Accuracy of computed tomography in staging acute appendicitis and its impact on surgical outcome and strategy: a multi-center retrospective case-control study.

AAST-CT appendicitis grading system seems to show a relevant prognostic value and a potential impact on the choice of surgical strategy, directing toward a laparoscopic approach in patients with grade 1 and 2, an initial laparoscopic approach, replaceable by the open one, for grade 3 and 4 and an open approach in patients with grade 5.