INTRODUCTION
Acute appendicitis and inguinal hernia are two very common conditions in the surgical field, both emergency and scheduled, with the lifetime risk of developing them being 7-8% 1-3 and 27% 4, respectively. However, it is a rare association that was first described in 1735 by Claudius Amyand in a 11-year-old boy, which is why this clinical condition is known as Amyand's hernia (AH).
AH is more common in children and men because of the persistence of processus vaginalis, and its incidence is higher on the right side of the inguinal hernia due to its location in the right lower quadrant. This condition is difficult to diagnose and is usually done intraoperatively, but its pre-surgical identification is becoming more frequent due to a better understanding of its pathophysiology and the fact that imaging studies are carried out to confirm its presence in the event of a diagnostic suspicion.
The treatment of AH is surgical and based on the Losanoff and Banson classification (Table 1) 5-10. One of the therapeutic options, according to these authors, is incidental appendectomy in young people, although its performance is controversial, and even contraindicated in adults, when no signs of appendiceal inflammation are observed.
Type of hernia | 1 | 2 | 3 | 4 |
---|---|---|---|---|
Features | Normal Appendix | Acute appendicitis located within an inguinal hernia | Acute appendicitis with peritonitis or abdominal sepsis | Acute appendicitis associated with other intra-abdominal disease |
Surgical management | Hernia reduction (appendectomy in young patients) and mesh repair | Appendectomy through hernia and hernia repair without mesh | Laparotomy, appendectomy, and hernia repair without mesh | Appendectomy and specific treatment of the associated disease as appropriate |
Source: Own elaboration based on Servide-Staffolani et al.8 and Losanoff & Basson 10.
The following is the case of a patient with AH in whom treatment was partially implemented using hernia repair with mesh according to the Losanoff and Basson classification and in whom no complications occurred during postoperative follow-up.
CASE PRESENTATION
A 57-year-old mestizo man from the southern coast of Ecuador, a longshoreman with a low socioeconomic status, consulted the emergency department of a secondary healthcare center due to a 24-hour history of painful and irreducible mass in the right inguinal region associated with general malaise and hyporexia. The patient did not report any known medical or surgical history.
Physical examination on admission revealed a 4x3cm inguinal mass with no color changes, painful on palpation and irreducible. Blood tests showed leukocytes of 10 000 with neutrophilia of 79%. Diagnostic imaging was not ordered because the symptoms were typical of an incarcerated right inguinal hernia and, consequently, therapeutic management would not change with or without an ultrasound or CT scan.
Based on the findings and on the resources available at the hospital, a conventional right inguinal hernioplasty was decided to avoid a major complication such as strangulation. During the procedure, a hernial ring of 1.5cm and a hernia sac of 6x7cm were found within the cecal appendix and cecum (Figure 1). An incidental appendectomy was performed and, since no contamination was found, a hernioplasty was performed using the Lichtenstein technique with a low-density polypropylene mesh. These procedures were performed on the same day of admission.
The patient progressed favorably and was discharged 24 hours after surgery. Medical check-ups were performed 8 and 15 days after the procedure and an adequate healing process was observed without complications.
DISCUSSION
AH is defined as the presence of the cecal appendix within an inguinal hernia sac. This condition was first described in 1735 by the French surgeon Claudius Amyand after performing an appendectomy for perforated appendicitis in a 11-year-old patient with an incarcerated inguinal hernia 4,8,11-18. If the cecal appendix is located in a femoral hernia, it is called a De Garengeot's hernia 19.
This type of hernia is an apparently rare condition in which two very common symptoms are associated: acute appendicitis and inguinal hernia. AH occurs in 0.1-1% of all inguinal hernias and in up to 0.3% of cases the appendix is inflamed 4,6,7,16,18,20-24. The mortality rate of this disease rises between 15% and 30% in cases of perforation due to subsequent sepsis 8,9,19.
It should be noted that there is a rise in the reports and papers on AH, showing an increase in the number of publications per year from 1985 to May 2020 25, as shown in Figure 2, which was created based on the results of a search made in PubMed by entering the terms "Amyand, hernia," regardless of the type of treatment and without a specific year range. Many of the publications found describe a pre-operative diagnosis established using imaging studies 5-9,14,17,19,25-28.
The significant increase in the number of AH cases, added to the lifetime risk of developing inguinal hernia and appendicitis (27% and 7-8%, respectively) 1-4, obliges health professionals to consider this condition for differential diagnosis when evaluating an inguinal hernia, especially on the right side. However, its diagnosis is usually intraoperative, as in the case reported here.
AH occurs most often in childhood due to persistent processus vaginalis and the incidence of inguinal hernia in men. These hernias are also more frequent on the right side, as found in the reported patient, although it is not ruled out that they can occur on the left side due to mobile cecum, situs inversus, or malrotation 8,9,11,27,29.
The most frequent post-surgical complications of AH are infection, ranging from 5% to 50% 6,19,26, and hernia recurrence, neither of which was observed in the reported case.
