Behaviour of the bowel wall during the first year after surgery is a strong predictor of symptomatic recurrence of Crohn's disease: a prospective study

Background: Recurrences after surgery for Crohn's disease are frequent and unpredictable. To date, there is little agreement as to which factors increase a patient risk of early recurrence. Aim: To assess whether the post-operative behaviour of diseased bowel walls, as determined by ultrasound, may be a useful predictor of relapse. Methods: A total of 127 Crohn's disease patients were monitored after surgery by means of bowel ultrasound as well as by clinical and laboratory evaluations for a median follow-up of 41.0 months. Bowel wall thickness of diseased loops measured at ultrasound during follow-up was compared with the presurgery values. Multivariable survival analysis was performed to elucidate predictors of early post-operative recurrence. Receiver operating characteristic curves were also constructed taking into account bowel wall thickness for selecting Crohn's disease patients with high risk of clinical/surgical recurrence. Results: The estimated 5 years survival probability of symptomatic Crohn's disease recurrence were 90% and 33%, respectively for unchanged/worsened bowel wall thickness vs. improved bowel wall thickness at 12 months from surgery. The hazard ratio for unchanged/worsened bowel wall thickness at 12 months was 8.9 (95% CI: 3.4-23.2). Receiver operating characteristic curve identified a bowel wall thickness > 6.0 mm at 12 months from surgery as directly associated with the risk of having a Crohn's disease recurrence (hazard ratio was 6.5, 95% CI: 2.8-15.4). Conclusions: Systematic ultrasound follow-up of diseased bowel walls after conservative surgery allows the early identification of patients at high risk of clinical/surgical recurrence.