Acute appendicitis in geriatric population: a clinical and prognostic comparison of surgical intervention and conservative management

BACKGROUND: Acute appendicitis in elderly patients is associated with atypical clinical presentation, delayed diagnosis, and increased morbidity and mortality. While non-operative management (NOM) has gained acceptance in selected patients, its safety and effectiveness in very elderly and frail populations remain controversial. METHODS: This retrospective cohort study included 300 patients aged ≥ 65 years diagnosed with acute appendicitis between 2014 and 2025. Patients were classified according to World Health Organization age groups (65-74, 75-84, and ≥ 85 years). Clinical features, laboratory findings, imaging results, treatment modality (non-operative vs. surgical), treatment failure, complications, intensive care unit (ICU) requirement, length of hospital stay, and mortality were analyzed. Factors associated with non-operative management failure and postoperative outcomes were evaluated. RESULTS: Eighty-three patients (27.7%) were initially managed non-operatively, and 217 patients (72.3%) underwent surgical treatment. In the non-operative group, early treatment failure requiring surgery within 30 days occurred in 24.1%, and recurrence requiring surgery within one year occurred in 25.3%. Failure rates increased significantly with age, reaching 54.5% in patients aged ≥ 85 years (P < 0.001). High frailty index, severe comorbidities, prolonged symptom duration, and extensive inflammatory findings on computed tomography were significantly associated with non-operative management failure. In the surgical group, increasing age was significantly associated with higher rates of open surgery, intraoperative conversion, postoperative complications, perforated appendicitis, ICU admission, prolonged hospital stay, and early postoperative mortality (all P < 0.001). CONCLUSION: Age and frailty strongly influence outcomes in elderly patients with acute appendicitis. Patients aged ≥85 years have markedly higher risks of non-operative treatment failure, postoperative complications, and mortality. Non-operative management should be reserved for carefully selected elderly patients and requires close monitoring. Early diagnosis and individualized, frailty-based treatment strategies are essential to improve clinical outcomes in this population.