A multilumen catheter and methods for making the catheter

ES 2 559 622 T3

DESCRIPTION

A multi-lumen catheter and methods of making the catheter

Related requests

This application claims the benefit of US Provisional Application Serial No. 60 / 331,882, filed November 21, 2001, entitled "Multilumen Cathether."

Field of the invention

The present invention relates generally to multi-lumen catheter assemblies, and more particularly to multi-lumen catheter assemblies having a smooth rounded unitary catheter portion for placement in a vessel wall insertion site and catheter tubes. independent free floats for placement within an area to be catheterized.

Background of the invention

Catheters for the introduction or removal of fluids can be placed in various locations and venous cavities throughout the body for the introduction or removal of fluids. Such catheterization can be done using a single catheter that has multiple lumens. Such a catheter is described in US6190349. A typical example of a multi-lumen catheter is a double-lumen catheter in which one lumen introduces fluid and one lumen draws fluid. Catheterization can also be performed using separate single-lumen catheters inserted through two different incisions in the area to be catheterized. Such sets of multiple catheters are known as Tesio catheters. Also known are procedures such as those described in US Patent No. 5,624,413 for inserting two completely independent single lumen catheters into a vessel through a single insertion site.

Generally, to insert any catheter into a blood vessel, the vessel is identified by aspiration with a long hollow needle according to the Seldinger technique. When blood enters a syringe connected to the needle, indicating that the vessel has been found, then a thin guide wire, typically through a syringe needle or other introduction device, is inserted into the vessel. The introducer device is then removed leaving the guide wire within the vessel. The guide wire protrudes beyond the surface of the skin.

At this point, several options are available for a practitioner to place a catheter. The simplest is to pass a catheter into the vessel directly over the guidewire. The guide wire is then removed leaving the catheter in position within the vessel. However, this technique is only possible in cases where the catheter is relatively small in diameter, made of rigid material and not significantly larger than the guidewire, for example, for insertion of small diameter double lumen catheters. If the catheter to be inserted is significantly larger than the guidewire, a dilator device is first passed over the guidewire to enlarge the hole. The catheter is then passed over the guidewire, and the guidewire and dilator are removed.

In the case of a single lumen single catheter typically used in multiple catheter assemblies (eg, a Tesio catheter), an introducer sheath may be used by a practitioner. If a Tesio catheter is used for hemodialysis, for example, each catheter is inserted into two different veins, such as the femoral vein. Alternatively, each catheter can be inserted into two different locations in the same vein, such as the internal jugular vein as noted above. The introducer sheath is simply a large, rigid, thin-walled tube that serves as a temporary conduit for the indwelling catheter being placed. Breakable sleeves are also available that split for easy removal. The introducer sheath is placed by placing a dilator device within the introducer instrument and passing both the dilator and the introducer instrument together into the vessel over a guide wire. The guidewire, left in the vessel after insertion as described above, and the dilator are then removed, leaving the thin-walled insertion sheath in place. The catheter is placed through the introducer sheath. Each of the catheters in the set is typically secured subcutaneously within the body of the patient by a ring located in a subcutaneous tunnel or by otherwise externally affixing the catheter to the body.

The Tesio catheter can also be inserted, according to the technique described in US Patent No. 5,624,413, as noted above, through a single point of insertion using a sheath in the vessel. The Tesio catheter, once inserted into the vessel, is then separately tunnelled through the patient into two subcutaneous tunnels for fixation of the proximal outer portions of the catheter.

The Tesio double catheter assembly, while comfortable for the patient, due to its soft durometer, and highly effective for hemodialysis, typically requires multiple procedures and incisions for insertion and / or tunneling, increasing the consequential risks of the catheterization procedure. Furthermore, in the case of side laying with

ES 2 559 622 T3 side of two catheter tubes through a single insertion site in a vessel, while minimizing the number of procedures, can present a potential for leakage between the catheter tubes at the point where the catheter tubes pass into the vessel.

However, Tesio catheter assemblies provide catheters that can perform independent movement within the vessel. Such catheters have several advantages over unitary multi-lumen catheters formed from a single internally divided tube when in the vessel. Because the individual tubes of a dual Tesio catheter assembly are independently movable at their fluid outlets, it is possible to provide fluid inlet and / or back flow around the entire circumference of the distal ends of the catheter tubes. Also, if a tube becomes blocked, or needs replacement for some other reason, it can be removed independently of the other tube. Furthermore, the softer durometer of such catheters, which are typically made of a silicone or similar material, reduces the risk of vessel wall damage. 360 ° circumferential flow provides a more stable tube within the vessel, which is less likely to be sucked against the vessel wall due to a pressure differential, as occasionally occurs in the use of some side-to-side multi-lumen catheters .

US Patent No. 5,718,692, issued to Schon, et al., ("The Schon catheter") describes a self-retaining dual catheter system in which each catheter can be secured subcutaneously without the use of eyelets. tissue re-growth fabric or external suture as a result of the placement of a retention sleeve that surrounds both individual catheters in a multi-catheter assembly to hold the catheters together at the location of the sleeve. The individual catheters are permanently attached in one part by a concentrator for self anchoring under the skin, as an alternative to requiring a fabric stabilizer ring, so such sleeves are optional. The distal ends are longitudinally spaced in advance an appropriate distance to prevent recirculation. Although this device only requires one incision, it requires two subcutaneous tunnels in order to facilitate the self-retention feature. This catheter provides independently movable distal ends within the vessel and 360 ° circumferential flow like a standard Tesio. In addition, since the retention sleeve is located outside the vessel when in place to provide the self-retention feature, at the point of entry into the vessel, the catheters are side-to-side like a standard Tesio catheter, and the potential risk of blood leakage between catheters at the vessel site.

US Patent No. 5,947,953 discloses a multiple divisible catheter assembly having a concentrator and at least two totally independent catheter tubes that are initially releasably joined together, for example, by a frangible membrane. A single subcutaneous tunnel can be used in insertion of the catheter, and the catheter tubes are at least partially separated by division of the catheter tubes prior to insertion into a vessel. As a result, the parts of the catheter within the vessel can move independently and have 360 ​​° circumferential flow from the distal part of each tube. The catheter can be secured using standard fixation means such as suture, re-growth, or other available fixation devices.

An additional multiple catheter set for use in acute Tesio catheterizations is disclosed in US Patent No. 5,776,111. The set includes two independent one-lumen catheters joined in one location by a generally flat disk that can be connected to the surface of a patient's skin to secure the set in an acute procedure. The distal ends are longitudinally spaced in advance to prevent recirculation.

