Colonoscopy-guided therapy for the prevention of post-operative recurrence of Crohn's disease.

backgroundAbout half of patients with Crohn's disease (CD) require surgery within 10 years of diagnosis. Resection of the affected segment is highly effective, however the majority of patients experience clinical recurrence after surgery. Most of these patients have asymptomatic endoscopic recurrence weeks or months before starting with symptoms. This inflammation can be detected by colonoscopy and is a good predictor of poor prognosis.Therapy guided by colonoscopy could tailor the management and improve the prognosis of postoperative CD.

objectivesTo assess the effects of prophylactic therapy guided by colonoscopy in reducing the postoperative recurrence of CD in adults. SEARCH

methodsThe following electronic databases were searched up to 17 December 2019: MEDLINE, Embase, CENTRAL, Clinical Trials.gov, WHO Trial Registry and Cochrane IBD specialized register. Reference lists of included articles, as well as conference proceedings were handsearched. SELECTION CRITERIA: Randomised controlled trials (RCTs), quasi-RCTs and cohort studies comparing colonoscopy-guided management versus management non-guided by colonoscopy. DATA COLLECTION AND ANALYSIS: Two review authors independently considered studies for eligibility, extracted the data and assessed study quality. Methodological quality was assessed using both the Cochrane 'Risk of bias' tool for RCTs and Newcastle-Ottawa scale (NOS) for cohort studies. The primary outcome was clinical recurrence. Secondary outcomes included: endoscopic, surgical recurrence and adverse events. We calculated the risk ratio (RR) for each dichotomous outcome and extracted the hazard ratio (HR) for time-to-event outcomes. All estimates were reported with their corresponding 95% confidence interval (CI). Data were analysed on an intention-to-treat (ITT) basis. The overall quality of the evidence was evaluated using GRADE criteria. MAIN

resultsTwo RCTs (237 participants) and five cohort studies (794 participants) met the inclusion criteria. Meta-analysis was not conducted as the studies were highly heterogeneous. We included two comparisons. Intensification of prophylactic-therapy guided by colonoscopy versus intensification guided by clinical recurrence One unblinded RCT and four retrospective cohort studies addressed this comparison. All participants received the same prophylactic therapy immediately after surgery. In the colonoscopy-based management group the therapy was intensified in case of endoscopic recurrence; in the control group the therapy was intensified only in case of symptoms. In the RCT, clinical recurrence (defined as Crohn's Disease Activity Index (CDAI) > 150 points) in the colonoscopy-based management group was 37.7% (46/122) compared to 46.1% (21/52) in the control group at 18 months' follow up (RR 0.82, 95% CI: 0.56 to 1.18, 174 participants, low-certainty evidence). There may be a reduction in endoscopic recurrence at 18 months with colonoscopy-based management (RR 0.73, 95% CI 0.56 to 0.95, 1 RCT, 174 participants, low-certainty evidence). The certainty of the evidence for surgical recurrence was very low, due to only four cohort studies with inconsistent results reporting this outcome. Adverse events at 18 months were similar in both groups, with 82% in the intervention group (100/122) and 86.5% in the control group (45/52) (RR 0.95, 95% CI:0.83 to 1.08, 1 RCT, 174 participants, low-certainty of evidence).The most common adverse events reported were alopecia, wound infection, sensory symptoms, systemic lupus, vasculitis and severe injection site reaction. Perforations or haemorrhages secondary to colonoscopy were not reported. Initiation of prophylactic-therapy guided by colonoscopy versus initiation immediately after surgery An unblinded RCT and two retrospective cohort studies addressed this comparison. The control group received prophylactic therapy immediately after surgery, and in the colonoscopy-based management group the therapy was delayed up to detection of endoscopic recurrence. The effects on clinical and endoscopic recurrence are uncertain (clinical recurrence until week 102: RR 1.16, 95% CI 0.73 to 1.84; endoscopic recurrence at week 102: RR 1.16, 95% CI 0.73 to 1.84; 1 RCT, 63 participants, very low-certainty evidence). Results from one cohort study were similarly uncertain (median follow-up 32 months, 199 participants). The effects on surgical recurrence at a median follow-up of 50 to 55 months were also uncertain in one cohort study (RR 0.79, 95% CI 0.38 to 1.62, 133 participants, very low-certainty evidence). There were fewer adverse events with colonoscopy-based management (54.8% (17/31)) compared with the control group (93.8% (30/32)) but the evidence is very uncertain (RR 0.58, 95% CI 0.42 to 0.82; 1 RCT, 63 participants). Common adverse events were infections, gastrointestinal intolerance, leukopenia, pancreatitis and skin lesions. Perforations or haemorrhages secondary to colonoscopy were not reported. AUTHORS'

conclusionsIntensification of prophylactic-therapy guided by colonoscopy may reduce clinical and endoscopic postoperative recurrence of CD compared to intensification guided by symptoms, and there may be little or no difference in adverse effects. We are uncertain whether initiation of therapy guided by colonoscopy impacts postoperative recurrence and adverse events when compared to initiation immediately after surgery, as the certainty of the evidence is very low. Further studies are necessary to improve the certainty of the evidence of this review.