US 20090018502 A1
A stiffenable balloon catheter assembly capable of being converted from an “over-the-wire” mode with respect to a guidewire extending therethrough to a “rapid-exchange” mode with respect to a guidewire extending therethrough, and vice versa. The catheter has a plurality of lumens, one lumen however, having a side opening with an obstructable galp, the orientation of which, determines the utilization “mode” of the catheter assembly. Stiffening stylets may be adjustably locked into the lumens, depending upon the “mode”, to control the stiffness of the catheter assembly during its utilization within a patient.
29. A rapid-exchange balloon catheter, comprising:
an elongated polymer catheter body and an inflatable balloon, inflatable by delivering an inflation fluid through the body, said catheter operable in rapid-exchange mode by locating a guidewire through a side wall of said catheter body and into a first lumen of said catheter body, said catheter body having a separate second lumen including an elongated stiffener.
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This is a continuation of application Ser. No. 07/681,805, filed Apr. 5, 1991.
1. Field of the Invention
This invention relates to a catheter having a balloon at its distalmost end, and having means for adjustably controlling the stiffness of the catheter shaft, and more particularly to a convertible-type balloon catheter having stiffener means disposed within the catheter.
2. Prior Art
Balloon catheters are utilized for insertion into the human body into lumens therewithin. The catheters are of necessity made of a flexible plastic extrusion such as polyethelene, polyester or polyamide. Advancement and manipulation of a catheter requires a certain stiffness or pushability of the catheter itself, by the physician, without injuring the patient in which the catheter is placed.
A number of approaches have been made, in attempting to provide stiffness to catheters. U.S. Pat. No. 4,964,853 to Sugiyama et al shows a balloon catheter having a braided wire member disposed within the catheter body itself in a meshlike manner. Mesh is imbedded in the wall of the inner tube. U.S. Pat. No. 4,875,841 to Higgins shows a balloon catheter having a coiled wire arranged within the proximalmost hub, which coiled wire extends in an uncoiled manner within the body of the catheter shaft itself. The coil and the wire itself being co-rotatable so as to provide rotational stiffness to the catheter.
U.S. Pat. No. 4,822,345 to Danforth shows a variable stiffener balloon catheter, for percutaneous transluminal coronary angioplasty procedures. This patent to Danforth shows a method of providing for variable flexibility, by the use of a longitudinally extended balloon arranged along the exterior of the catheter shaft. Pressurization or depressurization of this balloon is effectuated by a syringe, which pressurizably controls the rigidity of the balloon itself. A further embodiment of this concept of Danforth utilizes relatively stiff wires running through channels in the periphery of the catheter, the wires adding the stiffness to the catheter.
The preformed catheter assembly shown in U.S. Pat. No. 4,738,667 to Galloway discloses a sheath which is slideably mounted over the catheter so as to be moved from the proximal to the distal end, to straighten out the distal end during insertion and removal of the catheter from a body. The catheter assembly shown in U.S. Pat. No. 4,737,152 to Alchas shows a stylet or stiffening wire arranged within a lumen connected to the closed distal end of the catheter and also there is a loop on its proximalmost end. The loop is arranged in a rotatable knob to facilitate rotation of the distal end of the catheter while providing stiffness, while the proximal end is turned.
U.S. Pat. No. 4,586,923 issued to Gould et al shows a curving tip catheter having a catheter body which includes a sheath of braided wire having a meshlike configuration positioned around the wall of the tubular body to provide tortional stiffness to the body relative to the flexible tip. In an alternative embodiment, a relatively stiff but bendable inner plastic tubing can be inserted within the tubular body to provide tortional stiffness to that body. In a somewhat similar vein, U.S. Pat. No. 4,516,972 to Sampson shows a guiding catheter having a helically wound ribbon of flexible material embedded within the wall of the catheter, so as to provide tortional rigidity and stiffness.
In yet a further embellishment on the idea of stiffening a balloon catheter, U.S. Pat. No. 4,448,195 to LeVeen et al shows a reinforced balloon catheter which has a guidewire adapted to be inserted for stretching the catheter when it is inserted into a blood vessel to stiffen the catheter and position it. In an alternative arrangement, a braided shell wire reinforcement is used within the braids, which are placed at the beginning and endings of the thinned portion of the catheter. U.S. Pat. No. 4,033,331 to Guss et al, discloses a contour or stiffening wire slideably disposed within a lumen extending substantially the full length of the catheter. Slight retraction of the stiffening wire from the distal end of the lumen permits catheter to assume a predetermined curvature thereat.
It is thus an object of the present invention to provide a catheter having variable stiffness capabilities therewithin. The catheter of the present invention should overcome the problems of the prior art by getting the physician to properly adjust the rigidity or stiffness of the catheter shaft according to the particular situation that warrants it in conjunction with the capability of utilizing the catheter shaft in a convertible manner between a “rapid-exchange” mode and an “over-the-wire” mode.
The present invention comprises a balloon catheter having a catheter shaft with at least three lumens extending from the proximal to the distal ends thereof. The first and second lumens may preferably but not necessarily be of cresent shape in cross-section, and the third lumen is of circular cross-section. At, least one of the cresent shaped lumens has a stiffening mandrel extending therethrough. In a preferred embodiment, the third lumen has a side opening arranged relatively close yet proximal to the balloon at the distal end of the catheter assembly.
The balloon on the distal end of the catheter shaft is in fluid communication with one of the cresent shaped lumens. The first shaped lumen has a closed distalmost end, at the proximal end of the balloon.
