INTEGRATED DUAL-FUNCTION CATHETER SYSTEM FOR BALLOON ANGIOPLASTY AND STENT DELIVERY

摘要

An integrated catheter system utilizes a balloon angioplasty catheter placed through a central passageway of a stent delivery catheter to enable balloon angioplasty and stent delivery to be accomplished with a single device. The integrated catheter system is able to perform dilatation of an arterial stenosis, placement of the stent at the site of the stenosis and then the angioplasty catheter balloon can be used to further embed the stent into the arterial wall. Balloon angioplasty, stent placement and stent embedding into the arterial wall are all accomplished while the catheter's angioplasty balloon remains situated at the site of the stenosis. A conically-shaped distal portion of the stent delivery catheter allows stent placement over the deflated balloon after balloon angioplasty even when intimal dissection causes an intimal flap to be pushed inwardly against the deflated balloon. A proximal portion of the integrated catheter system employs longitudinal motion constraining spacers to prevent the stent from being inadvertently positioned beyond the distal end of the balloon. The balloon of the balloon angioplasty catheter can be readily advanced through tortuous coronary arteries because the distal end of the stent delivery catheter can be placed back by 0.5 to 20 cm from the balloon's proximal end during insertion. Thus, the stiffness of the stent and the stent delivery catheter do not add stiffness to the distal portion of the balloon angioplasty catheter, which stiffness can prevent catheter advancement through such tortuous vessels.