CA1278487C - Variable stiffness angioplasty catheter - Google Patents
Variable stiffness angioplasty catheterInfo
- Publication number
- CA1278487C CA1278487C CA000508919A CA508919A CA1278487C CA 1278487 C CA1278487 C CA 1278487C CA 000508919 A CA000508919 A CA 000508919A CA 508919 A CA508919 A CA 508919A CA 1278487 C CA1278487 C CA 1278487C
- Authority
- CA
- Canada
- Prior art keywords
- catheter
- shaft
- balloon
- distal end
- waist portion
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
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Abstract
Abstract of the Disclosure An improved vascular catheter for angioplasty providing a variable stiffness lengthwise of the catheter. A relatively stiff shaft portion is provided for transmitting the necessary axial forces for advancing the catheter along a guide wire through a series of sharp bends to the arterial branch for dila-tation, and a more flexible waist portion connects from the shaft to the balloon and tip portion. This allows the tip and balloon portions to follow sharply bending turns in the guide wire without the shaft portion tending to push the tip beyond a branch or dislodge the guide wire. A set of such catheters may be provided for a surgical procedure, having varying lengths of the waist portion according to the circumstances of the case. If a sharp turn is encountered that cannot be tracked, the catheter can be withdrawn leaving the guide wire in place, and another catheter of the set having a longer waist portion can be inserted to suc-cessfully follow the turn.
Description
~27~
VARIA~LE STIFFNESS ANGIOPLASTY C~THETER
Field of the Invention This invention relates to vascular catheters for use in percutaneous transluminal angioplasty proce-dures. In particular, the invention is especiallyadapted to treatment of coronary arteries with cathe-ters introduced percutaneously remote from the heart and advanced along a guide wire to a coronary artery for dilating a stenosis therein.
Back round of the Prior Art 9 ~
Angioplasty has become an accepted and rapidly expanding method for the treatment of certain types of vascular disease. In percutaneous transluminal angio-plasty, a guide ~ire is introduced percutaneously into the patient's vascular system and advanced and steeredto the site of the stenosis. A dilatation catheter is then advanced over the guide wire until it is posi-tioned at the stenosis site so that it can be inflated to dilatate the artery and reestablish a more adequate blood flow path therethrough.
Such techni~ues are especially important in the treatment of coronary artery disease by per-cutaneous transluminal coronary angioplasty. In coro-nary applications, guide catheters, guide wires and angioplasty catheters have been specially developed formaneuvering through numerous arterial branches and into the particular coronary artery branch where treatment is desired. Because of the many branches which must be successfully negotiated and the convoluted, tortuous path which must be followed by th0 catheter, numerous specialized instruments have been developed for this purpose, with the result that an increasingly large number of cases can be successfully treated. However, ~27~
certain problems still can be encountered in the posi-tioning of the angioplasty catheter, especially in ~he final few tight branches and turns leading to a steno-sis site in a coronary artery. The problem can occur after a guide wire has successfully been advanced into position and while the dilatation catheter is being advanced over the guide wire. When encountering a sharp turn to branch to a smaller artery, it i5 possible that the distal end of the dilatation catheter may be too stiff to make the small radius turn. This can cause great difficulty in trying to manipulate and maneuver the catheter around the turn, and in extreme cases can result in the catheter actually advancing down the wrong branch and pulling the guide wire out of the intended branch.
Prior art catheters tend to have a relatively stiff shaft which transitions at the beginning of the balloon to a lower stiffness. This means that the flexible distal portion of a prior art catheter con-sists only of the relatively small tip and the balloon,with the stiffer shaft starting immediately adjacent the balloon. This may not provide sufficient flexibi-lity to permit the catheter to follow sharp bends, and may result in the stiff ~shaft pushing the balloon past the branch and even pulling the guide wire out of the branch.
An alternate construction in the prior art uses a central lumen defining tube, and an outer, rela-tively flexible tube which forms the shaft and which has the balloon formed integrally therewith at the end.
While this type of construction provides great flexibi-lity for following sharp bends, after a number of such ~" ~
~27~3~a7 ~ -3-bends have been encountered, the shaft is too soft to transmit sufficient axial force without buckling, and it becomes impossible to advance the catheter any farther.
Summary of the Invention To overcome these and other problems, the pre-sent invention provides a variable stiffness, or variable softness catheter, which has a tip area that is soft enough to follow sharp tortuous bends of a guide wire withou~ dislodging it, and which has a shaft portion which is stiff enough to provide the necessary axial force transmission so that the catheter can be advanced even after following a great number of bends.
This is accomplished in the present invention by pro-viding a catheter construction which has a shaft por-tion which is stiff enough to transmit axial forces needed to advance the catheter, a relatively flexible tip and balloon portion, and an intermediate portion, reerred to herein as a "waist" portion between the shaft and the balloon, which has less stiffness than the shaft and permits a greater degree of flexi~ility of the whole tip area for following sharp turns as the catheter is being advanced.
According to another aspect of the invention, a set of matched catheters is provided for use in an angioplasty procedure, with individual catheters of the set having different lengths of the less-stiff waist portion. This allows the physician to match the catheter to the particular procedure at hand, and if a sharp bend is encountered which the tip cannot follow without tending to "pull" the wire from the intended branch, as referred to above, then it is a simple matter to withdraw the catheter, leaving the guide wire in place, and reintroduce another catheter form the set with a longer waist, so that the sharp bend can be accomplished.
Other aspects of this invention are as follows:
A dilatation catheter for entry into the vascular system of the patient along a guide wire, comprising:
said catheter including an elongate flexible shaft having a distal end for entry into the vascular system and a proximal end for manipulation externally of the body and for attachment to instruments for use in a dilatation procedure;
said catheter having an inflatable balloon member at the distal end thereof;
said catheter having means defining a walst portion between said balloon portion and said shaft, said waist portion having a lower stif~ness than said shaft, the length o~ the waist portion between said balloon portion and said shaft being such that the tractability of said catheter through sharp bends is enhanced such that said catheter may follow sharp bends and the tendency to dislodge a guide catheter as it is advanced therealong is reduced;
means defining a fluid communication passage from the proximal end of said shaft to said balloon member so that inflation pressure can be applied thereto; and means de~ining a guide wire receiving opening extending throughout said catheter, so that the catheter can be advanced along a ~uide wire in the vascular system of the patient.
Vascular dilatation apparatus, comprising a plurality of dilatation catheters, each including an elongate flexible shaft having a distal end for entry into the vascular system of a patient and a proximal end for manipulation externally of the patient's body and for attachment for instruments for use in a dilatation ~2~4137 4a procedure, each catheter having an inflatable balloon member at the distal end thereof, each catheter having means defining a waist portion between its balloon portion and its shaft with said waist portion having a lower stiffness than said shaft, the length of the waist portion between said balloon portion and said shaf-t being such that the tractability of said catheter through sharp bends is enhanced such that said catheter may follow sharp bends and the tendency to dislodge a guide catheter as it is advanced therealong i~ reduced, each catheter including means defining a fluid communication passage from the proximal end of its shaft to its balloon member so that inflation pressure can be applied thereto, each catheter including means defining a guide wire-receiving opening extending throughout the catheter so that the catheter can be advanced along a guide wire in the vascular system of th~ patient, and said catheters having waist portions of different : lengths to provide dif~erent degrees of flexibility to accommodate varying sharpness of turns as a catheter is ~ advanced along a guide wire in the vascular system of : the patient.
A vascular dilatation catheter, comprisin~:
a first elongate tubular member defining a central lumen for receiving a guide wire;
an elongate tubular shaft member positioned substantially coaxially of said first tubular member and sixed to define an annular lumen between said first tubular member and the inside of said shaft member, the distal end of said first tubular member extending beyond the distal end of said shaft member;
a tubular balloon member positioned over said first tubular member adjacent the distal end thereof, means securing one end of said tubular balloon member to said first tubular member adjacent the distal end thereof and fastening the other end of said tubular balloon member to the distal end of said shaft member, said tubular ~27~
4b balloon member having an inflatable balloon portion formed in the distal end thereof and having a waist portion extending from the balloon portion of said shaft member; and said waist portion having a stiffness less than the stiffness of said tubular shaft member, to permit said catheter to follow sharp bends in a guide wire as it is advanced in the vascular system of a patient, the lenyth of the waist portion between said balloon portion and said shaft being such that the tractability of said catheter through sharp bends is enhanced such that said catheter may follow sharp bends and the tendency to dislodge a guide catheter as it is advanced therealong is reduced.
