|Publication number||CA1329092 C|
|Application number||CA 597115|
|Publication date||3 May 1994|
|Filing date||19 Apr 1989|
|Priority date||29 Apr 1988|
|Also published as||DE68918888D1, DE68918888T2, EP0339799A2, EP0339799A3, EP0339799B1, US4935017, US5267982|
|Publication number||CA 1329092 C, CA 1329092C, CA 597115, CA-C-1329092, CA1329092 C, CA1329092C|
|Inventors||John T. Sylvanowicz|
|Applicant||John T. Sylvanowicz, C.R. Bard, Inc.|
|Export Citation||BiBTeX, EndNote, RefMan|
|Classifications (8), Legal Events (1)|
|External Links: CIPO, Espacenet|
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VARIABLE SHAPED CATHETER SYSTEM
AND METHOD FOR CATHETERIZATION
FIELD OF THE INVENTION
;~ This invention relates to improved angiographic .. 5 and cardiovascular catheter systems and methods of ~ catheteriza~ion.
~ BACKGROUND OF THE INVENTION AND PRIOR ART
~' For many years it has been the common pr~ctice in angiographic and cardiovascular procedures to use various angiographic catheters having different distal tip shapes in order to perform various `~ angiographic studies. For example, when performing coronary angiography, it is common to perform studies of the left coronary artery, the right coronary artery, and the left ventrical by injecting X-ray opaque contrast liquid into each of the right and lPft coronary arteries and also into the left ~, ventrical. Each injection is done with a separate catheter having a specially formed distal tip , ~, ~..
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i adapted to facilitate entry into the ostium of the s right or left coronary artery. Typically, a catheter having a pigtail shape is used for left ~; ventricular studies. In order to perform these s 5 studies it has been the typical practice to exchange: catheters for each study. That is time consuming and subjects the patient to ~he trauma of multiple catheter insertion and removal. Addionally, the use ~ of multiple catheters increases the risk of a blood,~ 10 clots and, in general, presents greater risk for ' complications.
.` The desirability of reducing the time involved i~ in perfarming such angiographic studies as well as minimizing trauma to the patient by making a 15 catheter having a tip shape adjustable while in the .: patient has been suggested iIl the prior art. U.S.
Patent 4,033,331 to Guss discloses a specially formed catheter having two l~mens, including a main ~ lumen through which the radiopaque contrast liquid .` 20 may be injected into the blood vessel and another x~ lumen which receives a relatively stiff elongated `~ contour wire. The distal end of the catheter has a predetermined curved shape which can be ,'~5 progressively straightened by advancing the contour25 wire distally through its lumen. The system ~,' discussed in the Guss pa~ent has several s. disadvantages, the principal one being that it cannot be used with a conventional angiographic .,:
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' catheter. The practice of the technique disclosed in the Guss patent requires the use of the special two lumen catheter construction. Additionally, that ~;~ catheter construction necessarily has reduced flow area in the main lumen because of the necessity of providing the cross-sectional area for the contour ~ wire lumen. In that regard, it is important to ?~ maintain a large flow area as possible in an ,~ angiographic catheter so that the radiopaque contrast liquid can be injected at a relatively high flow rate. Wi~h the two lumen catheter construction ,~ this desirable feature of such catheters is compromised.
~ SUMMARY OF THE INVENTION
In accordance with the present invention an s,~ angiographic catheter assembly is provided which ~, includes a flexible angiographic catheter of conventional construction having a full size lumen and a pre-shaped curve at its distal end. The catheter extends through a sheath that is several centimeters shorter than the catheter, by an amount ,~ at least as great as the length of the curved distal .. $` segment of the catheter. The shape of the curve at ,~ the distal end of the catheter can be varied by .~ 25 advancing the sheath over the catheter. The sheath sJs ~
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.~, has sufficient stiffness so that it tends to straighten the catheter curve as it advances over it, thereby progressively changing the shape of the ,. curve. The catheter assembly enables a method of 5 angiography by which different procedures can be .~- performed on the patient without requiring catheter , exchanges for each procedure.
In another aspect of the invention, the sheath ~ also may be used to deliver fluids or make pressure x 10 measurements at the distal tip of the sheath. To this end the proximal end of the sheath may be ....
$: provided with a fitting having a side leg for liquid ~ infusion. The inner diameter of the shčath may be r~", somewhat larger than the outer diameter of the 15 catheter to define an annular flow space along the ~, length of the assembly. It is desirable that the . distal tip of the sheath fit closely to the outer , diameter of the catheter, the tip of the sheath .~ being tapered for this purpose. In order to provide ,~,A,~ 20 for fluid communication at the distal end of the sheath, the sheath may be provided with several side holes at its distal end. In addition, the sheath ~. may be used as an introducer should it be desired to "r"~, remove the catheter and replace it with another ,.,~, .