There is a need in the art for a multi-catheter assembly and a need to make such a catheter assembly that can provide the advantages of the aforementioned multi-lumen catheters with respect to easy insertion by a single tunneling procedure and that can prevent the potential risk of leakage at the point of entry of the glass, but still able to provide the advantage of multiple catheter assemblies with respect to independent movement within a vessel and good flow properties.

Compendium of the invention

The present invention is a method of making a multi-lumen catheter assembly as further described in claim 1 that provides easy catheter insertion by a single tunneling procedure and aids in the prevention of leakage at the site of entry of vessel by using a unitary outer wall configuration. The catheter assembly also provides independent free floating movement within the vessel through the use of separate distal end catheter tubes and provides efficient fluid flow properties within the lumens of the catheter assembly.

The multi-lumen catheter assembly includes a unitary part having an outer wall, a distal end, a proximal end, and a plurality of lumens extending longitudinally through the unitary part. In this regard, the catheter assembly also includes a plurality of distal end tubes, each defining a lumen extending longitudinally therethrough, in which each lumen of the end tubes

The distal ES 2 559 622 T3 is in fluid communication with a respective lumen of the unitary part, and the distal end tubes can move independently of each other. In this aspect of the invention, the outer wall of the unitary part, the outer wall of the distal end tubes, and the lumens, may have various cross-sectional shapes, such as, but not limited to, a circular, semicircular, or circular shape. oval. The unitary part, the distal end tubes, and the lumens may also have different shape or configuration at different points along a respective longitudinal length of each.

The multi-lumen catheter assembly includes a unitary catheter having a rounded outer surface, a first lumen and a second lumen extending longitudinally therethrough, a distal end and a proximal end; and a first distal end tube defining a first longitudinally extending passageway and a second distal end tube defining a second longitudinally extending passageway, wherein the first and second distal end tubes extend distally from the distal end of the catheter. unitary, the first passage in the first distal end tube is in fluid communication with the first lumen, the second passage in the second distal end tube is in fluid communication with the second lumen and the first and second distal end tubes can move independently of each other.

The distal end tubes are releasably connected to each other for part, or all, of their longitudinal length, allowing the first and second distal end tubes to be split, using minimal force, and to separate anywhere along their length. longitudinal length.

The first and second distal end tubes are releasably connected to each other, and possibly have an outer wall with semicircular cross section, from the distal end of the unitary catheter to a point of attachment located between the distal end of the unitary catheter and the distal end. of the catheter assembly, allowing the first and second distal end tubes to be split, using minimal force, at any longitudinal point between the distal end of the unitary catheter and the transition point, the first and second distal end tubes are spaced from each other, and possibly are of circular cross-section, from the transition point to the distal end of the catheter assembly, providing the first and second distal end tubes with individual and independent movement from the transition point to the distal end of the catheter assembly. In this aspect of the present invention, the unitary catheter may have a generally oval cross section.

The multi-lumen catheter assembly includes two catheter tubes, each having a round lumen extending longitudinally therethrough and each having an exterior of generally semi-circular cross-sectional shape. In this regard, the catheter assembly also includes a hub that secures the two catheter tubes in juxtaposed alignment with each other, wherein the tubes in juxtaposed alignment have a generally oval shape in cross section together.

A method for making a multi-lumen catheter assembly is also described, the method includes forming a unitary catheter tube having a proximal part and a distal part, the distal part ends at a distal end, and the proximal part ends at one end. proximally, the unitary catheter tube has a first lumen and a second lumen, the first lumen and the second lumen each extend longitudinally through the unitary catheter tube. The unitary catheter tube formed is then divided longitudinally along the distal portion to form a first distal end tube and a second distal end tube. The unitary catheter tube, the distal end tubes, and the lumens within each, can then each be finished, if desired, to have one or more configurations, or cross-sectional shapes, in a respective longitudinal length of each. one.

The distal end tubes are then releasably connected along any part or all of their longitudinal lengths. In another aspect, the distal end tubes are releasably connected from a transition point (the transition point, after splitting, between the unitary catheter and the first and second distal end tubes) to a point of attachment located between the transition point and the distal end of the catheter assembly.

Brief description of the drawings

The foregoing compendium, as well as the following detailed description of the invention, will be better understood when read in conjunction with the accompanying drawings. For the purpose of illustrating the invention, certain embodiments of the present invention are shown in the drawings. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown. In the drawings, the same reference numerals are used to designate the same elements throughout the various figures. In the drawings:

Figure 1 is a top view of a multi-lumen catheter assembly according to a first embodiment of the present invention;

Figures 1a and 1b are enlarged cross-sectional views of the multi-lumen catheter assembly of Figure 1 taken along lines 1a-1a and 1b-1b, respectively;

ES 2 559 622 T3

Figures 2a to 2e are enlarged cross-sectional views of alternative embodiments of the multi-lumen catheter assembly of Figure 1 taken along line 1b-1b;

Figure 2f is an enlarged cross-sectional view of an alternate embodiment of the multi-lumen catheter assembly of Figure 1 taken along line 1a-1a;

Figure 3 is an enlarged cross-sectional view of the hub of the multi-lumen catheter assembly of Figure 1;

Figure 4 is a top view of a multi-lumen catheter assembly according to a second embodiment of the present invention;

Figures 4a, 4b, and 4c are enlarged cross-sectional views of the multi-lumen catheter assembly of Figure 4 taken along lines 4a-4a, 4b-4b, and 4c-4c, respectively;

Figure 5 is a top view of a multi-lumen catheter assembly according to a third embodiment of the present invention;

Figures 5a and 5b are enlarged cross-sectional views of the multi-lumen catheter assembly of Figure 5 taken along lines 5a-5a and 5b-5b, respectively;

Figure 6 is a top view of a multi-lumen catheter assembly in accordance with a fourth embodiment of the present invention;

Figures 6a and 6b are enlarged cross-sectional views of the multi-lumen catheter assembly of Figure 6 taken along lines 6a-6a and 6b-6b, respectively;

Figure 7 is a top view of a multi-lumen catheter assembly according to a fifth embodiment of the present invention;

Figures 7a and 7b are enlarged cross-sectional views of the multi-lumen catheter assembly of Figure 7 taken along lines 7a-7a and 7b-7b, respectively;

Figure 8 is a top view of a multi-lumen catheter assembly in accordance with a sixth embodiment of the present invention;

Figures 8a and 8b are enlarged cross-sectional views of the multi-lumen catheter assembly of Figure 8 taken along lines 8a-8a and 8b-8b, respectively;

Figure 9 is a top view of a multi-lumen catheter assembly according to a seventh embodiment of the present invention;

Figures 9a and 9b are enlarged cross-sectional views of the multi-lumen catheter assembly of Figure 9 taken along lines 9a-9a and 9b-9b, respectively;

Figure 10a is a top view of a unitary catheter tube for use in making a multi-lumen catheter assembly in accordance with one embodiment of the invention;

Figure 10a 'is an enlarged cross-sectional view of the unitary catheter tube of Figure 10a taken along line 10a'-10a';

Figure 10b is a top view of the unitary catheter tube of Figure 10a that has been split at a distal end to form distal end tubes; Y

Figure 10b 'is an enlarged cross-sectional view of the unitary catheter tube of Figure 10b taken along line 10b'-10b'.