~ dilatation catheter for entry into the vascular system of a patient along a guide wire, comprising:
a tubular shaft having a distal end for entry into the vascular system and a proximal end for manipulation externally of the body and for attachment to pressure control and other instruments for use in a dilatation procedure;
an innsr tubular member positioned within said shaft member and extending therethrough and for a distance beyond tha distal end thereof, said tubular shaft member sized to define an annular lumen between its inner ~all and the outer wall of said inner tubular member:
a tubular balloon member positioned over the end of said inner tubular member which extends beyond said shaft member, said tubular balloon member having one end thereof secured to the distal end of said shaft member and the other end thereof secured to said inner tubular member adjacent the distal end thereof, said tubular balloon member having an inflatable balloon portion formed therein adjacent the distal end thereof and in fluid communication with said annular lumen so that it may be inflated by pressure applied thereto, and having 4c a waist portion between said balloon portion and said shaft member, said waist portion having less stiffness than the stiffness of said shaft, so that said catheter may ~ollow sharp bends without tending to dislodge a guide wire as it is advanced therealong, the length of the waist portion between said balloon portion and said shaft being such that the tractability of said catheter through sharp bends is enhanced such that said catheter may follow sharp bends and the tendency to dislodge a lo guide catheter as it is advanced therealong is reduced.
A coronary angioplasty dilatation catheter, comprising:
a) an elongated flexible shaft having a distal end for entry into the vascular system and a proximal end for manipulation externally of the body and for attachment to instruments for use in a dilatation procedure;
b) means ~or definin~ a guide wire receiving lumen, so that the catheter can be advanced along a guide wire in the vascular system of the patient, c) an inflatable balloon member disposed at the distal end of the shaft;
d) means for fluid communication between the proximal end of said shaft and said balloon so as to provide an inflation pressure: and e) means for definin~ a waist portion disposed between said balloon member and said shaft, said waist portion being disposed at the distal end of said shaft and being of reduced outer diameter and reduced wall thickness as compared to said shaft, the length of said waist portion between said balloon member and said shaft being such that the trackability of said catheter through sharp bends is enhanced such that said catheter may follow sharp bends without tending to dislodge a guide catheter as it is advanced therealong.
A coronary angioplasty dilatation catheter, comprising:
~2~34~t7 4d a) an elongated tubular shaft having a distal end for entry i~to the vascular system and a proximal end for manipulation externally o~ the body and for attachment to instruments for use in a dilatation procedure, b) an elongated tubular member defining a guide wire receivi.ng lumen, disposed axially within said shaft, 50 that the catheter can be advanced along a guide wire in the vascular system of the patient, the distal end of said tubular member extending beyond thP
distal end of said shaft;
c) an inflatable balloon member disposed at the distal end of the shaft, positioned substantially coaxially over said tubular member, sealably connected at the distal end to said tubular member, and sealahly connected at the proximal end to said shaft, d) means for fluid communication between the proximal end of said shaft and said balloon member so as to provide an inflation pressure; and e) means for defining a waist portion disposed between said balloon member and said shaft wherein said ; tubular member is of reduced outer diameter and red~ced wall thickness, the length of said waist portion between said balloon member and said shaft being such that the trackability of said cath~ter through sharp bends is snhanced such that said catheter may follow sharp bends without tending to dislodge a guide catheter as it is advanced therealong.
An angioplasty dilatation catheter, comprising:
an elongated flexible shaft having a distal end for entry into the vascular system and a proximal end ~or manipulation externally of the body and for attachment to instruments for use in a dilatation procedure;
an elongated tubular member defining a guide wire receiving lumen, disposed axially within said shaft, so that the catheter can be advanced along a guide wire in the vascular system of the patient;
`` ~.;2'7~348~
4e an inflatable balloon member disposed at the distal end of the shaft, positioned substantially coaxially over sa.id tubular member, sealably connected at the distal end to said tubular member;
means for fluid communication between the proximal end of the shaft and said balloon member; and means for defining a waist portion formed integrally with said balloon member and disposed at the distal end of said shaft between said shaft and said balloon member, said waist portion being of reduced outer diameter and reduced wall thickness as compared to said shaft, the length of said waist portion between said balloon member and said shaft being such that the trackability of said catheter through sharp bends is enhanced such that said catheter may follow sharp bends without tending to dislodge a guide catheter as it is advanc~d therealong.
Brief DesCriPtiOn o~ the Drawinqs In the drawings, Figure 1 is a sectional view of a catheter and hub assembly in accordance with one embodiment of the invention;
Figure 2A is an enlarged sectional view of the tip portion of a catheter according to the present invention;
Figure 2B is a view similar to Figure 2A but showing a catheter having a different length of the waist portion;
Figure 3A is a diagrammatic view illustrating the problem encountexed in the prior art of attempting to maneuver a stiff catheter into a sharp turn to a branch of an artery;
Figure 3B is a diagra~matic view similar to Figure 3A illustrating th~ operation of a catheter of the present invention in accomplishing the sharp turn;
~27~341~7 4f Figures 4A and 4B are enlarged sectional views of the tip portions of short and long waist catheters according to an alternative embodiment of the invention:
Figures 5~ and 5B are enlarged sectional views of shork and long waist catheters according to another embodiment of the invention; and Figures 6A and 6B are enlarged sectional views showing shQrt and long waist catheters according to a further embodiment of the invenkion.
~2~71!~
Detailed Description of the Preferred Embodiments A preferred embodiment of the present inven-~ion is shown generally in Figure 1, and the tip por-tion thereo is shown in greater detail in enlargedsectional views 2A and 2B which are substantially iden-tical except for a diEference in the length of the intermediate or waist portion.
The catheter generally has a tip area 10, an inflatable balloon area 12~ an intermediate or waist portion 14, and a shaft portion 16 which extends all the way up to the proximal end of the catheter and includes an appropriate fitting or hub assembly 18 for connection to the apparatus for applying dilatation ; 15 pressure, and for administering medication and sensing arterial pressure as is generally known in the art.
In construction of the catheter, a hollow inner tube 21 is provided which runs the entire length of the catheter, and which defines the central lumen 22. Inner tube 21 may be made of any number of materials, and in the preferred embodiment is made of a blend of high and low density polyethylene in order to give desired mechanical properties. Central lumen 22 receives the guide wire ~not shown) in use so that the catheter can be advanced over the guide wire to the site of the stenosis.
The shaft portion 1~ comprises a hollow outer tube 25 o sufficient inside diameter to receive inner tube 21 and to define an annular lumen 26 between the inside diameter of tube 25 and the outside diameter of tube 21. ~his annular lumen is used for transmitting pressure from pressure control apparatus outside the ~73~
patient to the dilatation balloon. Outer tube 25 can be made from any suitable material, for example a blend o high and low density polyethylene selected to give desired mechanical properties. Tube 25 should be stiff enough mechanically to provide axial pushing forces so that the catheter can be advanced over the guide wire without buckling, yet flexible enough to follow the typical multiple-turn tortuous path from the site of introduction in the body to the arterial branch where the dilatation will take place. ~owever, so~ne of the needed flexibility is provided in the tip, balloon and waist as described below. At its distal end 27 outer tube 25 is necked down slightly so as to receive tubing section 30, which fits ouer the necked down portion and is secured thereto by any suitable method, for example adhesive bonding, heat fusion or shrink fitting. In this manner the joint is made without a bump or protu-sion on the outside of the catheter which would inter-fere with movement of the catheter through arterial branches.
Tubing section 30 is used to form the waist portion 14 and the balloon portion 12. Section 30 is made in the preferred embodiment of polyoleEin copo-lymer formed in a tube section of sufficient diameter to substantially match outer tube 25 and be positioned over inner tube 21, while still keeping annular lumen 26 open. The balloon section 12 and the waist section 14 are formed integrally of the same tubing section 30, but the dilatation balloon 12 is expanded as is gener-ally known to provide the inflatable balloon area fordilatation. This balloon can be formed in any of several ~ays as is generally known, for example by blow ~2~
molding, or blowing while applying heat.
