FR2719224A1 - Rapid exchange dilation catheter. - Google Patents

Abstract

A dilatation catheter comprising a flexible tubular member with two non-communicating inner lumens. The catheter body (1) further comprises a third inner lumen (8) non-communicating with the first lumen (5) in the region of the balloon portion (2), said third lumen being opened at one end to the outside of the body via a port (9) while its other end is sealingly connected to said second lumen. The third lumen is shaped so that the distal portion of the guidewire remains within said body while leaving the second lumen clear to enable the at least temporary insertion of an other guidewire into said body. The catheter may thus be exchanged rapidly while holding the guidewire in position during stenosis treatment, and the guidewire may be replaced without moving the catheter.

Description

The subject of the present invention is an exchange dilation catheter.

  rapid, intended to be introduced into a body channel such as in particular a

blood vessel.

  The invention mainly finds application in the field of treatment of affections of the coronary arteries but can also be used in the field of treatment of affections of other bodily channels, such as

example the eosophagus or the urethra.

  These affections generally result from the presence, on the internal walls

  canal, deposits causing narrowing or stenosis of it.

  In the treatment of this type of condition, a dilation catheter is generally used to restore the normal cross-section of the canal to the level

  compression stenosis using a balloon (or balloon).

  A guide, generally made in the form of a metal wire is used

  to facilitate the progression of the catheter to the stenosis.

  The guidewire is generally longer than the catheter (of the order of 20 to cm) to allow the catheter to advance inside the body canal, by

sliding along the wire.

  A conventional dilatation catheter generally comprises a flexible tubular element comprising a distal part and a proximal part and having at its distal part a radially deformable portion forming a balloon, and at its proximal part a connector. This tubular element comprises a first internal through conduit intended to allow the passage of the guide wire inside the catheter and a second internal conduit, not communicating with said first conduit, opening out inside the balloon and connected to a source of fluid supply to allow inflation and

deflating the balloon.

  The aforementioned first internal conduit can also be used for the injection, at the level of the stenosis, of various diagnostic or treatment products intended for example to make the recovery of the

passage of the body canal.

  During an intervention using a dilation catheter, it may be necessary to change the guide wire, possibly leaving the catheter in position, for example in case of difficulty in progressing within the

coronary.

  It may also be necessary to change the catheter, and in this case it is

  advantageous to keep the guide wire in position.

  To remove a conventional catheter, of the type described above (i.e.

  say crossed over its entire length by the guide wire) while maintaining the guide wire in position, it is necessary to have outside the body a length of wire

greater than that of the catheter.

  For example, in the case of a catheter with a length of between approximately 120 and 140 cm and a guidewire with a length of the order of 175 cm, the total length of the wire at during the exchange procedure must be

about 300 cm.

  This is why, during the catheter exchange procedure, a special long wire is used to replace the conventional guide wire (for example

example 300 cm).

  Another known technique consists, during the exchange procedure, of adapting to the free end of the guide wire another wire forming an extension (for example

about 125 cm long).

  US patent 4,827,941 incorporated herein by reference illustrates this perfectly.

state of the art.

  The use of a specific exchange wire or an extension however makes the

  more complex exchange procedure.

  To avoid this drawback, it has been proposed, in particular in US Pat. No. 4,748,982 also incorporated here by reference, to use a so-called rapid exchange catheter which is crossed by the guide wire only at its part. distal, for example over a length of about 20 to 25 cm for a catheter of a

total length of about 130 cm.

  The catheter described in this prior document comprises a distal part comprising two juxtaposed non-communicating internal channels, one of which (intended

  when the guide wire passes) opens to the outside of the catheter.

  Insofar as the catheter is crossed by the guide wire only over a small portion of its length (20 to 25 cm), less than the length of the wire extending outside the body (35 to 55 cm ), it is possible to remove the catheter by sliding it along the guide wire and to replace it with another catheter, without calling

  to a specific exchange wire or to an extension.

  The use of such a catheter simplifies the exchange procedure, but

  has different drawbacks.

  First of all, the specific structure of this catheter gives no

  possibility of exchanging the guide wire.

  In addition, this catheter does not have a distal access route for

  injecting a diagnostic or treatment fluid into the stenosis.

  Finally, the workability of the guide wire is poor, insofar as it

  largely extends outside the catheter.

