Differentiating Complicated Acute Appendicitis From Non-complicated Acute Appendicitis Based on Ultrasound...

Area of Science:

• Radiology and Medical Imaging
• Gastroenterology
• Surgical Diagnostics

Background:

• Acute appendicitis is common, but differentiating complicated (CAA) from non-complicated (NCAA) forms preoperatively is challenging.
• Accurate preoperative diagnosis is crucial for appropriate patient management and resource allocation.
• Ultrasound (US) is a widely available imaging modality with potential for appendicitis assessment.

Purpose of the Study:

• To identify key ultrasound (US) characteristics differentiating complicated acute appendicitis (CAA) from non-complicated acute appendicitis (NCAA).
• To develop and validate a US-based predictive model for preoperative diagnosis of CAA.
• To enhance preoperative risk stratification and guide treatment decisions for acute appendicitis.

Main Methods:

• Retrospective analysis of 178 patients with surgically confirmed appendicitis.
• Standardized preoperative US examinations and comparison of clinical and sonographic variables between CAA and NCAA groups.
• Development of a predictive model using LASSO and multivariable logistic regression, with performance evaluation via AUC, calibration plots, and DCA.

Main Results:

• Complicated appendicitis (CAA) patients were older with longer symptom duration, higher white blood cell (WBC) count, and neutrophil percentage (NE%).
• Key US predictors for CAA included greater appendiceal outer diameter (AOD), increased periappendiceal inflammatory fat thickness (PIFT), periappendiceal fluid collection (PAFC), marginal indistinctness (MI), and altered bowel peristalsis (ABP).
• The final US-based nomogram demonstrated excellent discrimination (AUC = 0.890) and good calibration, with high clinical utility confirmed by DCA.

Conclusions:

• The developed US-based nomogram is an accurate, non-invasive tool for preoperative differentiation of CAA from NCAA.
• This tool can aid in preoperative risk stratification for patients with acute appendicitis.
• The nomogram supports informed treatment decision-making, potentially optimizing patient outcomes.