Detailed description of the invention

In describing embodiments of the invention illustrated in the drawings, specific terminology will be used for the sake of clarity. However, the invention is not intended to be limited to the specific terms so selected, each specific term is understood to include all technical equivalents that function in a similar manner to achieve a similar purpose. It is understood that the drawings are not drawn exactly to scale. In the drawings, like reference numerals are used to designate like elements throughout the various figures.

The following describes particular embodiments of the invention. However, it should be understood, based on the description, that the invention is not limited to the embodiments detailed herein. Generally, the following

ES 2 559 622 T3 description refers to dual lumen catheter assemblies, although catheter assemblies having three or more lumens and / or distal end tubes are within the scope of the invention. Furthermore, the described methods for making the catheter assemblies of the present invention are also applicable to making catheter assemblies having more than two lumens and / or distal end tubes. It is for convenience only that the following description refers to two-light embodiments of the present invention.

The multi-lumen catheter assemblies of the present invention are inserted into an area of ​​a patient's body to be catheterized to remove and introduce fluids into the body. The catheter assemblies of the present invention are secured to a fixed location in the patient's body, such as a subcutaneous area, before the catheter assembly is inserted and properly positioned in the area to be catheterized. This method is particularly preferred for chronic catheterization. Alternatively, in acute catheterization, the catheter assemblies of the present invention can be secured to an external surface of the body before or after the catheter assembly is inserted and appropriately positioned in the area to be catheterized.

The multi-lumen catheter assemblies of the present invention can be adapted for use in various applications where fluids, drugs, and other solutions are introduced into and out of the body, such as perfusion, infusion, plasmapheresis, hemodialysis, chemotherapy, and the like. The catheter assemblies of the present invention are particularly suitable for chronic hemodialysis and apheresis. The area to be catheterized is preferably a blood vessel, such as an internal jugular vein, but it can be any suitable area within the body. Other areas in which catheter assemblies can be used include other blood vessels, including the femoral and subclavian veins, any abscess cavity, postoperative cavity, the peritoneal cavity, and other areas of the body including intra-abdominal, subdiaphragmatic, and subhepatic areas. It is understood that the areas referred to above are exemplary, and that the catheter assemblies of the present invention can be used to withdraw or introduce fluids in various areas to be catheterized.

The embodiments of the present invention shown in the figures are particularly useful for entering, or withdrawing, blood to be purified from a blood vessel, such as the internal jugular vein, and introducing purified blood into the same vessel. Blood can be purified by any suitable hemodialysis apparatus (not shown), connected in communication with lights of the described catheter assemblies. The catheter assemblies of the present invention can also be used to introduce medication or other fluids, including glucose or saline, into the body.

For the purpose of describing the embodiments of the present invention shown in the figures, the catheter assemblies will be described with respect to a hemodialysis application; more specifically, an application to purify blood flowing through an internal jugular vein. However, it is understood that the catheter assemblies of the present invention can be configured and adapted by increasing or decreasing a size (diameter or length) and / or the number of distal end tubes and / or lumens in the respective catheter assembly, so that the catheter assembly can be used beneficially for other medical applications where fluids are introduced and / or withdrawn from the body.

A first realization

Figure 1 illustrates an embodiment in which a catheter assembly 5 has at least two lumens. The two-lumen illustration is exemplary, and the scope of the invention encompasses catheters having more than two lumens.

The catheter assembly 5 includes a unitary catheter 12, a first distal end tube 14, a second distal end tube 16, a concentrator 18, and a first and a second extension tube 20, 22. The multi-lumen catheter assembly 5 includes a first lumen 24 and a second lumen 26 extending longitudinally therethrough (see Figures 1a and 1b), the first lumen 24 and the second lumen 26 have proximal ends 28, 30 , respectively, terminating within the hub 18, and distal ends 32, 34, respectively, terminating at distal ends 32, 34 of the first and second distal end tubes 14, 16.

The first light 24 is continuous and is through the first extension tube 20, and the second light 26 is continuous and is through the second extension tube 22, both by connection at the hub 18. The first and second extension tubes 20, 22 lead to a proximal end of catheter assembly 5, through which materials entering and leaving the patient enter and / or exit catheter assembly 5. The words "proximal" and "distal" refer to directions farther or closer, respectively, to the inserted end of catheter assembly 5.

An imaginary transition point 36 exits at a point along a longitudinal length of the first and second lights 24, 26. The catheter assembly 5 may be provided (manufactured) so that the first distal end tube 14 and the second distal end tube 16 are divisible (releasably connected) or are spaced apart at their respective distal ends 32, 34, and divisible or spaced from their distal ends 32, 34 to the transition point 36 (over a longitudinal length in Figure 1 generally denoted by arrow "B). Divisible is defined as releasably connected, which means that the first and second distal end tubes 14, 16 are adhered, joined, fused, or otherwise connected, so that only a minor force is needed

ES 2 559 622 T3 for separating or dividing tubes 14, 16. Minor force could be defined as approximately 0.45 kg to 2.27 kg (one to five pounds) of force.

The portion of the catheter assembly 5 between the proximal ends 28, 30 of the first and second lumens 24, 26 and the transition point 36 includes the unitary catheter 12 (at a longitudinal length in Figure 1 generally denoted by the arrow "A ”). An exterior of the unitary catheter 12 includes a smooth curved and generally convex surface with no ridges or grooves. Any of a number of shapes that provide a smooth, curved, and generally convex surface without ridges are contemplated in the present invention.

