OP13 Postoperative Crohn’s disease recurrence: unanswered questions and future directions in diagnosis, pathophysiology, prevention and treatment. Conclusions from the 8th ECCO Scientific workshop

Abstract Background Despite the increased availability of biological therapies, postoperative recurrence (POR) after an ileocolonic resection with ileocolonic anastomosis frequently occurs in patients with Crohn’s disease. Methods Over the last two years, a mixed panel of 24 gastroenterologists and colorectal surgeons collaborated within the 8th Scientific Workshop of ECCO. The available evidence on diagnosis, pathophysiology and risk factors, prevention and treatment of POR was reviewed and unanswered research questions were listed. Results In recent years, surgeons have been utilising innovative surgical techniques to reduce POR. Whilst the side-to-side anastomosis has become more common, the benefits of newer procedures such as Kono-S anastomosis or over-the-valve strictureplasty remain unproven. Consistency in describing and reporting POR is crucial both in routine practice and in clinical research. Ileocolonoscopy six to twelve months after ileocolonic anastomosis remains the gold standard to diagnose POR. However, an effort to adapt the Rutgeerts score to surgical techniques different from end-to-end anastomosis is required. Significance of isolated ulcers of the anastomotic line, specifically in case of stapled anastomoses, is still debated. In the coming years, intestinal ultrasound combined to faecal calprotectin may ultimately decrease the reliance on ileocolonoscopy. Research on the microbiome and genetic background of patients with POR is promising although not applicable in daily clinical practice yet. Smoking is the only risk factor clearly identified in POR, whereas previous ileocolonic resection or penetrating disease have not been validated in prospective studies. Stronger emphasis on smoking cessation for all patients should include specific active measures to make it successful. The prevailing gap in accurate predictors of POR disempowers clinicians from stratifying between systematic prophylaxis and endoscopy-driven approach. Immediate prophylaxis therapy may lead to overtreatment.Ongoing randomized controlled trials comparing (i) systematic prophylaxis and endoscopy-guided introduction of biological therapy (NCT05169593), and (ii) therapy escalation to status quo in patients with moderate endoscopic POR (NCT05072782) should be informative. Conclusion Despite important progress in the field of POR in the last 30 years, POR management remains a challenge. The IBD community should strive to optimise diagnostic procedures of POR including ileocolonoscopy and non-invasive techniques, define patients at high risk of POR using microbiome and/or genetic profiling and clarify the optimal medical treatment strategy after surgery.