Revisiting Amyand's Hernia: A 20-Year Systematic Review

Purpose Protrusion of the appendix within an inguinal hernia is termed an Amyand's hernia. A systematic review of case reports and case series of Amyand's hernia was performed, with emphasis on surgical decision-making. Methods The English literature (2000-2019) was reviewed, using PubMed and Embase, combining the terms "hernia", "inguinal", "appendix", "appendicitis" and "Amyand". Overall, 231 studies were included, describing 442 patients. Results Mean age of patients was 34 +/- 32 years (adults 57.5%, children 42.5%). 91% were males, while a left-sided Amyand's hernia was observed in 9.5%. Of 156 elective hernia repairs, 38.5% underwent appendectomy and 61.5% simple reduction of the appendix. 88% of the adult patients had a mesh repair, without complications. Of 281 acute cases, hernial complications (76%) and acute appendicitis (12%) were the most common preoperative surgical indications. Appendectomy was performed in 79%, more extensive operations in 8% and simple reduction in 13% of cases. A mesh was used in 19% of adult patients following any type of resection and in 81% following reduction of the appendix. Among acute cases, mortality was 1.8% and morbidity 9.2%. Surgical site infections were observed in 3.6%, all of which in patients without mesh implantation. Conclusion In elective Amyand's hernia cases, appendectomy may be considered in certain patients, provided faecal spillage is avoided, to prevent mesh infection. In cases of appendicitis, prosthetic mesh may be used, if the surgical field is relatively clean, whereas endogenous tissue repairs are preferred in cases of heavy contamination.