As shown in Figure 1a, the cross-section of the unitary catheter 12 may be generally oval in shape (outer configuration), Figure 1a illustrates in cross-section a generally oval-shaped outer wall 38, having the first and second lumens 24, 26 a circular cross section (as shown by the outer walls 39 of the first and second lumens 24, 26) and a first and a second lumen spacing member 40. Another non-limiting example of a unitary catheter 12 cross section is shown in Figure 2f. The lumens 24, 26 within an oval configuration of outer wall 38 of unitary catheter 12 (such as Figure 1a) or a more rounded, or even circular, outer wall 38 configuration of unitary catheter 12 (such as Figure 2f ), they could be any of various shapes, such as, but not limited to, circular, semicircular, oval, triangular, square, elliptical, or bean-shaped.

A ring 42 can be located at a point along the unitary catheter 12. The rings 42 are known in the art and provide a surface on which internal tissue can adhere to stabilize the catheter assembly 5 within the patient.

The transition point 36 can be located exactly at a point midway between the lumens 24, 26 (i.e., at a point midway between the proximal ends 28, 30 and the distal ends 32, 34 of the lumens 24, 26, the midway point measured using the longest of lights 24, 26 if lights 24, 26 are of different length, such as in figure 1). The transition point 36, however, could be located at any point along the longitudinal length of the catheter assembly 5. In Figure 1, for example, the transition point 36 is located midway between the end distal 32 and proximal end 28 of first lumen 24.

The transition point 36 is located at a point along the longitudinal length of the lumens 24, 26 such that a longitudinal length of the spaced or divisible portion of the lumens 24, 26 (i.e., the distal end tubes first and second 14, 16, as generally denoted by arrow "B") is greater than a longitudinal length of unitary catheter 12 (as generally indicated by arrow "A"). In this alternative embodiment, the longitudinal length of the spaced or divisible portion of the lights 24, 26 (the arrow portion "B") is measured using the longest of the lights 24, 26. Alternatively indicated, the first and second lumens 24, 26 are spaced or divisible from each other (i.e., releasably connected) from their respective distal ends 32, 34 to a point on the lumens 24, 26 that is at least the half the length of the lumens 24, 26 measured from the distal end of the longest lumen to the respective proximal end of the longest lumen.

In the aforementioned embodiments, it should be noted that the proximal ends 28, 30 of the lumens 24, 26 may occur at different locations on various catheters. It is within the scope of the present invention to incorporate, in the dimensional aspects of the length described above, all locations in which the proximal ends 28, 30 could be said to occur in catheters known in the art, described herein, or in which they will be developed.

The smooth, curved, and generally convex outer surface of unitary catheter 12 passes through and remains in place at a vessel wall insertion site during insertion of catheter assembly 5 into a patient. A vessel wall seals very well around the smooth curved outer surface of unitary catheter 12, as shown in cross-section in Figure 1a, and seals particularly well with a ligature. Since the exterior of the unitary catheter 12 provides a good seal at the insertion site, the risk of blood loss around the catheter assembly 5 at the insertion site is minimized. This is especially true in relation to a situation where individual lights pass through and remain located at a vessel wall insertion site, as a tight seal around individual lights that generally have a number 8 configuration is difficult (reference to the number 8 configuration refers to the outer cross section of two individual circular lights, as shown in figure 1b).

The first and second distal end tubes 14, 16 extend distally from the unitary catheter 12 at the transition point 36, the first and second lumens 24, 26 have continuous fluid communication between them. The first and second distal end tubes 14, 16 preferably have exterior surfaces that are continuous with the exterior wall 38 of the unitary catheter 12 and are capable of independent movement when divided from each other.

The first and second distal end tubes 14, 16 may be well known in the art, or be newly developed. In Figure 1b, the first and second distal end tubes 14, 16 are defined by circular outer walls 44 of the first and second distal end tubes 14, 16, the first and second lumens 24, 7

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26, the circular outer walls 39 of the first and second lumens 24, 26, and a junction point 46. Figures 2a to 2e illustrate cross-sections of alternate embodiments of the first and second distal end tubes 14, 16 (i.e. alternatives to the embodiment of figure 1b). Splice point 46 can be created by weak adhesives (Figures 2a, 2c, and 2e), by molding (Figure 2b), by tongue and groove arrangement (Figure 2d), or by other methods that allow the distal end tubes 14, 16 to be split with the use of minimal force, so that the junction of the lights is not fixed.

The first and second distal end tubes 14, 16, and the first and second lumens 24, 26 within the distal end tubes 14, 16, have a generally circular cross section in the Figure 1 embodiment of the present invention, as shown shown in Figure 1b. The first and second lumens 24, 26 are circular, as shown by the outer walls 39, since circular cross-sections are most conducive to fluid flow properties. However, within the scope of the invention there are also other shapes such as D-shaped steps and / or lights (figure 2c), oval, triangular, square, elliptical, bean-shaped steps and / or lights, or other configurations. (some of which are shown in Figures 2a to 2e). Furthermore, while the distal end tubes 14, 16 and lumens 24, 26 are preferably identical in cross section, it is within the scope of the invention to vary the size, shape and / or configuration of the distal end tubes 14, 16 and / or lights 24, 26 so that distal end tubes and / or smaller lights, or varying types of lights and distal end tubes can be used for other applications, such as an addition of a third smaller lumen and the corresponding distal end tube for the introduction of medication.

Figure 3 illustrates a cross section of the hub 18 of Figure 1, the hub 18 provides a reinforced area for termination of the proximal ends 28, 30 of the first and second lumens 24, 26, and for termination of the distal ends of extension tubes 20, 22. The hub could also include one or more suture wings to secure the catheter assembly to the body, if desired. The present invention also envisions the use of other concentrator configurations, as well as the use of a detachable concentrator.

A second realization

Figure 4 illustrates a catheter assembly 6, which is a second embodiment, an embodiment having additional limitations relative to the catheter assembly 5 of Figure 1. The catheter assembly 6 of figure 4 is distinguished mainly from the catheter assembly 5 of figure 1 in the part of the catheter assembly 6 between the distal ends 32, 34 and the transition point 36 (in the part of the longitudinal length of catheter assembly 6 generally denoted by arrow "B" in Figure 4). In one aspect of the embodiment of Figure 4, the transition point 36 is located at a point along the longitudinal length of the lumens 24, 26 such that the length of the longest of the first and second distal end tubes 14,16 (arrow "B") is greater than the longitudinal length of unitary catheter 12 (arrow portion "A").

