WESTERN TRAUMA ASSOCIATION

The finding of a “blush,” or pooling of intravenous contrast material within the liver parenchyma, on CT scanning is indicative of active hemorrhage. Earlier studies suggested that these patients should undergo operative intervention, regardless of hemodynamic stability, though the availability of angiographic embolization may have successfully managed the hemorrhage.^9,24,25 More recently, Fang et al.^22,26 reported on the significance of a blush in stable patients with blunt hepatic trauma. Their initial study in 1998 followed up eight hemodynamically stable patients with pooling into the peritoneal cavity.²⁵ Six of these patients rapidly became unstable and underwent emergent laparotomy, and the other two required delayed operations for liver-related complications. In a later study, they attempted to categorize pooling of contrast material into free extravasation with pooling into the peritoneal cavity, intraparenchymal contrast pooling with associated hemoperitoneum, and intraparenchymal contrast pooling without hemoperitoneum.²⁶ Although the sample size was very low, all patients (6/6) with free pooling required laparotomy for hemodynamic deterioration, 66% (4/6) of patients with intraparenchymal pooling and hemoperitoneum required operation, while no patient (3/3) with intraparenchymal pooling alone required surgery or angioembolization. Finally, a larger study by this group confirmed that intraperitoneal extravasation was the most specific sign to predict the need for surgery by both univariate and logistic regression analysis.²² Although data are very limited, it seems logical to suggest that hemodynamically stable patients with free intraperitoneal extravasation undergo immediate angiography if readily available, performed in a monitored setting, and at an institution where blood products and an operative team are immediately available. More controversial is the group of stable patients with intraparenchymal contrast pooling. It is not clear from available data whether immediate angiographic embolization is required. Close observation alone with planned angiographic embolization for signs of ongoing bleeding, such as a drop in hematocrit or need for transfusion, is also an option in appropriate facilities.^26–28 Neither the true incidence of pseudoaneurysm or arteriovenous fistula nor their natural history (regression or rupture) are well defined. With the current use of multichannel detector CT scanners, pooling of contrast is an increasingly common finding. A well-performed clinical trial to address the optimal management of hemodynamically stable patients with contrast pooling on CT scanning is needed.