Reply to Drs Leung an Sung: The Scope and the Capsule: a Reunited Family?

Since its clinical introduction in 2001, video capsule endoscopy of the small bowel with the M2A capsule has rapidly gained acceptance as novel noninvasive imaging method for detecting obscure bleeding sources located in the small bowel. Initial controlled and well-designed studies assessing its accuracy in detecting obscure gastrointestinal bleeding have recently been published [1] [2]. All studies published to date unequivocally show that capsule endoscopy is better than push enteroscopy and much better than all radiographic procedures in this setting [3]. These data suggest that capsule endoscopy is a safe, reliable, and highly sensitive tool for detecting sources of occult bleeding located in the entire length of the small bowel. Capsule endoscopy has already been widely adopted in gastroenterology centers around the world, despite country-specific problems with cost reimbursement policies such as those in Germany, where most health insurance companies are still refusing to reimburse costs associated with the diagnostic use of the video capsule.

The clinical use of video capsule endoscopy is substantially limited in particular by the high cost of the procedure, as well as other obstacles such as suspected small-bowel obstruction (e. g., due to unsuspected stenosis, previous abdominal surgery, or even diabetic or functional gastroparesis) that may enhance the risk of capsule retention. While relevant ”organic” stenoses can be reliably ruled out in most patients (over 98 %) by careful clinical history taking, small-bowel ultrasonography, and/or radiographic imaging in doubtful cases ([1] [2] [3]; authors’ unpublished experience), functional obstruction can still cause capsule retention in any part of the gastrointestinal tract. In patients who are at risk, this phenomenon occurs most frequently in those with moderate to severe gastroparesis due to diabetic or other neuropathies, as well as other chronic motor disorders including chronic intestinal pseudo-obstruction (CIP). There has therefore recently been growing clinical interest in finding simple but effective ways of reducing the risk of capsule retention in patients with impaired motility - particularly those with known or suspected functional motor problems such as gastroparesis - before capsule endoscopy, with its potential cost implications, is used [4].

We are grateful for the case report by Leung et al. [5] describing a patient with functional obstruction of both the esophagus and the antropyloric region, in whom the authors started successful capsule imaging of the bleeding source in the small bowel after using an overtube to facilitate esophageal transport and a polypectomy snare to ensure entry into the small bowel. The technique described is in keeping with our previous observations [4] and extends current knowledge of ways of successfully overcoming transit problems in the clinical setting. As in our own study, the combination of the digital recording capsule with a conventional scope and snare is attractive. It shows that the video capsule is a complementary technique that can serve as an adjunct to classic endoscopic methods by extending their reach. However, the principal problem - and a major goal for future studies - is to identify patients with functional motor problems that may substantially delay the capsule’s transit through the small bowel. Ideally, the future endoscopist’s armamentarium might include a carrier scope equipped with an additional self-propelling capsule unit that is transported as distally as possible by the conventional scope, but can be released after reaching the limit of the endoscope. Such a unit would also be capable of being guided online and of taking brush cytology samples during its passage. Until this visionary technology becomes available, however, the goal is to achieve clinical identification of patients in whom an expensive capsule may become trapped due to motility problems, and to use the conventional scope immediately to ensure an appropriate capsule-endoscopic examination of the entire small bowel.

References

• 1 Ell C, Remke S, May A. et al . The first prospective controlled trial comparing wireless capsule endoscopy with push enteroscopy in chronic gastrointestinal bleeding.  Endoscopy. 2002;  34 685-689
• 2 Saurin J C, Delvaux M, Gaudin J L. et al . Diagnostic value of endoscopic capsule in patients with obscure digestive bleeding: blinded comparison with video push-enteroscopy.  Endoscopy. 2003;  35 576-584
• 3 Pennazio M. Small-bowel endoscopy.  Endoscopy. 2004;  36 32-41
• 4 Hollerbach S, Kraus K, Willert J. et al . Endoscopically assisted video capsule endoscopy of the small bowel in patients with functional outlet obstruction.  Endoscopy. 2003;  35 226-229
• 5 Leung W K, Sung J JY. Endoscopically assisted video capsule endoscopy.  Endoscopy. 2004;  36 573-574