Contrast-enhanced axial CT scan of the abdomen
Abdominal imaging
Case TypeClinical Cases
AuthorsA. Díaz García, S. Mosteiro Añón, I. Requejo Isidro
Patient82 years, female
Clinical examination revealed only a distended abdomen. Laboratory tests detected an elevated white blood cell count of 17000 cells/mm3 (normal, 4000-9800 cells/mm 3).
Abdominal plain film only revealed clustered dilated small bowel loops. Six hours later, the general condition of the patient declined and a CT scan with 5mm slice thickness was performed following intravenous administration of contrast medium. CT signs of small bowel volvulus were observed and the posibility of an internal hernia was suggested.
Laparoscopy confirmed the presence of a transmesenteric hernia complicated by a secondary small bowel volvulus and ischaemia. Ischaemic small bowel was resected and the mesentery defect repaired.
In the left paraduodenal hernia the small bowel invaginates through a congenital defect in the descendent mesocolon to the fossa of Landzert. Transmesenteric hernias occur due either to a congenital or acquired defect in the small bowel mesentery or transverse mesocolon. The increasing frequency of surgical procedures in which a Roux-en-Y anastomosis is performed is raising the incidence of this last type of internal hernia.
The risk of strangulation of the sac contents, especially in transmesenteric hernias, is high, and so a prompt diagnosis istherefore crucial. Clinical diagnosis is challenging. Symptoms are nonspecific and sometimes intermittent. During asymptomatic intervals no abnormality might be found.
Imaging studies, especially CT, are helpful in establishing a preoperative diagnosis of the presence, type and possible complications. CT criteria of internal hernia include clustering of small bowel loops, stretched and engorged mesenteric vessels and displacement of other bowel segments with signs of intestinal obstruction. Fixed small bowel loops adjacent to the abdominal wall, the lack of omental fat overlying the herniated bowel and central displacement of the colon have been proposed as distinctive features of transmesenteric hernia. Superimposed signs of volvulus and ischaemia are frequently found as complications of this type of internal hernia.
[1]
Blachar A, Federle MP, Brancatelli G, Peterson MS, Oliver JH 3rd, Li W.
Radiologist performance in the diagnosis of internal hernia by using specific CT findings with emphasis on transmesenteric hernia.
Radiology. 2001 Nov;221(2):422-8. (PMID: 11687686)
[2]
Blachar A, Federle MP, Dodson SF.
Internal hernia: clinical and imaging findings in 17 patients with emphasis on CT criteria.
Radiology. 2001 Jan;218(1):68-74. (PMID: 11152781)
[3]
Miller PA, Mezwa DG, Feczko PJ, Jafri ZH, Madrazo BL.
Imaging of abdominal hernias.
Radiographics. 1995 Mar;15(2):333-47. (PMID: 7761639)
URL: | https://www.eurorad.org/case/1613 |
DOI: | 10.1594/EURORAD/CASE.1613 |
ISSN: | 1563-4086 |