Sensitivity and specificity of surgeons' intra-operative diagnosis of appendicitis. A systematic review and meta-analysis.

Background: Appendicitis is a frequently encountered surgical condition, yet its diagnosis can be challenging. There is increasing research on the safety of leaving macroscopically normal appendices in situ, the necessity of routine histopathological assessment, and the impact of the intra-operative assessment on the post-operative course. We aimed to determine the sensitivity and specificity of the surgeon's intra-operative diagnosis of appendiceal pathology, which is an important factor in answering these questions.

Methods: Medline, Embase, the Cochrane Library and Web of Science were searched for studies listing the corresponding intra-operative and histopathological diagnoses of appendicectomies performed for suspected appendicitis. The primary outcome was the sensitivity and specificity of the surgeon at recognising an abnormal appendix, which we subjected to meta-analysis. Subgroup analysis was performed for paediatric and adult populations. Incidence of unexpected findings and if they were recognised intra-operatively was recorded.

Result: 42 articles were included in the systematic review. 26 studies featuring 17,374 patients were included in the meta-analysis, which found that surgeons' intra-operative diagnosis was 95.2 % (95 % CI 94.8-95.5 %) sensitive and 60 % (95 % CI 58.1-62 %) specific. Surgeons are slightly more sensitive and specific in paediatric populations (sensitivity 95.7 % (95 % CI 95-96.4 %), specificity 64.1 % (95 % CI 60-68 %)) compared with adult populations (sensitivity 93 % (95 % CI 91.3-94.5 %), specificity 56.5 % (95 % CI 50.1-62.6 %)), however, this difference was only statistically significant in sensitivity. 1.7 % of appendicectomy specimens had unexpected histopathological findings, of which very few were suspected intra-operatively.

Conclusion: Surgeons are highly sensitive but not very specific at recognising abnormal appendices intra-operatively.