  Under these conditions, the main object of the present invention is to solve the technical problem consisting in the supply of a rapid exchange dilation catheter, of a new design, which can be easily produced on an industrial scale, including the implementation work is easy, and allowing on the one hand a possible exchange of the guide wire by maintaining the catheter in position and the distal injection of liquid through the internal conduit of passage of the guide wire, and on the other

  share a possible catheter exchange by keeping the guide wire in position.

  The solution, in accordance with the present invention, to solve this technical problem consists of a rapid exchange dilation catheter, intended to be introduced into a body channel such as in particular a blood vessel, of the type comprising: - a flexible tubular body comprising a distal part and proximal part; - a radially deformable portion forming a balloon, disposed at the distal part of said body; - A first internal conduit extending longitudinally inside said body, said conduit opening at one end inside the balloon in a sealed manner, and being connected at the other end to a source of fluid supply to allow inflating and deflating the balloon; - A second internal conduit, passing longitudinally through said body and not communicating with said first conduit, adapted to allow the passage of a guide wire inside said body; characterized in that it further comprises a third internal conduit not communicating with said first internal conduit extending in the vicinity of the balloon portion, opening at a first end outside said body and communicating at its other end in a fashion sealed with said second internal conduit; said third internal conduit being shaped so that the distal portion of said guide wire can remain engaged in said body, while freeing said second internal conduit and thus allowing the establishment, at least

  temporary, of another guide wire in said body.

  Thus, the originality of the present invention with respect to the state of the art lies in the fact that the catheter body has a third internal conduit whose conformnnation allows: - on the one hand, operation in exchange fast "classic", that is to say the possibility of changing the catheter without adding an extension or using a special wire, and while keeping the guide wire in position, the catheter being thus extracted by sliding the along the wire; - on the other hand, a possibility of exchanging the guide wire while maintaining the balloon in position, the conduit 8 then allowing withdrawal of the guide wire in a "waiting position" thus releasing the second internal conduit which allows setting

  place a second guidewire in the body of the catheter.

  According to a particular characteristic, the third internal conduit of the dilatation catheter according to the invention is provided, at its end opening into the second internal conduit with a locating means consisting of

  preferably by a radiopaque element such as a metal ring.

  This location means that the first wire can be positioned securely.

  guide in waiting position in the third internal duct.

  According to another characteristic, the third internal conduit has at the level of its end opening to the outside of the catheter, the shape of a ramp

  intended to guide the wire towards the outside of the catheter.

  According to a first embodiment of the invention, the above-mentioned flexible tubular body comprises: - a proximal part in which the aforementioned first and second internal channels extend substantially longitudinally, coaxially; - a distal part in which the aforementioned first and second internal channels extend substantially longitudinally, in a coaxial fashion; - An intermediate part providing a tight junction between the proximal and distal parts, and on the proximal portion of which said first, second and third internal conduits are juxtaposed and preferably substantially parallel

between them.

  According to a second embodiment of the invention, the above-mentioned flexible tubular body comprises: - a proximal part in which the first and second aforementioned internal channels are juxtaposed and extend substantially longitudinally and parallel to one another; - a distal part in which the aforementioned first and second internal channels extend substantially longitudinally, coaxially; - An intermediate part providing a tight junction between the proximal and distal parts, and on the proximal portion of which said first, second and third internal conduits are juxtaposed and preferably substantially parallel

between them.

  Advantageously, in these two embodiments, the length of the distal part increased by that of the intermediate part is less than the length of the guide wire outside the body when the latter is in position

of use.

  According to a particularly advantageous characteristic of the invention, the opening of the aforementioned third internal conduit comprises a closure element

  forming a non-return valve comprising a slot allowing the passage of a wire

  guide. This conformation makes it possible to stabilize the guide in position

  waiting in the third internal duct.

  The invention will be better understood, and other aims, characteristics and

  advantages of it will appear more clearly on reading the description

  explanatory document which follows, made with reference to the appended schematic drawings given solely by way of nonlimiting examples illustrating several currently preferred embodiments of the invention, and in which: - Figure 1 is a longitudinal section view of a rapid exchange dilatation catheter according to the present invention; - Figure 1A is a cross-sectional view along the line AA of Figure 1; - Figure lB is a cross-sectional view along line BB of Figure 1; - Figure 1C is a cross-sectional view along the line CC of Figure 1; - Figure 2 is a view similar to Figure 1 illustrating a first guide wire in the standby position in the third internal conduit; - Figure 2A is a cross-sectional view along the line AA of Figure 2; - Figure 2B is a cross-sectional view along line BB of Figure 2; - Figure 2C is a cross-sectional view along the line CC of Figure 2; - Figure 3 is a view similar to Figure 1 illustrating a first guide wire in the standby position in the third internal conduit and a second guide wire in the position of use in the second internal conduit; - Figure 3A is a cross-sectional view along the line AA of Figure 3; - Figure 3B is a cross-sectional view along line BB of Figure 3; - Figure 3C is a cross-sectional view along line CC of Figure 3; - Figure 4 is a view similar to Figure 3 of a rapid exchange dilation catheter according to a second embodiment of the invention; - Figure 5 is a detail view in longitudinal section illustrating the intermediate part of a catheter according to the present invention; - Figure 6 is a view similar to Figure 5 illustrating an alternative embodiment; - Figure 7 is a view similar to Figure 5 without a guide wire illustrating

