Bowel and Mesenteric Blunt Trauma

Summarized by: Nadiv Hossain

Reviewed by: Prasaanthan Gopee-Ramanan, M.D.

Original publication details

Authors: Nicole Brofman, Mostafa Atri, John M. Hanson, Leonard Grinblat, Talat Chughtai, Fred Brenneman

DOI: https://doi.org/10.1148/rg.264055144

Reference: Brofman, N., Atri M., Epid, D., Hanson J.M., Grinblat L., Chughtai T., Brenneman F. (2006). Evaluation of bowel and mesenteric blunt trauma with Multi-detector CT. Radiographics, (26)4. 1119-1131.

Multi-detector CT → test of choice for evaluating blunt abdominal trauma in hemodynamically stable patients. 

Most sensitive and specific modality for diagnosing bowel and mesenteric injuries.

Bowel injury

Findings specific to bowel injury

Bowel wall discontinuity: Uncommon finding on CT, likely due to the small size of the discontinuities

Mesenteric features: Mesenteric foci of fluid, air, or fat stranding may be due to bowel injury alone. Retroperitoneal air can be seen with injury to duodenum or to the retroperitoneal parts of ascending or descending colon

Extraluminal air: high specificity and low sensitivity for bowel perforation. Can also be seen in absence of bowel perforation. Air originating from bowel rupture accumulates in locations deep to the anterior abdominal wall, porta hepatis, mesentery or mesenteric veins, and portal vein

Mimicker: pseudopneumoperitoneum

Findings less specific to bowel injury

Extraluminal contrast material: also an infrequent finding, likely due to bowel distension during CT or transient nature of extraluminal contrast enhancement

Note: a bladder injury that causes intraperitoneal extension of contrast material can result in false positive

Bowel wall thickening: Isolated, localized, unequivocal bowel wall thickening in the context of trauma indicates bowel wall contusion and may not be associated with significant injury. 

Diffuse thickening of small bowel wall is atypical for contusion, and instead may represent bowel edema due to systemic volume overload or shock bowel

Abnormal bowel wall enhancement: may represent bowel injury with vascular involvement or may be part of hypoperfusion complex

Areas of decreased or absent contrast enhancement indicate bowel ischemia 

Mesenteric injury

Findings specific to mesenteric injury

Mesenteric extravasation: 100% specificity for significant mesenteric injury; indication for urgent laparotomy

Mesenteric vascular beading: indicative of vascular injury; look for irregularities in mesenteric blood vessels

Termination of mesenteric vessels: highly specific for vascular injury; look for abrupt terminations of mesenteric artery or vein

Findings less specific to mesenteric injury

Mesenteric infiltration: high sensitivity but non-specific for mesenteric injury; haziness and fat stranding in mesentery indicates mesenteric injury with or without bowel wall injury  

Mesenteric hematoma: well-defined mesenteric hematoma indicative of mesenteric vessel laceration; does not always indicate need for surgery 

Bowel features: bowel wall thickening and abnormal enhancement; note bowel ischemia due to mesenteric injury may not be evident in initial CT images

Common Features in Bowel and Mesenteric Injuries

Intraperitoneal and retroperitoneal fluid: non-specific because they could be due to other injuries; location of fluid can help localize injury; if hemoperitoneum present without solid organ injury, consider bowel or mesenteric injury 

Abdominal wall injury: significant association between abdominal wall injury (tear, hematoma, “seat belt” sign and bowel and mesenteric injury

Note: When non-specific features of bowel or mesenteric injury are the only CT findings present, the need for surgery will depend on clinical judgment. Reevaluate with CT within 6–8 hours after initial evaluation to elucidate significance of non-specific findings

Citation

Brofman, N., Atri M., Epid, D., Hanson J.M., Grinblat L., Chughtai T., Brenneman F. (2006). Evaluation of bowel and mesenteric blunt trauma with Multi-detector CT. Radiographics, (26)4. 1119-1131.