Introduction
Crohn's disease (CD) is a chronic inflammatory bowel disease, characterized by a progressive course that leads to structural bowel damage (SBD). There is no clear definition of SBD. The Lémann index has been proposed, but it's too complicated to calculate. However, the presence of detectable complications through imaging techniques, such as strictures, fistulas or abscesses is widely accepted to describe SBD. Their presence is strongly associated with the severity of the disease and predicts the risk of hospitalization and surgery. Therefore, reversing structural bowel damage is an emerging medical goal in the time of biological treatments.
Aims & Methods
The main objective of this study was to assess the ability of biological treatments to reverse structural bowel damage monitored by intestinal ultrasound (IUS) and compare the disease course of patients with CD with inflammatory behaviour vs complicated behaviour (stricturing or penetrating -abscesses and fistulas-).
This was a longitudinal observational study, which included patients with CD who started a biological treatment in our center and that were monitored with IUS. Clinical, laboratory and ultrasound variables were collected at the beginning of biological treatment, after 12 weeks and after one year of treatment in order to study the evolution of the disease.
To achieve our objective, we compared the transmural healing (TH) at 12 weeks and one year after starting biological treatment. TH is defined as intestinal parietal thickness ≤3 mm, with no detectable Doppler signals and absence of complications.
As a secondary objective, we compared the need for medical treatment, hospital admission and surgery during the first year of biological treatment
Results
A total of 137 patients with CD were included in this study. Their characteristics and treatments are shown in Table 1.
| Variables |
| Absolute frequency (%) |
|---|
| Male |
| 67 (48.9%) |
| Initial bowel damage | Stricturing | 31 (22.6%)
|
| Abscesses
| 11 (8%)
|
| Fistula
| 21 (15.3%)
|
| Montreal Classification | Age
| ≤16 years: 12 (8.8%)
17-40 years: 79 (57.7%)
≥ 41 years: 46 (33.6%)
|
| Location
| Ileal: 75 (54.7%)
Colonic: 19 (13.9%)
Ileocolonic: 43 (31.4%)
Upper disease: 1 (0.7%) |
| Behaviour | Inflammatory: 53 (38.7%)
Stricturing: 30 (21.9%)
Penetrating: 54 (39.4%) |
| Indication for initiating biologic treatment | Stenotic complication | 25 (18.2%)
|
| Penetrating complication | 22 (16.1%) |
At the beginning of biological treatment, 50 patients (36.5%) exhibited a complicated behaviour (strictures, abscesses, and fistulas).
After 12 weeks of treatment, TH was achieved in 22.9% of all evaluated patients. By groups, 8.2% of patients with complicated CD and 31.3% with an inflammatory behavior achieved TH, being the last difference statistically significant (p 0.02). After one year of treatment, TH on IUS was achieved in 46% of all evaluated patients. 31.8% of these patients had a complicated EC and 45.1% presented an inflammatory behavior, without reaching statistical significance (p 0.159).
Furthermore, the group with complicated behavior exhibited a significantly higher need for corticosteroid therapy, hospital admission, and surgery.
Conclusion
Patients with SBD showed a significantly lower rate of TH compared to patients with an inflammatory behaviour after 12 weeks of biological treatment. Additionally, the need for corticosteroid therapy, hospital admission, and surgery was significantly higher in patients with a complicated CD. However, after one year, the TH rate showed no differences between groups. This suggests that reversing structural bowel damage is possible but that the treatment of these patients is more complex.
References
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