Surgical treatment of complicated forms of acute appendicitis

Background: Complicated appendicitis (CA) represents a clinically and economically significant subset of acute appendicitis, characterized by gangrene, perforation, abscess, or phlegmon. Despite advances in imaging and minimally invasive surgery, management remains heterogeneous worldwide.Methods: A narrative review of the literature published between 2020 and 2025 was conducted using PubMed and major guideline repositories (WSES, SAGES, EAES, EAST). Recent systematic reviews, meta-analyses, and practice guidelines focusing on the surgical and non-operative management of CA were analyzed.Results: Accurate pre-operative classification using the AAST and CAA systems enables individualized management. Laparoscopic appendectomy has become the preferred approach in most cases, associated with lower wound infection, shorter hospitalization, and faster recovery, without increased intra-abdominal abscess rates. Open surgery remains indicated in hemodynamic instability, diffuse peritonitis, or where laparoscopic resources are limited. Routine drainage and prolonged antibiotic therapy are no longer recommended; short, tailored postoperative courses (2–5 days) are safe after adequate source control. Selected patients with localized abscess or phlegmon can be treated non-operatively with antibiotics ± percutaneous drainage, while interval appendectomy is reserved for recurrence or suspicion of neoplasm. Unexpected appendiceal tumors require tumor-specific surgical management.Conclusions: Modern management of complicated appendicitis emphasizes precise imaging, minimally invasive techniques, selective nonoperative treatment, and antimicrobial stewardship. Integration of standardized classifications and evidence-based algorithms has improved outcomes and reduced postoperative morbidity, transforming CA from a high-risk emergency into a predictable and controllable surgical condition.