Surgery – Instruments – Internal pressure applicator
Reexamination Certificate
1997-12-19
2001-01-30
Thaler, Michael H. (Department: 3731)
Surgery
Instruments
Internal pressure applicator
C604S096010
Reexamination Certificate
active
06179856
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to catheters and, particularly, to catheters of the type used in percutaneous transluminal coronary angioplasty.
BACKGROUND OF THE INVENTION
Percutaneous transluminal coronary angioplasty (PTCA) is a procedure by which a balloon catheter is inserted into and manipulated within a patient's coronary arteries to unblock an obstruction (a stenosis) in the artery. Typically, the catheter is about 150 cm long and is inserted percutaneously into the patient's femoral artery in the region of the groin. The catheter then is advanced upwardly through the patient's arteries to the heart where, with the aid of a guidewire, the catheter is guided into the coronary artery where it can be controlled to perform the angioplasty procedure.
In one type of PTCA catheter, the catheter has two lumens. One lumen, for inflation and deflation of the balloon, extends from a fitting at the proximal end of the catheter and opens distally into the interior of the balloon. The balloon is inflated with a liquid and is deflated by aspirating the liquid from the balloon through the inflation/deflation lumen. The second lumen extends from another fitting at the proximal end of the catheter through the catheter and is open at the distal tip of the catheter shaft. The second lumen is adapted to receive a guidewire, such as the steerable small diameter type of guidewire disclosed in U.S. Pat. No. 4,545,390 (Leary) issued Oct. 8, 1985.
In a typical procedure, the guidewire is preliminarily loaded into the catheter and the assembly is inserted into a previously percutaneously placed guide catheter that extends to the region of the patient's heart and terminates at the entrance to the coronary arteries. The assembly of the balloon angioplasty catheter and the steerable guidewire is advanced through the guide catheter to the entrance to the coronary arteries. The guidewire then is projected into the coronary arteries and is steered by manipulation from its proximal end, while being observed under a fluoroscope, until the guidewire passes through the stenosis in the artery. Once the guidewire is in place, the balloon dilatation catheter is advanced over the guidewire, being thus guided directly to the stenosis so as to place the balloon within the stenosis. Once so placed, the balloon is inflated under substantial pressure to dilate the stenosis.
The anatomy of coronary arteries varies widely from patient to patient. Often a patient's coronary arteries are irregularly shaped and highly tortuous. The tortuous configuration of the arteries may present difficulties to the physician in properly placing the guidewire and then advancing the catheter over the guidewire. A highly tortuous coronary anatomy typically will present considerable resistance to advancement of the catheter over the guidewire. With some types of catheter construction, the increased resistance may cause a tendency for portions of the catheter to collapse or buckle axially. For example, in a catheter having a shaft formed from inner and outer coaxial tubes and a balloon mounted to the distal ends of the tubes, there may be a tendency for the tubes to telescope when presented to an increased resistance. The telescoping of the tubes will tend to draw the ends of the balloon together slightly but sufficiently to permit the balloon to become bunched up as it is forced through the stenosis. The bunching up of the balloon makes it more difficult for the balloon to cross the stenosis. It is among the principal objects of the invention to provide an improved construction for a PTCA catheter, particularly a coaxial catheter, which reduces the tendency for the catheter to telescope and buckle and for the balloon to become bunched up under such axial loads.
SUMMARY OF THE INVENTION
The invention is embodied in a coaxial type of PTCA catheter in which the elongate catheter shaft is formed from an inner tube and a coaxial outer tube. The inner tube extends from the proximal end fully to the distal end of the catheter and terminates in an open distal outlet. The lumen extending through the inner tube serves as a guidewire lumen. The outer tube extends from the proximal end of the catheter and terminates short of the distal end of the inner tube. The dilatation balloon is mounted on the distal end of the catheter with its proximal end adhesively attached to the distal end of the outer tube and the distal end of the balloon being adhesively attached to the distal end of the inner tube. The annular lumen defined between the inner tube and the outer tube communicates with the interior of the balloon and serves as the inflation/deflation lumen.
The present invention is intended to resist the tendency for the inner tube of the catheter shaft to telescopically buckle or collapse within the outer tube when being pushed from its proximal end as the distal end of the catheter meets resistance in the coronary arteries. Such resistance typically is met when crossing a stenosis during the negotiation of tightly curved coronary arteries. By preventing such telescoping, the present invention is intended to resist a tendency for the thin walled balloon to become bunched as it is pushed through the stenosis. In accordance with the invention, the column strength of the catheter is improved, telescoping of the inner and outer tubes and bunching of the balloon is avoided in that the distal end of the outer tube is securely anchored to the inner tube at a location within the balloon, preferably adjacent the proximal end. By preventing telescoping of the inner and outer tubes, the axial distance between the ends of the balloon does not contract and bunching of the balloon is avoided. Openings are formed in the distal end of the outer tube, adjacent the point of attachment to the inner tube, to communicate the inflation/deflation lumen with the interior of the balloon. By anchoring the distal end of the outer tube to the inner tube and thereby increasing the column strength of the catheter, it has been found that relative axial motion and telescopic buckling of the inner tube within the outer tube is avoided when the distal end of the catheter meets substantial resistance to advancement, as when crossing a difficult stenosis or negotiating tightly curved coronary arteries.
It is among the objects of the invention to provide an improved PTCA catheter construction.
Another object of the invention is to provide a PTCA catheter having a coaxial construction in which there is a reduced tendency for the balloon to become bunched as it is advanced through a resisting stenosis.
Another object of the invention is to provide a PTCA catheter having a coaxial construction in which there is a reduced tendency of the inner tube of the catheter shaft to buckle or telescope within the outer tube when the catheter is advanced through a resisting coronary anatomy.
A further object of the invention is to provide a coaxial PTCA catheter in which the outer tube of the catheter shaft is attached, at its distal end, to the inner tube of the catheter shaft.
REFERENCES:
patent: 3543759 (1970-12-01), McWhorter
patent: 4323071 (1982-04-01), Simpson et al.
patent: 4638805 (1987-01-01), Powell
patent: 4646742 (1987-03-01), Packard et al.
patent: 4665925 (1987-05-01), Millar
patent: 4689041 (1987-08-01), Corday et al.
patent: 4702252 (1987-10-01), Brooks et al.
patent: 4794928 (1989-01-01), Kletschka
patent: 4892519 (1990-01-01), Songer et al.
patent: 4955895 (1990-09-01), Sugiyama et al.
patent: 5032113 (1991-07-01), Burns
patent: 5061273 (1991-10-01), Yock
patent: 5085636 (1992-02-01), Burns
patent: 5100381 (1992-03-01), Burns
patent: 5129887 (1992-07-01), Euteneuer et al.
patent: 2008642 (1990-07-01), None
patent: 8401513 (1984-04-01), None
patent: 0213752 (1987-11-01), None
patent: 8804560 (1988-06-01), None
Promotional Sheet for Probe Balloon-On-A-Wire Dilatation System, distributed by USCI Division. C.R. Bard, Inc., Jan. 1989.
Medtronic Ave Inc.
Sterne Kessler Goldstein & Fox P.L.L.C.
Thaler Michael H.
LandOfFree
Coaxial PTCA catheter with anchor joint does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Coaxial PTCA catheter with anchor joint, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Coaxial PTCA catheter with anchor joint will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2528760