The distal end 32 of tubing section 30, beyond balloon 12, necks down -to substantially the diameter of inner tube 21 and is secured thereto for example by adhesive bonding, heat fusion or heat shrinking. A
section of inner tube 21 extends beyond distal end 32 to form the flexible tip portion. A pair of radiopa~ue markers 34 are bonded onto inner tube 21 at the ends o~
balloon section 12 for use in fluoroscopic obserYation of balloon position.
The catheters of Figures 2A and 2B are substantially ide~tical, except that the waist portion 14' of Figure 2B is intentionally made longer than the waist portion 14 of ~igure 2A. In practice a number of models of the catheter can be made having a number of steps or gradations of length of the waist 14 for dif-ferent applications.
It will be appreciated that the catheter pro-vided by the present invention provides a variable stiffness or softness along the length of the catheter.
The tip 10 may be the softest, as it consists essen-tially of only the inner tube, and balloon section 12 may also be relatively soft. On the other hand, shaft section 16 will be relatively stiff since it includes outer tube 25. The waist portion 14 will be less stiff than shaft portion 16, since outer tube 25 does not extend into the waist portion 14, and tubing section 30 is less stiff than outer tube 25.
Thus, the entire distal end, which includes tip 10, balloon 12 and waist 14, is soft and flexible enough to follow sharp bends in a guide wire r while the shaft 16 provides sufficient mechanical stiffness to ~ 2~
transmit axial pushing forces without buckling. The waist 14 provides added length to keep the stiff part oE shaft 16 away from the zone in which the distal portion is attempting to follow a sharply-turning guide wire, so that pushing on the shaft 16 will not cause dislodging of the guide wire as in the prior art.
The problem existing in the prior art is illustrated in Figure 3A, which diagrammatically shows a catheter which consists of a shaft portion 40 and a balloon portion 41 being advanced over a guide wire 23 which is previously positioned in an arterial branch 31 of an artery 30. Due to the sharp bend of the guide wire from artery 30 to branch 31, and due to stiffness of shaft 40 which extends up to the softer tip 41, the catheter is unable to make the sharp turn and further axial pushing on the catheter will push the tip thereof down straight branch 32, and may actually pull guide wire 23 from out of branch 31 which of course causes great difficulty.
The similar maneuver is shown diagrammatically in Figure 3B, but this time using a catheter according to the present invention, which has a relatively stiff shaft 16, and a less stiff waist portion 14 between the shaft 16 and the balloon portion 12. Because of the more flexible waist portion the distal end including tip 10, balloon 12 and waist 14 is able to make the sharp bend and follow guide wire 23 in branch 31. By the time that the stiffer shaft portion 16 reaches the branch, the balloon and waist portion will already be well into the branch, so the shaft will be likely to follow without dislodging the catheter or guide wire.
Alternatively, if the turn to branch 31 is extremely . .
. .
~27~
~ g sharp, and depending on the location of the stenosis at which the balloon 12 must be positioned, the catheter may be withdrawn while leaving guide wire 23 in place, while another catheter according to the present inven-tion with an even longer waist 14 can be inserted, toprovide a longer flexible portion or possibly to reach the stenosis without shaft 16 having to make the sharp bend.
Alternate ~ethods of construction for cathe-ters according to the present invention are show~ inFigures 4a and 4b, 5a and 5b, and 6a and 6b. In each case, the catheters have tip portions 10, balloon por-tions 12, a waist or intermediate portion 14 or 14', and a shaft portion 16. lt will be understood that in each case the catheter shaft would extend or connec-tion to a hub assembly or fitting 18 as suggested inFigure 1 and as generally known in the art for use in applying the dilatation pressure, administering medica-tion, and sensing arterial pressure.
In the embodiment o~ Figures 4A and 4B the balloon section 12 is formed integrally with the waist portion 14 and the outer tubular member of the shaft 16, with the thickness thereof being stepped or decreased in the waist and balloon area to provide greater flexibility. The catheters of Figures 4A and 4B each include a hollow inner tubular member 51 which defines central lumen 52 which extends through the catheter for receiving the guide wire as the catheter is being advanced. At its distal end, inner tube 51 Eorms the tip portion 10. Radiopaque markers 34 are bonded to tube 51 in the balloon area 12 as is generally known. The shaft portion 16 comprises a ~2~134~
~10-hollow outer tube 55 which has a large enough inside diameter to receive inner tube 51 and to define an annular lumen 56 between the inside wal:L of tube 55 and the outside wall of tube 51. As in the case of the previous embodiment, the annular lumen is used for supplying dilatation pressure to the balloon. The material and wall thickness for tube 55 is chosen to give sufficient axial mechanical rigidity as described previously, so as to withstand and transmit axia~
pushing forces while the catheter is being advanced through the arteries.
In the balloon and waist portions are formed integr~lly ~ith tube 55, by stepping or necking down the wall thickness of tube 55 at the zone indicated by reference number S7, which in effect defines the end of the shaft portion 16 and the beginning of the waist portion 14. The balloon portion 12 is formed in the thin walled distal end of tube 55 by known techniques previously described, and the end thereof is bondecl to the inner tube to seal off the balloon. Since waist portion 14 has a thinner sectioned wall than the main portion of tube 55 which defines shaft 16, it will have less stif~ness and greater flexibility to permit it to follow turns as the catheter is advanced.
E'igure 4B is similar, except that the length of waist portion 14' is longer to provide even greater ~lexibility for following sharply turning branches, as described above. In practice, a set of catheters can be provided as in Figures 4A and 4B but with a number of different lengths of waist portion 14 or 14' to Eit the requirements of a particular application.
The embodim~nts of Figures 5A and 5B also use a balloon portion 14 for~ed integrally with the tubing which forms the outer walls of the shaft portion 16.
However, in this case the variable stiffness of the waist portion 14, 14' is provided by varying the wall thickness and stiffness of the inner tube of the catheter. Specifically, the catheters of Figures 5A
and 5B each have an inner tube 61 which changes wall thickness at zone 62, which in effect marks the tran-sition between the relatively stiff shaft portio~ 16 of the catheter and the more flexible waist portion 14, 14' of the catheter. The thinner walled portion of inner tube 61 extends through the balloon portion 12 and ~orms the tip portion 10, and has radiopaque markers 34 as in the previous embodiments. Inner tube 61 includes central lumen 63 which receives the guide wire (not shown). Outer hollow tube 64 has an inside diameter large enough to fit over inner tube 61 and define annular lumen 65 therebetween which is used for inflating the dilatation balloon. The balloon portion 12 is formed integrally with outer tubing 64 by tech-niques previously discussed.
The length of the waist portion 14 between the transition zone 62 where the thickness of the inner tube 61 is reduced and the beginning of the balloon portion can be varied in length as suggested in the Figures, and a large number of different lengths can once again be provided for the physician to meet the needs of a particular procedure. Since the wall thickness of the inner tube 61 in the waist portion 14 is reduced, the overall stiffness of the waist portion is reduced as compared with shaft portion 16, in accor-dance with the invention.
~\
~Z~1~4~7 The catheters of Figures 6A and 6B make use of double lumen tubing for the shaft portion 16. Double lumen tubing is generally known and is used in some types of catheter construction. As seen in the sec-tional views the tubing includes an outer wall 71 and acentral partition 72, thus defining two separate lumens 73 and 74, which are within wall 71 and separated by partition 72, and hoth of which extend axially through the catheter from a hub assembly (not shown) at the proxi~al end, to a distal end which includes the dila-tation balloon. Lumen 73 is sized to receive the guide wire as the catheter is advanced. Lumen 74 is used for applyin~ dilating pressure to the balloon. The choice of material and wall thickness ~or double lumen tube 71 is selected to give sufficient stiffness to transmit axial forces to advance the catheter, as previously described. At zone 75 tubing 71 is necked down somewhat so that a tube member 80 can fit over it while maintaining the approximate same outside profile to the catheter. Tubing 80 forms both the waist portion 14 and the balloon portion 12. The balloon portion 12 is ~ormed using one of the techniques previously described.
