WOFAPS 2025 8th World Congress of Pediatric Surgery

Igor Khvorostov ¹, Aleksey Sinitsyn ²

¹ Pirogov Russian National Research Medical University, Moscow, Russia
² Volgograd State Medical University

Introduction. Chronic аppendicitis (CA) is a diagnosis characterized by long-standing right lower quadrant pain. We analyzed clinic, morphology and immunohistochemical studies of the appendix in order to confirm the adequacy of surgical treatment CA in children.

Materials and methods. We carried out comparative studies of the clinical picture, results of morphological and immunohistochemical studies of remote appendicitis in 55 CA children and 35 children with acute appendicitis (AA).

Results: The low prognostic significance of appendicular scales for determining indications for surgical treatment of chronic appendicitis (CA) has been established. Laparoscopic surgery is the preferred treatment method for chronic appendicitis. Morphological examination of CA in most cases revealed signs of chronic inflammation with fibrosis in the mucosa and submucosa of the appendix.

Immunohistochemical studies of CA showed a pronounced expression of proteins VEGF, MMP-9, and VCAM-1 in the submucosal and muscular layers, as well as moderate expression of Collagen-II-alpha-1. However, the number of cells expressing the VIP protein was low, both in the mucosa and the submucosa.

The number of MMP-9-positive cells was the highest, followed by VEGF and Collagen-II alpha-1, with a moderate number of VIP-positive cells.. In patients with appendicitis, an immunohistochemical study showed a decrease in the expression of all the proteins studied. This could be due to damage to antigenic determinants by hydrolytic enzymes from neutrophilic segmented granulocytes in the focus of acute inflammation. The expression of VEGF was moderate, while that of VIP (mainly in blood vessels of the muscle layer), Collagen-III-alpha-1 and MMP-9 was doubtful. All the proteins were detected in single cells, mostly in the muscle and serosal layers. After appendectomy, 6% of children experienced resolution of abdominal symptoms. Recurrence of pain was more common in girls with irregular menstrual cycles during puberty.

Conclusions: We have identified immunohistochemical and morphological changes that suggest autoimmune and vascular mechanisms in appendix damage in children with acute appendicitis. Laparoscopic surgery can help eliminate abdominal pain for most patients.