Hematoma size a factor in weighing embolization

January 1, 2009

Perirenal hematoma characteristics determined by computed tomography may be suggestive of the need for angiographic embolization in patients who present with blunt renal trauma, a study from the University of Texas Southwestern Medical Center, Dallas, suggests.

"The size of the hematoma is a new way of looking at these injuries," said senior author Allen F. Morey, MD, professor of urology at UT Southwestern. "Traditional staging calls for evaluating renal injuries in terms of the depth of the injury and involvement of the collecting system. The magnitude of perirenal hematoma also appears to be an important radiographic feature.

"We noted a trend toward increased use of computed tomography in evaluating trauma patients. We also noted that urologists nationwide were becoming increasingly comfortable managing some of the major injuries in a non-operative fashion."

The average hematoma area in embolized patients was 103.5 cm2 compared to 65.7 cm2 (p=.008) in those who did not receive embolization. Similarly, the average hematoma-to-kidney ratio was higher in embolized patients (2.8 vs. 1.8 in nonembolized patients, p=.007). The difference between hematoma and kidney areas was 65.6 cm2 in embolized patients compared to 29.0 cm2 in nonembolized patients (p=.006), and the perirenal hematoma rim distance was higher in embolized patients (4.2 cm vs. 2.7 cm, p=.041).

"While angioemobilization was correlated with hematoma size, transfusion and nephrectomy, surprisingly, were not. It is possible that these patients had associated injuries whereby they may have lost blood from other organs," Dr. Morey said.

"We hope now to get a larger series assessing the relationship between hematoma size and the need for embolization. By better using CT imaging technology, we may be able to identify radiographic features associated with significant renal bleeding. This may further promote non-operative nephron-sparing management in challenging cases."