Abstract
Three different trade names of microspheres (MS) have been available in Japan since last February. Of those one is for bland embolization and two are exclusively for trans-catheter arterial chemoembolization (TACE). MS have unique characteristics compared to traditional materials. They are spherical, slippery and redistribute themselves after aggregation followed by restoration of the blood flow. As a result of redistribution the embolization effect might be unexpectedly weak. Preparing well agitated and diluted suspension is a clue in minimizing the redistribution as well as mistargeted embolization due to back-flow. In MS-TACE for hepatocellular carcinoma (HCC), 100-300 microns MS is mainly used. At an application of larger MS special attention must be paid to microcatheter compatibility. To optimize the drug absorption to MS an operator should follow the instructions provided by each manufacturer. In the ionic interaction a sodium atom plays a special role. It matters whether the saline or deionized water is used for the chemotherapeutic solution. Both products for MS-TACE are similar in drug eluting profiles. Mistargeted embolization in MS-TACE for HCC includes intestinal ulcer, cholecystitis, pancreatic necrosis and biloma. As uncommon adverse effects pulmonary embolization, posterior reversible encephalopathy syndrome (PRES) and eosinophilic pneumonia are documented.