Regarding pathophysiology, two situations may occur in AH. In the first, the appendix migrates into the hernia sac, where some authors state that a fibrous connection between the appendix (retrocecal) and the testicles added to the persistence of processus vaginalis favor the passage of the appendix into the inguinal canal and this would be the reason for the higher incidence of this condition in children and premature infants. In the second situation, the appendix becomes inflamed inside the hernia, and this may be secondary to the vascular involvement caused by the pressure of the hernial neck, triggering the inflammatory process and the subsequent bacterial proliferation 11,17,25,30, without ruling out luminal obstruction by fecaliths, ganglionic hypertrophy, parasites, or other causes.
Due to the presence of the inguinal ring, the inflammatory process of the appendix in AH may not extend into the abdominal cavity and may be limited to the inguinal canal, affecting the cecum or the base of the ring if they are also within the hernia sac 27.
As mentioned above, the diagnosis of AH is usually incidental during surgery since the symptoms are nonspecific and accompanied by lower abdominal tenderness and irreducible mass in the inguinal region, which are also symptoms of an incarcerated or strangulated inguinal hernia. Although laboratory findings are not specific, imaging studies, such as ultrasound and computed tomography 6,28, allow identifying the presence or absence of the appendix and deciding on the best approach.
Surgery is the treatment for AH and three conditions must be met before performing it: 1) it must be determined whether appendectomy is necessary, 2) the need to use prosthetic material to repair the continuity solution must be established, and 3) the best approach must be decided. Since there are so many variables, there is no general consensus on what the management of this disease should be, so Losanoff and Basson classified AH into four types with their corresponding treatment (Table 1).
When signs of inflammation are detected, an appendectomy is required; however, its use for prophylaxis is controversial when findings are incidental. Those in favor argue that if it is performed carefully avoiding contamination, morbidity and mortality, as well as the cost of future appendicitis, are reduced without increasing the anesthetic risk in young patients, although some experts do not recommend it in pediatric patients 31. On the other hand, those who oppose it claim that appendectomy transforms the procedure from a clean one to a contaminated one, which might result in infectious complications and recurrence 8,16,32.
The patient in the case reported here was diagnosed during hernioplasty with type 1 AH. Therefore, according to this classification, management included prophylactic appendectomy and hernia repair with a polypropylene mesh since there is a low probability of infection in these cases 11. The intervention was effective, and the patient's progress was favorable in follow-up.
The satisfactory evolution of the patient reported here, as well as that of other cases mentioned in the literature, seems to be related to the use of a clean surgical technique when correcting the wall defect with a mesh after incidental appendectomy 5,16 or during the inflammatory phase, preventing contamination of the surrounding tissues because the appendix is manipulated to a minimum, the remnant appendix is isolated from the hernia sac with a good closure, and the procedure is accompanied by adequate antibiotic prophylaxis. It is worth mentioning that this technique has also reported good results in more advanced stages of appendicitis 6,8,21,32, although its performance is not usually indicated due to the high risk of infection it entails.
There is a modification or complement to the Losanoff and Basson classification known as the Rikki's classification 33 (Table 2), in which incisional hernia is added and its management depends on the inflammatory status of the appendix.
Classification | Features | Surgical treatment |
---|---|---|
1 | Normal appendix | Hernia reduction (appendectomy in young patients) and mesh repair |
2 | Acute appendicitis within the sac | Appendectomy through hernia and repair of hernia, without mesh |
3 | Acute appendicitis with peritonitis or abdominal sepsis | Laparotomy, appendectomy, and hernia repair, without mesh |
4 | Acute appendicitis associated with other intra-abdominal disease | Appendectomy and specific treatment of the associated disease as appropriate |
5a | Normal appendix within an incisional hernia | Appendectomy plus mesh herniorrhaphy |
5b | Acute appendicitis within incisional hernia, without abdominal sepsis | Appendectomy plus herniorrhaphy, without mesh |
6c | Acute appendicitis within the incisional hernia, abdominal sepsis or secondary disease | Same management as type 4. |
Source: Own elaboration based on Patoulias et al.9, Villarreal et al.11 and Desai et al.29
Both classifications mentioned above are an important guide to surgical management when AH is diagnosed intraoperatively, with herniotomy and laparotomy as access methods. However, due to clinical suspicion and the use of diagnostic imaging, pre-surgical diagnosis is becoming more common, allowing for intervention before complications with the appendix occur and even allowing a laparoscopic approach to the resolution of the hernia 9.
The first case of AH was described in 1 999 by Vermillion et al.34; since then, there has been an increase in the number of reported cases that have been resolved with this technique 17,30. For its part, the first preperitoneal mesh repair of a hernia of this type was carried out by Saggar et al. in 2004, as reported by Michalinos et al.27
CONCLUSIONS
AH is an apparently rare disease that is increasingly reported in the literature. It is difficult to diagnose preoperatively since it does not present with specific symptoms. Therefore, when it is suspected, imaging studies should be performed to help its visualization and guide, along with the current classifications, early individualized treatment of both appendicitis and hernia.