In the embodiment of Figure 4, the outer walls 44 of the first and second distal end tubes 14, 16 are releasably connected from the transition point 36 to an imaginary point of attachment 48 (at a longitudinal length generally denoted by the arrow "B1" in figure 4). The releasable connection of the first and second distal end tubes 14, 16, from the transition point 36 to the attachment point 48 allows the first and second distal end tubes 14, 16 to be divided, with the use of minimal force, at any Longitudinal point selected between transition point 36 and adhesion point 48.

Between the transition point 36 and the point of adhesion 48, the cross-section of the first and second distal end tubes 14, 16 (Figure 4b) illustrates that the outer configuration of the first and second distal end tubes 14, 16 over the length Arrowhead "B1" resembles that of unitary catheter 12 (ie, smooth curved and generally oval shape). Figure 4b also illustrates that the first and second distal end tubes 14, 16, when viewed individually, are semi-circular in shape, each having a generally "D" shaped outer wall 44, with an adhesive splice point 46. weak between the flat side portions of the outer "D" shaped walls 44, the weak adhesive provides spreadability with the use of minimal force. In Fig. 4b, the flat side portions are looking at each other, and are identical to each other such that a cannula portion of the catheter assembly 6 maintains a generally rounded oval cross section.

The flat sides, when placed back-to-back to provide an overall oval outer configuration for the distal end tubes, help prevent blood from running between the tubes as there are no rounded or grooved surfaces between the tubes for it to travel the blood. The flat side portions of the tubes allow the tubes to snap together (if separate independent tubes are not desired) as if the tubes had never been separated, and are still in a unitary configuration.

Catheter assembly 6 includes adhesive, or a divisible membrane, to provide releasable connection between tubes 14, 16. The adhesive extends longitudinally between, and bonds, the generally opposite flat side portions of the first and second distal end tubes 14 , 16 (figure 4b). The adhesive (not shown in the figures) may extend longitudinally along a center line of the flat side portions of the tubes 14,16 to provide dimensional stability. However, the adhesive could spread between edges

ES 2 559 622 T3 of the flat side parts, or among other regions of the flat side parts, or the rounded wall parts of the tubes 14, 16.

The adhesive, or divisible membrane, performs multiple functions. First, the membrane joins the tubes 14, 16 so that the tubes 14, 16 can be easily manipulated, particularly when the membrane is unbroken. When the membrane is fully intact, catheter assembly 6 can be manipulated as a single catheter (eg, unitary catheter 12). Second, the membrane allows the first and second distal end tubes 14, 16 to be longitudinally separated from each other at least partially, without damaging the outer walls 44 of the tubes 14, 16, to allow independent movement of the divided parts in the vessel or other area to be catheterized. The membrane is constructed to split easily when the first and second tubes 14, 16 separate from each other, tearing or splitting thereby before the opposing forces exerted on the tubes 14, 16 reach a level sufficient to cause damage to the the same. However, the membrane must be strong enough to resist tearing during normal handling of the catheter assembly 6.

From the point of attachment 48, to the distal ends 32, 34 of the first and second lumens 24, 26, the first and second distal end tubes 14, 16 are spaced apart (unconnected) and independent (in a longitudinal length generally denoted by arrow "B2" in figure 4). In one aspect of the present invention, the cross-section of the first and second distal end tubes 14, 16 (Figure 4c) illustrates that the outer walls 44 of the first and second distal end tubes 14, 16 in the arrow length "B2 ”Are rounded. As shown in Figures 4a, 4b and 4c, the outer walls 39 of the first and second lights 24, 26 illustrate a circular cross section for the lights 24, 26.

A third realization

Figure 5 illustrates a catheter assembly 7, which is a third embodiment. The catheter assembly 7 of Figure 5 is mainly distinguished from the catheter assembly 5 of Figure 1 in the part of the catheter assembly 7 between the distal ends 32, 34 and the transition point 36 (in the part of the longitudinal length of catheter assembly 7 generally denoted by arrow "B" in Figure 5).

In the embodiment of Figure 5, the outer walls 44 of the first and second distal end tubes 14, 16 are spaced apart (unconnected) and independent from the transition point 36 to the distal ends 32, 34 (in the longitudinal length of the entire arrow "B" in figure 5), as shown in figure 5b. The cross-section of the first and second distal end tubes 14, 16 (Figure 5b) illustrates that the outer walls 44 of the first and second distal end tubes 14, 16 along the length of arrow "B", as well as the outer walls 39 of the first and second lights 24, 26, are rounded or circular.

The portion of the catheter assembly 7 between the proximal ends 28, 30 of the first and second lumens 24, 26 and the transition point 36 includes the unitary catheter 12 (at a longitudinal length in Figure 5 generally denoted by the arrow "A ”). As in the embodiments of Figures 1 and 4, the exterior of unitary catheter 12 includes a smooth, generally convex, curved surface. As shown in Figure 5a, the cross-section of the unitary catheter 12 is generally oval in shape, Figure 5a illustrates in cross-section the generally oval-shaped outer wall 38 of the unitary catheter 12 and the circular-shaped outer walls 39 of the first and second lights 24, 26.

A fourth realization

Figure 6 illustrates a catheter assembly 8, which is a fourth embodiment. Catheter assembly 8 of Figure 6 does not include a distinct unitary catheter portion 12, but instead includes first and second distal end tubes 14, 16 extending substantially the entire length of catheter assembly 8 (at the longitudinal length denoted generally by arrow "B" in figure 6). Although the catheter assembly 8 of Figure 6 does not include a distinct unitary catheter 12, a proximal portion of the first and second distal end tubes 14, 16 (through and including termination of the proximal ends of the first and second distal end tubes second 14, 16 within concentrator 18) includes an outer configuration having a smooth, rounded and generally oval perimeter. The concentrator 18 is similar to that shown in cross section in Figure 3.

As shown in figure 6a, the cross section of catheter assembly 8 at the part of its longitudinal length denoted generally by arrow "A" in figure 6, is generally oval in shape, figure 6a illustrates outer wall 38 generally oval in shape and the outer walls of circular shape 39 of the first and second lumens 24, 26. An embodiment of the invention is shown in Figure 6, the cross section of the arrow portion "A" of the catheter assembly 8 could include a single oval-shaped portion (as shown in Figure 6a) or two distal end tubes. semicirculars (“D” shape) 14, 16, placed back to back (that is, with the flats of the semicircle adjoining, as shown in figure 2e and 4b) with the flats permanently attached, perhaps with a suitable adhesive , each.

