P366 Risk factors and outcomes of chronic antibiotic-refractory pouchitis in Korean ulcerative colitis patients: a single center retrospective study

Abstract

Abstract Background Chronic inflammation of the pouch after total proctocolectomy with ileal pouch-anal anastomosis (IPAA) remains a morbid complication in ulcerative colitis (UC). The goal of this study was to investigate risk factors and clinical outcomes of chronic antibiotic-refractory pouchitis (CARP) in Korean patients with UC. Methods This was a single center retrospective study on patients with UC who underwent total proctocolectomy with IPAA at Asan Medical Center in Korea between January 1987 and December 2022. CARP was defined as failure to respond to a 4-week course of a single antibiotic, needing more than 4 weeks of therapy with 5-aminosalicylates, steroids, immunomodulators or biologics/small molecules, while chronic antibiotic-dependent pouchitis (CADP) was defined as more than 3 episodes of pouchitis per year or persistent symptoms requiring long-term antibiotics to maintain disease remission. Primary outcomes were endoscopic remission defined as complete mucosal healing of chronic pouchitis and pouch failure defined as the requirement of diverting loop ileostomy or pouch excision. Univariable and multivariable logistic regression analysis were used to identify risk factors of CARP. Results A total of 251 patients were included and 232 were analyzed (Male, 57.3%; Current smoker, 13.4%; Median age at surgery, 44 years; Disease duration at surgery, 4 years; Previous exposure to biologics/small molecules, 23.7%; Extra-intestinal manifestations, 8.2%; Preoperative cytomegalovirus infection, 19.4%). The most common cause of surgery was steroid refractoriness (50.9%), followed by dysplasia/colorectal cancer (26.7%). The median time from surgery to chronic pouchitis was 48 months (interquartile range 23.5–100.0). Among 74 patients (31.9%) with chronic pouchitis, 31 patients (13.4%) were CARP and 43 patients (18.5%) were CADP. The most frequent endoscopic phenotype according to Chicago classification was focal inflammation of the pouch in all groups (chronic pouchitis, 47.3%; CARP, 35.5%; CADP, 55.8%). Patients with CARP were less likely to have concomitant probiotics compared with CADP (29.0% vs 72.1%; p<0.01). Endoscopic remission rate in chronic pouchitis, CARP, and CADP were 14.9% (11/74), 9.7% (3/31), and 18.6% (8/43), respectively (Table 1). Pouch failure rate in chronic pouchitis, CARP, and CADP were 13.5% (10/74), 16.1% (5/31), and 11.6% (5/43), respectively (Table 1). In a multivariable analysis, current smoking status was positively associated with CARP development (OR: 3.56; 95% confidence interval 1.33–9.52; p=0.01). Conclusion Current smoker with UC who underwent IPAA had a higher risk of CARP. Concomitant use of probiotics was less likely to be associated with developing CARP.