Do the 'Eyes' have it? How good are surgeons at identifying appendicitis macroscopically? A retrospective study in NewZealand.

AIMS: The management of a macroscopically normal appendix during diagnostic laparoscopy depends on the accuracy of surgeons' intra-operative assessments. This study aims to determine the accuracy of this assessment and identify factors affecting it.

METHODS

We reviewed appendicectomies on adult patients at Waikato District Health Board in 2017. The primary outcome was the agreement between the operative assessment and the gold standard histopathologic assessment. Secondary outcomes were predictors of this agreement.

RESULTS

420 patients were included. Among 74 appendixes assessed as normal by surgeons, 16 (21.6%) had appendicitis on histology. Surgeons assessed 346 appendixes as inflamed; however, 22 (6.3%) were revealed to be histologically normal. Only 2 of the 14 appendiceal neoplasms on histology were identified at the time of laparoscopy. Overall, there was disagreement in 9.1% of cases. This yielded a kappa of 0.69, indicating moderate inter-rater reliability. An inflamed appendix was significantly more likely to be falsely assessed as normal by non-trainee registrars, in female patients and in patients with a pre-operative ultrasound. A pre-operative computerised tomography scan (CT) decreased the odds of false negative operative diagnoses, but it increased the odds of false positives.

CONCLUSIONS

Macroscopic assessment of the appendix lacks accuracy and may be challenging in certain groups of operators and patients.