Is it possible to diagnose perforative appendicitis in children with ultrasound?

Abstract

Acute appendicitis is one of the most common pathologies in children that requires surgery. Ultrasonography (US) is considered as the first method of instrumental diagnosis in children with acute appendicitis. Despite numerous studies on US diagnostics of acute appendicitis, questions of ability of this method to separate uncomplicated and complicated acute appendicitis, in particular perforated, have not been studied enough.
Aim of the study was to conduct a retrospective analysis of the results of US compared with intraoperative findings regarding the determination of US criteria for perforated acute appendicitis.
Materials and Methods. The study is based on the results of US examination and surgical treatment of 97 children at surgical department of Lviv regional children’s clinical hospital «OXMATDYT» during 9 months of 2019. US was done according to the protocol, that includes an examination of all regions of abdominal cavity with a thorough examination of the right iliac region using the method of graded compression. The diagnosis of perforated appendicitis was established during surgery by the presence of a visible perforated hole. The presence of gangrenous appendicitis without a perforated hole, even in the presence of periappendicular abscess, was not considered as perforated appendicitis.
Results. Perforated appendicitis was diagnosed in 29 (29.9%) patients. During US, an increase of maximal diameter of the appendix was found in 23 (79.3%), in 19 (65.5%) – thickening of the appendix wall >3 mm, loss of echogenicity of submucosal layer of the appendix wall and presence of fluid – in 12 (41.4%) and in 11 (37.9%) patients were diagnosed with fecalith in the lumen of the appendix and inflammatory changes in the periappendiceal adipose tissue. Although children with perforated appendicitis often have an increase of maximal diameter of the appendix, these changes are not specific to this form of the disease. Other indicators also have low sensitivity and/or specificity for the presence of perforation of the appendix.
Conclusions. Ultrasonography has high specificity, but low enough sensitivity to determine the presence of perforated appendicitis in children. Increasing of maximal diameter of the appendix, thickening of its wall (>3 mm) and impaired echogenicity of the submucosal layer can be considered as the main US symptoms of perforated appendicitis in children, but they should be evaluated only in conjunction with physical examination data and other US symptoms.
The research was carried out in accordance with the principles of the Helsinki Declaration. The study protocol was approved by the Local Ethics Committee of institution. The informed consent of the patient was obtained for conducting the studies.