Title : Negative appendectomy rates in the department of general surgery, Galway University Hospital, Republic of Ireland, 2025: A retrospective chart review
Abstract:
Introduction: Acute appendicitis is one of the most common surgical emergencies, but diagnostic uncertainty can lead to removal of a histologically non-inflamed appendix. The negative appendicectomy rate (NAR) is therefore used as a surgical quality indicator. This study aimed to determine the NAR in the Department of General Surgery at Galway University Hospital (GUH) during 2025 and identify associated clinical and radiological predictors.
Methods: A retrospective cohort study was performed using 2025 surgical handover sheets. Electronic health records, radiology reports, histology and laboratory results were reviewed. Demographic data, inflammatory markers, preoperative imaging, operative findings and appendicular histology were collected. Statistical analysis was performed using IBM SPSS Statistics.
Results: Among 509 admissions with suspected appendicitis, 335 patients (65.8%) underwent appendicectomy. Histology confirmed appendicitis in 300 patients (89.6%), while 35 patients had no histological evidence of appendicitis, giving an NAR of 10.4%. Fourteen patients had no appendicular pathology, giving a true NAR of 4.2%; alternative findings included lymphoid hyperplasia, Enterobius vermicularis and malignancy. Female sex was significantly more common in the negative appendicectomy group (62.9% vs 43.3%, p=0.028). Inflammatory markers were lower in the negative group, including WBC (10.0 vs 14.5 ×10?/L, p<0.001), CRP (22.1 vs 47.2 mg/L, p=0.002), neutrophil count (6.8 vs 11.4 ×10?/L, p<0.001) and leukocyte shift (22.9% vs 66.3%, p<0.001). Ultrasound was more frequently used in the negative group (57.1% vs 32.3%, p=0.004), with equivocal ultrasound findings also more common (65.0% vs 34.0%, p=0.033). CT was performed in 31.4% of the negative group, and 72.7% of these scans were reported positive despite negative histology.
Conclusion: GUH demonstrated an NAR of 10.4% and a true NAR of 4.2%, comparing favourably with reported Irish benchmarks. Lower inflammatory markers, female sex and equivocal imaging were associated with negative appendicectomy. Structured use of clinical scoring, appropriate preoperative imaging and continued prospective audit may help further reduce unnecessary appendicectomy.
