Increased unenhanced bowel-wall attenuation: a specific sign of bowel necrosis in closed-loop small-bowel obstruction
To identify computed tomography (CT) findings associated with bowel necrosis in patients with surgically confirmed strangulating closed-loop small-bowel obstruction (CL-SBO) due to adhesions or internal hernia.
This retrospective study was approved by our institutional review board, and informed consent was waived. To identify CT signs of bowel necrosis, two gastrointestinal radiologists performed blinded, independent, retrospective reviews of 41 CT studies from consecutive patients who had CL-SBO due to adhesions or internal hernias and who underwent surgery within 48 h. On the basis of surgical and pathological findings, patients were classified as having reversible ischemia or histologically documented necrosis. Univariate statistical analyses were performed to assess associations between CT signs and bowel necrosis. Kappa statistics were computed to assess interobserver agreement.
We included 25 (61%) women and 16 (39%) men with a median age of 79 years. Bowel necrosis was found in 25/41 (61%) patients and ischemic but viable bowel in 16/41 (39%) patients. Increased unenhanced bowel-wall attenuation was the only CT finding significantly associated with bowel necrosis (p = 0.0002). This sign had 58% (95% CI, 37–78) sensitivity and 100% (95% CI, 79–100) specificity for necrosis. Interobserver agreement was fair (0.59; 95% CI, 0.37–0.82).
Increased unenhanced bowel-wall attenuation is specific for bowel necrosis and should lead to prompt surgery for bowel resection.
• Increased unenhanced bowel-wall attenuation is the only sign specific for necrosis
• Decreased bowel-wall enhancement is not relevant for differentiating reversible ischemia from necrosis
• Preoperative knowledge of bowel necrosis is helpful to plan adequate surgery
KeywordsSmall intestine Ischemia Intestinal obstruction Helical computed tomography Imaging
Closed-loop small-bowel obstruction
Negative predictive value
Positive predictive value
Region of interest
The authors thank Dr Véronique Duchatelle, Department of Pathology, Saint Joseph Hospital, Paris, France; Dr Wassef Khaled, Department of Medical Imaging, Saint Joseph Hospital, Paris, France; Dr Anh Minh Chuong, Department of Medical Imaging, Saint Joseph Hospital, Paris, France.
The authors state that this work has not received any funding.
Compliance with ethical standards
The scientific guarantor of this publication is Marc Zins.
Conflict of interest
The authors of this manuscript declare no relationships with any companies whose products or services may be related to the subject matter of the article.
Statistics and biometry
One of the authors has significant statistical expertise.
Written informed consent was waived by the institutional review board.
Institutional review board approval was obtained.
Study subjects or cohorts overlap
Some study subjects or cohorts have been previously reported in a previous study “Assessment of bowel wall enhancement for the diagnosis of intestinal ischemia in patients with small bowel obstruction: value of adding unenhanced CT to contrast-enhanced CT” by Chuong et al. (Radiology 280:98–107; 2016).
• diagnostic or prognostic study
• performed at one institution
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