The portion of tubing 71 above partition 72 is cut away under the waist portion 14 adjacent necked down portion 75, so that lumen 74 communicates to the interior of the balloon portion 12 for applying infla-tion pressure thereto. The end of tube 80 is adhesive-ly or otherwise bonded to tubing 71 adjacent the necked down transition portion, and the distal portion of tube %0, which is the distal portion of the balloon portion, is adhesively or otherwise secured to tip lO, which is ~713D~L8~7 formed by partition 72 and the portion of tube 71 which was not cut away.
Since the waist portion 14 does not include the portion of tube 71 associated with inflation lumen 74, since this has been cut away, waist portion 14 will have less stiffness and greater 1exibility than shaft portion 16. In Figure 6B, the same technique of construction is used, but the waist portion 14' between balloon portion 12 and shaft portion 16 is longerO In accordance with the invention, a set or range of cathe-ters can be provided with different incremental lengths of waist portion 14 or 14' to provide the degree of flexibility required for given applications.
Thus, the present inv~ntion provides an improved angioplasty dilatation catheter having a variable stiEfness lengthwise of the catheter, and spe-cifically providing a waist or intermediate portion behind the inflatable portion that provides maneuverlng flexibility to allow the distal end to follow sharp bends in the guide wire. At the same time, the rela-tiYely stier shaft provides sufficient mechanical rigidity for transmitting axial force to advance the catheter, but is separated from the soft balloon por-tion a sufficient distance that it does not tend to push the balloon beyond sharp branches or dislodge the guide wire.
VARIA~LE STIFFNESS ANGIOPLASTY C~THETER
Field of the Invention This invention relates to vascular catheters for use in percutaneous transluminal angioplasty proce-dures. In particular, the invention is especiallyadapted to treatment of coronary arteries with cathe-ters introduced percutaneously remote from the heart and advanced along a guide wire to a coronary artery for dilating a stenosis therein.
Back round of the Prior Art 9 ~
Angioplasty has become an accepted and rapidly expanding method for the treatment of certain types of vascular disease. In percutaneous transluminal angio-plasty, a guide ~ire is introduced percutaneously into the patient's vascular system and advanced and steeredto the site of the stenosis. A dilatation catheter is then advanced over the guide wire until it is posi-tioned at the stenosis site so that it can be inflated to dilatate the artery and reestablish a more adequate blood flow path therethrough.
Such techni~ues are especially important in the treatment of coronary artery disease by per-cutaneous transluminal coronary angioplasty. In coro-nary applications, guide catheters, guide wires and angioplasty catheters have been specially developed formaneuvering through numerous arterial branches and into the particular coronary artery branch where treatment is desired. Because of the many branches which must be successfully negotiated and the convoluted, tortuous path which must be followed by th0 catheter, numerous specialized instruments have been developed for this purpose, with the result that an increasingly large number of cases can be successfully treated. However, ~27~
certain problems still can be encountered in the posi-tioning of the angioplasty catheter, especially in ~he final few tight branches and turns leading to a steno-sis site in a coronary artery. The problem can occur after a guide wire has successfully been advanced into position and while the dilatation catheter is being advanced over the guide wire. When encountering a sharp turn to branch to a smaller artery, it i5 possible that the distal end of the dilatation catheter may be too stiff to make the small radius turn. This can cause great difficulty in trying to manipulate and maneuver the catheter around the turn, and in extreme cases can result in the catheter actually advancing down the wrong branch and pulling the guide wire out of the intended branch.
Prior art catheters tend to have a relatively stiff shaft which transitions at the beginning of the balloon to a lower stiffness. This means that the flexible distal portion of a prior art catheter con-sists only of the relatively small tip and the balloon,with the stiffer shaft starting immediately adjacent the balloon. This may not provide sufficient flexibi-lity to permit the catheter to follow sharp bends, and may result in the stiff ~shaft pushing the balloon past the branch and even pulling the guide wire out of the branch.
An alternate construction in the prior art uses a central lumen defining tube, and an outer, rela-tively flexible tube which forms the shaft and which has the balloon formed integrally therewith at the end.
While this type of construction provides great flexibi-lity for following sharp bends, after a number of such ~" ~
~27~3~a7 ~ -3-bends have been encountered, the shaft is too soft to transmit sufficient axial force without buckling, and it becomes impossible to advance the catheter any farther.
Summary of the Invention To overcome these and other problems, the pre-sent invention provides a variable stiffness, or variable softness catheter, which has a tip area that is soft enough to follow sharp tortuous bends of a guide wire withou~ dislodging it, and which has a shaft portion which is stiff enough to provide the necessary axial force transmission so that the catheter can be advanced even after following a great number of bends.
This is accomplished in the present invention by pro-viding a catheter construction which has a shaft por-tion which is stiff enough to transmit axial forces needed to advance the catheter, a relatively flexible tip and balloon portion, and an intermediate portion, reerred to herein as a "waist" portion between the shaft and the balloon, which has less stiffness than the shaft and permits a greater degree of flexi~ility of the whole tip area for following sharp turns as the catheter is being advanced.
According to another aspect of the invention, a set of matched catheters is provided for use in an angioplasty procedure, with individual catheters of the set having different lengths of the less-stiff waist portion. This allows the physician to match the catheter to the particular procedure at hand, and if a sharp bend is encountered which the tip cannot follow without tending to "pull" the wire from the intended branch, as referred to above, then it is a simple matter to withdraw the catheter, leaving the guide wire in place, and reintroduce another catheter form the set with a longer waist, so that the sharp bend can be accomplished.
Other aspects of this invention are as follows:
A dilatation catheter for entry into the vascular system of the patient along a guide wire, comprising:
said catheter including an elongate flexible shaft having a distal end for entry into the vascular system and a proximal end for manipulation externally of the body and for attachment to instruments for use in a dilatation procedure;
said catheter having an inflatable balloon member at the distal end thereof;
said catheter having means defining a walst portion between said balloon portion and said shaft, said waist portion having a lower stif~ness than said shaft, the length o~ the waist portion between said balloon portion and said shaft being such that the tractability of said catheter through sharp bends is enhanced such that said catheter may follow sharp bends and the tendency to dislodge a guide catheter as it is advanced therealong is reduced;
means defining a fluid communication passage from the proximal end of said shaft to said balloon member so that inflation pressure can be applied thereto; and means de~ining a guide wire receiving opening extending throughout said catheter, so that the catheter can be advanced along a ~uide wire in the vascular system of the patient.
Vascular dilatation apparatus, comprising a plurality of dilatation catheters, each including an elongate flexible shaft having a distal end for entry into the vascular system of a patient and a proximal end for manipulation externally of the patient's body and for attachment for instruments for use in a dilatation ~2~4137 4a procedure, each catheter having an inflatable balloon member at the distal end thereof, each catheter having means defining a waist portion between its balloon portion and its shaft with said waist portion having a lower stiffness than said shaft, the length of the waist portion between said balloon portion and said shaf-t being such that the tractability of said catheter through sharp bends is enhanced such that said catheter may follow sharp bends and the tendency to dislodge a guide catheter as it is advanced therealong i~ reduced, each catheter including means defining a fluid communication passage from the proximal end of its shaft to its balloon member so that inflation pressure can be applied thereto, each catheter including means defining a guide wire-receiving opening extending throughout the catheter so that the catheter can be advanced along a guide wire in the vascular system of th~ patient, and said catheters having waist portions of different : lengths to provide dif~erent degrees of flexibility to accommodate varying sharpness of turns as a catheter is ~ advanced along a guide wire in the vascular system of : the patient.
