Epidemiology, etiology, pathogenesis, and pathological underlying in acute appendicitis

Authors

  • Paulina Vladova Medical University of Pleven, Bulgaria, Propedeutics of surgical desiases Author https://orcid.org/0000-0002-2200-8156
  • K. Petrakieva Medical University of Pleven, Bulgaria, Propedeutics of surgical desiases Author
  • Rosa Cavallaro Medical University of Pleven, Bulgaria, Propedeutics of surgical desiases Author
  • Sergey Iliev Medical University of Pleven, Bulgaria, Propedeutics of surgical desiases Author https://orcid.org/0000-0001-8245-1937

DOI:

https://doi.org/10.67572/apshcj62

Keywords:

acute appendicitis, epidemiology, pathogenesis, classification, pathology

Abstract

Acute appendicitis remains one of the most frequent surgical emergencies worldwide, affecting approximately 10% of the population, with peak incidence in the second and third decades of life. Although its overall incidence has remained stable, the last two decades have witnessed evolving management strategies, including non-operative treatment for uncomplicated cases and interval appendectomy. The pathogenesis of acute appendicitis is multifactorial, traditionally attributed to luminal obstruction and subsequent bacterial infection. Alternative theories emphasize viral triggers, vascular spasm, allergic reactions, and environmental factors such as diet and air quality. The appendix is now recognized as an organ with neuroendocrine and immunological functions rather than a vestigial structure.
Histopathological and clinical classifications distinguish between uncomplicated and complicated appendicitis, with the latter encompassing phlegmonous, gangrenous, and perforated forms. Modern imaging-based systems, such as the Classification of Acute Appendicitis (CAA), integrate radiological findings to guide management. Despite extensive research, the disease’s pathophysiology remains incompletely understood. Continued multidisciplinary investigation is required to refine diagnostic accuracy, optimize therapeutic algorithms, and reduce postoperative complications.

References

1. Di Saverio, S., Birindelli, A., Kelly, M.D. et al. WSES Jerusalem guidelines for diagnosis and treatment of acute appendicitis. World J Emerg Surg 11, 34 (2016). https://doi.org/10.1186/s13017-016-0090-5. DOI: https://doi.org/10.1186/s13017-016-0090-5

2. Di Saverio S, Podda M, De Simone B, Ceresoli M, Augustin G, Gori A, Boermeester M, Sartelli M, Coccolini F, Tarasconi A, De' Angelis N, Weber DG, Tolonen M, Birindelli A, Biffl W, Moore EE, Kelly M, Soreide K, Kashuk J, Ten Broek R, Gomes CA, Sugrue M, Davies RJ, Damaskos D, Leppäniemi A, Kirkpatrick A, Peitzman AB, Fraga GP, Maier RV, Coimbra R, Chiarugi M, Sganga G, Pisanu A, De' Angelis GL, Tan E, Van Goor H, Pata F, Di Carlo I, Chiara O, Litvin A, Campanile FC, Sakakushev B, Tomadze G, Demetrashvili Z, Latifi R, Abu-Zidan F, Romeo O, Segovia-Lohse H, Baiocchi G, Costa D, Rizoli S, Balogh ZJ, Bendinelli C, Scalea T, Ivatury R, Velmahos G, Andersson R, Kluger Y, Ansaloni L, Catena F. Diagnosis and treatment of acute appendicitis: 2020 update of the WSES Jerusalem guidelines. World J Emerg Surg. 2020 Apr 15;15(1):27. doi: 10.1186/s13017-020-00306-3. PMID: 32295644; PMCID: PMC7386163. DOI: https://doi.org/10.1186/s13017-020-00306-3

3. Petroianu, A. and Villar Barroso, T.V. (2016) Pathophysiology of Acute Appendicitis. JSM Gastroenterology & Hepatology, 4, 1-4.

4. Bhangu, Aneel et al. Acute appendicitis: modern understanding of pathogenesis, diagnosis, and management. The Lancet, 2017, Volume 386, Issue 10000, 1278 – 1287. DOI: https://doi.org/10.1016/S0140-6736(15)00275-5

5. GBD 2021 Appendicitis Collaborator Group. Trends and levels of the global, regional, and national burden of appendicitis between 1990 and 2021: findings from the Global Burden of Disease Study 2021. Lancet Gastroenterol Hepatol. 2024 Sep;9(9):825-858. doi: 10.1016/S2468-1253(24)00157-2. Epub 2024 Jul 17. PMID: 39032499; PMCID: PMC11306195.

6. Guan L, Liu Z, Pan G, Zhang B, Wu Y, Gan T, Ouyang 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 Feb 22;23(1):44. doi: 10.1186/s12876-023-02678-7. PMID: 36814190; PMCID: PMC9945388. DOI: https://doi.org/10.1186/s12876-023-02678-7

7. Mahdi BD, Rahma C, Mohamed J, Hayet Z, Riadh M. Single port laparoscopic orchidopexy in children using surgical glove port and conventional rigid instruments. Korean J Urol. 2015 Nov;56(11):781-4. doi: 10.4111/kju.2015.56.11.781. Epub 2015 Oct 30. PMID: 26568797; PMCID: PMC4643175. DOI: https://doi.org/10.4111/kju.2015.56.11.781

8. Guinane CM, Tadrous A, Fouhy F, et al. Microbial composition of human appendices from patients following appendectomy. mBio 2013; 4: e00366-12. DOI: https://doi.org/10.1128/mBio.00366-12

9. Andersson RE. Short and long-term mortality after appendectomy in Sweden 1987 to 2006. Influence of appendectomy diagnosis, sex, age, co-morbidity, surgical method, hospital volume, and time period. A national population-based cohort study. World J Surg 2013; 37: 974–81. DOI: https://doi.org/10.1007/s00268-012-1856-x

10. StatPearls-Appendicitis from National Center for Biotechnology Information (updated 2023) https://www.ncbi.nlm.nih.gov/books/NBK493193/.

