Procedure and catheter instrument for treating patients for aortic stenosis

A dilatation procedure for treating patients having adult calcific aortic stenosis, including employing a catheter having an inflatable balloon,

• providing a multilumen dilatation catheter having at least two pressure-measuring lumens in addition to lumen means that inflates said balloon, one of said pressure-measuring lumens terminating in distal sensing port means disposed on the portion of the catheter distal of said balloon, said sensing port means adapted for measuring pressure in the left ventricle of the heart, and a second of said pressure-measuring lumens terminating in a proximal sensing port means disposed along said catheter proximal of said balloon, at least 15 cms proximal of said distal sensing port means, said second sensing port means adapted for measuring aortic pressure, said distal sensing port means being spaced distally from said balloon a distance sufficient that, while said balloon resides proximal of said aortic valve, the distal portion of the catheter extending through said valve can position said distal sensing port means entirely within the left ventricle of the heart,
• said procedure including the step of positioning said catheter so that said balloon lies proximal of said valve and said distal sensing port means lies entirely within the left ventricle,
• and while said catheter is thus disposed, by use of said distal and proximal sensing port means, measuring the pressure gradient across said valve while the heart is beating,
• and said procedure including the step of positioning and inflating said balloon within said valve to cause said gross deflection of said valve leaflets.

A method of aortic valvuloplasty, comprising the steps of:

• A. providing an inflatable balloon catheter selected to have an effective balloon size and shape to deflelct valve leaflets without occluding the outer portions of the commissures, the balloon catheter having a relatively flexible, curved distal portion defining a conduit that has a multiplicity of side holes for measurement of pressure and injection of fluid, a relatively stiff distal segment of catheter substantially smaller than the balloon disposed between said flexible curved distal portion of catheter and said balloon, and an elongated catheter body proximal of said balloon and defining an opening proximal of said balloon for measurement of pressure;
• B. advancing said balloon catheter until said distal flexible portion is passed through said valve into said ventricle, and said distal stiff segment of catheter is lodged within said valve, blood flow through the valve being only minimally impeded because of the relatively small diameter of said stiff segment;
• C. measuring the pressure in the ventricle by means of said openings in said flexible distal catheter portion and measuring the pressure in the aorta by means of the proximal opening to determine the pressure gradient across the valve, such gradient being minimally affected by the presence of the small diameter, stiff segment of the catheter within the valve;
• D. advancing said catheter until the balloon is positioned within said valve;
• E. inflating said balloon to deflect the leaflets of the valve for treatment of adult calcific aortic stenosis;
• F. deflating the balloon and withdrawing the balloon catheter until the stiff segment is again lodged within the valve;
• G. repeating step C to determine the pressure gradient resulting from said treatment;
• and
• H. removing the balloon catheter from the patient.

An aortic valvuloplasty dilatation catheter comprising

• a multilumen catheter having a dilatation balloon, balloon inflation lumen means, at least two pressure-measuring lumens, and means for repeatedly introducing said diltation balloon into an aortic valve for treatment of adult calcific aortic stenosis and for withdrawing the balloon proximally from the valve for measuring pressure in the heart and in the aorta for determination of aortic valve efficiency, said means for introducing comprising a flexible distal tip portion adapted to be introduced through the aortic valve, into the left ventricle of the heart, and an extended sleeve proximal of said distal tip portion and integral with said balloon, said sleeve extending distally of said balloon a distance between about 1 and 2 centimeters and, serving to stiffen the corresponding portion of the catheter, said sleeve having a diameter sufficiently small so as not to impede blood flow through the valve,
• one of said pressure-measuring lumens terminating in a distal sensing port means disposed on said distal tip portion of the catheter, distal of said balloon, said sensing port means adapted for measuring pressure in the left ventricle of the heart,
• a second of said pressure-measuring lumens terminating in a proximal sensing port means disposed along said catheter proximally of said balloon, said second sensing port means adapted for measuring aortic pressure, said distal sensing port means being spaced distally from said balloon a distance sufficient that, while said balloon resides proximal of the aortic valve, the distal tip portion of the catheter extending through the aortic valve can position said distal sensing port means entirely within the left ventricle of the heart,
• whereby when said catheter is positioned so that said balloon lies proximally of the aortic valve while said distal sensing port means lies entirely within the left ventricle, by use of said distal and proximal sensing port means, the pressure gradient across the valve can be measured while the heart is beating,
• and whereby, by relatively little motion from said position, said balloon can be positioned within the valve to be inflated to cause gross deflection of the leaflets of the valve for treatment of adult calcific aortic stenosis.