Introduction

Recurrence of Crohn’s disease (CD) lesions after surgery remains high. Identifying patients at high risk of recurrence who may benefit from prophylactic therapy would be relevant. However, data on specific preoperative risk factors remain scarce, while onset and severity of Post Operative Recurrence (POR) are assessed with the Rutgeerts score (RS)(1). Still, the value of early endoscopic lesions, and RSi2, to predict the later course of the disease and the risk of late (from 1 to 10 years) POR in any individual patient is unclear. Non-invasive Small Intestine Contrast Ultrasonography (SICUS) assesses intramural extension of CD lesions, their progression, and is as effective as RS in detecting early POR lesions (2).

Aims & Methods

1. To develop a risk score based on pre-operative clinical predictors to estimate POR likelihood;
2. to identify predictors of severity of mucosal lesion according to RS;
3. to assess the overtime progression of transmural lesion.
Prospective cohort study (1998-2022). CD patients were evaluated at ileo-colonic surgery and every 6-12 months thereafter. Sex, age at diagnosis/surgery, active smoking, CD behaviour (B)/location (L), perianal disease (PD), length of resected bowel, steroids, immunosuppressants/biologics therapy use, and CD duration before surgery were analysed using multivariable proportional hazards regression. Cumulative POR rates and risk score were calculated with Poisson models, taking for each predictor the integer part of the Poisson model parameter.

Results

Over a median follow-up of 7.6 years (IQR 4.1–12), 78 patients (32 F; median age 30 years; 60% smokers) were analysed. CD characteristics: B1 8%; B2 67%; B3 25%; L1 63%; L3 36%; PD 22%; immunosuppressive/biologics 17%; median CD duration pre-surgery 4.7 years; median resected bowel length 28 cm. Cumulative POR rates were 51.8% (IQR,41%-63.4%), 65.2% (54.4%-75.7%), 69% (58.6%-79%), 75.9% (65.8% -84.8%), 78.9% (69.0%-87.3%), at 1, 2, 3, 4, and 5 years. POR risk factors included active smoking, age ≥35 years at surgery, and marginally B1 (Table). Predictors of RS were PD (HR=3.39; 95% CI 1.12-10.26; p=0.03 and CD duration ≥5 years pre-surgery (3.45; 1.15–10.32; p=0.03). The estimated cumulative probability of POR increased with higher risk scores (from 1 to 3) being 22%, 58%, 83% and, respectively, 43%, 80% and 100% at 1 and 4 years. Lesion length at POR varied by RS (median, IQR): RSi1 (32%): 0.5 cm (0.5-0.5), RSi2 (35%): 4 cm (0.5-7), RSi3 (15%): 15 cm (8.5-21.5), RSi4 (5%): 16 cm (9.5-23.5). Lesions remained stable in patients with RSi1 and RSi3 (45%) but fluctuated in those with RSi2 and RSi4 (31% increased, 24% decreased).

Conclusion

The present score based on preoperative factors predicts the risk of postoperative recurrence. Patients with preoperative higher risk scores or RSi2 at recurrence would require early and close monitoring due to significant transmural lesion progression.

References

1.Rutgeerts R et al. 1990; 2. Pallotta N et al. 2010.

Disclosure

Nothing to disclosure

Introduction

Intestinal ultrasound (IUS) is increasingly used as a point-of-care tool for patients with ulcerative colitis (UC). Non-invasive monitoring is essential for managing disease progression and therapeutic intervention in pediatric UC patients. The Milan Ultrasound criteria (MUC), ulcerative colitis intestinal ultrasound score (UC-IUS), and Civitelli score show promise as real-time disease activity assessment tools, potentially reducing the need for invasive procedures like endoscopy.

Aims & Methods

A prospective cohort of 34 pediatric UC patients underwent IUS and colonoscopy to assess disease activity using MUC, UCIUS, and Civitelli scores. Assessments were conducted within a 7-day interval, with no therapeutic changes between procedures. Diagnostic accuracy was determined using receiver operating characteristic (ROC) curves, with endoscopy as the reference
standard, and histological parameters assessed in a subset of patients using the Nancy Index.

