Catheter Y-connector with guidewire locking means

A Y-connector for attachment to the proximal end of a guide catheter which includes an arm projecting from the side of the Y-connector, the arm including a clamp for securing a catheter guidewire against movement relative to the guide catheter.

BACKGROUND OF THE INVENTION 
I. Field of the Invention 
This invention relates generally to apparatus for performing transluminal 
angioplasty and related procedures, and more particularly to an improved 
Y-connector or hub for attachment to the proximal end of a guide catheter 
for limiting movement of a guidewire used in the placement of the working 
catheter within the vascular system. 
II. Discussion of the Prior Art 
In carrying out various surgical procedures, such as coronary artery 
balloon angioplasty, a balloon-tipped catheter must be routed through the 
vascular system and across the stenotic lesion so that when the balloon 
tip on the working catheter is inflated, the partially occluded coronary 
artery will be spread to a patent condition. In carrying out this 
procedure, an incision is usually made in the patient's leg to gain access 
to the femoral artery and a relatively large diameter guiding catheter is 
inserted through an introducer and routed through the vascular system 
until its distal end approaches the coronary ostium. 
Following the insertion of the guide catheter, a relatively small diameter 
flexible guidewire is inserted through the proximal end of the guide 
catheter and advanced through it until the distal end of the guidewire 
exits the distal end of the guide catheter. By appropriately manipulating 
the proximal end portion of the guidewire, the physician is able to steer 
the guidewire into the coronary artery to be treated. Once the guidewire 
has been advanced so that its distal end is downstream of the lesion to be 
treated, a balloon catheter, such as described in U.S. patent application 
Ser. No. 893,558, filed July 14, 1986, and entitled DILATION CATHETER is 
fitted over the guidewire in the manner described in that application and 
then fed through the guide catheter. In that the distal end portion of the 
balloon-tipped catheter is captured onto the guidewire, as the balloon 
catheter exits the guide catheter, it follows the guidewire until the 
balloon is made to bridge the stenotic lesion to be treated. 
The angioplasty procedure often dictates that working catheters having 
balloons of differing shapes and diameters be utilized successively. Thus, 
it is frequently required that a first balloon catheter be removed and 
replaced sequentially with one or more other working catheters. It is 
important that the guidewire remain in place until the procedure is 
completed, thus avoiding the necessity of repositioning the guidewire. 
When it is considered that several different working catheters are passed 
back and forth along the guidewire during the course of a procedure, it 
has required that the physician or a nursing attendant be able to readily 
grasp and hold the proximal ends of both the guidewire and guide catheter 
as the working catheters are repositioned. This is an impediment to the 
physician's ability to effectively manipulate the working catheter in that 
both hands are occupied with holding the guidewire and guide catheter. 
All of the foregoing is by way of background for a better understanding of 
the construction and use of the present invention. In accordance with the 
present invention, the conventional Y-connector or hub used on the distal 
end of the guide catheter is replaced by a hub having an arm extending 
laterally and proximally from an exterior side surface thereof. This arm 
extends slightly beyond the proximal end of the hub body and on the free 
end of the arm is a releasible clamp which may be used to grip the 
guidewire and thereby hold it fixed relative to the guide catheter. 
Because of this clamping arrangement, there is no relative movement of the 
guidewire within the guide catheter and, hence, the possibility that the 
guidewire is inadvertently retracted is greatly reduced. Moreover, the 
lateral displacement of the proximal ends of the guidewire and working 
catheter provided by the arm maintains the guidewire out of the way when 
manipulating the working catheter. 
OBJECTS 
It is accordingly a principal object of the present invention to provide an 
improved Y-connector or hub for a vascular guide catheter. 
Another object of the invention is to provide a guide catheter having a 
proximal hub including means for clamping a guidewire thereto. 
Yet another object of the invention is to provide an improved catheter 
assembly for use in coronary angiography or angioplasty procedures, 
including a guide catheter, a guidewire insertable therethrough and a 
working catheter movable about said guide wire where the guide catheter 
has a proximal hub which includes means for immobilizing the guidewire 
relative to the guide catheter and spacing the guidewire's proximal end 
relative to that of the working catheter. 
