At present, CT or MRI enterography / enteroclysis is considered to be the imaging technique with the greatest diagnostic accuracy in detecting small bowel involvement in CD, including the extramural complications of the disease (ECCO 2008 consensus). (MRE atlas) La endoscopia con cápsula de intestino delgado debe reservarse para los pacientes con una sospecha clínica elevada de EC a pesar del resultado negativo de las exploraciones de ileocolonoscopia y otras técnicas de imagen.
Figure 1. Endoscopic capsule image. No mucosal alterations in the small bowel are seen. A normal endoscopic capsule exploratory result in the small bowel has a very high negative predictive value, and practically discards CD of the small bowel.
The lesions associated to CD that are described by capsule endoscopy require more precise definition. In effect, over 10% of all healthy individuals show small bowel erosions, and a large proportion of patients receiving treatment with nonsteroidal antiinflammatory drugs (NSAIDs) (up to 70% according to some studies) present erosions at endoscopic capsule exploration of the small bowel.
Figure 2. Endoscopic capsule image: Aphthoid erosions seen in different small bowel segments in a patient with known CD. The erosions are similar to those seen in patients treated with NSAIDs.
Endoscopic capsule images.
In a patient with known CD, the most common lesions found at endoscopic capsule exploration are aphthae, erosions, ulcers (linear, serpiginous or deep), and stricture zones.
Before performing endoscopic capsule exploration in patients with CD involving the small bowel, the possibility of strictures must be discarded, in view of the risk of capsule retention and secondary obstruction. Imaging techniques are used to this effect – generally computed tomography (CT) or MRE – or alternatively a prior patency test capsule can be used.
Figure 3. Patient with CD subjected to surgery, showing early clinical recurrence after the operation. The capsule study revealed longitudinal or irregular ulcerations in the distal ileum causing partial luminal stricture. The capsule initially slowed its advance in this zone, but was able to pass it. In cases of more marked strictures the capsule may be retained and cause secondary obstruction.
Figure 3Bis. CD with severe ileal involvement: extensive stellate-shaped ulcers and inflammatory involvement with secondary stricture and complications for capsule transit.
Although there are many opportunities for using the endoscopic capsule in CD (determination of the extent and severity of the lesions, postoperative recurrence, assessment of mucosal healing), in clinical practice the applications are limited. In effect, the previous need to rule out strictures and the introduction of highly sensitive radiological techniques that afford global information on the disease (luminal and extraluminal involvement) limit the indications of capsule endoscopy.
Figure 4. Endoscopic capsule evaluation of a patient with ileal CD. Confluent longitudinal ulcerations were seen over an erythematous mucosa. Since this was an inflammatory presentation in a recently diagnosed patient, no rigidity or motility problems were observed in the affected zone.
Figure 5: Patient operated on for CD with early clinical disease recurrence. Endoscopic capsule exploration revealed extensive involvement with extensive ulcerations of the terminal ileum compatible with Rutgeerts score i4 recurrence. The capsule is seen to pass through the ileocolic anastomosis. (Clinical case 5)
Figura 6. Imagen de capsula endoscópica en paciente con recurrencia postquirúrgica precoz. Se observa una úlcera amplia a nivel de neo-ileon y 2-3 ulceraciones menos llamativos, compatible con recurrencia i2.