Procedure and catheter instrument for treating patients for aortic stenosis
First Claim
1. A dilatation procedure for treating patients having adult calcific aortic stenosis, in which there are calcific deposits on the leaflets of the aortic valve that impair their opening movement during systole, comprising the steps of:
- introducing a dilatation balloon into the stenosed aortic valve via the aorta while the blood circulation of the patient is maintained by the heart via the aortic valve,inflating the balloon to grossly deflect the calcific leaflets of the valve in a manner avoiding blocking the outer portions of the commissures of the valve, said inflating step enabling substantial blood flow through said outer portions of the commissures during systole despite the presence in the valve of the inflated balloon,and prolonging the inflation of the balloon over an interval of at least thirty seconds spanning a large multiplicity of heart beats whereby the calcific deposits on the leaflets are disturbed to increase the pliability of the leaflets and the degree of their opening in response to systolic pressure,said calcific deposits, though thus disturbed by said dilatation, remaining as part of the leaflets so that life-threatening emboli do not form.
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Accused Products
Abstract
Dilatation procedures and catheter instrument for treating patients having acquired aortic stenosis, typically in which there are calcific deposits on the leaflets of the aortic valve. A dilatation balloon introduced into the stenosed aortic valve via the aorta while the blood circulation of the patient is maintained by the heart via the aortic valve, is inflated to grossly deflect the leaflets of the valve in a manner avoiding blocking the outer portions of the commissures of the valve. This inflating step enables substantial flow of blood through the outer portions of the commissures during systole despite the presence in the valve of the large inflated balloon. By prolonging the inflation for at least 30 seconds, over a large multiplicity of heart beats the calcific deposits are disturbed to increase the pliability of the leaflets and the degree of their opening, in an action found not to produce emboli. The catheter instrument incorporates means for measuring the pressure gradient across the valve and has features facilitating introduction, retention of position during inflation, withdrawal and re-crossing of the valve to achieve progressive enlargement of the aortic valve.
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Citations
40 Claims
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1. A dilatation procedure for treating patients having adult calcific aortic stenosis, in which there are calcific deposits on the leaflets of the aortic valve that impair their opening movement during systole, comprising the steps of:
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introducing a dilatation balloon into the stenosed aortic valve via the aorta while the blood circulation of the patient is maintained by the heart via the aortic valve, inflating the balloon to grossly deflect the calcific leaflets of the valve in a manner avoiding blocking the outer portions of the commissures of the valve, said inflating step enabling substantial blood flow through said outer portions of the commissures during systole despite the presence in the valve of the inflated balloon, and prolonging the inflation of the balloon over an interval of at least thirty seconds spanning a large multiplicity of heart beats whereby the calcific deposits on the leaflets are disturbed to increase the pliability of the leaflets and the degree of their opening in response to systolic pressure, said calcific deposits, though thus disturbed by said dilatation, remaining as part of the leaflets so that life-threatening emboli do not form. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 10, 11, 12)
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9. 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.
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13. A method of aortic valvuloplasty, comprising the steps of:
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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. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20, 21, 22)
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23. An aortic valvuloplasty dilatation catheter having a dilatation balloon and balloon inflation lumen means, said catheter having a curved distal portion of a stiffness no greater than a first value over a length extending from the distal tip of the catheter to a point close to but distal of said balloon and having a second portion of substantially greater stiffness extending from said point, proximally at least beyond the portion of said catheter adapted to lie in the aortic arch during inflation of said balloon,
said distal portion adapted to flex and follow a guidewire over which it is threaded to pass through said valve and into the left ventricle, and to conform atraumatically to the wall of said ventricle while the heart is beating, and said second, relatively stiffer portion of said catheter adapted to resist collapse under axial compression to enable repeated thrusting of the balloon into the valve, and, by reaction of the catheter against the wall of the aortic arch, to hold the balloon in axial position within the valve during inflation while the balloon is confronted by pressurized oncoming flow of blood from the heart.
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29. 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.
Specification