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Traumatic retroperitoneal hematoma spreads through the interfascial planes.

BACKGROUND
The purpose of this study was to reevaluate extension of traumatic retroperitoneal hematoma (RH) and related management strategies in light of the new concept of retroperitoneal fascias as interfascial planes communicating with three compartments.


METHODS
Diagnostic computed tomographic images of 169 patients with traumatic RH treated between 1997 and 2003 were retrospectively reviewed. The extension of RH was measured in relation to 10 components: 3 compartments and 7 parts of the interfascial planes. On the basis of careful horizontal and vertical assessment of computed tomographic images, distribution, extent, and volume in each component of RH were assessed.


RESULTS
In 88.8% of patients, RH was detected in interfascial planes. Interfascial planes absorbed a large amount of hematoma (mean, 223 +/- 309 mL; range, 0-1,519 mL), whereas the anterior and posterior pararenal spaces absorbed only 5 +/- 16 mL and 21 +/- 30 mL, respectively. The volume of RH in interfascial planes accounted for 78.1% of the total volume. In all cases, RH spread within interfascial planes with regularity: transversely by means of retromesenteric planes and vertically by means of combined interfascial planes. Regular extension patterns allowed RH to be classified by bleeding source. RH originating from retrorenal or combined interfascial plane had a poor prognosis; 51.7% of such patients died as a result of uncontrollable hemorrhage.


CONCLUSION
RH was based in the interfascial planes, not the three compartments. Our findings that RH extends and is largely confined within interfascial planes, regardless of cause or volume, could be useful in estimating the extent of RH and developing breakthrough strategies for RH.