the shutter element 21.

  - Figure 8 is a detail view illustrating the shutter element of the opening of the

third conduit.

  In the description which follows, the body channel chosen by way of example

  is a blood vessel not shown, such as in particular a coronary artery.

  FIG. 1 therefore shows schematically a catheter for

  rapid exchange expansion according to the present invention.

  This catheter comprises a flexible tubular body 1, comprising a part

  proximal la, an intermediate part lb and a distal part lc.

  In the example shown, the flexible tubular body 1 has a section

  substantially circular transverse constant over most of its length.

  The body 1 has at its distal part lc a radially deformable portion forming a balloon 2, and at its proximal part la an element

connector 3.

  The connector element 3 is a conventional element with two Y-shaped channels allowing the connection of a balloon inflation system on the lateral channel.

  4a and the passage of a guide wire in the axial path 4b.

  The flexible body 1 can be made for example from one or more semi-rigid thermoplastic materials chosen from polyethylenes,

  polyamides or else copolymers of the PEBAX or HYTREL type.

  The radially deformable portion forming a balloon 2 can be integrated into the flexible body 1, as in the example shown, or attached thereto by being fixed therein in a sealed manner by known means such as for example by

  heat sealing or by means of an adhesive.

  The portion forming a balloon 2 may also be made of a thermoplastic material such as in particular a polyamide, a polyethylene or a polyester. In order to position the balloon 2 at the level of the stenosis (before inflation), the body 1 could be equipped with a locating means such as for example a radiopaque metallic ring 12; a metal such as gold, platinum, tungsten or their

  alloys which can be used for the production of this radio-opaque ring.

  In general, the flexible body 1 comprises a first internal conduit 5 extending longitudinally inside said body, this conduit 5 opening at one end inside the balloon 2, in a sealed manner, and being connected to its other end via the connector element 3 to a fluid supply source not shown to allow inflation and

deflating the balloon 2.

  The flexible body 1 also comprises a second internal conduit 6 passing longitudinally through said body, and not communicating with the first internal conduit 5, this second conduit being adapted to allow the passage of a

  guide wire inside said body.

  In the currently preferred embodiment shown in FIG. 1, the internal conduits 5 and 6 which extend substantially longitudinally inside the flexible body 1 are coaxial in the proximal part 1a (see FIG.

  1A) and in the distal part lc (see Figure 1C).

  The proximal parts la and distal lc are tightly connected to one another by the intermediate part lb shown in enlarged view in section

  longitudinal in Figures 5 to 7, and which will be described later.

  The flexible body 1 comprises, at its intermediate part 1b, a third internal conduit 8 not communicating with the first internal conduit 5,

  extending in the vicinity of the balloon portion 2, upstream thereof, that is

  ie on the side of the proximal part of the body 1 of the catheter.

  More specifically, this third internal conduit 8 opens at a first end through an opening 9 outside the body 1 and communicates with its other

  end, sealingly, with the second internal conduit 6.

  Advantageously, the third internal conduit has, at its end opening out to the outside of the catheter, the shape of a ramp intended to

  guide the wire outward from the catheter.

  It should be noted that on the proximal portion of the intermediate part 1b, that is to say on the length portion over which the third conduit 8 extends,

  the internal conduits 5, 6 and 8 are juxtaposed (see FIG. 1B).

  The length of the distal part lc including the balloon portion increased by that of the intermediate part lb will generally be much more

  smaller than that of the proximal part.

  In particular, provision will be made, by construction, for a body 1 whose length of the distal part lc increased by that of the intermediate part lb is less than the length of the wire remaining outside the patient's body when the said wire is in position of use, that is to say for example when the balloon is located at the level of the stenosis to be treated. By way of example, for a catheter with a total length of about 130 cm and for a guide wire with a length of around 175 cm, the length of the distal part lc increased by that of the part intermediate lb will be about 20 to 25 cm being specified that the balloon part will have a length of the order of

1 to 5cm.

