The impact of malnutrition on clinical outcomes in patients with perianal fistulizing Crohn's disease undergoing seton placement: A retrospective study

Abstract Background Perianal involvement occurs in up to 50% of patients with Crohn's disease (CD). Despite combined management, 10%–20% require fecal diversion or proctectomy. Nutritional status may influence prognosis, but its role in fistulizing perianal disease is unclear. This study examines the impact of malnutrition on clinical outcomes in patients with perianal fistulizing CD. Methods A retrospective cohort study was conducted. Clinical data were collected from the health records of patients with perianal CD at two centers from January 2010 to December 2022. Nutritional screening followed Nutrition Risk Screening‐2002. Patients with a score ≥3 were evaluated for malnutrition using the Global Leadership Initiative on Malnutrition (GLIM) criteria. The prevalence of malnutrition and its association with the risk of adverse clinical outcomes were analyzed. Results Of 64 patients, 17 (26.6%) had malnutrition. Malnourished patients had higher proctitis rates (100% vs. 78.7%, P = 0.038), lower serum albumin (3.47 vs. 3.97 g/dL, P = 0.002), and lower hemoglobin (10.9 vs. 12.5 g/dL, P = 0.003). They were younger at diagnosis (24.2 vs. 30 years, P = 0.046), had lower body mass indices (19.7 vs. 24.9 kg/m 2 , P < 0.001), higher Harvey‐Bradshaw index (10 vs. 5, P < 0.001), and more corticosteroid use (29.4% vs. 4.3%, P = 0.012). Malnourished patients had lower fistula healing (17.6% vs. 44.7%, P = 0.048), more proctectomies (47.1% vs. 14.9%, P = 0.007), and were more likely to undergo abdominal surgery (70.6% vs. 38.3%, P = 0.022). In the prespecified parsimonious multivariable model, malnutrition was significantly associated with proctectomy (aOR 4.478; 95% CI: 1.227–16.343; P = 0.023). Conclusion Malnutrition is a significant clinical risk marker associated with the requirement for proctectomy in patients with perianal fistulizing CD who undergo seton placement.