ES 2 559 622 T3

The outer walls 44 of the first and second distal end tubes 14, 16 may be spaced apart (unconnected) and independent in the arrow portion "B" of the longitudinal length of the catheter assembly 8 of Figure 6, or the tubes first and second distal ends 14, 16 can be releasably connected (divisible) at this length. In each case, the cross-section of the first and second distal end tubes 14, 16, as shown in Figure 6b, illustrates that the outer walls 44 of the first and second distal end tubes 14, 16, as well as the outer walls 39 of the first and second lights 24, 26, are rounded or circular.

Furthermore, it is envisioned that the first and second distal end tubes 14, 16 may have alternative features, such as, but not limited to, those shown in Figures 2a to 2e, or as previously described in connection with the first embodiment of the present invention.

A fifth realization

Figure 7 illustrates a catheter assembly 9, which is a fifth embodiment. Catheter assembly 9 of Figure 7 is similar to catheter assembly 8 of Figure 6, distinguished only by the incorporation of an alternative hub 18.

A hub provides a reinforced area for the proximal ends 28, 30 of the first and second lumens 24, 26, respectively, to communicate with the distal ends of the extension tubes. The hub also provides means for securing one or more lights to each other, thereby limiting the ability for the lights to be separated or divisible. Accordingly, the present invention contemplates the use of any hub-type device that achieves the foregoing, whether known in the art or to be developed, including detachable hub devices.

As is known in the art, the hub 18 can be sealed, such as by bonding, bonding, hot molding, or other connection, to a distal end of an extension tube (or extender) and a proximal end of a tube or tube. light. In one aspect of the invention, the extension tubes are proximal parts of two separate lumens that are coated with an outer layer, perhaps by hot molding, to form a unitary body part of the assembly. Accordingly, the extension tubes are continuous with the proximal ends of the lumens, and the hub 18 can simply be molded or otherwise bonded around the proximal ends of the lumens and around the distal ends of the extension tubes. In another aspect of the invention, the hub 18 (outer layer) is molded or otherwise adhered around some midpoint portion of a first or second tube or lumen, creating extension tubes and a catheter assembly from of a set of tubes or lights. If any aspect, above, is the embodiment of the concentrator 18 incorporated in the catheter assembly 9 of Figure 7, it is understood that the proximal end 28, 30 of the first and second lumens 24, 26 occurs at the point where extension tubes 20, 22 diverge diagonally from hub 18.

A sixth realization

Figure 8 illustrates a catheter assembly 10, which is a sixth embodiment. The catheter assembly 10 of Figure 8 is similar to the catheter assembly 8 of Figure 6, but includes the first and second distal end tubes 14, 16 that are spaced apart (unconnected) and independent of a substantial length from the set of catheter 10 (over the entire longitudinal length generally denoted by arrow "B" in Figure 8). Figure 8b illustrates a cross section of the first and second distal end tubes 14, 16, showing circular outer walls 44 for the first and second distal end tubes 14, 16, as well as circular outer walls 39 for the first and second lumens 24. , 26.

The catheter assembly 10 of Figure 8 also includes a proximal portion of the first and second distal end tubes 14, 16 with an outer configuration having a smooth, rounded, and generally oval perimeter. As shown in Figure 8a, the cross-section of catheter assembly 10 at the arrow portion "A" of the longitudinal length is generally oval in shape, Figure 8a illustrates the generally oval-shaped outer wall 38 and the outer walls circularly 39 of the first and second lights 24, 26. In addition, the cross section of the arrow portion "A" of the catheter assembly 10 could include a single oval-shaped portion (as shown in Figure 8a) or two semi-circular distal end tubes ("D" -shaped) 14, 16, placed back to back (that is, with the flats of the semicircle adjoining, as shown in Figure 2e and 4b) with the flats permanently attached to each other. The hub 18 of the catheter assembly 10 of Figure 8 is the hub 18 detailed in Figure 3.

A seventh realization

Figure 9 illustrates a catheter assembly 11, which is a seventh embodiment. Catheter assembly 11 of Figure 9 is similar to catheter assembly 10 of Figure 8, distinguished only by the incorporation of an alternative concentrator 18. It is envisioned that the present invention may incorporate any concentrator known in the art, any concentrator described in this memory or any hub to be developed.

ES 2 559 622 T3

General and alternative aspects of the present invention

Also described is a multi-catheter assembly, having two independently and freely movable distal ends 32, 34, while also providing aspects of a one-insert method and an ability to easily manipulate a proximal portion of unitary catheter 12 with only one method of insertion. tunneling. Unitary catheter 12, which has a smooth and generally convex outer surface, passes easily through an insertion site. A vessel wall can easily seal around the smooth curved surface of the unitary catheter 12. If round individual distal end tubes 14, 16 are located at the insertion site, the vessel wall will not seal as easily, or will not be able to seal as tightly, as if a generally oval or circular rounded unitary catheter 12 were used, as there is a potential risk of leakage around and between multiple rounded distal end tubes due to its "number 8" configuration.

The releasably connected (ie, divisible) portion of the catheter assemblies (eg, the arrow portion "B1" of Figure 6, the portion between the transition point 36 and the attachment point 48) provides, for a given patient, additional adaptability and flexibility of use and insertion of the respective catheter assembly. The height and weight of the patient each have consequences that affect what the desirable length of a unitary catheter-like portion of the catheter assembly would be, relative to the remainder of the catheter assembly, to ensure that a cross-sectional configuration The generally oval smooth of the catheter assembly is located at a vessel wall insertion site. The divisible portion of the catheter assembly provides flexibility, upon insertion of the catheter assembly, to determine an ideal length of a generally oval smooth cross-section (such as provided by the unitary catheter configuration of the present invention), and an ideal length of free-floating independent (ie, spaced) distal end tubes.

When releasable connection using adhesive is employed, the outer surfaces of the tubes are releasably bonded using an adhesive having an adhesive strength, relative to the material forming the tubes, greater than the cohesive strength of the adhesive. Since the adhesive is applied as a very thin layer or coating, it is not shown in the figures. However, one skilled in the art will understand, based on the description, that the adhesive is applied as a partial or complete coating on one or both of the outer walls 44 of the tubes 14, 16 such that when the tubes 14, 16 pressed together, the outer walls 44 will adhere. As a result of using an adhesive that adheres more strongly to the tubes than to itself, the adhesive will initially hold the desired part of the catheter assembly together, allowing manipulation of the catheter assembly in the same manner as a unitary multi-lumen catheter. . However, with the application of opposite transverse forces to the distal end portions and / or the distal ends 32, 34, the adhesive will lose cohesive strength and will separate longitudinally along the catheter assembly so that the tubes 14, 16 can be pulled apart. split longitudinally at least partially.