Results

The study included 34 pediatric UC patients (median age: 14.7 years; 65% male) with varied disease severities and durations (median duration: 12.6 months; median PUCAI: 30; median fecal calprotectin: 1041 μg/g). Bowel wall thickness (BWT) correlated significantly with all IUS scores; however, no correlation was observed between BWT and baseline Mayo endoscopic disease activity. The area under the curve (AUC) was 0.528 (CI:0.348–0.704) for MUC, 0.602 (CI: 0.418–0.768) for UC-IUS, and 0.572 (CI: 0.388–0.742) for the Civitelli score, indicating moderate diagnostic accuracy. While differences among scores were not statistically significant, UC-IUS demonstrated the highest accuracy. In 16 patients with available Nancy Index data, the AUC values were 0.500 for MUC, 0.579 for Civitelli, and 0.563 for UC-IUS, further supporting moderate accuracy (Table 1).

Conclusion

Both MUC, Civitelli, and UC-IUS scores provide moderate diagnostic accuracy in assessing pediatric UC, though potentially less effective than in adult populations. UC-IUS, with its emphasis on vascularization, haustration and wall thickness, may offer enhanced sensitivity in pediatric patients. Lowering the cut-off for bowel wall thickness may improve accuracy in children, given their thinner, yet highly vascularized bowel walls, particularly in early disease stages.

References

1. van Wassenaer EA, van Rijn RR, Zwetsloot SLM, et al. Intestinal Ultrasound to Assess Ulcerative Colitis Disease Activity in Children: External Validation and Comparison of 2 Intestinal Ultrasound Activity Indices. Inflamm Bowel Dis. 2023;29:1217-1222.
2. Allocca M, Dell'Avalle C, Craviotto V, et al. Predictive value of Milan ultrasound criteria in ulcerative colitis: A prospective observational cohort study. United European Gastroenterol J. 2022;10:190-197

Introduction

The Mayo Endoscopic Subscore (MES) is the most widely used endoscopic index for assessing disease activity in ulcerative colitis (UC). Although artificial-intelligence　(AI)–assisted colonoscopy is expected to reduce inter-observer variability, the MES 4-point scale (0–3) lacks sufficient sensitivity to detect subtle changes in mucosal activity, limiting its ability to capture incremental improvement or deterioration. Moreover, because MES focuses on qualitative features—such as bleeding and erosions—without considering the extent or surface area of inflammation, it provides an incomplete estimate of a patient’s overall inflammatory burden.

Aims & Methods

We sought to develop and validate a quantitative, AI–driven colonoscopic score—Quantitative Ulcerative Colitis Assessment using Deep-learning (QUAD)—and to determine whether it predicts clinical relapse in patients with UC. The QUAD system was trained on 84 743 colonoscopic images from 998 UC patients at three centers and comprises three main functions: i) Image filtering: Automatic exclusion of low-quality images that are unsuitable for analysis owing to light saturation (halation), inadequate insufflation, excessive proximity to the mucosa, chromoendoscopy, or virtual chromoendoscopy. ii) Frame-level scoring: Each frame is divided into four quadrants; inflammation in each quadrant is graded from 0 to 3, and the quadrant scores are summed to yield a QUAD score of 0–12. iii) Video-level aggregation: Full-length withdrawal videos are processed to generate (i) an Entire QUAD score (0–60), representing pan-colonic inflammation, and (ii) a Distal QUAD score (0–12) for the rectosigmoid segment (final 20 % of the video).
The QUAD system contains mainly three function: i) automatically exclude low quality images that is ineligible for analysis in cases of halation, inadequate air de­livery, proximity to mucosa, chromoendoscopy, and virtual chromoendoscopy; ii) fully auto­mated twelve-class score output based on frame analysis: Each frame was divided into four quadrants; inflammation in each quadrant was graded 0–3 and summed to yield a QUAD score of 0–12; and iii) full-length withdrawal videos were processed to generate (I) an Entire QUAD (0–60) for considering whole-colon inflammation status and (II) a Distal QUAD (0–12) for the distal rectum–sigmoid segment (final 20 % of the video). An open-label cohort of adults with quiescent UC (partial Mayo score ≤ 2 for ≥6 months) was prospectively enrolled at a single center (August 2022–February 2023), and followed for 24 months after baseline colonoscopy; clinical relapse was defined as partial Mayo score > 2. The predictive value of QUAD scores for relapse was evaluated.

