Ultrasound for differentiation between perforated and nonperforated appendicitis in pediatric patients

OBJECTIVE. Acute appendicitis is the most common condition requiring emergency surgery in children. Differentiation of perforated from nonperforated appendicitis is important because perforated appendicitis may initially be managed conservatively whereas nonperforated appendicitis requires immediate surgical intervention. CT has been proved effective in identifying appendiceal perforation. The purpose of this study was to determine whether perforated and nonperforated appendicitis in children can be similarly differentiated with ultrasound. MATERIALS AND METHODS. This retrospective study included 161 consecutively registered children from two centers who had acute appendicitis and had undergone ultrasound and appendectomy. Ultrasound images were reviewed for appendiceal size, appearance of the appendiceal wall, changes in periappendiceal fat, and presence of free fluid, abscess, or appendicolith. The surgical report served as the reference standard for determining whether perforation was present. The specificity and sensitivity of each ultrasound finding were determined, and binary models were generated. RESULTS. The patients included were 94 boys and 67 girls (age range, 1-20 years; mean, 11 ± 4.4 [SD] years) The appendiceal perforation rate was significantly higher in children younger than 8 years (62.5%) compared with older children (29.5%). Sonographic findings associated with perforation included abscess (sensitivity, 36.2%; specificity, 99%), loss of the echogenic submucosal layer of the appendix in a child younger than 8 years (sensitivity, 100%; specificity, 72.7%), and presence of an appendicolith in a child younger than 8 years (sensitivity, 68.4%; specificity, 91.7%). CONCLUSION. Ultrasound is effective for differentiation of perforated from nonperforated appendicitis in children.