Ultrastructural and Immunohistochemical Alterations in Muscle and Vascular Tissues in Patients with Omphalocele.

Omphalocele is a congenital abdominal wall defect whose underlying muscular and fascial structural characteristics remain incompletely understood. This study aimed to investigate the anatomical and ultrastructural features of the abdominal wall in patients with omphalocele to provide additional insight into tissue organization at the defect margins. We report a series of 11 term-born patients diagnosed with omphalocele between 2024 and 2025 who were admitted to a pediatric surgery department for operative management. Following informed consent from legal guardians, two small intraoperative biopsies were obtained during surgical repair from the rectus abdominis muscle and its anterior aponeurosis, sampled from the supraumbilical and subumbilical regions. Tissue specimens were fixed within 48 h and analyzed using conventional histopathology and scanning electron microscopy to assess potential structural and ultrastructural alterations. The combined microscopic approaches allowed for a detailed evaluation of muscle and aponeurotic architecture in different abdominal regions. These observations contribute to a more comprehensive understanding of abdominal wall tissue characteristics in omphalocele and may support improved interpretation of the structural changes associated with this congenital condition.