Can interval appendectomy be justified following conservative treatment of perforated acute appendicitis?

Background: There continues to be controversy about the necessity of interval appendectomy for delayed presentation of acute appendicitis. While recent studies suggest that the risk of recurrent disease is small, the risk of interval appendectomy is also small and does provide histologic identification and usually definitive treatment of the right lower quadrant inflammatory process. Methods: A retrospective analysis of medical records gathered from 2002 to 2007 at a major teaching hospital of 986 adult patients over the age of 13 with appendicitis were analyzed. Forty-six patients (5%) were found to have right lower quadrant abscess or phlegmon, and were managed with intravenous antibiotics. Some patients also underwent percutaneous drainage. These patients were then readmitted 6 to 26 wk later for an elective laparoscopic interval appendectomy. Results: There were 19 males and 27 females with an average age of 43 y. Ninety-four percent of the appendectomies were completed laparoscopically; 16% of patients were found to have a normal or obliterated appendix on pathologic evaluation and likely did not benefit from interval appendectomy. On the other hand, 84% of patients had persistent acute appendicitis, chronic appendicitis, evidence of inflammatory bowel disease, or neoplasm identified, and likely benefited from surgical appendectomy. Conclusions: Interval appendectomy provides diagnostic and therapeutic benefit to patients who present with a right lower quadrant abdominal inflammatory focus, and should be carefully considered in all adult patients.