SUMMARY OF THE INVENTION 
The foregoing characteristics, advantages and objects of the present 
invention are realized by providing as a part of the proximal hub on a 
guide catheter, a laterally and proximally extending arm where the arm 
includes a means for frictionally engaging and clamping a portion of a 
guidewire extending outwardly beyond the proximal end of the guide 
catheter's hub.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to FIG. 1, there is illustrated a guide catheter, indicated 
generally by numeral 10, which comprises an elongated, flexible plastic 
tube 12 having a distal end 14 and a proximal end 16. Typically, the guide 
catheter body 12 may be approximately one meter in length and may have an 
outside diameter in the range of from 2.34 mm to 3.05 mm and an inside 
diameter of approximately 1.90 mm. 
In the view of FIG. 1, the guide catheter is seen to contain a working 
catheter 18 and a guidewire 20 running in side-by-side relationship 
through the lumen 22 of the guide catheter. The working catheter may be 
used for diagnostic purposes or, as illustrated in FIG. 1, may be a 
balloon angioplasty catheter. The working catheter 18 and the guidewire 20 
are preferably of the type described in the aforereferenced application 
Ser. No. 893,558 and, as such, the guidewire 20 does not extend through 
the main lumen 22 of the working catheter along its entire length but, 
instead, passes through a short length of tubing 24 located near the 
distal end 26 of the working catheter and beneath the expander (balloon) 
28. The expander member 28 may be inflated and deflated by injecting or 
aspirating a fluid at the proximal end 30 of the working catheter. The 
fluid traverses the lumen 22 and passes through ports 32 formed through 
the distal end portion of the tube beneath the expander member 28. 
Attached to the proximal end of the tubular guide catheter body 12 is a hub 
member identified generally by numeral 34. The hub is illustrated as being 
a so-called Y-connector which, except for the feature yet to be described, 
is conventional in its construction. That is to say, it includes a 
conventional luer swivel 36 which allows the hub 34 to rotate relative to 
the guide catheter body 12 to which it is attached. Included in the swivel 
are suitable O-ring seals to preclude blood from seeping through the 
swivel joint when the assembly shown is being used in a surgical 
procedure. The hub 34 also includes a tubular body member 38 having a luer 
fitting 40 extending at a predetermined angle to the longitudinal axis of 
the body 38, thus accounting for the common designation, "Y-connector". 
The luer fitting 40 communicates with the longitudinal bore 42 extending 
through the body 38 and provides a means whereby a suitable X-ray contrast 
medium may be injected into the lumen 22 of the guide catheter for 
allowing fluoroscopic observation as the guide catheter is being routed 
through the vascular system. Moreover, the port in the tube 40 may be 
available for taking pressure measurements. 
Affixed to the proximal end of the hub body 38 is a compression cap 44 
which is received on a cylindrical enlargement 46 integrally formed with 
the tubular body 38. One or more elastomeric gaskets 48 fit into a recess 
50 formed in the end cap 44. The proximal end portions of the guidewire 20 
and the working catheter 18 pass through a bore 52 formed in the end cap 
44 as illustrated. When the compression cap 44 is twisted onto the 
enlargement 46, the gaskets 48 are compressed to effectively seal the exit 
port 52 to prevent loss of blood or other fluids through that port. 
In accordance with the present invention, the hub 34 is also provided with 
a laterally and proximally extending arm 54 which is preferably integrally 
molded to the hub's tubular body 38. Alternatively, it may be separately 
bonded to the exterior surface of the tube 38 along the line 56. While not 
essential, it has been found convenient to form the arm 54 so as to be 
coplanar with the support web 58 joining the tubular branch 40 to the body 
member 38. As noted in the drawing of FIG. 1, the arm 54 extends 
proximally beyond the end of the compression cap 44. 