The length of the partition can be varied depending on the desired application. For example, for hemodialysis-type applications where the catheter assembly is inserted into an area to be catheterized, it may be desirable to split the tubes 14, 16 only the amount necessary to facilitate independent movement within the catheterized area. In blood flow and other fluid flow applications, such partial division may be desirable to avoid the possibility of fluid leaking from the catheterized area as it passes between tubes 14,16 of the catheter assembly. While adhesive is described herein to provide releasable connection, it will be understood that other suitable techniques could be used for releasable bonding of tubes 14, 16, such as breakable ultrasonic welding, or a polymeric breakable thin layer molded between tubes 14. , 16, or other similar structures, without departing from the scope of the invention, provided that the tubes 14, 16 remain longitudinally divisible with only a small amount of manual force. Using releasable connection, splittable layers, coatings, adhesives, and / or membranes described elsewhere in this specification, tubes 14,16 will not distort, stretch, or otherwise structurally altered during cleavage of tubes 14,16.

Each of the catheter assemblies may have round smooth distal ends 32, 34, which do not have protrusions on their surfaces that promote coagulation. A rough outer surface provides bumps, which can be points where clotting can begin. The distal ends 32, 34, which have round smooth outer surfaces that float freely within the vessel, do not provide a source of clot formation. The free floating distal ends of the present invention provide beneficial features in a single catheter tube, not including a tendency to suck against an interior surface of the vessel wall, which minimizes the tendency to stenosis. The catheter assemblies of the present invention also have little tendency to kink, as the unitary catheter-like configuration provides good support handling due to its wall thickness and cross section, and due to the smoothness of the spaced distal end tubes. .

As shown in the embodiments referred to above, the first and second distal end tubes 14, 16, and the first and second lumens 24, 26, have a generally circular cross section, since a circular cross section is most conducive to properties of fluid flow. However, other shapes are also within the scope of the invention, such as "D", oval, triangular, square, elliptical, bean or other shapes. In addition, while the distal end tubes 14, 16 and lumens 24, 26 with

ES 2 559 622 T3 preferably identical in cross section, it is within the scope of the invention to vary the size, shape or configuration of the distal end tubes and the lumens in cross section so that smaller tubes and / or lumens can be used, or Variable types of lights and distal end tubes for other applications, such as an addition of a third smaller lumen and the corresponding distal end tube for the introduction of medication.

The distal end tubes have various diameters or distal end shapes as is known in the art or to be developed. For example, the distal end tubes may have a larger diameter near the unitary catheter that makes a sharp or gradual transition to a smaller diameter near the distal ends of the tubes. Alternatively, a tapered, tapered, or angled distal end may be provided for various applications. However, blunt ends are preferred, preferably formed of soft durometer material so that the catheter assembly and distal ends provide patient comfort and avoid vessel wall trauma and stenosis.

In addition to an end hole 49 at each distal end 32, 34, the first and second distal end tubes 14, 16 may have a plurality of side holes 50 that extend through outer surfaces of the distal end tubes 14, 16 proximate to the distal ends 32, 34 of the first and second lumens 24, 26 (as shown in the various figures). Side ports 50 provide additional or alternate flow paths for fluids flowing between an area outside tubes 14, 16 and an area within tubes 14, 16, and vice versa. The side holes 50 may be arranged circumferentially and helically around the distal end tubes 14, 16 to provide optimal flow properties, and to avoid suction of the distal tubes 14, 16 against an area to be catheterized, such as a wall. of glass. The side holes 50 can be of various shapes, but are typically circular or oval, or some combination thereof.

The side holes 50 may also vary in number between the shorter and longer distal end tubes 14, 16. In one aspect of the present invention, the catheter assembly 6 of Figure 4 includes six side holes 50 in the second distal end tube 16 that is coiled on the side facing the first distal end tube 14, and five side holes 50 in the first distal end tube 14, in which all side holes 50 are circular except for the most proximal hole in the first distal end tube 14, which is oval. In this aspect of the present invention, the side holes 50 are located 60 ° apart in a 360 ° spiral.

Side ports 50 minimize vibratory movement of distal end tubes 14,16 by equalizing inflow and return disturbances through side ports 50.

Minimizing vibratory motion helps prevent stenosis. The side ports 50 also provide alternate openings in the distal end tubes 14, 16 so that if flow becomes blocked at one or both of the end ports 49 at the distal ends 32, 34, dialysis can continue until a replacement catheter assembly. It is to be understood that the present invention also envisions embodiments having no side holes 50, employing only end holes 49 at the distal ends 32, 34.

Materials forming the present invention

The catheter assemblies can be made of biocompatible elastomers or plastics, and are preferably made of biocompatible elastomers. Biocompatible plastics can be selected from materials such as polyurethane, polyethylene, homopolymers and copolymers of vinyl acetate such as ethylene vinyl acetate copolymer, poly (vinyl chloride), homopolymers and copolymers of acrylates such as poly (methyl methacrylate), polymethacrylate, ethylene glycol ethylenedimethacrylate and hydroxymethylmethacrylate, polyurethanes, polyvinylpyrrolidone, 2-pyrrolidone, polyacrylonitrilebutadiene, polycarbonates, polyamides, fluoropolymers such as homopolymers and copolymers of polytetrafluoroethylene and polyvinyl fluoride, polystyrenes, homopolymers and copolymers of styrenacrylonitrile, cellulose acetate, homopolymers and copolymers of acrylonitrilebutadienestyrene, polymethylpentene, other known polymethylpentene compounds, polymethylpentene, and other similar polyethersulftylene compounds by those skilled in the art. It should be understood that those possible biocompatible polymers are included above for exemplary purposes and are not to be construed as limiting.

If a biocompatible polymeric material is used to form the unitary catheter 12, it is preferred that the distal end tubes 14, 16 and extension tubes 20, 22 be made of polymeric material, including a polyurethane polymer or a polyolefin polymeric material that have a soft durometer, as specified below.

Extension tubes 20, 22 can be made separately from unitary catheter 12 and distal end tubes 14, 16, and formed from a material such as polyurethane or a polyvinyl chloride elastomer or polymer. However, it is preferred that the extension tubes 20, 22 be formed of the same material as the unitary catheter 12 and the distal end tubes 14, 16.

