capsule experience - MG Lorenzatto

Chapter 6
Iatrogenic Diseases
David R. Cave, M.D.
INTRODUCTION
Capsule endoscopy [CE] has provided a revolutionary and
sensitive method for the visualization of the small intestinal
mucosa at an 8:1 magnification with excellent resolution. This
technology allows us for the first time to view non-invasively
the majority of the intestinal mucosa. Any technology is
subject to the Heisenberg uncertainty principle. In brief, this
states that, in the process of making an observation, the
measurement alters the behavior of the object of study. In
the case of CE, the capsule behaves as a large particle of food.
Because of this, the mucosal folds are in their near natural
state unlike during conventional push enteroscopy where the
insufflation of air opens the lumen and flattens the mucosa.
Furthermore, the process of mucosal flattening may obscure
subtle villous changes. Similarly diverticula are generally not
seen with CE, because the lumen is collapsed and are therefore
unlikely to trap a capsule.
It is important to understand that succus entericus and partially
digested food are liquid and rarely contain large food particles.
Therefore quite tight strictures may only be revealed by
passage or retention of the video capsule that has a diameter
of 11mm. The implications of this are, that the pros and cons
of the procedure should be carefully considered, by both
patient and physician, prior to capsule ingestion. This is
particularly true in patients who use NSAIDs and who have
had radiation, because these strictures may not be
demonstratable by conventional technology including
enteroclysis. Therefore, CE should not be performed on
patients who are an unacceptable operative risk, since
retention of a capsule in such a patient could put all concerned
in a serious predicament. Retained capsules have remained
in patients for up to 14 weeks without causing symptoms,
but more long-term data regarding retained capsules is
needed. The small bowel may be injured by a variety of
medications, ionizing radiation and surgery with short and/or
long-term consequences. This chapter will review these
conditions and provide images that demonstrate each of
these situations.
CAPSULE EXPERIENCE
NSAIDS AND OTHER MEDICATIONS
NSAIDs are well known to cause gastro-duodenal injury. Less
commonly, injury to the more distal small bowel and colon
has been reported. Well described, but rare, are NSAID
associated webs or strictures. How common these latter
lesions are is unknown, as they will only draw attention to
themselves if they cause bleeding or iron deficiency anemia.
Generally small bowel series or enteroclysis will not show
them, as they are often only more rigid versions of the normal
63