Early or mild appendicitis on CT imaging and its correlation with a negative appendicectomy: an observational retrospective study


  • Matthew L. Basa Department of General Surgery, Royal Brisbane and Women’s Hospital, Queensland Health, Brisbane, Queensland, Australia
  • Liam Convie Department of General Surgery, Royal Brisbane and Women’s Hospital, Queensland Health, Brisbane, Queensland, Australia




Appendicitis, Laparoscopic appendicectomy, Mild, Early, CT


Background: A computerized tomography scan is frequently performed to confirm or exclude appendicitis. The interpretation of such CT scans is crucial in determining which patients should be offered surgery. In a subset of patients with undifferentiated abdominal pain, the radiological diagnosis of “early” or “mild appendicitis” is encountered. It is unclear, based on the current literature, how to manage this entity and hence it may be exposing patients to unnecessary surgery. This raises the question if “early” or “mild appendicitis” on CT imaging correlates with an increased rate of negative appendicectomies.

Methods: All laparoscopic appendicectomies from 2018 to 2023 at a single Australian tertiary hospital were reviewed retrospectively for pre-surgical imaging, appendix histopathology, age, gender, and white cell count. The CT early/mild appendicitis group was compared with the CT uncomplicated appendicitis group.

Results: Of 599 patients who had uncomplicated appendicitis on CT imaging, 63 of these patients received a diagnosis of early or mild appendicitis. Twenty-two in this group had a normal appendix on histological assessment. The “early” or “mild” appendicitis group had a significantly increased likelihood (OR>10, p<0.001) of having a normal appendix on histology, compared to the CT uncomplicated appendicitis group. Women and lower WCC were associated with early appendicitis (p<0.05).

Conclusions: Results of this study suggest that the diagnosis of “early” or “mild appendicitis” on CT imaging results in a greater number of negative laparoscopic appendicectomies.


Youens D, Doust J, Ha TN. Association of regulatory body actions and subsequent media coverage with use of services in a fee-for-service system: a longitudinal cohort study of CT scanning in Australia. BMJ. 2022; 12(4):e057424.

Guan L, Liu Z, Pan G. The global, regional, and national burden of appendicitis in 204 countries and territories, 1990-2019: a systematic analysis from the Global Burden of Disease Study 2019. BMC Gastroenterol. 2023;23(1):44.

Kline JA. A Randomized Trial comparing antibiotics with appendectomy for appendicitis. New Eng J Med. 2020;383(20):1907-19.

Novelline RA. Antibiotics versus Appendectomy for Acute Appendicitis Longer-Term Outcomes. New Eng J Med. 2021;385(25):2395-7.

Pelaccia T, Messman AM, Kline JA. Misdiagnosis and failure to diagnose in emergency care: Causes and empathy as a solution. Patient Educ Couns. 2020; 103(8):1650-6.

Schiff GD, Puopolo AL, Huben-Kearney A. Primary care closed claims experience of Massachusetts malpractice insurers. JAMA Intern Med. 2013; 173(22):2063-8.

Computed tomography (CT) exams - OECD. Available at: https://data.oecd.org/healthcare/ computed-tomography-ct-exams.htm. Accessed on 20 November 2023.

Medicare Benefits Scheme 2023 - Australian Government 203. Available at: https://www. mbsonline.gov.au/. Accessed on 20 November 2023.

Alvarado A. A practical score for the early diagnosis of acute appendicitis. Ann Emerg Med. 1986;15(5): 557-64.

Rao PM, Rhea JT, Novelline RA. Sensitivity and specificity of the individual CT signs of appendicitis: experience with 200 helical appendiceal CT examinations. J Comput Assist Tomogr. 1997;21(5): 686-92.

Choi D, Park H, Lee YR. The most useful findings for diagnosing acute appendicitis on contrast-enhanced helical CT. Acta Radiol. 2003;44(6):574-82.

Centers for medicare & medicaid services (CMS) - ICD 10 Procedural codes 2023. Available at: https://www.cms.gov/medicare/coding-billing/icd-10-codes/2023-icd-10-pcs. Accessed on 20 November 2023.

Australian Atlas of Healthcare Variation 2017: 4.5 Appendicectomy - Safety and Quality - Australian Government 2017. Available at: https://www.safety andquality.gov.au/sites/default/files/migrated/4.5-Appendicectomy.pdf. Accessed on 20 November 2023.

Margenthaler JA, Longo WE, Virgo KS. Risk factors for adverse outcomes after the surgical treatment of appendicitis in adults. Ann Surg. 2003;238(1):59-66.

Miller FG, Colloca L, Kaptchuk TJ. The placebo effect: illness and interpersonal healing. Perspect Biol Med. 2009;52(4):518-39.

Wang E, Jootun R, Foster A. Management of acute appendicitis in an acute surgical unit: a cost analysis. ANZ J Surg. 2018;88(12):1284-8.

Arthur T, Gartrell R, Manoharan B. Emergency appendicectomy in Australia: findings from a multicentre, prospective study. ANZ J Surg. 2017; 87(9):656-60.

Schaaf S, Schwab R, Güsgen C. Recommendations on Postoperative Activities After Abdominal Operations and Incisional Hernia Repair-A National and International Survey. Front Surg. 2021;8:713138.

Güsgen C, Willms A, Schaaf S. Lack of Standardized Advice on Physical Strain Following Abdominal Surgery. Dtsch Arztebl Int. 2020;117(44):737-44.

Ma S, Kong B, Liu B. Biological effects of low-dose radiation from computed tomography scanning. Int J Radiat Biol. 2013;89(5):326-33.

Marci R, Mallozzi M, Di Benedetto L. Radiations and female fertility. Reprod Biol Endocrinol. 2018;16(1): 112.






Original Research Articles