Outcomes of interval appendectomy in comparison with appendectomy for acute appendicitis

Background: Traditionally, patients treated conservatively for periappendiceal abscess or phlegmon would subsequently undergo interval appendectomy (IA); however, recent evidence has shed doubt on the necessity of this procedure. This study aimed to assess the outcomes of patients who underwent IA, in comparison with those operated acutely for appendicitis. Materials and methods: A retrospective analysis identified patients who underwent IA between 2000 and 2016. Their course and outcomes were compared with those of our previously published cohort of patients who underwent appendectomy for acute appendicitis. Results: During the study period, 106 patients underwent IA. Their mean age was 39.7 ± 16.2 y, and 60.4% were females. In their index admission, 75.5% presented with abscesses. IA was performed successfully in all patients, and no patient required colectomy. Pathology demonstrated neoplastic lesions in 6/106, but only one was malignant. IA patients were compared with a cohort of 1649 acute appendectomy patients. This group was significantly younger (33.7 ± 13.3 y). Operation time was comparable between the groups (46.0 ± 26.2 versus 42.7 ± 20.9 min, respectively, P = 0.33). In the IA group, significantly more laparoscopic operations were performed (100% versus 93.9%), but with a higher conversion rate to open (1.9% versus 0.13%, P < 0.001). Although the overall complication rate was comparable, more intraoperative complications (2.8% versus 0.3%, P < 0.001) and deep/organ-space surgical site infections (surgical site infection; 4.7% versus 1.2%, P = 0.003) were reported in the IA group. Conclusions: IA can be a challenging procedure and should not be performed on a routine basis. However, neoplasia must be actively ruled out, particularly in the older age group.