The present invention pertains generally to medical catheters. More particularly, the present invention pertains to catheters having inflatable balloons. The present invention is particularly, but not exclusively, useful for folding a balloon onto a catheter tube during a balloon deflation.
Arterial blockages caused by the build up of plaque in the arteries of a patient can have grave consequences. Specifically, the build up of plaque in arteries can reduce and eventually block blood flow through the affected vessel. When blood flow is reduced in a coronary artery, the heart muscle becomes deprived of oxygen, and the patient is prone to suffer angina. In severe cases of coronary artery blockage, the patient can suffer a heart attack.
Many modern surgical techniques have been developed to alleviate the stenoses that are formed when plaque builds up in a patient's arteries. For example, a large number of balloon angioplasty devices exist for relieving arterial stenoses by compression of the stenosis. In several respects, balloon angioplasty devices afford numerous advantages over alternative methods. Foremost among these advantages is that open heart bypass surgery can often be avoided by using angioplasty surgical techniques to relieve stenoses in the arteries that supply blood to the heart. For obvious reasons, it is preferable to avoid open heart surgery when possible because such surgery, as is well known, is invasive and typically requires a significant post-operative recovery time. Accordingly, it is preferable to use relatively simpler angioplasty surgical procedures when such procedures are feasible. Importantly, angioplasty procedures are efficacious in the peripheral arteries as well as in the arteries that supply blood to the heart.
In angioplasty surgery, the balloon of a balloon catheter is initially attached to a catheter tube in a deflated configuration, with the catheter tube connecting a fluid source in fluid communication with the balloon. The balloon is then positioned at the desired location in the affected artery by advancing the catheter through the artery until the balloon is positioned across a stenosis that is to be treated. Once the balloon has been properly positioned, fluid is infused into the balloon. As the balloon expands, it dilates the lumen of the artery and compresses the plaque which may then break up or flatten out against the arterial wall. The balloon is then deflated and, once in its deflated configuration, it is either withdrawn from the artery or placed across another stenosis, to restore normal blood flow through the artery.
A particular problem associated with an angioplasty procedure exists during the deflation stage of the balloon, prior to its removal from the artery. Specifically, it is desirable that the balloon be deflated as tightly as practicable to facilitate its removal from the arterial passageways. In any case, the key to removing the balloon catheter with ease is having the balloon collapse evenly and compactly during balloon deflation. Once deflated, the balloon catheter must often travel through the tortuous vasculature of the patient and it is, therefore, important for the balloon to deflate uniformly into a predictable configuration. If the balloon fails to deflate in a uniform manner, an irregular bulge in the balloon may cause difficulties in withdrawing the balloon catheter from the artery.
In addition to the conventional, percutaneous, transluminal coronary angioplasty (PTCA) and percutaneous, transluminal angioplasty (PTA) procedure described above, cutting balloons are currently viewed by many as the next generation treatment option for the revascularization of both coronary and peripheral vessels. The cutting balloon mechanism is unique in that the balloon pressure is distributed over one or more blades (i.e. microtomes). The blade(s) function as stress concentrators and cut initiators in PTCA and PTA procedures. Consequently, PTCA and PTA procedures have been proven to minimize vessel recoil, lessen vessel injury and lower the rate of restenosis, as compared to conventional PTCA and PTA procedures. However, the cutting blades used in cutting balloons are extremely sharp (e.g. three to five times sharper than a conventional scalpel), and in the absence of special precautions, have the potential to inadvertently incise non-target tissue during in vivo movement of the cutting balloon to and from a stenosis.
In light of the above, it is an object of the present invention to provide a device that is useful for folding a balloon predictably and compactly onto a catheter tube during balloon deflation to facilitate in vivo movement of the balloon catheter. Another object of the present invention is to provide a device for maintaining the balloon tightly wrapped on a balloon catheter when the balloon is in a deflated configuration. It is yet another object of the present invention to provide a device that is useful for folding a cutting balloon during balloon deflation into a configuration in which the blades become nestled within a pair of adjacent balloon pleats to prevent the blades from inadvertently incising tissue during an in vivo movement of the balloon catheter. Yet another object of the present invention is to provide a device which is relatively simple to manufacture, easy to use, and comparatively cost effective.
The present invention is directed to a device for folding a balloon of a balloon catheter onto a catheter tube during a balloon deflation. The device includes a first band that is positioned on the catheter tube distal to the balloon and a second band that is positioned on the catheter tube proximal to the balloon. The device further includes one or more elastic member(s) that are positioned for interaction with the outer surface of the balloon. Each elastic member extends between a distal end that is attached to the first band and a proximal end that is attached to the second band.
In a typical embodiment, the device includes three or four elastic members that are uniformly distributed around the circumference of the balloon. In addition, each elastic member assumes a substantially straight shape and is axially aligned (i.e. aligned with an axis defined by the catheter tube) when the balloon is in a deflated condition. On the other hand, during inflation of the balloon, each elastic member expands on the balloon in substantial conformation with the shape of the balloon's outer surface. When the balloon is subsequently deflated, each elastic member recovers its original shape (e.g. becomes straight), and in the process folds the balloon onto the catheter tube. Specifically, the balloon is folded into a plurality of axially aligned pleats with each pleat being formed between a pair of adjacent elastic members.
