Amyand's hernia with concurrent appendicitis: A case of interval laparoscopic herniorrhaphy and literature review

Abstract

Introduction and importance

Amyand's hernia with concurrent appendicitis is rare, with a reported incidence of 0.13 % of all inguinal hernias. This condition is challenging to diagnose and manage and no optimal treatment has been established.

Case presentation

A 71-year-old man presented with an acutely painful, tender, and irreducible right inguinal hernia. He had a history of a right inguinal hernia for several months and had undergone open left inguinal hernia repair. The patient had no other medical comorbidities. Blood test results were nonspecific, with a C-reactive protein of 90 mg/L. Ultrasound scan suggested a strangulated right inguinal hernia. Laparoscopy revealed an Amyand's hernia with concurrent appendicitis and a pus-filled right inguinal hernia sac. The patient underwent laparoscopic appendicectomy, followed by staged laparoscopic transabdominal preperitoneal right inguinal hernia repair with mesh after eight weeks to reduce mesh infection. Histopathological examination confirmed acute uncomplicated appendicitis without perforation or malignancy. The patient had an unremarkable post-operative recovery.

Discussion

This case highlights the diagnostic challenges associated with Amyand's hernia and concurrent appendicitis. Laparoscopy provides both diagnostic and therapeutic opportunities. In this case, laparoscopic mesh herniorrhaphy was delayed and staged until local hernia sac inflammation resolved following appendicectomy.

Conclusion

Surgeons should have an index of suspicion for Amyand's hernia given the heterogeneity of presentations. A case-by-case approach is required to prevent post-operative complications and determine the safe timing of definitive hernia repair when the inguinal hernial sac is inflamed. Further research is required to provide surgeons with evidence-based approaches for this unique condition.

Highlights

• •Amyand's hernia and concurrent appendicitis present diagnostic challenges.
• •Surgeons should consider Amyand's hernia when patients have acute groin lumps.
• •Laparoscopy can offer both diagnostic and therapeutic benefits.
• •Hernia repair after appendicectomy should be personalized.
• •It should consider hernia sac inflammation and mesh infection risk.

1. Background

Amyand's hernia (AH) is defined as the protrusion of the vermiform appendix within an inguinal hernia sac [1]. It was named after Claudius Amyand (1660–1740), who first documented a successful appendicectomy in an 11-year-old boy who presented with a perforated appendix in his inguinal hernia sac [1]. AH is an uncommon condition, occurring in approximately 1 % of all inguinal hernia cases. Acute appendicitis associated with AH is even rarer, with a reported incidence of 0.13 % [2].

AH has been reported in neonates and the elderly, and almost exclusively in males [3]. Several theories have been proposed to explain the pathophysiology of AH; however, the cause-effect relationship between inguinal herniation and appendicitis remains unclear [1,3].

Preoperative diagnosis remains challenging and is typically made intraoperatively [3]. The majority of patients present with no specific symptoms or signs to indicate an AH and the clinical presentation of AH often mimics that of an incarcerated or strangulated inguinal hernia [4]. In the presence of peritonitis and abdominal sepsis, mortality ranges from 14 to 30 % [2,3].

Owing to the paucity of data, there are no standard treatments or guidelines available to guide the timing and type of hernia reconstruction and the use of prosthetic mesh materials following appendicectomy [5].

Herein, we describe a rare case of AH with concurrent appendicitis, the challenges in diagnosis, and successful management using a two-stage surgical approach. This case report has been reported in line with the SCARE criteria [6].

