TOP 32 - Association of Histopathological Findings and Clinical Outcomes in Preterm Infants with Surgical Necrotizing Enterocolitis

Publication Number: 2783.TOP 32

Astha Amrit, The Hospital for Sick Children, Toronto, ON, Canada; Dwayne Mascarenhas, The Hospital for Sick Children, Toronto, ON, Canada; Ujjwala Mantha, The Hospital for Sick Children, Toronto, ON, Canada; Shravan Kanaparthi, The Hospital for Sick Children, Toronto, ON, Canada; Doaa Al-Dweik, The University of Western Ontario - Schulich School of Medicine & Dentistry, London, ON, Canada; Bonny Jasani, The Hospital for Sick Children, Toronto, ON, Canada

Background: Histopathological findings in Necrotizing enterocolitis (NEC) are characterised by coagulative necrosis, inflammation, interstitial haemorrhage, bacterial invasion, and reparative changes such as neovascularisation, fibroblast proliferation, and epithelial regeneration. Transmural necrosis and extensive bacterial invasion are linked to higher mortality, whereas reparative features may indicate better outcomes. Necrosis at surgical margins predicts increased mortality and longer hospitalization. Long-term gastrointestinal sequelae, including strictures, short bowel syndrome, and adhesive obstruction, arise from necrosis, inflammation, and fibrosis.

Objective: Although NEC histopathology is well described, most studies focus on limited outcomes and often combine surgical NEC with spontaneous intestinal perforation. Comprehensive evaluation linking NEC-specific histopathologic features to full spectrum of clinically relevant short- and long-term outcomes—including clinical profile, gastrointestinal morbidity, neonatal morbidities and long-term neurodevelopment is lacking.The objective of this study is to characterise histopathological features of surgically treated NEC and their associations with clinical profiles and long-term neurodevelopmental outcomes.

Design/Methods: This is a single-centre, research ethics board-approved retrospective cohort study of preterm infants ( < 30 weeks GA) diagnosed with NEC who have undergone surgical intervention between Jan 1, 2016, to June 30 2024. Infants with major congenital anomalies, those who have not undergone intestinal resection or intestinal biopsy, or with the non-availability of histopathology data will be excluded. Baseline demographic, histopathological findings of surgical NEC, including extent of necrosis, inflammatory and reparative changes and clinical outcomes including in-hospital mortality, need for > 1 laparotomy, short bowel syndrome associated intestinal failure, bronchopulmonary dysplasia, periventricular leukomalacia, significant retinopathy of prematurity and neurodevelopmental impairment (NDI) assessed at 18-24 months corrected age, will be collected. Association between specific histopathological features and mortality or NDI will be assessed using univariate and multivariate logistic regression models, using clinically relevant covariates. Data extraction is expected to be completed by December 2025, and analyses will be completed by January 2026.