In one particular embodiment, the device may be configured for use on a cutting balloon having a plurality of longitudinally aligned blades that extend radially from the surface of an inflatable balloon. In this embodiment, each elastic member is formed with a slot to allow a respective blade to extend through the elastic member. With this cooperation of structure, the elastic members fold the cutting balloon into a configuration in which the blades become nestled within a pair of adjacent balloon pleats. This nestled configuration prevents the blades from inadvertently incising tissue during a movement of the balloon catheter through the vasculature of a patient.
The novel features of this invention, as well as the invention itself, both as to its structure and its operation, will be best understood from the accompanying drawings, taken in conjunction with the accompanying description, in which similar reference characters refer to similar parts, and in which:
Referring to
The folding device 22 can be prepared from a starting tube (not shown) that is made of a low durometer, elastic material such as a Silastic® material comprising a silicone elastomer. The tube 14 can then be cut, for example using a laser beam to create the elastic members 28. In some embodiments, a plurality of slits can be cut in the tube. A slit can extend between the cylindrical bands 24, 26, and material between adjacent slits can comprise the elastic members 28. In some methods, the tube 14 can be expanded prior to cutting. In one embodiment, a starting tube 14 having an inner diameter, d, that is larger than the outer diameter, D, of the catheter tube 14 is used. The bands 24, 26 (which have an inner diameter, d, in the relaxed state) are then expanded to fit on the catheter tube 14. The residual tension in the bands 24, 26 is then used to hold the bands 24, 26 in place.
As best seen in
For the folding device 22′ shown in
While the particular balloon refolding device as herein shown and disclosed in detail is fully capable of obtaining the objects and providing the advantages herein before stated, it is to be understood that it is merely illustrative of the presently preferred embodiments of the invention and that no limitations are intended to the details of construction or design herein shown other than as described in the appended claims.
Number | Name | Date | Kind |
---|---|---|---|
4141364 | Schultze | Feb 1979 | A |
4273128 | Lary | Jun 1981 | A |
4444186 | Wolvek et al. | Apr 1984 | A |
4710181 | Fuqua | Dec 1987 | A |
4723549 | Wholey et al. | Feb 1988 | A |
4784636 | Rydell | Nov 1988 | A |
4881547 | Danforth | Nov 1989 | A |
4921483 | Wijay et al. | May 1990 | A |
4941877 | Montano, Jr. | Jul 1990 | A |
5015230 | Martin et al. | May 1991 | A |
5015231 | Keith et al. | May 1991 | A |
5100425 | Fischell et al. | Mar 1992 | A |
5147302 | Euteneuer | Sep 1992 | A |
5196024 | Barath | Mar 1993 | A |
5209799 | Vigil | May 1993 | A |
5221261 | Termin et al. | Jun 1993 | A |
5226887 | Farr et al. | Jul 1993 | A |
5254091 | Aliahmad et al. | Oct 1993 | A |
5318587 | Davey | Jun 1994 | A |
5336234 | Vigil et al. | Aug 1994 | A |
5342301 | Saab | Aug 1994 | A |
5350361 | Tsukashima et al. | Sep 1994 | A |
5456666 | Campbell et al. | Oct 1995 | A |
5458572 | Campbell et al. | Oct 1995 | A |
5478319 | Campbell et al. | Dec 1995 | A |
5490839 | Wang et al. | Feb 1996 | A |
5496276 | Wang et al. | Mar 1996 | A |
5571086 | Kaplan et al. | Nov 1996 | A |
5693089 | Inoue | Dec 1997 | A |
5713913 | Lary et al. | Feb 1998 | A |
5718684 | Gupta | Feb 1998 | A |
5738901 | Wang et al. | Apr 1998 | A |
5783227 | Dunham | Jul 1998 | A |
5792158 | Lary | Aug 1998 | A |
5792172 | Fischell et al. | Aug 1998 | A |
5797935 | Barath | Aug 1998 | A |
5853389 | Hijlkema | Dec 1998 | A |
5863284 | Klein | Jan 1999 | A |
6013055 | Bampos et al. | Jan 2000 | A |
6033380 | Butaric et al. | Mar 2000 | A |
6071285 | Lashinski et al. | Jun 2000 | A |
6110192 | Ravenscroft et al. | Aug 2000 | A |
6126652 | McLeod et al. | Oct 2000 | A |
6258108 | Lary | Jul 2001 | B1 |
6283743 | Traxler et al. | Sep 2001 | B1 |
6425882 | Vigil | Jul 2002 | B1 |
6623451 | Vigil | Sep 2003 | B2 |
6632231 | Radisch, Jr. | Oct 2003 | B2 |
7279002 | Shaw et al. | Oct 2007 | B2 |
20020183779 | Vigil | Dec 2002 | A1 |
20030153870 | Meyer et al. | Aug 2003 | A1 |
20050021071 | Konstantino et al. | Jan 2005 | A1 |
Number | Date | Country | |
---|---|---|---|
20050137618 A1 | Jun 2005 | US |