An infusion port is provided on the catheter body, for METHOD FOR MINIMIZING RESTENOSIS infusing a transparent media in the area of the light
aperture.
BACKGROUND OF THE INVENTION In accordance with a further aspect of the present
The present invention relates generally to the field of 5 invention, there is provided a method of inhibiting reangioplasty and angioplasty catheters. More specifi- stenosis in a body lumen following dilatation thereof, cally, the present invention relates to methods and appa- The method comprises the steps of selecting a site ratus for minimizing the occurrence of restenosis fol- within a body lumen having a previously dilated stenolowing dilatation of a narrowing in a body lumen. sis, and exposing the site to a restenosis inhibiting
Percutaneous transluminal coronary angioplasty 10 amount of light energy. (PTCA), a procedure for treating a patient having a In a modification of the method of the present invenstenosis or constricted region in a coronary artery, has tion, there is provided a method of percutaneous tranbecome a widely accepted therapeutic alternative to sluminal coronary angioplasty and inhibiting restenosis coronary arterial bypass surgery for many patients. following dilatation. This method comprises the steps of PTCA increases the diameter of the lumen by radial 15 inserting a balloon dilation catheter into an artery, said expansion, such as through the use of a dilatation bal- catheter of the type having an inflatable balloon and a loon. In the appropriate circumstances, PTCA has a light aperture thereon. The balloon is positioned within variety of advantages over coronary bypass surgery, a stenotic region, and inflated to dilate the stenotic including reduction in morbidity, and avoidance of region. Either prior to dilation, during dilation or folimmediate post-operative discomforts and recovery 20 lowing dilation, the dilated region is exposed to a source period. Balloon dilatations are also accomplished in a of light sufficient to induce a restenosis inhibiting effect, wide variety of other locations in the body to restore accordance with a further aspect of the present
patency to an undesirably constricted lumen. invention, there is provided a method of inhibiting arte
Notwithstanding the advantages of balloon dilatation rial spasms. fhe method comprises identifying the site over more invasive alternatives, balloon dilatation often 25 q{ ^ spgsm> ^ j^^^g a catheter having
does not result m a permanent treatment of a stenotic a Ught aperture thereon mto the artery. ^ light aper. site. Rather, a renarrowmg or restenosis of the treat- toe is itioned within y ht propagating range of the ment site is often observed at varying lengths of time gi ^ ^ is ropagated from the catheter to the site following the mitial procedure. This ,s particularly true tQ a effect
in the case of PTCA. Patients experiencing a restenosis 30 ^ rf ^ t
must thereafter be evaluated for a subsequent medical .„ , r . c , t , , ... „
, , rrrr^K J-i * *• i* will become apparent from the detailed descnption of
procedure, such as a further PTCA dilatation or alter- . , ,, , r .,
native thera v preferred embodiments which follows, when consid
^Accordingly, there remains a need for a method of ered toSether ^ ^ attached damia^ claimsminimizing the occurrence of restenosis in a dilated 35 BRIEF DESCRIPTION OF THE DRAWINGS
region of body lumen. Optimally, the method would _ „ ,.,
either lengthen time between dilatation procedures, or F}G-lis a side elevational view of a dilatation light
prevent entirely the need for a subsequent dilatation catheter m accordance with one embodiment of the
procedure. present mvention.
40 FIG. 2 is a cross-sectional view of the catheter of
SUMMARY OF THE INVENTION FIG. 1, taken along the lines 2—2. There is provided in accordance with one aspect of FIG- 3 is a side elevational view of the distal portion
the present invention a catheter for percutaneous tran- of a two balloon embodiment of the light catheter of the
sluminal insertion into a body lumen, and exposing a present mvention.
portion of the lumen to light. The catheter comprises an 45 FIG- 4 is a cross-sectional view of the catheter of
elongate flexible catheter body having proximal and FIG. 3, taken along the lines 4—4. distal ends, and at least one first inflatable balloon on the F10- 5 is a side elevational view of a light catheter in
catheter body, in fluid communication with an elongate accordance with a further embodiment of the present
inflation lumen extending axially through the catheter invention.
b0<^\ ,. ^ 50 DETAILED DESCRIPTION OF PREFERRED
At least one light aperture is provided on the catheter EMBODIMENTS body for launching light from the catheter to the wall of
the body lumen. The light aperture is in various embodi- The present invention provides methods and appara
ments disposed proximally of the balloon, distally of the tus for the post-dilatation treatment of a preselected site
balloon, and within the balloon for propagating light 55 in a body lumen, to minimize the occurrence of resteno
through the inflation media and material of the balloon. sis following dilatation. Although the present invention
In a further embodiment of the invention, a catheter will be discussed primarily in the context of a post-balis provided as above, further comprising a second inflat- loon dilatation angioplasty procedure, it is to be underable balloon. The second balloon is spaced axially apart stood that the methodology and apparatus disclosed from the first balloon, and a light aperture is disposed on 60 herein are of broader applicability, the catheter body intermediate the two balloons. Prefer- For example, the efficacy of the present invention is ably, an infusion port is provided on the catheter body not limited to the coronary artery. Instead, the present intermediate the two balloons, for infusing a media with invention may be utilized in a post-dilatation treatment or without medication which is transparent to the in any of a wide variety of cardiovascular or other body wavelength of light launched from the light aperture. 65 lumen. In addition, the methods and apparatus of the
In accordance with a further aspect of the catheter of present invention are applicable to minimize restenosis
the present invention, there is provided an elongate following dilatation by means other than conventional
catheter body having at least one light aperture thereon. balloon angioplasty.