The third lumen, preferably of circular cross-section, extends from the proximal end of the catheter shaft, and through the balloon, open at its distalmost end at the distal end of the balloon. The third lumen is adapted to receive a guidewire, either through the entire length thereof, or from an opening proximal of the balloon and through to its distalmost end.
In a preferred embodiment, a guidewire is adaptable to enter the third “distal” lumen at its opening at the distalmost end of the catheter and extend through that lumen, through the balloon, and exit out the side opening through the sidewall of the catheter, proximal of the balloon. The side “guidewire” opening of the third lumen being disposed through the wall of the catheter shaft at a location which is also proximal to the distal end of the stiffening mandrel in the first cresent shaped lumen. This rapid exchange mode with a guidewire extending partway through may occur with a stiffening stylet disposed within the third lumen, the stylet extending up to a location adjacent the side opening, from the proximal end of the catheter. This same lumen, a portion of which is utilized for the “rapid-exchange” mode, is utilized in its entire length, for the catheter in its “over-the‘wire” mode, where a guidewire enters the distal opening of the third “distal” lumen, and exits at the proximal end of the catheter at the proximal end of that third lumen, through a connector or adaptor.
The present invention thus comprises a multiple lumen catheter (at least three lumens) having proximal and distal ends, the proximal end having a Y-connector thereat for adaptation of inflation devices or control functions, the distal end comprising an inflatable elongated balloon.
A first of the lumens has an elongated stiffening mandrel disposed therein, the lumen being closed at its distalmost end. The stiffening mandrel being preferably made of Nitinol. A second of the lumens extending from the connector, and into the balloon, providing fluid communication therewith. The third of the lumens being preferably circular in cross-section, extending from the connector and through the balloon, and open through the distal tip of the catheter shaft. A “side” orifice being disposed through the wall of the catheter and into the third lumen, just proximal (about 15 to 35 cm) of the balloon. The stiffening mandrel in the first lumen extending distally of the side orifice in the third lumen to the proximal end of the catheter, so as to allow a smoother transition of catheter stiffness when the assembly is utilized in a rapid exchange mode—that is, when a guidewire extends only part way through the third lumen, out through the “side” orifice after entering that lumen distally and to help transmit “push” on the catheter shaft from its proximal end. The same lumen therefore, in the same catheter, functioning as a lumen for an “over-the-wire” mode, as well as a “rapid-exchange-wire” mode, using part of the lumen for a guidewire and part of that lumen for catheter stiffening assistance.
The objects and advantages of the present invention will become more apparent when viewed in conjunction with the following drawings, in which:
Referring to the drawings now in detail, and particularly to
The catheter shaft 12 has an elongated balloon 20 disposed about its distalmost end, in a known manner. The first lumen 14 extends from an opening, not shown, in a connector 22, shown in
The second lumen 16 extends from the connector 22, through the shaft 12, parallel to the first lumen 14, except that the second lumen 16 is in fluid communication with the balloon 20, as shown in phantom lines 17, in
The third lumen 18, of generally circular cross-section, extends from the connector 22, through the shaft 12, and through the balloon 20, opening distally of the balloon 20, as shown in
An opening or side orifice 30 is disposed through the wall of the catheter shaft 12, and into the third lumen 18, as shown in
An RO (radio opaque) marker band 34 is disposed about the catheter shaft 12, (essentially the structure comprising the third lumen 18), at the mid-point of the balloon 20 in either the “over-the-wire” mode or the “rapid-exchange” mode.
In one embodiment of the present invention, where the catheter assembly 10 is utilized as aforementioned in the traditional “over-the-wire” catheter, a guidewire 50, normally initially having been inserted into a patient's vessel, and having its proximal end outside of the patient, has that proximal end inserted through the distal end of the catheter assembly 10, through the “distal” or third lumen 18, and it extends proximally, out of the proximal guidewire connector 42, as shown in
In a further embodiment of the present invention, where the catheter assembly 10 may be utilized in the aforementioned “rapid-exchange” mode, the guidewire 50, normally initially inserted into a patient's vessel, and having its proximal end outside of the patient, has that proximal end inserted through the distal end of the catheter assembly 10, through the “distal” lumen 18, and extending outwardly proximally, through the side opening 30 as shown in
Additionally, when the catheter assembly 10 is utilized in this “rapid-exchange” mode, a stiffening stylet 52 may be inserted within the “distal” or third lumen 18 through the connector 22, as shown in
It is critical to the present invention that the location of the distalmost end of the stiffening mandrel 26 emplaced within the first lumen 14, as shown in
A further embodiment of the side hole 30 is shown in
A yet another embodiment of the side hole 30 is shown in
Thus what has been shown is a novel stiffened catheter assembly 10 capable of being utilized by a physician as an “over-the-wire” catheter with adjustable stiffness means therewith, or optionally as a “rapid-exchange-wire” catheter apparatus, also including the capability of being able to control or vary the stiffness of the catheter shaft by selective insertion and/or controlled withdrawal of a stiffening stylet adaptably arranged within the guidewire lumen, the “rapid-exchange-wire” mode being facilitated by a side opening having valve-like obstructable flap across its inner side to minimize fluid exchange when that lumen accepts the catheter to be utilized in its full length “over-the-wire” mode. In its use as either a “rapid-exchange-wire” or an “over-the-wire” mode, the portion of the “distal” lumen enclosing the guidewire may have a plurality of orificii through the wall of the catheter shaft just proximal and just distal of the elongated inflated balloon, to permit perfusion of body fluid across the then expanded balloon in the body vessel.