Crohn's disease (CD) is a chronic condition characterized by a high recurrence rate after surgery, which seriously affects the quality of life of patients. Many studies have explored the risk factors for the recurrence of CD after surgery, there is a lack of meta-analysis focusing on endoscopic postoperative recurrence (ePOR) as a clinical outcome. Therefore, this paper aims to identify the risk factors for ePOR in CD patients through systematic review and meta-analysis.

PubMed, Embase, Cochrane Library, and Web of Science databases were searched for related literature from inception to 17th October 2023. Two researchers independently screened the literature and extracted information. Data analysis was performed using Stata18.0.

Twenty-three papers were included, with 5 case-control studies and 18 cohort studies. The National Institutes of Health quality assessment tool rated 17 studies as good and 6 studies as fair. The sample size of the 23 studies ranged from 40 to 346, and the number of patients with ePOR ranged from 23 to 169. The results of multivariate meta-analysis showed that smoking [OR = 2.06, 95% CI (1.65, 2.57), P = 0.0001], previous ileocolonic resection [OR = 1.71, 95% CI (1.23, 2.38), P = 0.002], disease localization at ileocolic resection [OR = 2.68, 95% CI (1.38, 5.22), P = 0.004], perianal disease [OR = 1.47, 95% CI (1.07, 2.03), P = 0.017], and anastomotic scattered ulcer [OR = 3.39, 95% CI (1.83, 6.28), P = 0.001] were risk factors for ePOR in CD patients. Postoperative prophylactic medication [OR = 0.53, 95% CI (0.38,0.75), P = 0.0001] was a protective factor for ePOR in CD patients.

This systematic review identified multiple factors for ePOR in CD patients, as well as a protective factor. However, the number of articles included was limited. More high-quality clinical studies are required to further validate the conclusions.

This study was registered in the International Prospective Register of Systematic Reviews (PROSPERO) (CRD42023483671).

Surgery for Crohn's disease (CD) is not curative, as postoperative recurrence (POR) after ileocolonic resection is the rule in the absence of prophylactic treatment. In the present article, we critically review available data on the role of anti-tumour necrosis factor (TNF) agents and new biologics (including vedolizumab and ustekinumab) in the prevention and treatment of POR after surgery in CD. Several studies (summarised in various meta-analyses) have confirmed the efficacy of anti-TNFs in the prevention of POR. We identified 37 studies, including 1863 CD patients, with mean endoscopic POR at 6-12 months of 29%. Only few randomised controlled trials (RCTs) have directly compared thiopurines and anti-TNFs, with controversial results, although the superiority of the latter is supported by several meta-analyses. Infliximab and adalimumab seem equally effective. The combination of anti-TNFs and immunosuppressives should be considered in patients previously exposed to anti-TNFs. Several studies have shown that anti-TNFs remain an effective option to prevent POR also in patients with anti-TNF failure before surgery. In fact, the use of the same anti-TNF before and after surgery might be effective for the prevention of POR. Prophylactic anti-TNF treatment, once started, should be continued long term. Anti-TNFs are also effective for the treatment of established POR. Retreatment with anti-TNFs for POR is a valid strategy even after their preoperative failure. In six studies (including 156 patients) evaluating vedolizumab, mean endoscopic POR at 6-12 months was 41%. The non-randomised comparison of anti-TNFs and vedolizumab has provided controversial results. One placebo-controlled RCT confirmed that vedolizumab is quite effective in preventing POR in CD patients with increased risk of recurrence. Seven studies (including 162 patients) evaluated ustekinumab, with a mean endoscopic POR at 6-12 months of 41%. The comparative efficacy of ustekinumab and anti-TNFs is still unclear. Ustekinumab and vedolizumab seem to be equally effective, although the experience is very limited. In conclusion, to date, anti-TNFs are the most effective agents in preventing and treating POR in CD. Anti-TNFs remain an effective option to prevent POR also in patients with anti-TNF failure before surgery. Vedolizumab seems to be quite effective in the prevention of POR in patients with increased risk of recurrence. Ustekinumab is probably also effective in the postoperative setting, although the comparative efficacy with anti-TNFs or vedolizumab is still unclear.

[This corrects the article DOI: 10.4103/sjg.sjg_499_21].