Histopathological Analysis as Support for the Applicaibility of Interval Appendectmy: A Single-Center Retrospective Study

Background: The management of perforated appendicitis with abscess, including interval appendectomy, remains controversial. Materials and Methods: The study was a retrospective analysis of patients diagnosed as having perforated appendicitis with abscess who were treated in our hospital between April 2014 and December 2020. A total of 51 patients who underwent successful interval appendectomy protocol were included. Residual pathological inflammation in the resection specimens and the relationship between preoperative computed tomography imaging and residual inflammation findings were evaluated. Results: All patients who had successful interval appendectomy received laparoscopic appendectomy as an elective surgery. Postoperative complications included superficial surgical site infection in two patients (4%). Pathological assessment of the resection specimens of interval appendectomy revealed acute inflammation and chronic inflammation in 11 patients (22%) and 25 patients (49%), respectively. Preoperative computed tomography imaging showed elevated peri-appendiceal fat tissue concentration and residual abscesses in 11 patients (22%) and five patients (10%), respectively. Residual inflammation was significantly higher in patients who had exhibited elevated peri-appendiceal fat tissue concentration on preoperative computed tomography imaging. Conclusions: Despite the absence of abdominal pain or other inflammatory symptoms, 70% patients showed pathological evidence of ongoing inflammation even after 3 months of conservative treatment. Given the high percentage of resection specimens showing acute or chronic appendicitis, interval appendectomy should be performed for complete elimination of inflammation.