RESUMO
BACKGROUND: The mini-invasive techniques have revolutionized the surgery; however, the superiority of laparoscopic access for complicated appendicitis is still controversial. The most critical point has been the dismal quality of the methodology found in the series comparing laparoscopic and laparotomic procedures. The lack of stratification criteria to evaluate the inflammation in the appendix and abdomen has been pointed out by several authors. PURPOSE: To validate the laparoscopic grading system for acute appendicitis. METHODS: Prospective study of 186 patients with presumed acute appendicitis who underwent an appendectomy if diagnostic laparoscopy showed appendicitis or normal-looking appendix without any other intra-abdominal disease. The appendix was graded as to different levels based upon its visual appearance: grade 0 (normal looking), 1 (redness and edema), 2 (fibrin), 3A (segmental necrosis), 3B (base necrosis), 4A (abscess), 4B (regional peritonitis), and 5 (diffuse peritonitis). This was then compared with a histologic assessment of the removed appendix supplemented by a biochemical study of collected peritoneal fluid (gold standard) to determine the diagnostic indexes. Besides that, the κ coefficient confirmed concordance between them. RESULTS: Laparoscopic sensitivity, specificity, and accuracy for acute appendicitis diagnosis were 100%, 63.3%, and 84.1%, respectively, and presented substantial concordance [κ=0.74 (95% confidence interval, 0.60-0.88)]. Sensitivity, specificity, and accuracy of the laparoscopic grading system were 63%, 83.3%, and 80.1%, respectively, and presented moderate concordance [κ=0.39 (95% confidence interval, 0.23-0.55)]. The biochemical-histologic grading system changed for 48 (25.8%) patients who had been previously classified by surgeons during laparoscopy. Most incorrect graduation occurred in grades 0 and 1. The presence of exudates was confirmed in all cases classified as grades 4A, 4B, and 5. CONCLUSIONS: Laparoscopy showed good to excellent accuracy for diagnosis and grading of acute appendicitis. The better grading system allowed the evaluation of patients with acute appendicitis in the same clinical stage.