Ultrasound features of secondary appendicitis in pediatric patients

Area of Science:

• Radiology
• Pediatric Imaging
• Gastrointestinal Imaging

Background:

• Secondary appendicitis (SA) is a less common cause of appendiceal inflammation.
• Distinguishing SA from primary appendicitis (PA) is crucial for appropriate management.
• Ultrasonography is a key imaging modality for evaluating appendicitis in children.

Purpose of the Study:

• To evaluate the ultrasonographic findings characteristic of secondary appendicitis (SA).
• To compare these findings with those of primary appendicitis (PA) to aid differential diagnosis.
• To identify key ultrasonographic features that differentiate SA from PA in pediatric patients.

Main Methods:

• Retrospective analysis of ultrasonographic findings in 94 pediatric patients with SA and comparison with 99 patients with PA and 44 controls.
• Inclusion criteria for SA: bowel inflammation, inflamed appendix >6 mm diameter, improved with non-surgical treatment.
• Statistical analysis included ANOVA, Pearson chi-square, and Fisher exact tests.

Main Results:

• Secondary appendicitis (SA) cases had a significantly smaller appendix diameter (mean 6.6 mm) compared to primary appendicitis (PA) (mean 9.8 mm).
• Periappendiceal fat inflammation (6% vs. 98%) and appendicoliths (11% vs. 34%) were significantly less frequent in SA than PA.
• Mural hyperemia on color Doppler ultrasonography was observed with similar frequency in both SA and PA (P=0.887).

Conclusions:

• Ultrasonographic features of SA include an increased appendix diameter, often in the equivocal range (mean 6.6 mm), and rare periappendiceal fat inflammation.
• Similar mural hyperemia in SA and PA suggests this finding is not a reliable differentiator.
• These ultrasonographic characteristics can help differentiate SA from PA, guiding clinical management.