Therapeutic decision-making in appendiceal abscess: Results of the 2025 Italian Society of Research in Surgery/Italian Society of Emergency and Trauma Surgery consensus conference

Background: The management of appendiceal abscess remains a challenging area in emergency surgery because of heterogeneity in anatomic presentation, inflammatory severity, and patient physiologic reserve. The absence of standardized pathologic definitions, imaging-based grading systems, and clear escalation criteria has contributed to substantial variability in clinical practice. A unified, physiology-driven framework is therefore needed to support transparent and reproducible decision-making. Methods: This study represents the management-focused component of the Italian Society of Research in Surgery-Italian Society of Emergency and Trauma Surgery consensus initiative on appendiceal abscess. A modified Delphi methodology was applied, including 3 rounds of anonymous remote voting, followed by a final in-person consensus meeting. Standardized pathologic definitions and an imaging-based grading classification developed within the same initiative were adopted as reference standards. Agreement thresholds were predefined: ≥80% indicating consensus and ≥95% strong consensus. Results: Early appendectomy was considered the most definitive treatment for grade 1 phlegmons and small abscesses, although a short, closely monitored trial of conservative management may be acceptable in clinically stable, low-risk patients. For abscesses larger than 3-4 cm, image-guided percutaneous drainage was selectively recommended as a temporizing bridge in high-risk surgical candidates rather than as definitive therapy. Mesenteric abscesses were identified as particularly high risk because of limited anatomic containment and rapid progression, and early surgical source control was considered the most reliable strategy. Clinical instability or generalized peritonitis represented absolute indications for immediate surgery, regardless of abscess morphology. The panel also addressed salvage surgery, the selective role of interval appendectomy, and the optimal timing of delayed surgery, supporting a risk-stratified rather than routine approach. Conclusion: This consensus provides a reproducible, physiology-driven framework for the management of appendiceal abscess, integrating anatomic patterns, radiologic grading, and explicit escalation criteria. These recommendations aim to reduce unwarranted variability and improve the consistency and quality of care.