A vascular dilatation catheter, comprisin~:
a first elongate tubular member defining a central lumen for receiving a guide wire;
an elongate tubular shaft member positioned substantially coaxially of said first tubular member and sixed to define an annular lumen between said first tubular member and the inside of said shaft member, the distal end of said first tubular member extending beyond the distal end of said shaft member;
a tubular balloon member positioned over said first tubular member adjacent the distal end thereof, means securing one end of said tubular balloon member to said first tubular member adjacent the distal end thereof and fastening the other end of said tubular balloon member to the distal end of said shaft member, said tubular ~27~
4b balloon member having an inflatable balloon portion formed in the distal end thereof and having a waist portion extending from the balloon portion of said shaft member; and said waist portion having a stiffness less than the stiffness of said tubular shaft member, to permit said catheter to follow sharp bends in a guide wire as it is advanced in the vascular system of a patient, the lenyth of the waist portion between said balloon portion and said shaft being such that the tractability of said catheter through sharp bends is enhanced such that said catheter may follow sharp bends and the tendency to dislodge a guide catheter as it is advanced therealong is reduced.
~ dilatation catheter for entry into the vascular system of a patient along a guide wire, comprising:
a tubular shaft having a distal end for entry into the vascular system and a proximal end for manipulation externally of the body and for attachment to pressure control and other instruments for use in a dilatation procedure;
an innsr tubular member positioned within said shaft member and extending therethrough and for a distance beyond tha distal end thereof, said tubular shaft member sized to define an annular lumen between its inner ~all and the outer wall of said inner tubular member:
a tubular balloon member positioned over the end of said inner tubular member which extends beyond said shaft member, said tubular balloon member having one end thereof secured to the distal end of said shaft member and the other end thereof secured to said inner tubular member adjacent the distal end thereof, said tubular balloon member having an inflatable balloon portion formed therein adjacent the distal end thereof and in fluid communication with said annular lumen so that it may be inflated by pressure applied thereto, and having 4c a waist portion between said balloon portion and said shaft member, said waist portion having less stiffness than the stiffness of said shaft, so that said catheter may ~ollow sharp bends without tending to dislodge a guide wire as it is advanced therealong, the length of the waist portion between said balloon portion and said shaft being such that the tractability of said catheter through sharp bends is enhanced such that said catheter may follow sharp bends and the tendency to dislodge a lo guide catheter as it is advanced therealong is reduced.
A coronary angioplasty dilatation catheter, comprising:
a) an elongated flexible shaft having a distal end for entry into the vascular system and a proximal end for manipulation externally of the body and for attachment to instruments for use in a dilatation procedure;
b) means ~or definin~ a guide wire receiving lumen, so that the catheter can be advanced along a guide wire in the vascular system of the patient, c) an inflatable balloon member disposed at the distal end of the shaft;
d) means for fluid communication between the proximal end of said shaft and said balloon so as to provide an inflation pressure: and e) means for definin~ a waist portion disposed between said balloon member and said shaft, said waist portion being disposed at the distal end of said shaft and being of reduced outer diameter and reduced wall thickness as compared to said shaft, the length of said waist portion between said balloon member and said shaft being such that the trackability of said catheter through sharp bends is enhanced such that said catheter may follow sharp bends without tending to dislodge a guide catheter as it is advanced therealong.
A coronary angioplasty dilatation catheter, comprising:
~2~34~t7 4d a) an elongated tubular shaft having a distal end for entry i~to the vascular system and a proximal end for manipulation externally o~ the body and for attachment to instruments for use in a dilatation procedure, b) an elongated tubular member defining a guide wire receivi.ng lumen, disposed axially within said shaft, 50 that the catheter can be advanced along a guide wire in the vascular system of the patient, the distal end of said tubular member extending beyond thP
distal end of said shaft;
c) an inflatable balloon member disposed at the distal end of the shaft, positioned substantially coaxially over said tubular member, sealably connected at the distal end to said tubular member, and sealahly connected at the proximal end to said shaft, d) means for fluid communication between the proximal end of said shaft and said balloon member so as to provide an inflation pressure; and e) means for defining a waist portion disposed between said balloon member and said shaft wherein said ; tubular member is of reduced outer diameter and red~ced wall thickness, the length of said waist portion between said balloon member and said shaft being such that the trackability of said cath~ter through sharp bends is snhanced such that said catheter may follow sharp bends without tending to dislodge a guide catheter as it is advanced therealong.
An angioplasty dilatation catheter, comprising:
an elongated flexible shaft having a distal end for entry into the vascular system and a proximal end ~or manipulation externally of the body and for attachment to instruments for use in a dilatation procedure;
an elongated tubular member defining a guide wire receiving lumen, disposed axially within said shaft, so that the catheter can be advanced along a guide wire in the vascular system of the patient;
`` ~.;2'7~348~
4e an inflatable balloon member disposed at the distal end of the shaft, positioned substantially coaxially over sa.id tubular member, sealably connected at the distal end to said tubular member;
means for fluid communication between the proximal end of the shaft and said balloon member; and means for defining a waist portion formed integrally with said balloon member and disposed at the distal end of said shaft between said shaft and said balloon member, said waist portion being of reduced outer diameter and reduced wall thickness as compared to said shaft, the length of said waist portion between said balloon member and said shaft being such that the trackability of said catheter through sharp bends is enhanced such that said catheter may follow sharp bends without tending to dislodge a guide catheter as it is advanc~d therealong.
Brief DesCriPtiOn o~ the Drawinqs In the drawings, Figure 1 is a sectional view of a catheter and hub assembly in accordance with one embodiment of the invention;
Figure 2A is an enlarged sectional view of the tip portion of a catheter according to the present invention;
Figure 2B is a view similar to Figure 2A but showing a catheter having a different length of the waist portion;
Figure 3A is a diagrammatic view illustrating the problem encountexed in the prior art of attempting to maneuver a stiff catheter into a sharp turn to a branch of an artery;
Figure 3B is a diagra~matic view similar to Figure 3A illustrating th~ operation of a catheter of the present invention in accomplishing the sharp turn;
~27~341~7 4f Figures 4A and 4B are enlarged sectional views of the tip portions of short and long waist catheters according to an alternative embodiment of the invention:
Figures 5~ and 5B are enlarged sectional views of shork and long waist catheters according to another embodiment of the invention; and Figures 6A and 6B are enlarged sectional views showing shQrt and long waist catheters according to a further embodiment of the invenkion.
~2~71!~
Detailed Description of the Preferred Embodiments A preferred embodiment of the present inven-~ion is shown generally in Figure 1, and the tip por-tion thereo is shown in greater detail in enlargedsectional views 2A and 2B which are substantially iden-tical except for a diEference in the length of the intermediate or waist portion.
The catheter generally has a tip area 10, an inflatable balloon area 12~ an intermediate or waist portion 14, and a shaft portion 16 which extends all the way up to the proximal end of the catheter and includes an appropriate fitting or hub assembly 18 for connection to the apparatus for applying dilatation ; 15 pressure, and for administering medication and sensing arterial pressure as is generally known in the art.
In construction of the catheter, a hollow inner tube 21 is provided which runs the entire length of the catheter, and which defines the central lumen 22. Inner tube 21 may be made of any number of materials, and in the preferred embodiment is made of a blend of high and low density polyethylene in order to give desired mechanical properties. Central lumen 22 receives the guide wire ~not shown) in use so that the catheter can be advanced over the guide wire to the site of the stenosis.
The shaft portion 1~ comprises a hollow outer tube 25 o sufficient inside diameter to receive inner tube 21 and to define an annular lumen 26 between the inside diameter of tube 25 and the outside diameter of tube 21. ~his annular lumen is used for transmitting pressure from pressure control apparatus outside the ~73~
patient to the dilatation balloon. Outer tube 25 can be made from any suitable material, for example a blend o high and low density polyethylene selected to give desired mechanical properties. Tube 25 should be stiff enough mechanically to provide axial pushing forces so that the catheter can be advanced over the guide wire without buckling, yet flexible enough to follow the typical multiple-turn tortuous path from the site of introduction in the body to the arterial branch where the dilatation will take place. ~owever, so~ne of the needed flexibility is provided in the tip, balloon and waist as described below. At its distal end 27 outer tube 25 is necked down slightly so as to receive tubing section 30, which fits ouer the necked down portion and is secured thereto by any suitable method, for example adhesive bonding, heat fusion or shrink fitting. In this manner the joint is made without a bump or protu-sion on the outside of the catheter which would inter-fere with movement of the catheter through arterial branches.