2. Case presentation

A 71-year-old male patient presented with a one-day history of an acute right-sided groin pain and an irreducible groin lump. He had no fever, abdominal pain, or distension, and he reported having a normal bowel movement the day before the presentation. He had a history of a reducible right-sided inguinal hernia that had been managed conservatively for several months but developed increasing pain in the last four days. He had undergone left inguinal hernia repair 40 years ago and had no other medical comorbidities. On examination, he had an approximately 50 mm × 40 mm tender and non-reducible inguinal mass without overlying erythema or skin discoloration. No auscultation was performed. His abdomen was neither distended nor tender. There was no evidence of rectal bleeding on digital rectal examination. His hemoglobin (Hb) level was 123 g/L (reference range (Ref) 130–180 g/L), and white cell count was 8.7 × 10⁹/L (Ref 4.0–11.0 × 10⁹/L). The C-reactive protein level was elevated at 90 mg/L (Ref < 10 mg/L), and the lactate level was unremarkable at 1.1 mmol/L (Ref 0.3–1.3 mmol/L). There was acute kidney injury with estimated glomerular filtration rate of 32 mL/min/1.73 m² (Ref > 90 mL/min/1.73 m²) and serum creatinine of 179 mmol/L (Ref 60–110 mmol/L). The heart rate and blood pressure were 70 beats/min and 139/73 mmHg, respectively, with the patient not on any regular medications. An ultrasound scan of his right groin and scrotum suggested a non-reducible bowel containing a right inguinal hernia with a hernia sac measuring 43 mm × 36 mm in size, a hernia neck measuring 21 mm in diameter, and focal tenderness suggestive of bowel strangulation (Fig. 1).

Fig. 1.

Ultrasound imaging of right groin. (A) Cross-sectional view showing the appendix (white arrow) with echogenic surrounding fat soft tissue within the inguinal canal (dotted) suggesting inflammatory changes. (B) Longitudinal view showing a thickened tubular structure (white arrow) with a blind-ended tip consistent with Amyand's hernia with appendicitis. This was originally reported as tender, non-reducible strangulated bowel contained right sided inguinal hernia, with a hernia sac measuring 46 mm × 36 mm, and the hernia neck measuring 21 mm in diameter.

The patient underwent an emergency laparoscopy which revealed an AH with an inflamed vermiform appendix incarcerated within the right inguinal hernia (Fig. 2). There was purulent fluid within the hernial sac with adhesions between the appendix and the sac. However, there was no macroscopic evidence of appendix perforation or suppuration. The inflamed appendix was bluntly dissected from the hernia sac, and the purulent fluid was removed from the sac. The appendiceal base was identified, and the mesoappendix was divided with a diathermy to completely skeletonize the appendix. There was no abdominal contamination, and the small and large bowels appeared normal. Findings were consistent with a simple uncomplicated appendicitis. Laparoscopic appendicectomy was performed with a plan to repair the hernial defect in the future.

Fig. 2.

Intra-operative photographs showing Amyand's hernia. Photographs (A & B) taken during laparoscopic appendicectomy confirming the diagnosis of Amyand's hernia with an inflamed appendix (yellow arrow) entering the inflamed deep inguinal ring hernia sac (white dotted line) on the right-hand side.

No major post-operative complications were observed. Histopathological examination confirmed a 58 mm × 18 mm sized fragmented appendix with focal areas of fibrinopurulent exudate on the serosa without evidence of perforation. The findings revealed evidence of acute appendicitis without atypia. The patient underwent delayed elective transabdominal preperitoneal (TAPP) inguinal hernia repair eight weeks after laparoscopic appendicectomy, in which DP2 synthetic mesh was placed to encircle the deep inguinal ring on the right side and secured to the pubis medially, and minimal AbsorbaTacks were placed laterally (Fig. 3). The patient had an unremarkable post-operative recovery, with no recurrence of hernia or mesh infection on outpatient follow-up six months after the hernia repair.

Fig. 3.

Intra-operative photograph taken from laparoscopic transabdominal preperitoneal right inguinal hernia repair. DP2 mesh was placed to encircle deep inguinal ring (white arrow), secured to the pubis medially, with minimal AbsorbaTacks placed laterally.

3. Discussion

AH is a condition in which the vermiform appendix is contained within the inguinal hernia sac [7]. The pathogenesis of developing appendicitis in AH is not well understood. It is unclear whether the presence of the appendix within the hernial sac is responsible for the development of appendicitis, or whether appendicitis occurs coincidentally within the sac [7]. The proposed theories have been reviewed [7], and include: (1) incarceration and subsequent appendiceal inflammation; (2) development of adhesions between the hernia sac and appendix, resulting in irreducible hernia; (3) abdominal muscle contraction increasing intra-abdominal pressure leading to compression and obstruction of the appendix; and (4) primary appendicitis leading to an irreducible hernia from venous stasis and impaired microcirculation within the appendix.