  As we understand from reading the structural description which

  above, a dilation catheter according to the invention can be initially mounted in "rapid exchange", that is to say in a conformation as shown in FIG. 1, in which a guide wire 7 is placed along the body 1 of the catheter, outside of it partly proximal and inside of it partly

intermediate and distal.

  In this configuration, rapid catheter exchange is possible, without

  adding an extension or using a special wire and while maintaining the wire-

guide in position.

  It is also possible to inject various products up to the stenosis in

  using the second internal conduit 6.

  The presence in the intermediate part 1b of the body of the catheter, of a third internal conduit 8 also makes it possible to exchange the filguide while

holding the ball in position.

  In fact, the conduit 8 allows the first guide wire 7 to be withdrawn in a "waiting position" in the intermediate part 1b as illustrated in FIGS. 2,

2A, 2B and 2C.

  In order to correctly and safely place the guide wire 7 in the standby position in the internal conduit 8, a locating means constituted for example by a radiopaque element such as a radioopaque metallic ring 11 will be mounted on the end of the third internal conduit 8 communicating with the second internal conduit 6 (see Figures 5, 6 and 7). This locating means could be made up of

  same material as the radio-opaque ring 12 described above.

  As can be understood, when the first guide wire 7 is in the waiting position in the third internal conduit 8, it thus releases the distal part of the second internal conduit 6, and then allows the positioning, at least temporarily,

  another guidewire 10 in the body of the catheter.

  Of course, the second internal conduit 6 thus freed can also be used for the injection of products intended for the treatment of stenosis, or for the introduction of specific instruments such as for example a guide with sensor

Doppler type.

  Figure 4 shows a rapid exchange dilation catheter

  according to a second embodiment of the invention.

  In this example, the internal conduits 5 and 6 which extend substantially longitudinally inside the flexible body 1 are juxtaposed substantially parallel to one another in the proximal parts 1a (see FIG. 4A) and intermediate

  lb (see figure 4B) and coaxial in the distal part lc (see figure 4C).

  It should also be noted that in this embodiment, the body 1 also comprises a fourth internal duct 13 extending at the level of the proximal part 1a substantially between the connector 3 and the proximal part adjacent to

  the opening 9 of the third internal conduit 8.

  The fourth internal conduit 13 extends longitudinally inside said body 1 substantially parallel to the internal conduits 5 and 6, which in the

  the proximal part 1a are juxtaposed and parallel to each other.

  This fourth conduit makes it possible to introduce into the proximal part of the catheter body 1 an element intended to stiffen this part, produced for example under the

shape of a metal rod 14.

  With reference to FIGS. 5 to 8, the structure of various embodiments of the intermediate part 1b of a catheter will now be described in more detail.

  rapid exchange dillation according to the invention.

  In the embodiment shown in Figure 5, the internal conduits 5

  and 6 extend coaxially in the proximal part 1a.

  More specifically, the flexible body 1 is defined by an external envelope, the second internal conduit 6 disposed in a substantially central manner is defined by a wall 16 while the first internal conduit 5 which is arranged radially

  and externally relative to the internal duct 6 is defined by a wall 17.

  The proximal part 1a is extended in a sealed manner by a sleeve comprising three substantially parallel and juxtaposed internal channels, one of which defines the third internal conduit 8 and the other two communicate respectively with the internal conduits 5 and 6 of the proximal part described above. A radiopaque marker 11 consisting of a metal ring is arranged at

  the distal end of this sleeve.

  Beyond this sleeve is a part ensuring a tight junction with the distal part lc of the catheter, in which the internal conduits 5 and 6 are again coaxial as in the proximal part 1a. In fact, the internal conduits 8 and 6 meet beyond the sleeve

  aforementioned so as to form only a single conduit 6 in the distal part.

  FIG. 6 is a detailed view of the intermediate part 1b of a rapid exchange dilation catheter according to the second embodiment of the invention

previously described.

  In this embodiment, the proximal part 1a consists of a tube comprising three juxtaposed channels respectively defining the first,

  second and fourth internal conduits 5, 6 and 13 defined above.

  A stiffening element 14 is shown in the duct 13.

  This three-way tube continues in the proximal portion of the intermediate part 1b, thus defining the first, second and third conduits

  internal 5, 6 and 8 defined above.

