Small-bowel obstruction from adhesive bands and matted adhesions: CT differentiation.

OBJECTIVE: The purpose of this study was to evaluate the CT findings that can help to differentiate small-bowel obstruction (SBO) due to adhesive bands from SBO caused by matted adhesions.

MATERIALS AND METHODS: CT scans of 67 consecutive patients with adhesive SBO caused by either surgically confirmed adhesive bands or matted adhesions were analyzed. CT findings were compared between the two groups with regard to simple obstruction patterns (single abrupt transition zone, beak sign, "fat notch" sign), patterns of closed-loop obstruction (two adjacent beaks, C-shaped bowel, radial distribution of mesenteric vessels), the location of the obstruction in the abdominal cavity, and the presence of a whirl sign and a "small-bowel feces" sign. Statistical analyses were performed using the Fisher's exact test.

RESULTS: Closed-loop patterns and a whirl sign were seen only in cases of SBO from adhesive bands. Compared with SBO cases from matted adhesions, significantly more SBO cases that were due to adhesive bands showed a beak sign (p = 0.0001) and fat notch sign (p = 0.0001). The small-bowel feces sign was more frequently seen in cases of SBO from matted adhesions (p = 0.014). Bowel ischemia and bowel necrosis were more frequent findings with adhesive bands than with matted adhesions (p = 0.011 and p = 0.049, respectively). The location in the pelvis of the adhesive structure (p = 0.039) and a higher rate of accidental bowel perforation (p = 0.031) were associated with matted adhesions.

CONCLUSION: CT is useful for differentiating SBO caused by adhesive bands from SBO due to matted adhesions.