Risk factors for the development of pulmonary oil embolism after transcatheter arterial chemoembolization of hepatic tumors.

Pulmonary oil embolism (POE) is a rare fatal complication after transcatheter arterial embolization (TAE) and transcatheter arterial chemoembolization (TACE). As risk factors have not been clearly delineated, the aim of the present study was to identify the risk factors for development of POE after TACE. A retrospective analysis was carried out on patients with unresectable hepatocellular carcinoma who received TAE or TACE at the Tri-Service General Hospital (Taiwan) between January 2005 and December 2008. The diagnosis of TAE-induced or TACE-induced POE was based on development of respiratory signs and symptoms relatively soon after the procedure, as well as based on characteristic radiographic findings. Of the 219 enrolled patients in this study, 20 were diagnosed with POE after TAE or TACE. On univariate logistic regression analysis, patients developing POE were found to be older (67.95±15.95 vs. 61.44±12.59 years, P=0.033), with a lower serum albumin level (3.25±0.58 vs. 3.62±0.57 g/dl, P=0.009), a higher grade of liver cirrhosis as classified on the basis of Child's criteria (P<0.006), a larger tumor size (8.55±4.52 vs. 4.78±3.97 cm in diameter, P<0.001), a higher lipioidol dose (22.35±11.01 vs. 13.69±7.66 ml, P=0.003), and a higher doxorubicin dose (50.27±7.05 vs. 40.75±13.61 mg, P<0.001). Following multivariate logistic regression analysis, only lipiodol dose was found to be a significant risk factor for POE (odds ratio=1.133, 95% confidence interval: 1.004, 1.279; P=0.044). The receiver operator characteristic curve cutoff point for lipiodol dose level was 14.5 ml, with a sensitivity of 80% and a specificity of 66.3%. In conclusion, the lipiodol dose could be considered as a predictive factor for POE after TAE or TACE in hepatic malignant tumor patients. On the basis of this retrospective study, the safe lipiodol dose to minimize the risk for POE is 14.5 ml or lower; however, larger, prospective studies are needed to determine the optimally safe and yet efficacious dose.