Tubing section 30 is used to form the waist portion 14 and the balloon portion 12. Section 30 is made in the preferred embodiment of polyoleEin copo-lymer formed in a tube section of sufficient diameter to substantially match outer tube 25 and be positioned over inner tube 21, while still keeping annular lumen 26 open. The balloon section 12 and the waist section 14 are formed integrally of the same tubing section 30, but the dilatation balloon 12 is expanded as is gener-ally known to provide the inflatable balloon area fordilatation. This balloon can be formed in any of several ~ays as is generally known, for example by blow ~2~
molding, or blowing while applying heat.
The distal end 32 of tubing section 30, beyond balloon 12, necks down -to substantially the diameter of inner tube 21 and is secured thereto for example by adhesive bonding, heat fusion or heat shrinking. A
section of inner tube 21 extends beyond distal end 32 to form the flexible tip portion. A pair of radiopa~ue markers 34 are bonded onto inner tube 21 at the ends o~
balloon section 12 for use in fluoroscopic obserYation of balloon position.
The catheters of Figures 2A and 2B are substantially ide~tical, except that the waist portion 14' of Figure 2B is intentionally made longer than the waist portion 14 of ~igure 2A. In practice a number of models of the catheter can be made having a number of steps or gradations of length of the waist 14 for dif-ferent applications.
It will be appreciated that the catheter pro-vided by the present invention provides a variable stiffness or softness along the length of the catheter.
The tip 10 may be the softest, as it consists essen-tially of only the inner tube, and balloon section 12 may also be relatively soft. On the other hand, shaft section 16 will be relatively stiff since it includes outer tube 25. The waist portion 14 will be less stiff than shaft portion 16, since outer tube 25 does not extend into the waist portion 14, and tubing section 30 is less stiff than outer tube 25.
Thus, the entire distal end, which includes tip 10, balloon 12 and waist 14, is soft and flexible enough to follow sharp bends in a guide wire r while the shaft 16 provides sufficient mechanical stiffness to ~ 2~
transmit axial pushing forces without buckling. The waist 14 provides added length to keep the stiff part oE shaft 16 away from the zone in which the distal portion is attempting to follow a sharply-turning guide wire, so that pushing on the shaft 16 will not cause dislodging of the guide wire as in the prior art.
The problem existing in the prior art is illustrated in Figure 3A, which diagrammatically shows a catheter which consists of a shaft portion 40 and a balloon portion 41 being advanced over a guide wire 23 which is previously positioned in an arterial branch 31 of an artery 30. Due to the sharp bend of the guide wire from artery 30 to branch 31, and due to stiffness of shaft 40 which extends up to the softer tip 41, the catheter is unable to make the sharp turn and further axial pushing on the catheter will push the tip thereof down straight branch 32, and may actually pull guide wire 23 from out of branch 31 which of course causes great difficulty.
The similar maneuver is shown diagrammatically in Figure 3B, but this time using a catheter according to the present invention, which has a relatively stiff shaft 16, and a less stiff waist portion 14 between the shaft 16 and the balloon portion 12. Because of the more flexible waist portion the distal end including tip 10, balloon 12 and waist 14 is able to make the sharp bend and follow guide wire 23 in branch 31. By the time that the stiffer shaft portion 16 reaches the branch, the balloon and waist portion will already be well into the branch, so the shaft will be likely to follow without dislodging the catheter or guide wire.
Alternatively, if the turn to branch 31 is extremely . .
. .
~27~
~ g sharp, and depending on the location of the stenosis at which the balloon 12 must be positioned, the catheter may be withdrawn while leaving guide wire 23 in place, while another catheter according to the present inven-tion with an even longer waist 14 can be inserted, toprovide a longer flexible portion or possibly to reach the stenosis without shaft 16 having to make the sharp bend.
Alternate ~ethods of construction for cathe-ters according to the present invention are show~ inFigures 4a and 4b, 5a and 5b, and 6a and 6b. In each case, the catheters have tip portions 10, balloon por-tions 12, a waist or intermediate portion 14 or 14', and a shaft portion 16. lt will be understood that in each case the catheter shaft would extend or connec-tion to a hub assembly or fitting 18 as suggested inFigure 1 and as generally known in the art for use in applying the dilatation pressure, administering medica-tion, and sensing arterial pressure.
In the embodiment o~ Figures 4A and 4B the balloon section 12 is formed integrally with the waist portion 14 and the outer tubular member of the shaft 16, with the thickness thereof being stepped or decreased in the waist and balloon area to provide greater flexibility. The catheters of Figures 4A and 4B each include a hollow inner tubular member 51 which defines central lumen 52 which extends through the catheter for receiving the guide wire as the catheter is being advanced. At its distal end, inner tube 51 Eorms the tip portion 10. Radiopaque markers 34 are bonded to tube 51 in the balloon area 12 as is generally known. The shaft portion 16 comprises a ~2~134~
~10-hollow outer tube 55 which has a large enough inside diameter to receive inner tube 51 and to define an annular lumen 56 between the inside wal:L of tube 55 and the outside wall of tube 51. As in the case of the previous embodiment, the annular lumen is used for supplying dilatation pressure to the balloon. The material and wall thickness for tube 55 is chosen to give sufficient axial mechanical rigidity as described previously, so as to withstand and transmit axia~
pushing forces while the catheter is being advanced through the arteries.
In the balloon and waist portions are formed integr~lly ~ith tube 55, by stepping or necking down the wall thickness of tube 55 at the zone indicated by reference number S7, which in effect defines the end of the shaft portion 16 and the beginning of the waist portion 14. The balloon portion 12 is formed in the thin walled distal end of tube 55 by known techniques previously described, and the end thereof is bondecl to the inner tube to seal off the balloon. Since waist portion 14 has a thinner sectioned wall than the main portion of tube 55 which defines shaft 16, it will have less stif~ness and greater flexibility to permit it to follow turns as the catheter is advanced.
E'igure 4B is similar, except that the length of waist portion 14' is longer to provide even greater ~lexibility for following sharply turning branches, as described above. In practice, a set of catheters can be provided as in Figures 4A and 4B but with a number of different lengths of waist portion 14 or 14' to Eit the requirements of a particular application.
The embodim~nts of Figures 5A and 5B also use a balloon portion 14 for~ed integrally with the tubing which forms the outer walls of the shaft portion 16.
However, in this case the variable stiffness of the waist portion 14, 14' is provided by varying the wall thickness and stiffness of the inner tube of the catheter. Specifically, the catheters of Figures 5A
and 5B each have an inner tube 61 which changes wall thickness at zone 62, which in effect marks the tran-sition between the relatively stiff shaft portio~ 16 of the catheter and the more flexible waist portion 14, 14' of the catheter. The thinner walled portion of inner tube 61 extends through the balloon portion 12 and ~orms the tip portion 10, and has radiopaque markers 34 as in the previous embodiments. Inner tube 61 includes central lumen 63 which receives the guide wire (not shown). Outer hollow tube 64 has an inside diameter large enough to fit over inner tube 61 and define annular lumen 65 therebetween which is used for inflating the dilatation balloon. The balloon portion 12 is formed integrally with outer tubing 64 by tech-niques previously discussed.
The length of the waist portion 14 between the transition zone 62 where the thickness of the inner tube 61 is reduced and the beginning of the balloon portion can be varied in length as suggested in the Figures, and a large number of different lengths can once again be provided for the physician to meet the needs of a particular procedure. Since the wall thickness of the inner tube 61 in the waist portion 14 is reduced, the overall stiffness of the waist portion is reduced as compared with shaft portion 16, in accor-dance with the invention.
~\
~Z~1~4~7 The catheters of Figures 6A and 6B make use of double lumen tubing for the shaft portion 16. Double lumen tubing is generally known and is used in some types of catheter construction. As seen in the sec-tional views the tubing includes an outer wall 71 and acentral partition 72, thus defining two separate lumens 73 and 74, which are within wall 71 and separated by partition 72, and hoth of which extend axially through the catheter from a hub assembly (not shown) at the proxi~al end, to a distal end which includes the dila-tation balloon. Lumen 73 is sized to receive the guide wire as the catheter is advanced. Lumen 74 is used for applyin~ dilating pressure to the balloon. The choice of material and wall thickness ~or double lumen tube 71 is selected to give sufficient stiffness to transmit axial forces to advance the catheter, as previously described. At zone 75 tubing 71 is necked down somewhat so that a tube member 80 can fit over it while maintaining the approximate same outside profile to the catheter. Tubing 80 forms both the waist portion 14 and the balloon portion 12. The balloon portion 12 is ~ormed using one of the techniques previously described.
