Introduction

The appendix vermiformis (AV) is a narrow, blind-ended tubular organ connected to the cecum. Inflammation of the AV is known as acute appendicitis, and this is one of the most common inflammatory diseases of the gastrointestinal tract. A decrease in blood flow caused by obstruction in the appendiceal lumen, mucosal ischaemic damage and development of bacterial infection has influenced the pathogenesis of acute appendicitis. Acute inflammation is not observed in approximately 20% of patients undergoing appendectomy.¹

Lymphoid hyperplasia, faecalites, fruit and vegetable seeds, barium enemas and tumours are the main components of the aetiology of acute appendicitis. Although parasites have been reported to cause appendicitis only by occluding the lumen with acute inflammation or by creating an inflammatory reaction, the role of parasites in the pathogenesis of appendicitis has not been clearly defined.^2,3 Enterobius vermicularis (EV), Ascaris lumbricoides (AL), Schistosoma spp. and Taenia spp. are parasites that can cause acute appendicitis. Among these, the most widespread cause of acute appendicitis is EV.^4,5

This study aimed to retrospectively evaluate patients with parasitic infestation who underwent appendectomy and were diagnosed with acute appendicitis.

Materials and Method

Electronic records of 7,344 patients who underwent appendectomy and who had acute appendicitis were analysed retrospectively. The analysis covered the period from January 2009 to January 2020. The study was performed in Ankara Training and Research Hospital General Surgery Clinic. For this type of study, informed consent is not required. Patients with parasitic infestation were evaluated in terms of age, gender, type of parasite and presence of inflammation.

Results

A total of 7,344 patients underwent appendectomy. Parasites were seen in 24 appendectomy specimens. Among those with parasitic infestation, 12 (50%) were men and 12 (50%) were women, with a mean age of 36.5 (range: 12-74) years. EV was seen in 22 (91.6%) patients, and AL in 2 (8.4%) patients. Acute inflammation was observed in 7 (31.8%) of EV cases but not in 15 (68.2%). None of the AL cases had signs of acute inflammation (Table 1).

Discussion

Acute appendicitis is the most frequently observed condition that requires emergency surgery.⁶ Acute appendicitis most commonly occurs in the second and third decades of life and affects approximately 8.6% of men and 6.7% of women.⁷ Acute appendicitis can be caused by parasites, as they occlude the appendiceal lumen or lead to secondary inflammation.⁸ Acute inflammation findings may not be present in the histopathological examination of appendectomy specimens of parasitosis.⁹ Karatepe et al.⁸ showed that inflammation was not found in 25% of appendectomy specimens, while Ilhan et al.¹⁰ reported a rate of 52.7%. In the present study, acute inflammation findings were not observed in 70.9% of appendectomy specimens with parasite invasion (Table 2).

EV is the most frequent helminthic infection worldwide and is transmitted through faecal-oral transmission.¹¹ In general, it is a common intestinal parasite in boys and girls and is more common in underdeveloped countries and regions with low socioeconomic status.¹² Most people infected with EV are asymptomatic. Nevertheless, if symptoms develop, the most frequent one is anal pruritus.¹³ In addition, EV infections cause ileocolitis, enterocutaneous fistulas, urinary tract infections, mesenteric abscess, salpingitis and acute appendicitis. Mature forms of EV are most often located in the ascending colon, cecum, appendix and terminal ileum.^14,15 The relationship between EV and acute appendicitis was first discovered at the end of the 19^th century.¹⁶ Studies have established that EV caused pathological changes in the appendix, including lymphoid hyperplasia to acute phlegmatic appendicitis, gangrene appendicitis and peritonitis.⁴ In other studies, EV is present in 0.35%-12.5% of specimens of patients undergoing appendectomy for acute appendicitis.^{12,13,14,15,16,17} Akkapulu and Abdullazade¹⁸ reported an EV incidence rate of 0.62%. In present study, the incidence of EV was 0.32%. Appendectomy is not an adequate treatment for cases with EV, since it does not eliminate the main cause in these patients and anti-helminthic treatment should also be administered.¹⁹ In the present study, anti-helminthic treatment was given to patients with parasites.

Study Limitations

Ascariasis is one of the most common helminthic diseases and is most commonly caused by AL. It is most common in the jejunum and proximal ileum. AL can often mimic acute appendicitis clinically, but rarely causes acute appendicitis. In a rectrospective analysis of 324 appendectomy specimens, AL was detected in only 3 (0.9%) patients; none of whom had histopathological findings of acute appendicitis.²⁰ Wani et al.²¹ showed that while histolopathological findings of acute appendicitis were not observed in 8 (72.7%) of 11 patients with AL, acute appendicitis findings related to ascariasis were detected in 3 (27.2%) patients. In the present study, AL was seen in only two patients, neither of which had any histopathological findings associated with acute appendicitis.

Conclusion

In conclusion, parasites are among the possible aetiological causes of acute appendicitis. EV is the most common parasite in specimens of patients undergoing appendectomy. Negative laparotomy rates have been seen to be higher in the presence of parasitic invasion in the appendix. To reduce negative laparotomy rates and to minimise related side effects, patients with abdominal pain should be checked whether they have intestinal parasites, and this should be considered in the differential diagnosis. Patients with parasitic infestations should be given anti-helminthic therapy.

Ethics

Ethics Committee Approval: Ankara Training and Research Hospital Ethics Committee (date: 15.01.2021/no: 542).

Informed Consent: Retrospective study.

Peer-review: Externally peer reviewed.

Authorship Contributions

Surgical and Medical Practices: K.K., A.Ş., M.S., A.D., Concept: K.K., A.D., Design: K.K., M.S., Data Collection or Processing: K.K., M.S., Analysis or Interpretation: K.K., A.Ş., A.D., Literature Search: K.K., A.Ş., Writing: K.K., A.Ş.

Conflict of Interest: No conflict of interest was declared by the authors.

Financial Disclosure: The authors declared that this study received no financial support.