove all polyps 1.0-1.5 cm or larger. (For discussion, see PJS-type polyps.) For pediatric patients, polyp management is individualized depending on symptoms, age, previous surgeries, location and size of the polyp(s) in question, and available resources.
“The small intestine can be screened for polyps using magnetic resonance (MR) and CT enterography and enteroclysis, capsule endoscopy, and small intestine X-ray (Figures 24, 25, and 26; Movie Clips 2 and 4-6). The characteristics of small intestine polyp screening tests are shown in Table 12. Few studies have compared the different techniques for detecting small intestine polyps. One study showed similar information was gained from enteroclysis and enterography techniques for both CT and MR, but small intestine polyp detection was not specifically studied (169). Other studies in PJS patients have shown MR enterography and capsule endoscopy equivalent in identifying small intestine polyps greater than 1.5 cm and that capsule endoscopy detects more polyps than small intestine X-ray (170, 171).
“Mayo Clinic recommends MR enterography for small intestine surveillance. It has adequate sensitivity for 1.5 cm polyps, surveys the extraluminal abdominal organs, and does not involve exposure to radiation (172, 173). MR enterography is not widely available, so screening with CT enteroclysis or enterography are acceptable alternatives. CT enteroclysis is also used at Mayo Clinic. In the authors' opinion, it provides the highest quality images but is associated with radiation exposure and the discomfort of a naso-small intestine tube. Patients should be forewarned that CT and MR enteroclysis require insertion of a naso-small intestine tube that is unpleasant for all and not tolerated by some.”
From Familial Cancer Syndromes
Chapter One: Peutz-Jeghers Syndrome
By Douglas Riegert-Johnson, MD et al.
This reasoning is also reflected in the recent PJS screening guidelines from the National Comprehensive Cancer Network at http://www.nccn.org/about/news/newsinfo.asp?NewsID=227 or http://img.medscape .com/pi/editoria l/articlecme/ 2009/712885/ Colorectal_ Cancer_Screenin_ g_V.1.2010_ Medscape. pdf
The authors suggest "small bowel visualization (CT enterography, small bowel enteroclysis) evry 2-3 years, or with symptoms." A guideline author, Dr. Randall Burt of Huntsman Cancer Institute, explained, "The reason we did not recommend capsule endoscopy is that if often misses larger polyps, it tends to roll around them. It's great at small polyps and diffuse mucosal lesions, which generally aren't of clinical concern in PJS. Capsule endoscopy is dangerous if obstruction is present, which is not unusual in PJS patients. In fact, capsule endoscopy sees about 60% of the small bowel at best, although I know some studies suggest differently. The best study at present of the small bowel for larger growths and partial obstruction is small bowel enterography. It is now being more often recommended for small bowel visualization, especially in centers that deal with polyposis conditions. Imaging units across the country are quickly moving toward this capability." (personal correspondence).
So, what is small bowel enterography? Is it the same as CT enterography (CTE)? MR enterography (MRE)? What's CT enteroclysis?
The following free full text article describes both CT enterography and MR enterography, comparing them to small bowel x-rays with enterocylsis, barium x-rays, the PillCam. Though the authors focus on Crohn's Disease, they do a good job explaining the different techniques.
Computed Tomography Enterography and Magnetic Resonance Enterography: The Future of Small Bowel Imaging
Mark E. Baker, M.D., David M. Einstein, M.D., and Joseph C. Veniero, M.D., Ph.D.
Clin Colon Rectal Surg. 2008 August; 21(3): 193-212
For CTE & MRE patients will both drink a large volume of contrast and have a contrast delivered intravenously.
As noted in the first quote by Douglas Riegert-Johnson, MD et al., a naso-gastro tube is used in both CT enteroclysis and MR enteroclysis.
A recent article from the UK suggests that the PillCam or CE is better for children than barium enterography, “CE is a feasible, safe, and sensitive test for small bowel polyp surveillance in children with PJS. It is significantly more comfortable than BE and is the preferred test of most children for future surveillance.”
Postgate A, Hyer W, Phillips R, Gupta A, Burling D, Bartram C, Marshall M, Taylor S, Brown G, Schofield G, Bassett P, Spray C, Fitzpatrick A, Fraser C, Latchford A. Feasibility of video capsule endoscopy in the management of children
with peutz-jeghers syndrome: a blinded comparison with barium enterography for the detection of small bowel polyps. J Pediatr Gastroenterol Nutr. 2009
PubMed PMID: 19543117.
So friends, we may be facing newer, more accurate, though less physically pleasant tests than the PillCam. I'll let you know more as I learn more.
Up for more reading?
The PillCam misses a large polyp in a PJS person.
Postgate A, Despott E, Burling D, Gupta A, Phillips R, O'Beirne J, Patch D, Fraser C. Significant small-bowel lesions detected by alternative diagnostic modalities after negative capsule endoscopy. Gastrointest Endosc. 2008 Dec;68(6):1209-14.
PubMed PMID: 19028234.
CT Enterography as a Diagnostic Tool in Evaluating Small Bowel Disorders: Review of Clinical Experience with over 700 Cases
figure 17a & 17b at:
Enteroclysis for radiologists