The portion of tubing 71 above partition 72 is cut away under the waist portion 14 adjacent necked down portion 75, so that lumen 74 communicates to the interior of the balloon portion 12 for applying infla-tion pressure thereto. The end of tube 80 is adhesive-ly or otherwise bonded to tubing 71 adjacent the necked down transition portion, and the distal portion of tube %0, which is the distal portion of the balloon portion, is adhesively or otherwise secured to tip lO, which is ~713D~L8~7 formed by partition 72 and the portion of tube 71 which was not cut away.
Since the waist portion 14 does not include the portion of tube 71 associated with inflation lumen 74, since this has been cut away, waist portion 14 will have less stiffness and greater 1exibility than shaft portion 16. In Figure 6B, the same technique of construction is used, but the waist portion 14' between balloon portion 12 and shaft portion 16 is longerO In accordance with the invention, a set or range of cathe-ters can be provided with different incremental lengths of waist portion 14 or 14' to provide the degree of flexibility required for given applications.
Thus, the present inv~ntion provides an improved angioplasty dilatation catheter having a variable stiEfness lengthwise of the catheter, and spe-cifically providing a waist or intermediate portion behind the inflatable portion that provides maneuverlng flexibility to allow the distal end to follow sharp bends in the guide wire. At the same time, the rela-tiYely stier shaft provides sufficient mechanical rigidity for transmitting axial force to advance the catheter, but is separated from the soft balloon por-tion a sufficient distance that it does not tend to push the balloon beyond sharp branches or dislodge the guide wire.
Claims (13)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A dilatation catheter for entry into the vascular system of the patient along a guide wire, comprising:
said catheter including an elongate flexible shaft having a distal end for entry into the vascular system and a proximal end for manipulation externally of the body and for attachment to instruments for use in a dilatation procedure;
said catheter having an inflatable balloon member at the distal end thereof;
said catheter having means defining a waist portion between said balloon portion and said shaft, said waist portion having a lower stiffness than said shaft, the length of the waist portion between said balloon portion and said shaft being such that the tractability of said catheter through sharp bends is enhanced such that said catheter may follow sharp bends and the tendency to dislodge a guide catheter as it is advanced therealong is reduced;
means defining a fluid communication passage from the proximal end of said shaft to said balloon member so that inflation pressure can be applied thereto; and means defining a guide wire receiving opening extending throughout said catheter, so that the catheter can be advanced along a guide wire in the vascular system of the patient.
said catheter including an elongate flexible shaft having a distal end for entry into the vascular system and a proximal end for manipulation externally of the body and for attachment to instruments for use in a dilatation procedure;
said catheter having an inflatable balloon member at the distal end thereof;
said catheter having means defining a waist portion between said balloon portion and said shaft, said waist portion having a lower stiffness than said shaft, the length of the waist portion between said balloon portion and said shaft being such that the tractability of said catheter through sharp bends is enhanced such that said catheter may follow sharp bends and the tendency to dislodge a guide catheter as it is advanced therealong is reduced;
means defining a fluid communication passage from the proximal end of said shaft to said balloon member so that inflation pressure can be applied thereto; and means defining a guide wire receiving opening extending throughout said catheter, so that the catheter can be advanced along a guide wire in the vascular system of the patient.
2. Vascular dilatation apparatus, comprising a plurality of dilatation catheters, each including an elongate flexible shaft having a distal end for entry into the vascular system of a patient and a proximal end for manipulation externally of the patient's body and for attachment for instruments for use in a dilatation procedure, each catheter having an inflatable balloon member at the distal end thereof, each catheter having means defining a waist portion between its balloon portion and its shaft with said waist portion having a lower stiffness than said shaft, the length of the waist portion between said balloon portion and said shaft being such that the tractability of said catheter through sharp bends is enhanced such that said catheter may follow sharp bends and the tendency to dislodge a guide catheter as it is advanced therealong is reduced, each catheter including means defining a fluid communication passage from the proximal end of its shaft to its balloon member so that inflation pressure can be applied thereto, each catheter including means defining a guide wire-receiving opening extending throughout the catheter so that the catheter can be advanced along a guide wire in the vascular system of the patient, and said catheters having waist portions of different lengths to provide different degrees of flexibility to accommodate varying sharpness of turns as a catheter is advanced along a guide wire in the vascular system of the patient.
3. A vascular dilatation catheter, comprising:
a first elongate tubular member defining a central lumen for receiving a guide wire;
an elongate tubular shaft member positioned substantially coaxially of said first tubular member and sixed to define an annular lumen between said first tubular member and the inside of said shaft member, the distal end of said first tubular member extending beyond the distal end of said shaft member;
a tubular balloon member positioned over said first tubular member adjacent the distal end thereof, means securing one end of said tubular balloon member to said first tubular member adjacent the distal end thereof and fastening the other end of said tubular balloon member to the distal end of said shaft member, said tubular balloon member having an inflatable balloon portion formed in the distal end thereof and having a waist portion extending from the balloon portion of said shaft member; and said waist portion having a stiffness less than the stiffness of said tubular shaft member, to permit said catheter to follow sharp bends in a guide wire as it is advanced in the vascular system of a patient, the length of the waist portion between said balloon portion and said shaft being such that the tractability of said catheter through sharp bends is enhanced such that said catheter may follow sharp bends and the tendency to dislodge a guide catheter as it is advanced therealong is reduced.
a first elongate tubular member defining a central lumen for receiving a guide wire;
an elongate tubular shaft member positioned substantially coaxially of said first tubular member and sixed to define an annular lumen between said first tubular member and the inside of said shaft member, the distal end of said first tubular member extending beyond the distal end of said shaft member;
a tubular balloon member positioned over said first tubular member adjacent the distal end thereof, means securing one end of said tubular balloon member to said first tubular member adjacent the distal end thereof and fastening the other end of said tubular balloon member to the distal end of said shaft member, said tubular balloon member having an inflatable balloon portion formed in the distal end thereof and having a waist portion extending from the balloon portion of said shaft member; and said waist portion having a stiffness less than the stiffness of said tubular shaft member, to permit said catheter to follow sharp bends in a guide wire as it is advanced in the vascular system of a patient, the length of the waist portion between said balloon portion and said shaft being such that the tractability of said catheter through sharp bends is enhanced such that said catheter may follow sharp bends and the tendency to dislodge a guide catheter as it is advanced therealong is reduced.
4. A dilatation catheter for entry into the vascular system of a patient along a guide wire, comprising:
a tubular shaft having a distal end for entry into the vascular system and a proximal end for manipulation externally of the body and for attachment to pressure control and other instruments for use in a dilatation procedure;
an inner tubular member positioned within said shaft member and extending therethrough and for a distance beyond the distal end thereof, said tubular shaft member sized to define an annular lumen between its inner wall and the outer wall of said inner tubular member;
a tubular balloon member positioned over the end of said inner tubular member which extends beyond said shaft member, said tubular balloon member having one end thereof secured to the distal end of said shaft member and the other end thereof secured to said inner tubular member adjacent the distal end thereof, said tubular balloon member having an inflatable balloon portion formed therein adjacent the distal end thereof and in fluid communication with said annular lumen so that it may be inflated by pressure applied thereto, and having a waist portion between said balloon portion and said shaft member, said waist portion having less stiffness than the stiffness of said shaft, so that said catheter may follow sharp bends without tending to dislodge a guide wire as it is advanced therealong, the length of the waist portion between said balloon portion and said shaft being such that the tractability of said catheter through sharp bends is enhanced such that said catheter may follow sharp bends and the tendency to dislodge a guide catheter as it is advanced therealong is reduced.
a tubular shaft having a distal end for entry into the vascular system and a proximal end for manipulation externally of the body and for attachment to pressure control and other instruments for use in a dilatation procedure;
an inner tubular member positioned within said shaft member and extending therethrough and for a distance beyond the distal end thereof, said tubular shaft member sized to define an annular lumen between its inner wall and the outer wall of said inner tubular member;
a tubular balloon member positioned over the end of said inner tubular member which extends beyond said shaft member, said tubular balloon member having one end thereof secured to the distal end of said shaft member and the other end thereof secured to said inner tubular member adjacent the distal end thereof, said tubular balloon member having an inflatable balloon portion formed therein adjacent the distal end thereof and in fluid communication with said annular lumen so that it may be inflated by pressure applied thereto, and having a waist portion between said balloon portion and said shaft member, said waist portion having less stiffness than the stiffness of said shaft, so that said catheter may follow sharp bends without tending to dislodge a guide wire as it is advanced therealong, the length of the waist portion between said balloon portion and said shaft being such that the tractability of said catheter through sharp bends is enhanced such that said catheter may follow sharp bends and the tendency to dislodge a guide catheter as it is advanced therealong is reduced.
