The initial or early phase of ileal Crohn’s disease (CD) often presents an inflammatory phenotype. The tendency of ileal disease is to progress over time towards stricturing or penetrating forms – the course being conditioned by epidemiological or genetic factors.
Figure 1. Normal ileum
Figure 2. Ileum with inflammatory involvement. Edematous and thickened mucosa. Longitudinal, superficial ulcerations are observed, along with deeper ulcers with serpiginous or stellate margins.
The ileal disease is characterized by more frequent complications (abscesses, fistulas, intestinal obstruction) and need for surgery than disease located in the colon. In up to 14-36% of all cases these complications can manifest as the first symptoms of ileal disease.
The inflammatory form often progresses towards complicated presentations, and combined patterns can be observed (mixed forms with stricture zones and inflammation, penetrating forms associated to advanced strictures).
Knowledge of the phenotype and extent of the disease are factors influencing the treatment decision. Treatment conceived for predominantly inflammatory forms of the disease, with extensive ileal involvement, is most likely to be very different from treatment designed to deal with the predominantly stricturing forms of the disease that affect short bowel segments.
Figure 3. Ileal disease with predominantly inflammatory involvement and the development of strictures. Ileoscopic signs of inflammatory activity: edema, mucosal thickening, serpiginous ulcers, nodules. Presence of ulcerated annular strictures preventing ileoscopy from advancing.
Figure 4. Ileal disease with predominantly stenotic involvement. A predominance of ileal non inflammatory stenosis or stricturing is observed, with coexisting cicatricial lesions, pseudo-nodules and short ulcerated segments.
Figure 5. Evolved mixed pattern: strictures / inflammation / residual lesions. Ileoscopy corresponding to a patient treated with biological agents for ileal disease with predominantly inflammatory changes within a long ileal segment. The treatment has been able to reduce the mucosal inflammation, though edematous, friable mucosa is still seen, with a fibrinous exudate within an ileum showing probably non-recoverable partial stricturing. Regenerative-residual nodules. Destructured ileocecal valve with a small ileocecal fistular orifice.
Figure 6. Inflammatory / stricturing ileal disease. Upon penetrating the ileum, a marked and non-passable ulcerated stricture is observed. This probably corresponds to established stricturing disease in which overlying inflammatory activity with ulceration has conditioned the worsened symptoms.
Figure 7. Inflammatory component with disperse ulcers overlying rigid stricturing disease not passable at ileoscopy.
The presence of strictures often impedes adequate ileal assessment. Only the use of a complementary technique allows us to evaluate the extent and severity of inflammation. The existence of stenosis also conditions use of the endoscopic capsule due to the risk of retention. Advances in radiological techniques help us to adequately assess both the extent and the evolutive pattern (magnetic resonance enterography (MRE) evaluation of inflammatory activity).
Figure 8. Mixed ileal involvement: Predominance of the stenotic and pseudo-nodular component in relation to previous inflammatory conditions. As we advance along the ileum, longitudinal ulcerated areas are seen, though the associated stricturing precludes correct assessment of the entire affected segment.
Video 1 de MRE: La realización de Enterorresonancia en este caso permite valorar correctamente el grado de inflamación asociada aportando información importante para la decisión terapéutica.
In the presence of highly evolved and complicated forms with stricturing / penetrating phenotypes at the time of diagnosis, surgery may be regarded as first option. If inflammatory changes predominate over the other patterns, the early use of biological treatment may contribute to modify the evolutive pattern. (Reference 5 y Clinical case 1))
Figure 9. At cecal level we observe important local disarrange, probably related to advanced-complicated forms of the disease. Upon entering the ileum, marked stricturing is seen, with at least two fistular orifices showing active purulent drainage.
Figure 10. Ileoscopy in a patient with severe ileal disease refractory to corticosteroids, following treatment with anti-TNF agents. Residual cicatricial lesions are seen. Mild stricturing persists, without generating symptoms.
Mixed endoscopic involvement with a predominantly inflammatory component prior to treatment (ileoscopy before treatment). After treatment, mucosal healing is seen with an increased ileal caliber showing good peristalsis and motility. Cicatricial lesions in the previous ulcerated stenotic zone that are passed without difficulty. No inflammatory alterations are evidenced by the MRE study (Clinical case 1)