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~ The system is used in a method in which the `.~. relative position of the sheath on the catheter is .~
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selected to place the distal end of the catheter in a particular curved configuration suited for the angiographic procedure to be performed. After the dye injection and procedure have been completed, the longitudinal position of the sheath with respect to the catheter may be adjusted either to increase or decrease the curvature at the distal end or to permit the catheter to assume its more curved relaxed configura~ion, depending on which procedure J,' 10 is next to be performed. The change in configuration is effected quickly and simply with no additional trauma to the patient and without increasing the risk of complications that may result `~ from a succession of catheter exchanges.
It is among the general abjects of the invention to provide an improved catheter system for performing multiple cardiovascular and angiographic procedures while minimizing or reducing catheter .~ exchanges.
Another object of the present invention is to provide a catheter system and method for ~, catheterization by which the curvature at the distal ; end of a cardiovascular or angiographic catheter may be adjusted quickly and simply while within the patient.
Another object of the invention is to provide a system of the type described which utilizes a ., ~
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conventional angiographic catheter having a full size flow lumen.
A further object of the invention is to provide a catheter system of the type described in which the degree of curvature at the distal region of the catheter is controlled by a sheath that is slidably received over the catheter and which can be advanced ~; or withdrawn over the catheter.
Another object of the invention is to provide a system of the type described in which means are provided for injecting radiopaque contrast liquid and making pressure measurements at the distal end of the sheath.
A further object of the invention is to provide ` 15 system of the type described in which the sheath also may serve as a catheter introducer should it be desired to make a catheter exchange.
'. DESCRIPTION OF THE DRAWINGS
- - The foregoing and other objects and advantages . 20 of the invention will be appreciated more fully from the following further description thereof, with .. reference to the accompanying drawings wherein:
, FIG. 1 is a fraqmented illustration of the catheter system in accordance with the invention.
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FIG. 2 is an illustration of the system with the sheath advanced distally over the primary curve in a Judkins left coronary catheter;
FIG. 3 is an illustration similar to Fig. 2 but 5 with the sheath advanced over the secondary curve of the angiographic catheter;
, FIG. 4 is an enlarged illustration of the distal r end of the shea~h and catheter; and ;- FIG. 5 is a sectional illustration as seen along ' 10 the line 5-5 of FIG. 4.
'. DESCRIPTION OF THE PREFERRED EMBODIMENT
,, The system illustrated includes an angiographic catheter 10 having a proximal end 12 and a distal end 14. The proximal end is provided with a fitting 16 which can be connected to a syringe for injecting radiopaque contrast liquid t~lrough the catheter lo and into the patient. The distal end 14 of the catheter 10 is formed to define a predetermined curvature and, in the illus~rative embodiment, the curvature is that conventionally known as the left ~ Judkins curve, adapted for use in left coronary ;q artery angiography. The left Judkins shape may be considered as having a primary curve 18 and a secondary curve 20. A lumen 22 extends fully through the angiographic catheter 10, from the ~itting 1~ to the distal outlet tip 24. The lumen ~2 is full diameter, that is, it is uncompromised by .;
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,- The construction of the catheter 10 may be conventional as will be appreciated by those skilled in the art. For example, the catheter may be formed from extruded plastic material and may have woven or braided elements embedded in the catheter wall. By was of example the catheter may be approximately 125 centimeters in length although the length may be varied depending on the specific type of an~iographic or cardiovascular procedure that is to be employed. If desired, the distal tip of the angiographic catheter 10 also may be provided with ~ side holes 26 to increase outlet capacity.
.~ Typically, the tip of the catheter 10 will be ~; 15 tapered as indicated at 23 so that it may fit closely about a guidewire extending through the lumen 22 for smooth percutaneous entry, as will be appreciated by those familiar with the art.
~; The system of the present invention also includes an outer sheath indicated generally by the reference character 28 through which ~he catheter 10 ~, ex~ends. The sheath is circular in cross-section, as is the catheter 10, and may be formed from an appropriate extruded tube~ such as FEP or PTFB
.~; 25 fluorinated polymer. The sheath 28 is several centimeters shorter than the catheter 10, by an . amount at least equal to the length of the curved distal portion 14 of the catheter 10. In the , ~:
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illustrative embodiment, the sheath is between 5 and - 30 centimeters, preferahly approximately 10 centimeters shorter than the catheter. Typically, the sheath length will be between 30 to 150 cm, ~ 5 depending on the length of the catheter. The '~ proximal end of the sheath may be provided with a ~ hemostasis fitting 30 that receives the catheter 10 ~ and includes an internal proximal gasket 32 ~FIG. 2) that engages the outer surface of the catheter 10 to form a seal against the catheter 10. The fitting 30 ; may be provided with an adjustable gasket such as a Tuohy-Borst adapter ~illustrated in phantom at 33 in FI&. 3) ~y which the constricting force of the gasket about the catheter may be varied thereby to vary the degree with which the gasket seals against the catheter. The fitting 30 also may be provided with a side leg 34 through which liquids may be injected, pressure measurements may be made and sampling performed. The side leg on the sheath fitting also may be used to aspirate if there is to be a catheter exchange, in order to withdraw embolisms, or to inject heparin.