11. Kang CB, Li XW, Hou SY, Chi XQ, Shan HF, Zhang QJ, Li XB, Zhang J, Liu TJ reoperatively predicting the pathological types of acute appendicitis using machine learning based on peripheral blood biomarkers and clinical features: a retrospective study. Ann Transl Med 2021 https://atm.amegroups.org/article/view/69733/html. DOI: https://doi.org/10.21037/atm-20-7883

12. Int J Colorectal Dis.2021 Nov. From National Center for Biotechnology Information https://pubmed.ncbi.nlm.nih.gov/34143276/.

13. Cozzi DA from Frontiers in pediatric rontiersin.org/journals/pediatrics/articles/10.3389/fped.2022.908226/full.

14. S. Di Saverio Diagnosis and treatment of acute appendicitis: 2020 update of the WSES Jerusalem guidelines from World Journal of Emergency Surgery. https://wjes.biomedcentral.com/articles/10.1186/s13017-020-00306-3.

15. Hoffmann JC, Trimborn CP, Hoffmann M, Schröder R, Förster S, Dirks K, Tannapfel A, Anthuber M, Hollerweger A. Classification of acute appendicitis (CAA): treatment directed new classification based on imaging (ultrasound, computed tomography) and pathology. Int J Colorectal Dis. 2021 Nov;36(11):2347-2360. doi: 10.1007/s00384-021-03940-8. Epub 2021 Jun 18. PMID: 34143276. DOI: https://doi.org/10.1007/s00384-021-03940-8

16. Rushing A, Bugaev N, Jones C, Como JJ, Fox N, Cripps M, Robinson B, Velopulos C, Haut ER, Narayan M. Management of acute appendicitis in adults: A practice management guideline from the Eastern Association for the Surgery of Trauma. J Trauma Acute Care Surg. 2019 Jul;87(1):214-224. doi: 10.1097/TA.0000000000002270. PMID: 30908453. DOI: https://doi.org/10.1097/TA.0000000000002270

17. Kumar SS, Collings AT, Lamm R, Haskins IN, Scholz S, Nepal P, Train AT, Athanasiadis DI, Pucher PH, Bradley JF 3rd, Hanna NM, Quinteros F, Narula N, Slater BJ. SAGES guideline for the diagnosis and treatment of appendicitis. Surg Endosc. 2024 Jun;38(6):2974-2994. doi: 10.1007/s00464-024-10813-y. Epub 2024 May 13. PMID: 38740595. DOI: https://doi.org/10.1007/s00464-024-10813-y

18. Ghorbani A, Forouzesh M, Kazemifar AM. Variation in Anatomical Position of Vermiform Appendix among Iranian Population: An Old Issue Which Has Not Lost Its Importance. Anat Res Int. 2014;2014:313575. doi: 10.1155/2014/313575. Epub 2014 Sep 10. PMID: 25295193; PMCID: PMC4176911. DOI: https://doi.org/10.1155/2014/313575

19. Wickramasinghe DP, Xavier C, Samarasekera DN. The Worldwide Epidemiology of Acute Appendicitis: An Analysis of the Global Health Data Exchange Dataset. World J Surg. 2021 Jul;45(7):1999-2008. doi: 10.1007/s00268-021-06077-5. Epub 2021 Mar 23. PMID: 33755751. DOI: https://doi.org/10.1007/s00268-021-06077-5

20. Lotfollahzadeh S, Lopez RA, Deppen JG. Appendicitis. [Updated 2024 Feb 12]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK493193/

21. Salö M, Tiselius C, Rosemar A, Öst E, Sohlberg S, Andersson RE. Swedish national guidelines for diagnosis and management of acute appendicitis in adults and children. BJS Open. 2025 Mar 4;9(2):zrae165. doi: 10.1093/bjsopen/zrae165. PMID: 40203150; PMCID: PMC11980984. DOI: https://doi.org/10.1093/bjsopen/zrae165

22. Tolecova. Comparative studies of outcomes of laparoscopic and conventional appendectomy in pediatric acute appendicitis. 2028

23. Dimcheva. Diagnostic and treatment algorithm of complicated atipically located appendicitis with SIRS in children. 2019.

24. Ivanov. Role of inflammatory markers in diagnosis of acute appendicitis in children. 2018.

Published

19.10.2025

Issue

Section

LITERATURE REVIEW

How to Cite

Vladova, P., Petrakieva, K., Cavallaro, R., & Iliev, S. (2025). Epidemiology, etiology, pathogenesis, and pathological underlying in acute appendicitis. Surgery, 89(3). https://doi.org/10.67572/apshcj62