Incarcerated recurrent Amyand's hernia.

Amyand's hernia is a rarity and a recurrent case is extremely rare. A 71-year-old male with a previous history of right inguinal hernia repair presented to the emergency department with a 1-day history of pain in the right groin. A physical examination revealed a nonreducible right inguinal hernia. A computed tomography scan showed a 1.3-cm appendix with surrounding inflammation within a right inguinal hernia. An emergent right groin exploration revealed an incarcerated and injected non-perforated appendix and an indirect hernia. Appendectomy was performed through the groin incision, and the indirect hernia defect was repaired with a biological mesh (Flex-HD). We hereby present this unique case - the first reported case of recurrent Amyand's hernia and a literature review of this anatomical curiosity.

INTRODUCTION

Amyand's hernia is an inguinal hernia containing vermiform appendix. The diagnosis was accredited to Claudius Amyand, who was the first person to describe the condition in 1735.[1] The entity is rare with a reported incidence of 0.5-1% for those associated with normal appendix.[2] The incidence of acute appendicitis in the inguinal canal is about 0.1%.[3] We hereby present, to the best of our knowledge, the first case of recurrent nonperforated Amyand's hernia repaired with a biological mesh.

CASE REPORT

A 71-year-old male patient presented to the emergency department with an acute onset of a right groin pain of 24-hour duration. He denied any bowel symptoms. His surgical history includes a plug and patch (ULTRAPRO hernia system) repair of a symptomatic right inguinal hernia 17 months earlier and a sigmoid resection for complicated diverticulitis 20 years earlier. A physical examination revealed a nontoxic appearing male with an exquisitely tender, nonreducible, small right inguinal hernia. His laboratory results revealed a leukocyte count of 9.2 × 103/mm3(normal (4.3-10.8) × 103/mm3). A right incarcerated recurrent inguinal hernia was suspected, and this was confirmed by a computed tomography scan [Figure 1]. The patient was therefore taken to the operating room emergently for right groin exploration. At exploration, a chronically incarcerated, inflamed appendix within the indirect hernia sac [Figure 2] was identified. Appendectomy was performed through the groin incision, and the indirect hernia was repaired with a biological mesh (Flex-HD) due to the contaminated field [Figure 3]. The postoperative period was uneventful, and the patient was discharged home 2 days after the surgery. At 5-month follow-up, the patient is free from recurrence.

Figure 1

CT scan of abdomen/pelvics showing incarcerated Amyand's hernia (arrow indicates inflammed appendix within the hernia sac)

Figure 2

Appendix within the indirect hernia sac

Figure 3

Final repair with a biological mesh

DISCUSSION

Amyand's hernia was credited to Claudius Amyand after he performed the first reported successful appendectomy in an 11-year-old boy in 1735.[4] The patient presented with an enterocutaneous fistula due to the perforation of the appendix by a pin within an inguinal hernia sac. The procedure lasted half an hour and involved an open appendectomy with the primary repair of the hernia defect. Ironically, the first appendectomy in the United States occurred in 1887 and was also a case of appendicitis in an inguinal hernia.[5] Amyand's hernia is therefore an inguinal hernia containing vermiform appendix. The appendix can also be found in a femoral hernia, which is known as De Garengeot hernia.[6] The reported incidence of a normal appendix within the inguinal hernia is approximately 1%;[2] however, the presence of appendicitis in the inguinal hernia is only 0.l%.[3] Amyand's hernia is more common in men and is often right-sided.[7] Left-sided Amyand had been described,[7-9] and it is often associated with situs inversus, mobile cecum, and malrotation of the intestines.[7-9] Most patients present with a nonreducible and tender inguinal hernia.[310] Preoperative diagnosis is difficult, but imaging with computed tomography (CT) scan can suggest the diagnosis,[11] as was in our case. Most Amyand's hernias are therefore diagnosed intraoperatively.[10]

Management is surgical and it is based on intraoperative findings according to Losanoff: type 1 - normal appendix; type 2- inflamed appendix; type 3 - inflamed appendix with abdominal sepsis or perforated appendix; type 4- inflamed appendix and other unrelated abdominal pathology.[12] The management of Losanoff type 2-4 requires appendectomy followed by primary hernia repair.[312] The use of a prosthetic mesh to repair Amyand's hernia with Losanoff type 2-4 findings has been reported.[13] The management of Losanoff type 1 requires hernia repair with or without appendectomy, and this is very controversial. Proponents for routine appendectomy believe that the removal of the appendix at the first operation will decrease the risks of appendicitis and future surgery. However, antagonists to this practice argues that leaving the appendix in situ will allow for the use of a prosthetic mesh for the hernia repair and future use of the appendix as a conduit for urinary diversion when the need arises.

In the present case, routine appendectomy was deferred in the first operation because of the intraoperative finding of Losanoff type 1 Amyand. At recurrence, the appendix was incarcerated, inflamed, and injected, and this prompted immediate appendectomy. The hernia was repaired with a biological mesh due to the contaminated field. We used Flex-HD for the repair, and this is an acellular hydrated dermal matrix derived from human allograft skin developed by Ethicon through alliance with Musculoskeletal Transplant Foundation (http://www.ethicon360.com/products/flex-hd-acelular-hydrated-dermis-family). Similar to other biological meshes, this allograft serves as a scaffold to support cellular repopulation and vascularization.[14]

CONCLUSION

Amyand's hernia is a rare entity with diverse presentation, preoperative diagnostic dilemma, and requirement of knowledge of two surgical problems: symptomatic hernia and appendicitis. Management is surgical and includes hernioplasty with or without appendectomy depending on the intraoperative findings, and routine prophylactic appendectomy is not indicated. The biological mesh plays a role in the management of Losanoff type 2-4 Amyand's hernia. Our unique case of recurrent incarcerated Amyand's hernia elaborates the above findings.

DOD Disclaimer

The views expressed in this case report are those of the authors and do not reflect the official policy of the Department of the Navy (DON), Department of Army (DOA), Department of Defense (DOD), or US Government.