Abdominal imaging
Case TypeClinical Cases
Authors
Rangarajan Purushothaman, Freda Jawan, Chung Siok Li, Praveen Jayapal
Patient58 years, female
A 58-year-old female patient presented complaining of irreducible right-groin lump and pain for three days with associated fever, nausea, and vomiting. She was known to have a right femoral hernia. Ultrasound evaluation two months prior revealed the hernia to be reducible and containing mesenteric fat and fluid collection measuring 2.0cm.
Contrast-enhanced computed tomogram (CT) images were obtained on a 64 slice Siemens scanner after intravenous administration of 80ml of Iohexol 350. The right femoral hernia measuring about 3cm was seen medial to the femoral vessels and the sapheno-femoral junction. It contained a pocket of fluid (25HU) measuring about 2.2x1.5cm. Adjacent to the fluid collection, a separate long tubular structure was seen, the origins of which was traced back to the caecum representing the appendix. Dilated appendicular lumen, hyper enhancing walls, peri-appendiceal stranding were demonstrated. Findings were consistent with acute appendicitis within an incarcerated femoral hernia. There were no imaging signs of perforation or abscess formation. The targeted ultrasound that was done two months prior showed a femoral hernia containing fat and a cystic structure of 2.0 x 1.3cm at the site of interest. The appendix was not visualised within the hernia on the ultrasound exam.
A diagnosis of acute appendicitis within an incarcerated femoral hernia – de Garengeot’s hernia was made. The patient underwent emergent surgery. Intra-operatively the distal 2/3rd of the appendix was located within the femoral sac with features of acute gangrenous appendicitis, which was subsequently confirmed on surgical pathology. The femoral hernia was noted to have a narrow neck with infarcted mesenteric fat. The patient underwent laparoscopic appendectomy and open repair of the hernia with excision of non-viable fat. Post-operative recovery was uneventful. French surgeon Jacques Croissant de Garengeot first described the occurrence of appendix within a femoral hernia in 1731 [1,2]. Acute appendicitis within a femoral hernia is rare with less than 100 cases [1] published in the literature with pre-operative diagnosis established only in a handful of cases. There is a female preponderance (1:13 women) [1]. Pelvic location of the appendix, degree of embryonic caecal rotation and obesity are thought to be risk factors. The neck of the hernia tends to be narrow in most cases, thus limiting the development of peritonitis [3]. Groin pain, irreducible lump with signs of local inflammation is the most common presentation [3]. Incarcerated femoral hernia is usually considered as the first diagnosis, as assessing the hernia contents through physical examination is hard. Presence of an intramural density within the hernia sac should raise the suspicion of intestinal involvement and in most cases the long tubular structure originating from the caecum into the hernia sac can be identified. CT has 98% sensitivity and specificity for diagnosing or excluding appendicitis within a hernia sac [2]. The sensitivity of US is limited due to operator experience and the technical difficulties in differentiating cystic or hypoechoiec mass from fluid-filled bowel [5]. MR imaging has high sensitivity but its use in the clinical setting is limited due to high cost, longer scanning times and lack of easy availability. An open inguinal approach can be chosen for hernia repair and appendectomy while some centers advocating laparoscopy for appendectomy and an infra-inguinal approach for hernia repair. Most surgeons refrain from doing a mesh repair due to concerns of post-operative infection in the setting of acute inflammation [4]. Teaching Point: In a patient with a known femoral hernia, incarceration would be the first sought diagnosis resulting in satisfaction of search error. In all instances, the appendix should be identified and its course should be traced completely as only the distal end of the appendix may be inflamed and positioned within the hernia. Written informed consent for publication has been obtained.
[1] Carolina Talini, Luan Ocana Oliveira, Allan Cesar Faria Araujo, Fernando Antonio Campleo Spencer Netto, Andre Pereira Westphalen. de Garengeot hernia: Case report and review Int J Surgery Case Rep 2015 8: 35–37. (PMID: 25622240)
[2] Bardia Bidarmaghz, Chin Li Tee. A Case of de Garengeot hernia and literature review. BMJ case reports 2017- 220926. (PMID: 28882935)
[3] Zhaosheng Jin, Muhammad Rafizlmtiaz, Henry Nnajiuba, Suzette Samlalsingh and Akinye de Ojo. de Garengeot hernia: Two case reports with correct preoperative identification of the Vermiform Appendix in the hernia. Case reports in Surgery 2016, (PMID: 28070438)
[4] S. Linder, G. Linder and C. Mannson. Treatment of de Garengeot hernia: A meta-analysis. Hernia Feb 2019, vol 23, issue 1, pp 131-141 (PMID: 30536122)
[5] Katherine E. Maturen, Ashish P. Wasnik, Aya Kamaya, Jonathan R. Dillman, Ravi K. Kaza, Amit Pandya, Rishi K. Maheshwary. Ultrasound imaging of bowel pathology:Technique and keys to diagnosis in the acute abdomen. American Journal of Roentgenology December 2011, Volume 197, Number 6
URL: | https://www.eurorad.org/case/16506 |
DOI: | 10.35100/eurorad/case.16506 |
ISSN: | 1563-4086 |
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