In April 2004 the company announced that it had exercised an exclusive option to acquire Precision Vascular Systems, Inc., as part of a series of agreements between Boston Scientific and Precision Vascular in 2002 - for an undisclosed sum. In June Boston acquired Advanced Bionics Corporation for $740 million in cash, plus earn out payments. In December Boston completed its acquisition of Advanced Stent Technologies, Inc. for $120 million payable in Boston Scientific stock, plus the possibility of future contingent payments. AST had been developing stent and stent delivery systems specifically designed to address the anatomical needs of coronary artery disease in bifurcated vessels.