A new radiographic sign of acute appendicitis: fecal loading in the cecum for differential diagnosis of acute appendicitis in comparision with other abdominal inflammatory diseases. A prospective study

Objective: The purpose of this investigation was to verify the importance of the radiographic sign of fecal loading in the cecum for the differential diagnosis of acute appendicitis. Methods: A total of 470 consecutive patients of both sexes was admitted to hospital due to acute abdomen and pain in the right flank and prospectively studied. The patients were divided as follows: Group 1 (n = 170) - diagnosed with acute appendicitis and subdivided into two subgroups: Subgroup 1A (n = 100) - patients submitted to an abdominal radiographic study a few hours before surgical treatment, Subgroup 1B (n = 70) - patients submitted to two radiographic studies of the abdomen, one before the surgical procedure and the other on the next day; Group 2 (n = 100) - patients of both sexes with right nephrolithiasis submitted to an abdominal radiography during the episode of pain caused by the calculus; Group 3 (n = 100) - women diagnosed with right acute inflammatory pelvic disease that underwent an abdominal radiographic study during the pain crisis; Group 4 (n = 100) - patients of both sexes who underwent surgery due to acute cholecystitis and were submitted to abdominal radiography during the pain episode that preceded the surgical procedure. Results: The sign of fecal loading in the cecum was present in 97 patients of Subgroup 1A, in 68 patients of Subgroup 1B, in 19 patients of Group 2, in 12 patients of Group 3 and in 13 patients of Group 4. During the postoperative period the radiographic sign disappeared in 66 of the 68 cases who presented the sign. The sensitivity of the radiographic sign for acute appendicitis was 97.05% and specificity was 85.33%. The positive predictive value for acute appendicitis was 78.94% and its negative predictive value was 98.08%. Conclusion: The radiographic image of fecal loading in the cecum is associated with acute appendicitis. The image usually disappears soon after the appendix is removed. This sign is uncommon in other acute inflammatory diseases of the right side of the abdomen.