Risk Factors and Quality of Life in Patients with Diffuse Pouchitis After Ileal Pouch Anal Anastomosis According to the Chicago Classification for J Pouch: a Retrospective Multicenter Cohort Study in China

Background: Pouchitis is a common late complication in patients with ulcerative colitis (UC) who undergo ileal pouch-anal anastomosis (IPAA). The heterogeneous nature of the clinical and endoscopic presentations could affect the evaluation of therapeutic interventions for pouchitis. Thus, identifying the risk factors and clinical outcomes of pouch inflammation at different sites and severity is becoming increasingly important for colorectal surgeons.

Methods: Data on patients who underwent IPAA January from 2008 to June 2022 in our three pouch centers affiliated with the China UC Pouch Center Union were retrospectively collected. Pouchitis was categorized as a different phenotype according to the Chicago Classification. J pouches were classified into short (14 ± 2 cm) and long pouches (22 ± 2 cm) according to the distribution of ileal pouch length in our institute.

Results: Altogether, 143 patients with a median follow-up time of 5.0 years (interquartile range: 2.0-8.0) were enrolled. Among them, 41 patients (28.7%) developed pouchitis and 32 patients (78%) had diffuse inflammation of the pouch. Patients with diffuse pouchitis had a higher pouchitis disease activity index and more seriously impaired improvement of long-term quality of life than those with pouch phenotypes. A short J pouch, recurrent UC, and preoperative high white blood cell count were independent risk factors for diffuse pouchitis. Furthermore, a short J pouch could effectively predict the occurrence of diffuse pouchitis with an area under the receiver-operating characteristic curve of 0.614, a sensitivity of 62.5%, and a specificity of 60.4% (p = 0.049) and significantly decreased the overall diffuse pouchitis-free survival compared to a long J pouch (p = 0.0002).

Conclusion: Diffuse pouchitis is a common phenotype of pouchitis that seriously impairs long-term prognosis. For colorectal surgeons, decision-making regarding pouch construction with an appropriate length should be considered to prevent the development of diffuse pouchitis.