Distinguishing Between Early Acute Gangrenous Appendicitis and Uncomplicated Acute Appendicitis Using Ultrasonography: A Retrospective Observational Study.

Introduction: This study aimed to evaluate the diagnostic value of ultrasonography in distinguishing early acute gangrenous appendicitis (AGA) from uncomplicated acute appendicitis (UAA).

Methods: This retrospective observational study was conducted at a tertiary teaching hospital in Changsha Central Hospital, including 305 patients with AGA and 398 patients with UAA, confirmed through surgical and pathological examination. Univariate analyses of clinical and ultrasonographic data were followed by multivariate logistic regression modeling to identify significant risk factors for AGA.

Results: Univariate analysis revealed significant intergroup differences in sex, age, symptom duration, leukocyte count, neutrophil percentage, outer appendiceal diameter, peri-appendiceal mesentery thickness, appendicolith obstruction, intra-appendiceal fluid echogenicity, intra-appendiceal gas, appendiceal wall anomalies, and peri-appendiceal fluid. Multivariate analysis identified male sex (odds ratio [OR] = 1.788, p = 0.014), age ≥ 44 (OR = 2.174, p = 0.002), symptom duration ≥ 32 h (OR = 2.396, p < 0.001), neutrophils ≥ 84% (OR = 2.615, p < 0.001), peri-appendiceal mesentery thickness ≥ 7 mm (OR = 5.302, p < 0.001), intra-appendiceal fluid with poor ultrasound penetration (OR = 2.025, p = 0.004), appendicolith obstruction (OR = 2.030, p = 0.020), and appendiceal wall anomalies (OR = 16.772, p < 0.001).

Conclusion: Ultrasonographic findings like appendiceal wall anomalies, intra-appendiceal gas, and peri-appendiceal fluid offer high specificity for diagnosing early AGA, while peri-appendiceal mesentery thickness ≥ 7 mm demonstrates high sensitivity. Combining ultrasound with clinical evaluation facilitates AGA diagnosis and informed treatment decisions.