The sheath is formed so that when it is advanced over the curved distal portion 14 of th~ catheter 't', 25 10, the stiffness of the sheath will cause the curve in the angiographic catheter 10 to become somewhat ~$. straighter. To this end, the sheath should be formed from a material and should have a wall ~., ~' ...
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thickness and stiffness sufficient to cause the cathete~r to assume the particular desired shape.
FIG. 2 shows a sheath in an extended position in which it has been advanced over the primary curve 18 of the Judkins left catheter. In this configur~tion, the catheter is suited somewhat for a right coronary arteriography procedure. FI~. 3 iillustrates the configuration of the system with the sheath advanced over both the primary and the ~, ~- 10 secondary cur~es 18, 20 respectively. In this configuration, the assembly is best suited for an arteriography of coronary artery by-pass or for left ventriculography in the angiographic procedure. By way of example the catheter 10 may be between about : 15 .052 to about .117 (4F to 9F~ in outer diameter and '~ may be formed from polyurethene material with a ~ braided tubular element embedded therein. The r sheath preferably is formed from a tube of Teflon fluorinated polymer also in a 4F to 9F size with an n inside diameter to match and receive the catheter.
The sheath also preferably is radiopaque, as by ~ incorporating barium sulfate or some other suitable i radiopaque material into the polymer.
~i FIGS. 4 and 5 illustrates a tip construction for the sheath in which the sheath is adapted to provide fluid communication betweem its proximal and distal ends while receiving the catheter. In this ~, .,, ,.:, .
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embodiment the inner diameter of the sheath is ssmewhat larger than the outer diameter of the catheter to define an annular flow area 36 that communicates with the side leg 3~. In the S illustrated embodiment the tip of the sheath is - tapered as indicated at 38 and fits closely against ; the outer surface of the catheter 10 to facilitate ~ percutaneous introduction of the entire systems as a i` unit into ~he patient's blood vessel. One or more 10 side holes ~0 may be formed adjacent the tip of the sheath to provide for fluid communication with the ,~ annular area 36. The foregoing arrangement enables ~ infusate to be delivered, pressure recordings to be ,~ ,, made as well as sampling and purging. It may be ~ 15 noted that the distal portion of the sheath may have :. a straight configuration when relaxed or itself may be provided with a pre-formed curve.
. The foregoing system also enables pressure ~` diferentials to be measured across a patient's 20 aortic valve. By locating the system so that the distal tip of the ca~heter i.s located distally o~
the aortic valve and with the side holes 40 at the distal end of the sheath 28 located proximally of the aortic valve, pressure measurements can be made ~ 25 on both sides of the valve thereby providing an x indication of the pressure differential.
A, Bo550~7001 ~ 3 ~ 9 0 ~ 2 4~25/~8 From the foregoing it will be appreciated that the system may be percutaneio~sly introduced and : used by advancing into the patients blood vessels in a conventional manner as is well known to those skilled in the art. The sheath may be positioned along the catheter to present the desired curved configuration for the first study to be performed.
Ater that study is performed the relative position of sheath and catheter may be adjusted to change lo the configuration of the catheter distal curve without requiring catheter exchanges. Dye injections and pressure measurements also may be made through the side leg 34 of the sheath if desired. Should i~ be desired to perform catheter ~, 15 exchanges tha~ is facilitated by the sheath which may be permitted to remain in the patient's blood vessel thereby to serve as a catheter introducer.
The system utilizes a full bore conventional angiographic catheter and thus permits full flow of radiopaque contrast liquid into the patient's blood vessels.
It should be understood that the foregoing description of the invention is intended to be illustrative and that other modifications and embodiments may be apparent to those skilled in the art without departing from its spirit and scope as set forth in the appended claims.
Having thus described the invention what I
desire to claim and secure by letters patent is:
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|International Classification||A61B1/00, A61M25/08, A61M25/00|
|Cooperative Classification||A61M25/09025, A61M25/0041|
|European Classification||A61B1/00, A61M25/00R2, A61M25/09B1|