Early versus delayed (interval) appendicectomy for the management of appendicular abscess and phlegmon: a systematic review and meta-analysis.

OBJECTIVE: The safety and role of emergency (EA) versus interval appendicectomy (IA) for appendicular abscess and phlegmon remains debatable with no optimal strategy identified. The aim of this systematic review and meta-analysis is to evaluate outcomes of managing appendicular abscesses and phlegmon with emergency or interval appendicectomy.

METHODS: We conducted a systematic search of electronic databases using key terms including 'appendicular abscess', 'appendicular phlegmon' and 'interval appendicectomy'. Randomised controlled trials and observational studies comparing the two management approaches were included. Operative time, post-operation complication, unplanned bowel resection, rate of surgical site infection, post-operative length of stay and overall mortality rate were evaluated.

RESULTS: We identified six studies (2 RCTs and 4 observational studies) with a total of 9264 patients of whom (n = 1352) underwent IA, and (n 7912) underwent EA. The EA group was associated with statistically significant unplanned bowel resection (OR 0.55, 95% CI [0.33-0.90], P = 0.02) and longer total operating time (MD - 14.11, 95% CI [- 18.26-- 9.96] P = 0.00001). However, the following parameters were compared for both EA and IA groups; there were no significant statistical differences: surgical site infection (OR 0.49, 95% CI [0.17-1.38], P = 0.18), post-operative intra-abdominal collection (RD - 0.01, 95% CI [- 0.04-0.01], P = 0.29), total length of hospital stay (MD 1.83, 95% CI [- 0.19-3.85], P = 0.08), post-operative length of hospital stay (MD - 0.27, 95% CI [- 3.66-3.13], P = 0.88) and mortality rate (MD - 0.27, 95% CI [- 3.66-3.13], P = 0.66).

CONCLUSION: Emergency operation for appendicular abscess and phlegmon may lead to a higher rate of reported morbidity when compared with interval appendicectomy. Although emergency appendicectomy performed for appendicular abscess and phlegmon is a feasible and safe operative approach, it is associated with significantly increased operative time and unplanned bowel resection (ileocolic and right hemicolectomies) compared to interval appendicectomy.