Surgery – Means for introducing or removing material from body for... – Treating material introduced into or removed from body...
Reexamination Certificate
2000-10-05
2003-09-16
Milano, Michael J. (Department: 3731)
Surgery
Means for introducing or removing material from body for...
Treating material introduced into or removed from body...
C604S264000, C604S523000, C604S533000
Reexamination Certificate
active
06620149
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to the field of catheterization of lumen within the human body, particularly vasculature. Even more particularly, the invention will have application to the manufacture and construction of balloon catheters used in angioplasty.
Angioplasty procedures have gained wide acceptance as an efficient and effective method for treating certain types of vascular diseases. In particular, angioplasty is widely used for stenoses in the coronary arteries, although it is also used for the treatment of stenoses in other parts of the vascular system. The use of core members to provide rigidity and pushability for catheters is well known, and the incorporation of such core members is discussed, for example, in U.S. Pat. No. 5,921,958, entitled Intravascular Catheter with Distal Tip Guide Wire Lumen, which is hereby incorporated by reference.
The most widely used form of angioplasty makes use of a dilatation balloon catheter to treat a stenosis and thereby reestablish an acceptable blood flow through the artery. The dilatation catheter includes an elongated tubular shaft and an inflatable balloon carried at a distal end of the shaft. In operation, the catheter is inserted through a guide catheter which has been previously introduced into a patient's vascular system from a location remote from the heart (e.g., femoral artery). The proximal end of the guide catheter remains outside the patient while the distal end of the guide catheter is positioned at the coronary artery ostium. A dilatation catheter is introduced into the proximal end of the guiding catheter and advanced to the distal end of the guide catheter. Then, by using fluoroscopy, the physician guides the dilatation catheter the remaining distance through the vascular system until the balloon is positioned across the stenosis.
The balloon is then inflated by supplying fluid under pressure, through an inflation lumen in the catheter, to the balloon. The inflation of the balloon causes a widening of the lumen of the artery to reestablish acceptable blood flow through the artery. After a short inflation period (e.g., 30-90 seconds), the balloon is deflated and the arterial treatment evaluated to determine whether the procedure has reestablished an acceptable blood flow. The evaluation is conducted by introducing a radiopaque dye solution into the artery via the guiding catheter, and then observing the dye flow using fluoroscopy. If necessary, the dilatation procedure is repeated with the catheter balloon being re-inflated. In procedures in the peripheral vessels (vessels other than coronary vessels), a guide catheter may not always be used.
The placement of the dilatation balloon across a stenosis in a coronary artery can be a difficult procedure. Movement of the elongated dilatation balloon catheter (e.g., 135 cm) is achieved by manual manipulation of its proximal end outside the patient. The ability of a catheter to bend and advance through the vasculature is commonly referred to as the “trackability” of the catheter. “Pushability” refers to the ability of the catheter to transmit the longitudinal forces applied by the physician along the catheter shaft to advance the distal end of the catheter through a coronary artery to and across the stenosis. Preferably, a catheter has a low profile, and is relatively trackable and pushable.
One common type of dilatation catheter has a guide wire lumen extending through the catheter so that a guide wire can be used to establish the path through the stenosis. The dilatation catheter can then be advanced over the guide wire until the balloon on the catheter is positioned within the stenosis.
In a catheter design where the guide wire does not extend through the catheter balloon, it is important that the catheter structure provide sufficient rigidity along the catheter shaft and through the balloon (all the way to the distal tip of the catheter where the guide wire lumen is located), so that the catheter has the necessary pushability. A core member helps provide this rigidity and pushability. On some catheters, the core member may provide axial rigidity to the entire distal shaft section. On many catheters, particularly balloon catheters, the core member serves a strain relief function as well. The core member reduces kinking of the catheter lumen, such as the inflation lumen in a balloon catheter, which might otherwise occur due to a change in flexibility between a relatively stiff section of tubing, to that of a relatively flexible distal shaft portion.
Core members are typically affixed at the proximal end of the catheter to the catheter hub or manifold. They are affixed either by being embedded in the material from which the hub is formed at the time the hub is manufactured, being affixed with a solder or braze, or being embedded in a mass or glob of cyanoacrylate, epoxy, resin, or other adhesive affixed to the inner wall of the hub. These latter methods tend to complicate the manufacture of the catheter, as either the core member must be incorporated into the hub molding or machining, or else the adhesive must be added to the hub after the hub is formed. Correct placement of the core member adhesive within the hub lumen is a relatively delicate manufacturing procedure which may lead to errors and rejection of catheters under quality control standards. Furthermore, some of these methods of affixing the core member may not sufficiently bond the core member to the hub for all applications or situations.
SUMMARY OF THE INVENTION
The present invention pertains to an intralumenal catheter with a core member extending from a proximal hub and through some portion of a shaft distal to the hub. Fixation of the core member into the hub lumen is accomplished in a way that is easier to manufacture than prior methods of securing the core member. The present invention may increase the reliability of the production process, in addition to making the core member more securely fixed in the hub. A catheter of the present invention may also have an inflatable angioplasty balloon, or other devices for reducing or ablating a stenosis, such as an atherectomy-type cutter, a laser device, a water jet device, or sonic or ultrasonic therapeutic devices. The present invention may also be used with other interoperative devices such as drug delivery devices, ultrasonic imaging devices and perfusion devices.
One embodiment of the present invention is a catheter with a flexible, elongate tubular shaft. This shaft has a lumen throughout, and has a proximal and a distal end. A hub with an inner lumen is attached to the proximal end of the shaft. A core member, which runs though at least a portion of the catheter shaft, extends proximally into the hub lumen, and is secured within the lumen. While the core member is substantially in the center of the lumen when entering the distal end of the hub, proximally to this the core member contacts the inner wall of the hub lumen of the hub at two or more points, traversing the hub lumen between points of contact with the inner wall of the hub.
Moving along the core member from a distal opening of the hub to a proximal opening of the hub, the core member at some point is angled so as to gradually extend out from the center of the lumen and contact the inner wall of the hub lumen. After contacting the inner wall of the lumen, the core member is again angled so as to extend to another point on the hub lumen inner wall, such point located proximally from the first point of contact with the hub lumen, but not located on a longitudinal line on the hub lumen inner wall that crosses through the first point of contact. In reaching the second point of contact with the hub inner wall, therefore, the core member may cross substantially over the center of the hub lumen when viewed radially. The core member may then be again angled to contact yet another proximally located point on the hub inner wall. This point, proximal to the first and second points of contact, may be on a longitudinal line on the hub inner wall that crosses through the fir
Lenz Jason T.
Simer, Jr. Loren J.
Slayhi Mirna A.
Baxter Jessica R
Crompton Seager & Tufte LLC
Milano Michael J.
Sci-Med Life Systems, Inc.
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