Evaluation of clinical examination and preoperative imaging in patients with right iliac fossa pain and a medium or high risk score for appendicitis (RIFT-2)

Abstract

Introduction: Clinical risk models can be used to safely stratify UK patients with suspected appendicitis with low scores to ambulatory pathways, preventing admissions and unnecessary surgery. This study aimed to examine the diagnostic pathways in patients with medium or high risk scores.

Methods: This prospective cohort study included patients admitted with suspected appendicitis in the UK. Patients aged ≥16 years were included if they had a medium or high risk score for appendicitis (Appendicitis Inflammatory Response score >2 in men, Adult Appendicitis Score >8 in women). The primary outcome measure was the normal appendicectomy rate (NAR). The AIRS and AAS risk prediction models were validated against pre-determined criteria.

Results: This UK study included 2,231 women and 1,958 men. Overall, 57.7% of patients underwent surgery. The NAR was 18.4% in women aged 16-45 years, 9.5% in men aged 16-45 years, 4.5% in women aged ≥46 years, and 2.1% in men aged ≥46 years. Risk prediction models did not achieve the pre-determined threshold to be used to identify patients with appendicitis. Ultrasound was the most common imaging modality in women aged 16-45 years, whereas CT was most common in the other subgroups. CT was performed in 12.8% women aged 16-45 years, 21.1% in men aged 16-45 years, 69.3% in women aged ≥46 years, and 74.5% in men aged ≥46 years. The overall NAR in patients who had CT imaging alone (3.6%) was lower than in patients who had no imaging (12.4%) or ultrasound imaging alone (19.0%).

Conclusion: Patients with right iliac fossa pain should be risk scored, with low-risk patients triaged to ambulatory management and medium and high-risk patients routinely CT scanned. Normal appendicectomy should become a specific therapeutic option rather than a chance finding.