Introduction

An Amyand’s hernia is defined as an inguinal hernia containing the appendix vermiformis. In 1735, Claudius Amyand, described the first inguinal hernia in which the inflamed appendix protruded through. He reported about an 11-year-old boy who presented with a right inguinal hernia that had been existed since birth. Intraoperatively he found a right inguinal hernia containing a perforated appendix with faecal fistula. The surgeon performed an appendectomy and hernia repair. He described the appendix during the operation as “contracted, carnous, duplicated, and changed in its Figure and Substance” [1]. Historically, it was the first description of Amyand’s hernia as well as the first successfully documented conducted appendectomy [2]. Of all reported cases of inguinal hernias, Amyand’s hernia accounts for approximately 0.19% to 1.7% of inguinal hernias [3]. Inguinal hernias containing an inflamed or perforated appendix are rare and occur at an estimated rate of 0.07-0.13% [4].

Intraoperatively, Amyand’s hernia can be divided into four types based on the external appearance according to the classification of Losanoff and Basson [5]. While type 1 describes a normal appendix within an inguinal hernia sac, from type 2 onwards it is an appendicitis, and the extent of the inflammation determines the further classification. According to the type of Amyand’s hernia Losanoff and Basson recommend different management of Amyand’s hernia.  The classification was modified by Singal and Gupta in 2011 [6]. Type 5 which included incisional hernia was added. Type 5 was subdivided into 5a (normal appendix in incisional hernia), 5b (acute appendicitis in incisional hernia), and 5c (acute appendicitis within incisional hernia with abdominal wall or peritoneal sepsis). The revised classification is known as Rikki classification [7] (Table 1).

Table 1: Rikki’s classification of Amyand’s hernias

The exact pathophysiology of an Amyand’s hernia is not fully understood [8]. It is generally assumed that there is a correlation between the appendix becoming trapped in the inguinal canal and the development of inflammation. It has been suggested that the appendix becomes more vulnerable to trauma when the appendix moves into the inguinal canal. Further, the blood supply of the appendix can be reduced which can lead to inflammation and bacterial overgrowth. This mechanism can be strengthened by further compression of the appendix, for example, by a sudden increase in abdominal pressure due to contraction of the abdominal muscles [9].

In this study we present a case of an Amyand’s hernia diagnosed intraoperatively and treated with appendectomy and mesh free open hernia repair according to Shouldice.

Material and Methods

The case report has been reported in accordance with SCARE Guidelines for case report publication [10].

Case Description

The 71-year-old white male patient presented to the emergency department due to severe right groin pain for three days with a previously known right inguinal hernia. The swelling had been known for three weeks and had so far been only cosmetically disturbing. He reported continuously increasing pain in the past three days and an intensity of 8 on the numerical rating scale from 0 to 10 (where 10 stands for the worst pain possible) during movement. At rest he had just a sensation of pressure. The pain had become unbearable now, and the patient reported that he had “no more strength”. There was no pain in the testicles. Fever was denied, urination was unremarkable. The stool had a normal consistency on the morning of presentation, the three days before the patient was unable to pass stool. There were no known preexisting conditions other than arterial hypertension, which was treated with common antihypertensive medication. There were no known allergies. On examination, the patient was found to be in pain-reduced general condition and in good nutritional status, as well as alert and communicative. The auricular measured body temperature was 36.6 ^°C. The abdomen palpated softly and without resistance on deep palpation, regular bowel sounds could be auscultated over all quadrants. A nonreducible, doughy-hard bulge in the right groin was detected. It was hyperthermic, but not reddened. On coughing, the swelling remained unchanged. Discrete and sparse bowel sounds could be auscultated over the swelling. The lymph nodes were not palpable inguinally. No lower leg edema was found. The ECG revealed age-appropriate findings. Laboratory examination of the blood revealed leucocytosis of 23.5 G/L (normal value: 4-10 G/L) and an elevation of C-reactive protein of 180.1 mg/L (normal value < 5mg/l). The hematogram, electrolytes, and renal function parameters were normal. Hb 151 g/l, MCV 87 fl, MCH 29 pg, sodium 133 mmol/l, potassium 4.2 mmol/l, creatinine 115 umol/l, GFR 55 ml/min, glucose 7.9 mmol/L, urea 9.8 mmol/L. An externally obtained sonographic finding three weeks earlier showed a relatively slender hernial orifice of a large right indirect inguinal hernia with a hernial sac measuring 11 x 8 x 9 cm. Herniation of small bowel structures was noted, but there was no evidence of obstruction or incarceration. Elective scheduled surgical management was recommended. The surgeon in charge was consulted immediately after examination of the patient, the clinical suspect of incarcerated inguinal hernia was confirmed. An indication for emergency surgery was given.

At surgery, the classical right inguinal incision was made. After the incision, an abscess appeared. Already at the pressure the abscess cavity perforated and it drainaged creamy pus. Extensive irrigation and new washing and covering. Afterward, a direct hernia sac was identified. After preparation of the hernial sac the Amyand’s hernia revealed with the inflamed and perforated appendix at the tip of the appendix. The surrounding wall was inflamed (Figure 1). An appendectomy and hernia repair according to Shouldice were performed. The appendix showed a length of 9.8 cm. The abscess cavity was irrigated after further dissection and debridement was performed. The closure of the external aponeurosis was not possible, so the inguinal ligament was shirred. A vacuum suction drain was placed in the subcutaneous tissue for negative pressure wound therapy. The patient received Cefuroxim and Ornidazol during the operation. The antibiotic therapy was continued with Cefuroxim.

Figure 1: Intraoperative findings of the perforated appendix

Histopathological examination revealed acute peri appendicitis with chronic granulating inflammation, macro phagocytic reaction, foam cell aggregates, fibrinous purulent, and stercoral peritonitis in a transmural wall defect.

The postoperative course was uneventful. On postoperative day 3, a debridement, lavage, and VAC dressing change were carried out under spinal anesthesia. Further VAC dressing changes were performed on postoperative days 7 and 10. The patient was discharged with a vacuum pump on day 11 post-surgery. Regular changes of vacuum pumps took place and secondary wound closure was performed on postoperative day 38 (Figure 2). The follow-up examination 3 months after surgery did not show a reoccurrence of a hernia.