Background: In patients with right iliac fossa pain, the need for surgery is largely determined by the likelihood of appendicitis. Patients often undergo ultrasound scanning despite a low diagnostic accuracy for appendicitis. This study aimed to determine the feasibility of a larger trial of computed tomography in the evaluation of patients with atypical right iliac fossa pain.
Materials and methods: A single-centre, unblinded, parallel randomised controlled trial of computed tomography in the assessment of patients with atypical right iliac fossa pain. After a retrospective evaluation, standard care was defined as serial examination with or without ultrasound. Atypical right iliac fossa pain was defined as no firm diagnosis after initial senior review. Simple descriptions of the risks and benefits of computed tomography were devised for patients to consider. Primary objectives were to assess feasibility and acceptability of the study procedures.
Results: A total of 71 patients were invited to participate and 68 were randomised. Final analysis included 31 participants in the standard care arm and 33 in the computed tomography arm, with comparable demographics. Computed tomography was associated with superior diagnostic accuracy, with 100% positive and negative predictive value. The proportion of scans that positively influenced management was 73% for computed tomography and 0% for ultrasound. In the computed tomography arm, there was a trend towards a shorter length of stay (2.3 vs 3.1 days) and a lower negative laparoscopy rate (2 of 11 vs 4 of 9).
Conclusion: A large randomised trial to evaluate the use of unenhanced computed tomography in atypical right iliac fossa pain appears feasible and justified.
Keywords: Abdominal pain; Appendicectomy; Appendicitis; Computed tomography; Ultrasound; x-ray.