Adhesive and non-adhesive internal hernia: clinical relevance and multi-detector CT images

Abstract

Internal hernia (IH)-related surgical acute abdomen is not well understood because of the rarity of cases and underdiagnosis. This study was performed to further understand the clinicopathological features and multi-detector computed tomography (MDCT) findings of IH in cases confirmed by surgery. In all, 51 patients with a definite diagnosis of IH confirmed during surgical exploration from Feb. 2012 to Feb. 2018 in our hospital were included in this research. Medical records, including MDCT images and intra-operative findings, were collected retrospectively. In all, 39 and 12 cases were categorized as adhesive IH (76.5%) and non-adhesive IH (23.5%), respectively. Among the patients with adhesive IH, 73% had a history of abdominal or pelvic surgery. Additionally, the mesentery was the most common component of adhesive bands (64.1%). Congenital peritoneal abnormalities and gastrointestinal reconstruction were the main causes of non-adhesive IH.As a specific sign, the fat notch sign was much more common in adhesive IH than in non-adhesive IH (P = 0.023). Bowel wall thickening (P = 0.041), abnormal bowel wall enhancement (P = 0.006) and twisted bowels with the vessel swirl sign (P = 0.004) were indicators of bowel necrosis. Among all of the cases of IH, 34 (66.7%) were complicated by bowel necrosis, and 1 patient died. In conclusion, non-adhesive IH has different clinicopathological features and MDCT findings from those of adhesive IH. MDCT is a useful tool with high sensitivity for confirming IH and may help to guide the early treatment of IH.

Figure 1

Some common non-specific MDCT signs in IH patients. (A,B) Axial MDCT images of a patient with adhesive IH showing the dilated bowel with abnormal free fluid (arrows). (C,D) Axial and vascular remodelling MDCT images of a patient with adhesive IH showing the vessel swirl sign (arrows).

Figure 2

Representative MDCT images of patients with specific signs, including the hernia orifice and/or the fat notch sign. (A) The hernia orifice and the fat notch sign (arrow) in a patient with primary adhesive IH. The omentum and mesentery formed the adhesive band. (B) The hernia orifice and the fat notch sign (arrow) in a patient with secondary adhesive IH. The falciform ligament, omentum, and parietal peritoneum formed the adhesive band. (C) The hernia orifice and the fat notch sign (arrow) in a patient with secondary non-adhesive IH. The herniated bowel protruded via the mesenteric hiatus that formed after colectomy. (D) The hernia orifice (arrow) without the fat notch sign in a patient with primary non-adhesive IH, also known as paraduodenal hernia. The herniated bowel protruded into the Landzert fossa, which is an unusual congenital peritoneal defect behind the descending mesocolon.

Figure 3

Two representative abdominal X-ray in 2 patients with intestinal. obstruction, but confirmed with IH by surgery. (A) one patient with multiple abdominal surgical history had abdominal pain and abdominal distension. Abdominal X-ray diagnosed with intestinal obstruction, surgery confirmed with IH diagnosis. (B) one patient had abdominal distension and vomiting at 4 days after radical resection of sigmoid colon cancer. Abdominal X-ray diagnosed with intestinal obstruction, surgery confirmed with IH diagnosis.