Reduction of arteriohepatovenous shunting by temporary balloon occlusion in patients undergoing radioembolization.

Radioembolization with yttrium-90 resin microspheres is a treatment option that selectively targets hepatic tumors. One of the primary limiting factors for this therapy is the degree of arteriohepatovenous shunting, as excessive radiation to the lungs may cause radiation pneumonitis. To safeguard patients against this, a technetium Tc 99m macroaggregated albumin scan is performed before treatment to assess the degree of arteriohepatovenous shunting. As lung shunt fraction increases, activity reductions are mandated, with a 20% shunt sufficient to prohibit treatment. Temporary occlusion of shunts may be achieved by placement of balloon catheters in the hepatic veins. This endovascular technique used to reduce arteriohepatovenous shunting allows otherwise untreatable patients to undergo radioembolization.