Results

Frame-level QUAD scores correlated strongly with expert-assigned MES values (Spearman r = 0.68, p < 0.01). Among 156 participants (median age, 51 years; 49 % male), 22 experienced relapse during follow-up. Relapse occurred in 19.4 % (19/98) of patients with a QUAD score > 3 versus 5.2 % (3/58) with a score ≤ 3 (log-rank p = 0.01).
In video analysis, an Entire QUAD > 6 did not significantly stratify relapse risk (16.8 % [17/101] vs 9.1 % [5/55]; log-rank p = 0.17). In contrast, a Distal QUAD > 3 was strongly associated with relapse (43.8 % [7/16] vs 10.7 % [15/140]; log-rank p < 0.01).

Conclusion

AI-generated QUAD provides a sensitive, fully quantitative measure of mucosal inflammation and stratifies relapse risk in clinically quiescent UC. In particular, the automatically derived Distal QUAD—focused on the distal colon and independent of operator image selection—offers a practical, objective tool for longitudinal monitoring and treatment tailoring in UC.

Introduction

Aims & Methods

Results

Conclusion

Introduction

While ileocecal resection (ICR) is the most common surgical procedure in Crohn's disease (CD), non-ICR surgeries account for only 20% of cases and remain underrepresented in the literature. This study aimed to identify specific clinical risk factors for surgical recurrence in CD patients undergoing small bowel or colonic resections without involving the ileocecal valve.

Aims & Methods

This multicenter retrospective cohort study included 257 patients with CD (124 small bowel resections, 133 colonic resections) across 13 Italian centers from 1978 to 2023. Univariate and multivariate logistic regression and Cox proportional hazards analyses were performed to identify clinical risk factors associated with surgical recurrence.

Results

The cohort comprised two distinct groups: small bowel resections (n=124), characterized by male predominance (63.71%), a high prevalence of stricturing disease (60.48%), and a median follow-up of 75.5 months; and colonic resections (n=133), featuring a more balanced gender distribution (47.37% male), higher rates of penetrating disease (47.37%), and a median follow-up of 88.0 months. Penetrating disease behaviour emerged as the only significant predictor of recurrence in logistic regression analysis (OR 2.16, 95% CI 1.03-4.52, p=0.041), while factors typically predictive in ICR, such as smoking (OR 0.90, p=0.843) and prior resections (OR 0.96, p=0.913), were non-significant. Cox regression identified prior biologic exposure as a significant predictor of earlier recurrence (HR 2.52, 95% CI 1.22-5.18, p=0.012), with TNF experience specifically associated with increased risk (HR 2.28, 95% CI 1.12-4.67, p=0.024). The cumulative number of risk factors (HR 1.35, 95% CI 1.01-1.82, p=0.046) and postoperative intra-abdominal septic complications (HR 2.75, 95% CI 1.18-6.44, p=0.020) also contributed to recurrence risk. Disease phenotypes significantly differed between resection types (p<0.001), with stricturing disease most prevalent in small bowel resections (60.48% vs. 36.09% in colonic) and penetrating disease more common in colonic resections (47.37% vs. 36.29% in small bowel). Results are summarized in Table 1.

Table 1: Univariate logistic regression analysis of predictors for postoperative surgical recurrence in patients undergoing small bowel or colonic resections. Abbreviations: CI: Confidence Interval; CD: Crohn’s Disease; IBD: Inflammatory Bowel Disease; POR: Postoperative recurrence; TNF: Tumour Necrosis Factors.

Conclusion

This study reveals distinct risk factors for surgical recurrence after non-ICR surgeries in CD. Unlike ICR where smoking, perianal disease, and prior resections predominate, non-ICR recurrence is primarily associated with penetrating disease phenotype and prior biologic exposure. These findings demonstrate that risk stratification models developed for ICR are not applicable to non-ICR surgeries, highlighting the need for procedure-specific approaches to postoperative management. Tailored prophylactic strategies should address the unique recurrence dynamics of small bowel and colonic resection surgeries.