  The internal conduit 8 extending the fourth internal conduit 13 is separated from the latter by an element 20 defining a ramp at the opening 9

cited above.

  This element 20 is also present in the embodiment described in the

figure 5.

  In FIGS. 5 and 6, one can see a guide wire 7 placed in the waiting position in the third internal conduit 8, and a second guide wire 10 mounted at

  the interior of the second internal duct 6.

  Figure 7 is a view similar to Figure 5 illustrating an alternative embodiment of the intermediate portion 1b of a rapid exchange dilation catheter

according to the invention.

  In this alternative embodiment, the opening 9 of the third internal conduit 8 comprises a closure element 21 forming a non-return valve and comprising

  a slot 22 allowing the passage of a guide wire 7.

  This sealing element can be produced for example in the form of an elastomeric membrane such as for example a silicone membrane,

polyurethane or PEBAX.

  11 The slot 22 will be made without removal of material, so as to form a non-return valve for the injection liquids which can be used for the

treatment of stenosis.

  In addition, the membrane 21 will ensure, thanks to this slot 22, the stabilization of the

guide in waiting position.

  The catheter which has just been described can be used in a completely conventional manner and those skilled in the art can refer to the existing literature on this subject.

  which concerns its placement inside the body canal.

Claims (9)

  1. Rapid exchange dilation catheter, intended to be introduced into a body channel such as in particular a blood vessel, of the type comprising: - a flexible tubular body (1) comprising a distal part (1c) and a proximal part (la) and comprising: - a radially deformable portion forming a balloon (2), disposed at its distal part; - A first internal conduit (5) opening at one end inside the balloon in a sealed manner, and connected at the other end to a source of supply of fluid to allow the inflation and deflation of the balloon; - a second internal conduit (6), passing through, not communicating with said first conduit (5), adapted to allow the passage of a guide wire (7) inside said body; characterized in that said body (1) further comprises a third internal conduit (8) not communicating with said first internal conduit (5) extending in the vicinity of the balloon portion (2), opening at a first end by a opening (9) outside said body and communicating at its other end in a sealed manner with said second internal conduit; said third internal conduit being shaped so that the distal part of said guide wire can remain engaged in said body, while freeing said second internal conduit and thus allowing the installation, at least temporarily, of another wire- guide in said body.   2. dilation catheter according to claim 1, characterized in that the aforesaid third internal conduit (8) is provided, at its end   opening into the second internal conduit (6), a locating means.   3. dilation catheter according to claim 2, characterized in that the aforementioned locating means consists of a radiopaque element such as a metal ring (11).   4. Catheter according to one of claims 1 to 3, characterized in that   the aforementioned third internal conduit (8) has, at its end which opens out to the outside of the catheter, the shape of a ramp intended to guide the wire outward from the catheter.   5. dilation catheter according to one of claims 1 to 4,   characterized in that the aforesaid flexible tubular body (1) comprises: a proximal part (la) in which the aforesaid first and second internal channels (5, 6) extend substantially longitudinally, coaxially; - a distal part (1c) in which the aforesaid first and second internal channels (5, 6) extend substantially longitudinally, coaxially; - An intermediate part (lb) providing a tight junction between the proximal (la) and distal (lc) parts, and on the proximal portion of which said first, second and third internal conduits are juxtaposed and preferably substantially parallel to each other.   6. dilation catheter according to any one of claims 1 to   4, characterized in that the aforesaid flexible tubular body (1) comprises: - a proximal part (la) in which the aforementioned first and second internal channels (5, 6) are juxtaposed and extend substantially longitudinally and parallel to one another; - a distal part (1c) in which the aforesaid first and second internal channels (5, 6) extend substantially longitudinally, coaxially; - An intermediate part (lb) providing a tight junction between the proximal (la) and distal (1c) parts, and on the proximal portion of which said first, second and third internal conduits are juxtaposed and preferably substantially parallel to each other.   7. dilation catheter according to claim 5 or 6, characterized in that the length of said distal part (1c) increased by that of the intermediate part (lb) is less than the length of the guide wire outside the body   when it is in the use position.   8. dilation catheter according to claim 7, characterized in that the aforesaid flexible tubular body (1) further comprises a fourth internal conduit (13) extending at its proximal part (la) for introducing an element intended to stiffen this part, produced for example in the form of a metal rod (14).   9. Dilatation catheter according to any one of claims   above, characterized in that the opening (9) of the aforementioned third internal conduit (8) comprises a closure element (21) forming a non-return valve   having a slot (22) allowing the passage of a guide wire.