Acute and perforated appendicitis: current experience with ultrasound-aided diagnosis

The clinical value of high-resolution real-time sonography for the diagnosis of acute and complicated appendicitis was prospectively investigated in 857 patients admitted with suspected appendicitis. The ultrasound findings were correlated with history and physical examination on admission. Sonography was able to make the diagnosis of appendicitis with a sensitivity of 89.7%, a specificity of 98.2%, an overall accuracy of 96.3%, and a positive and negative predictive value of 93.6% and 97%, respectively. Routine use of ultrasound before making therapeutic decisions has reduced the rate of unnecessary laparotomies from 20.3% to 11.3%. In 48 (24.7%) of 194 patients with proven appendicitis, the disease had progressed to perforation at laparotomy. History and clinical findings on admission classified 30 (62.5%) of these patients as "highly suspect;" however, 9 (18.8%) were classified as "equivocal" and 9 (18.8%) as "very unlikely." Only half (48%) of the patients with appendiceal rupture had white blood cell counts higher than 13,000/mm3 or fever above 38 degrees C (50%). Sonography enabled the visualization of the inflamed appendix and/or appendicular abscess in 44 (91.7%) patients with perforation. In 47 of 48 patients with appendiceal rupture, the ultrasound-aided diagnosis was made on hospital admission. Thus, the incidence of complicated appendicitis (24.7%) in our study population must be attributed to disease progression before admission and preclinical diagnostic delay.