P440 Myenteric plexitis and active inflammation at surgical margins are high-risk predictors for postoperative clinical recurrence of Crohn’s disease

Abstract

Abstract Background Preventing postoperative recurrence is an important issue for clinical management of Crohn’s disease (CD). Identification of practical risk factors and an effective prophylactic treatment strategy has been desired for the prevention of postoperative recurrence. Although some of the clinical risk factors have been applied to select candidates for prophylactic treatments, these attempts have not fully prevented postoperative recurrence. In this study, we investigate the histological features at resected margins which predicted postoperative recurrence, and whether the initiation of prophylactic treatments could prevent postoperative recurrence in these cases. Methods We retrospectively reviewed the clinical recurrence rate in CD patients who underwent intestinal resection between January 2019 and December 2021. Clinical recurrence was defined by combination of serological, radiographic, and endoscopic findings or treatment escalation. To assess the histological risk factors for postoperative recurrence, resection margins of the surgical specimens were evaluated for the presence of myenteric plexitis, granulomas, and active inflammation. Each histological feature was evaluated from Grade 0 to 3. We also examined the ability of prophylactic treatments to prevent postoperative recurrence stratified with histological findings related to clinical recurrence rates. Results Of the 141 patients included in this study, 61.9% had plexitis (grade 3:Inflammatory cells at myenteric plexus, 10>HPF) at the proximal margin and 13.5% had active inflammation (grade 3: erosion or ulcer) at the distal margin. Log rank test identified the presence of plexitis (Grade3) (HR:1.84, 95%CI [1.05-3.22], p=0.029) at the proximal margin and active inflammation (Grade3) at the distal margin (HR:1.29, 95%CI [1.05-1.58], p=0.012) as possible risks of clinical recurrence (Figure). Multivariate analysis confirmed that the presence of plexitis (Grade3) at the proximal margin (HR 1.82, 95% CI 1.04-3.21, P=0.038) and active inflammation (Grade 3) at the distal margin (HR 2.31, 95% CI 1.18-4.46, P=0.013) were associated with postoperative clinical recurrence. Prophylactic use of immunomodulators (IM) and biologics did not show a significant reduction of clinical recurrence compared to treatment without IM and/or biologics in patient with histological risk factors (Table). Conclusion Our results indicate that the presence of plexitis in the proximal margin and active inflammation in the distal margin of the resected intestine are risk factors for postoperative recurrence. In these cases, initiation of prophylactic treatments with biologics and/or IM may not prevent the clinical recurrence.