5. A coronary angioplasty dilatation catheter, comprising;
a) an elongated flexible shaft having a distal end for entry into the vascular system and a proximal end for manipulation externally of the body and for attachment to instruments for use in a dilatation procedure;
b) means for defining a guide wire receiving lumen, so that the catheter can be advanced along a guide wire in the vascular system of the patient;
c) an inflatable balloon member disposed at the distal end of the shaft;
d) means for fluid communication between the proximal end of said shaft and said balloon so as to provide an inflation pressure; and e) means for defining a waist portion disposed between said balloon member and said shaft, said waist portion being disposed at the distal end of said shaft and being of reduced outer diameter and reduced wall thickness as compared to said shaft, the length of said waist portion between said balloon member and said shaft being such that the trackability of said catheter through sharp bends is enhanced such that said catheter may follow sharp bends without tending to dislodge a guide catheter as it is advanced therealong.
a) an elongated flexible shaft having a distal end for entry into the vascular system and a proximal end for manipulation externally of the body and for attachment to instruments for use in a dilatation procedure;
b) means for defining a guide wire receiving lumen, so that the catheter can be advanced along a guide wire in the vascular system of the patient;
c) an inflatable balloon member disposed at the distal end of the shaft;
d) means for fluid communication between the proximal end of said shaft and said balloon so as to provide an inflation pressure; and e) means for defining a waist portion disposed between said balloon member and said shaft, said waist portion being disposed at the distal end of said shaft and being of reduced outer diameter and reduced wall thickness as compared to said shaft, the length of said waist portion between said balloon member and said shaft being such that the trackability of said catheter through sharp bends is enhanced such that said catheter may follow sharp bends without tending to dislodge a guide catheter as it is advanced therealong.
6. A coronary angioplasty dilatation catheter, comprising:
a) an elongated tubular shaft having a distal end for entry into the vascular system and a proximal end for manipulation externally of the body and for attachment to instruments for use in a dilatation procedure, b) an elongated tubular member defining a guide wire receiving lumen, disposed axially within said shaft, so that the catheter can be advanced along a guide wire in the vascular system of the patient, the distal end of said tubular member extending beyond the distal end of said shaft;
c) an inflatable balloon member disposed at the distal end of the shaft, positioned substantially coaxially over said tubular member, sealably connected at the distal end to said tubular member, and sealably connected at the proximal end to said shaft;
d) means for fluid communication between the proximal end of said shaft and said balloon member so as to provide an inflation pressure; and e) means for defining a waist portion disposed between said balloon member and said shaft wherein said tubular member is of reduced outer diameter and reduced wall thickness, the length of said waist portion between said balloon member and said shaft being such that the trackability of said catheter through sharp bends is enhanced such that said catheter may follow sharp bends without tending to dislodge a guide catheter as it is advanced therealong.
a) an elongated tubular shaft having a distal end for entry into the vascular system and a proximal end for manipulation externally of the body and for attachment to instruments for use in a dilatation procedure, b) an elongated tubular member defining a guide wire receiving lumen, disposed axially within said shaft, so that the catheter can be advanced along a guide wire in the vascular system of the patient, the distal end of said tubular member extending beyond the distal end of said shaft;
c) an inflatable balloon member disposed at the distal end of the shaft, positioned substantially coaxially over said tubular member, sealably connected at the distal end to said tubular member, and sealably connected at the proximal end to said shaft;
d) means for fluid communication between the proximal end of said shaft and said balloon member so as to provide an inflation pressure; and e) means for defining a waist portion disposed between said balloon member and said shaft wherein said tubular member is of reduced outer diameter and reduced wall thickness, the length of said waist portion between said balloon member and said shaft being such that the trackability of said catheter through sharp bends is enhanced such that said catheter may follow sharp bends without tending to dislodge a guide catheter as it is advanced therealong.
7. An angioplasty dilatation catheter, comprising:
an elongated flexible shaft having a distal end for entry into the vascular system and a proximal end for manipulation externally of the body and for attachment to instruments for use in a dilatation procedure;
an elongated tubular member defining a guide wire receiving lumen, disposed axially within said shaft, so that the catheter can be advanced along a guide wire in the vascular system of the patient;
an inflatable balloon member disposed at the distal end of the shaft, positioned substantially coaxially over said tubular member, sealably connected at the distal end to said tubular member;
means for fluid communication between the proximal end of the shaft and said balloon member; and means for defining a waist portion formed integrally with said balloon member and disposed at the distal end of said shaft between said shaft and said balloon member, said waist portion being of reduced outer diameter and reduced wall thickness as compared to said shaft, the length of said waist portion between said balloon member and said shaft being such that the trackability of said catheter through sharp bends is enhanced such that said catheter may follow sharp bends without tending to dislodge a guide catheter as it is advanced therealong.
an elongated flexible shaft having a distal end for entry into the vascular system and a proximal end for manipulation externally of the body and for attachment to instruments for use in a dilatation procedure;
an elongated tubular member defining a guide wire receiving lumen, disposed axially within said shaft, so that the catheter can be advanced along a guide wire in the vascular system of the patient;
an inflatable balloon member disposed at the distal end of the shaft, positioned substantially coaxially over said tubular member, sealably connected at the distal end to said tubular member;
means for fluid communication between the proximal end of the shaft and said balloon member; and means for defining a waist portion formed integrally with said balloon member and disposed at the distal end of said shaft between said shaft and said balloon member, said waist portion being of reduced outer diameter and reduced wall thickness as compared to said shaft, the length of said waist portion between said balloon member and said shaft being such that the trackability of said catheter through sharp bends is enhanced such that said catheter may follow sharp bends without tending to dislodge a guide catheter as it is advanced therealong.
8. The angioplasty dilatation catheter of Claim 7 wherein the waist portion and said balloon member are made of a material comprising a polyolefin.
9. The angioplasty dilatation catheter of Claim 8 wherein said polyolefin comprises a polyethylene.
10. The angioplasty dilatation catheter of Claim 7 further including at least one radiopaque marker disposed within said balloon member.
11. The angioplasty dilatation catheter of Claim 7 further including a tip member extending distally from said balloon member, said tip member being more flexible than said balloon member.
12. The angioplasty dilatation catheter of Claim 11 wherein said tip member comprises a length of said annular tubular member extending distally of said balloon member.
13. The angioplasty dilatation catheter of Claim 7 wherein said shaft is formed integrally with said waist portion.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US76676385A | 1985-08-16 | 1985-08-16 | |
| US766,763 | 1985-08-16 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1278487C true CA1278487C (en) | 1991-01-02 |
Family
ID=25077461
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000508919A Expired - Lifetime CA1278487C (en) | 1985-08-16 | 1986-05-12 | Variable stiffness angioplasty catheter |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1278487C (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2022100403A1 (en) * | 2020-11-13 | 2022-05-19 | 微创神通医疗科技（上海）有限公司 | Balloon catheter |
-
1986
- 1986-05-12 CA CA000508919A patent/CA1278487C/en not_active Expired - Lifetime
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2022100403A1 (en) * | 2020-11-13 | 2022-05-19 | 微创神通医疗科技（上海）有限公司 | Balloon catheter |
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