AH is difficult to diagnose preoperatively and a definitive diagnosis is often made during surgery [7,8]. Symptomatic AH presents clinical features resembling those of an incarcerated or strangulated hernia. Patients present with a painful, irreducible inguinal bulge with swelling and overlying erythema. When appendicitis is present within a hernia, the clinical presentation resembles a strangulated or perforated intestine within the hernia. McBurney's sign is often negative in the absence of focal peritonitis. In our case, the patient presented with a painful, tender, and non-reducible right inguinal hernia, without overlying erythema, resembling an incarcerated hernia. The diagnosis of AH was not definitively established preoperatively.

Imaging studies, such as ultrasound scanning and computed tomography (CT), can facilitate the diagnosis. Ultrasound scanning is often the first imaging modality of choice for investigating right-sided abdominal pain. Sonographic features can include a noncompressible tubular structure within the hernia sac and wall thickening with hyperemia if there is evidence of appendicitis. A CT scan can similarly demonstrate a blind-ending structure within the hernia sac, fat stranding, wall thickening, and hyperemia if concurrent appendicitis is present [7,9]. In our case, ultrasound scans failed to detect both AH and appendicitis before the decision for surgery and there was no evidence of bowel strangulation intraoperatively. Upon reviewing the ultrasound imaging, no additional bowel loops were observed within the hernia sac, and there was no mention of Doppler flow, which is useful for supporting the diagnosis of bowel strangulation. This underscores the importance of the sonographer's experience and skill in achieving diagnostic accuracy in ultrasound assessments [9]. The laparoscopic approach can function both diagnostically and therapeutically.

Losanoff and Basson [10] proposed a classification system to guide the management of AH. The authors divided it into four subtypes: (1) type 1, AH with a normal-appearing appendix in the inguinal sac; (2) type 2, AH with an inflamed appendix; (3) type 3, AH with a perforation of the vermiform appendix; and (4) type 4, AH with complicated intra-abdominal pathology, such as abscess or malignancy. Rikki modification adds a fifth type of AH, an incisional hernia through which the vermiform appendix protrudes [11]. Based on this classification, our patient presented with type 2 AH, for which the proposed management was laparoscopic appendicectomy with primary hernia repair [10].

Controversy exists regarding AH repair with mesh when an inflamed or perforated appendix is present. The published literature initially suggested a combined treatment of appendicectomy and hernia repair [12]. However, mesh repair should be deferred if the inguinal canal has severe inflammation because the introduction of prosthetic material can trigger an inflammatory response and nidus infection [8]. Mesh repair is recommended when a noninflamed appendix is discovered during hernia repair [9]. An approach similar to that used for hernias containing a strangulated small bowel should be adopted. In our case, we considered the severity of appendicitis and inflammation of the hernia sac, with the presence of purulent fluid within the sac. A systematic review recommends against the placement of mesh if there is a local inflammation process even after resection of the sac. There is an increased risk of wound infection, mesh infection, rejection of allograft, and subsequent hernia recurrence [13]. Hence, laparoscopic mesh herniorrhaphy was delayed and staged until local inflammation resolved following appendectomy. Given the rarity of AH with concurrent appendicitis, a case-by-case evaluation is essential to determine the most suitable surgical approach for patients presenting with this condition.

4. Conclusion

AH with concurrent acute appendicitis is rare and presents significant diagnostic and decision-making challenges. Surgeons should have an index of suspicion for AH given the heterogeneity of presentations. A case-by-case approach is required to prevent post-operative complications and determine the safe timing of definitive hernia repair when the inguinal hernial sac is inflamed. Further research is required to provide surgeons with evidence-based approaches for this unique condition for optimal patient outcomes.

List of abbreviations

AH

Amyand's hernia

CT

computed tomography

Ref

reference range

TAPP

transabdominal preperitoneal

Declaration of competing interest

The authors declare no conflict of interest.

Data availability

Data sharing is not applicable to this article as no datasets were generated or analyzed during the current study.