With reference to FIGS. 1 and 2, it can be seen that the arm 54 includes an 
aperture 60 extending through the thickness dimension thereof and fitted 
through this aperture is a shaft 62 whose length is greater than the 
thickness dimension of the arm 54. The shaft 62 has a predetermined 
clearance fit with the aperture 60 and formed on opposed ends of the tube 
62 are end cap members 64 and 66. Elastomeric washers 68 and 70 are 
adhesively bonded to the end caps 64 and 66 as can be readily observed in 
FIG. 2. 
OPERATION 
When the apparatus of the present invention is employed in, for example, a 
balloon angioplasty procedure, the first step in the procedure is to 
insert the guide catheter into an incision made in the femoral artery and 
then advance the guide catheter through the vascular system until the 
distal end 14 of the guide catheter approaches the coronary ostium of the 
heart. This procedure is facilitated when a suitable radiopaque die is 
introduced, via side port 40, of the Y-connector 34 during the guide 
catheter placement step. 
Next, an elongated guidewire 20 is fed through the entrance port 52 formed 
in the compression cap 44 and is fed through the tubular body 38 of the 
hub 34 and through the lumen 22 of the guide catheter until the guidewire 
is steered into the coronary artery to be treated with its distal tip 
beyond the stenotic lesion. 
Next, the working catheter 18 has its distal tube portion 24 fitted over 
the proximal end of the guidewire 20 and then it is pushed through the 
port 52 and the sealing gaskets 48. Once the distal end portion 26 of the 
working catheter has been moved into the catheter body 38, the physician 
may then wrap the guidewire 20 over the shaft 62 and between the side 
surface of the arm 54 and the end cap 64. Now, when a lateral force is 
applied to the end cap 64, the guidewire 20 is effectively captured 
between the elastomeric surface 68 and the side surface of the arm 54. 
Frictional forces between the shaft 62 and the aperture 60 hold the clamp 
closed. 
Once the guidewire 20 is so clamped, its proximal end is held out of the 
way and the working catheter 18 may more readily continue to be fed 
through the guide catheter 10 with the guidewire serving as a rail along 
which the working catheter 18 is steered. Once the expander member 28 is 
appropriately positioned relative to the stenotic lesion, an inflation 
fluid may be injected into the lumen of the working catheter at its distal 
end and this fluid will flow the length of the catheter and through the 
ports 32 to inflate the expander 28. Inflation of the balloon 28 serves to 
spread the occluded opening in the coronary artery being treated. 
In the course of an angioplasty procedure, it often becomes necessary to 
start with a balloon of a relatively small outer diameter and then 
successively substitute working catheters having expander members of 
increasingly larger diameter. Because of the provision of the arm 54 on 
the hub member 34 with its guidewire clamping arrangement illustrated in 
FIG. 2, it is no longer required that the surgeon or the surgical 
attendant hold onto the proximal end portion 20 of the guidewire as he or 
she either advances or retracts the working catheter. It is only required 
that the guidewire 20 be unlocked when a working catheter is to be totally 
removed from the guidewire or when a new working catheter is to be fed 
onto that guidewire. 
When the guidewire is in the desired, proper position across the stenosis, 
any movement of the guidewire while advancing or retracting the working 
catheter, is generally detrimental. The arm and locking means which is 
added to the Y-connector is used to fix the guidewire in relationship to 
the guiding catheter. This permits the balloon catheter to be advanced and 
withdrawn without any inadvertent dislocation of the guidewire in the 
stenosis. A further advantage of the present invention is that the arm and 
lock arrangement maintains the guidewire and working catheter separated, 
facilitating the grasping of one or the other individually by a surgeon 
wearing surgical gloves, which gloves may be moist and somewhat slippery 
from exposure to body fluids. 
This invention has been described herein in considerable detail in order to 
comply with the Patent Statutes and to provide those skilled in the art 
with the information needed to apply the novel principles and to construct 
and use such specialized components as are required. However, it is to be 
understood that the invention can be carried out by specifically different 
equipment and devices, and that various modifications, both as to 
equipment details and operating procedures, can he accomplished without 
departing from the scope of the invention itself. For example, various 
devices for clamping the guidewire may be devised as a replacement for the 
push-button clamp disclosed herein. Hence, the scope of the invention 
should be determined from the following claims.