ES 2 559 622 T3

Most preferably, a biocompatible elastomer is used for all components of the present invention. Preferred biocompatible elastomers suitable for use in forming unitary catheter 12, distal end tubes 14, 16, and preferably extension tubes 20, 22, include biocompatible elastomers such as medical grade silicone rubbers, poly (chloride) elastomers. vinyl), polyolefin homopolymeric and copolymeric elastomers, urethane-based elastomers, and natural rubber or other synthetic rubbers. Preferably, the unitary catheter 12, the distal end tubes 14, 16 and the extension tubes 20, 22 are made of elastomeric material so that they are flexible, durable, soft and with respect to the inserted parts in the patient or tunnelled, they are easily conformable to the shape of the area to be catheterized and / or the subcutaneous area. In addition, these materials help to minimize the risk of damaging the vessel walls.

If the catheter assemblies are used for hemodialysis applications, the unitary catheter 12, the distal end tubes 14, 16, and the extension tubes 20, 22 are most preferably formed of a soft silicone elastomer having a hardness of about 75 -A to about 85-A on a Shore durometer scale. Suitable preferred elastomers include silicone or polyurethane elastomers, and most preferably polyurethane elastomers, such as, for example, Pellatane® from Dow Corning, or Tecothane®, Carbothane® or Tecoflex®, from Thermetics.

All components of the present invention can also optionally be made to include 20% barium sulfate in the elastomer to provide radiopacity if desired. While it is preferred to have a Shore-A durometer hardness in the above Shore-A durometer range and a somewhat soft material, if a biocompatible material is used, particularly for hemodialysis, it is also possible to use an elastomer having a durometer hardness. Lower Shore-A outside this range, particularly a stiffer material if a particular application requires it. It is also preferred that the concentrator is formed of an elastomeric material, and most preferably the same material as the other components of the catheter. However, the concentrator, while preferably somewhat flexible, may preferably also be somewhat harder and stiffer, approximately 5-10 points on the Shore-A durometer scale, than the other components of the catheter assemblies. It will be understood on the basis of this description that the softness or stiffness can be varied for different applications.

Unitary catheter 12, distal end tubes 14, 16, and extension tubes 20, 22 are formed of 85-A durometer Carbothane®. Alternatively, a preferred combination can be formed of about 80-A durometer Tecoflex® for the unitary catheter 12 and distal end tubes 14, 16, and about 80A durometer Pelletane® for the concentrator 18 and / or the extension tubes 20, 22. Additional components for connection to dialysis equipment or the like, including luers, connectors and the like, are preferably formed of an elastomeric and / or polymeric material, such as acetal, 80-A silicone or polyvinyl chloride. However, such connectors may be formed of any suitable material known or to be developed in the art to form such connectors and / or adapters.

Methods for making the present invention

Methods for making the multi-lumen catheter assemblies described above are also described. Referring now to Figures 10a and 10b, the method includes forming a unitary catheter tube 60 having a proximal portion 62, a distal portion 64, and a distal end portion 66 terminating in a distal end tip 68. Unitary catheter tube 60, as shown in FIG. 10a, can be formed using any suitable hot molding process, including injection molding, expansion / compression molding, and extrusion.

The unitary catheter tube 60 is formed by extrusion through a die to form internal lumens such as those shown in FIG. 10a '. In this embodiment, the lights are substantially the same and substantially identical in size and configuration. Unitary catheter tube 60, with longitudinally extending internal lumens, can also be formed by injection molding tube 60 around metal rods that are shaped like internal lumens.

Referring now to Figure 10b, the unitary catheter tube 60 is then split longitudinally along the distal portion 64 of the tube 60 using a sharp edge such as a heated razor blade or blade (not shown) for a distance predetermined, depending on the particular size desired for the catheter. In one aspect of the present invention, the unitary catheter tube 60 is divided a longitudinal length equal to at least half the total length of the tube 60. In another aspect of the present invention, the unitary catheter tube 60 is divided a longitudinal length greater than half the total length of tube 60.

Tube 60 is preferably divided as evenly as possible between the two lumens along an internal septum 70 (as shown in Figures 10b and 10b '). If more than two lumens are present in the catheter assembly, the unitary catheter tube would be divided equally along each inner septum, preferably with a substantially equal amount of tube material surrounding each of the divided portions of the tube.

ES 2 559 622 T3

The division of the unitary catheter tube 60 forms a first distal end tube 72 and a second distal end tube 74. The second distal end tube 74 can then be cut one size relative to the first distal end tube 72, if it is desired that an end tube distal is longer than the other. Separate lengths for the distal end tubes help prevent recirculation of fluids entering and leaving the tubes within the area to be catheterized.

After forming the unitary catheter tube 60 and distal end tubes 72, 74, the outer surface of the unitary catheter tube 60 and the outer surfaces of the distal end tubes 72, 74 are ground and polished to a smooth surface. Radio Frequency (RF) limb shaping can be used to provide the smooth surface. Radio Frequency (RF) limb shaping uses RF energy to reheat an outer surface until something melts and then polish the surface.

In addition, the unitary catheter tube 60 and the distal end tubes 72, 74 could undergo radiofrequency (RF) tip shaping on a mandrel, so that the tubes can be reshaped to have a generally circular cross section in both the passages interiors (lights) as well as exterior surfaces, if desired. In one aspect of the invention (referring to Figure 1), the outer surfaces of the distal end tubes are rounded to a circular cross section from the transition point 36 to the distal ends 32, 34 (the arrow portion "B ”). In another aspect of the invention (referring to Figure 4), the outer surfaces of the distal end tubes are rounded to a circular cross section from the point of attachment 48 to the distal ends 32, 34 (the arrow portion "B2 ”).

Once the surfaces are shaped and smoothed, then holes can be formed in the distal end tubes, if desired, using techniques well known in the art. The number, size, shape and spacing of the holes are as individually preferred, but some general and specific aspects have been described above.

Parts of the divided catheter can now be releasably connected, if desired, by adhering portions of the outer surfaces of the distal end tubes with a weak adhesive. In one aspect of the invention (referring to Figure 1), portions of the outer surfaces of the distal end tubes may be adhered (releasably connected) to a proximal portion or all of the arrow portion "B" of the catheter assembly 5 (i.e., in a length beginning at transition point 36 and extending toward distal ends 32, 34, or over the entire length beginning at the transition point 36 and extending to the distal ends 32, 34. In another aspect of the invention (referring to Figure 4), portions of the outer surfaces of the distal end tubes are they adhere (releasably connected) the entire length of the tubes beginning at transition point 36 and extending to point of attachment 48 (the arrow portion "B1").

In accordance with the invention, after forming tube 60, individual distal end tubes, which have been previously extruded and hot molded, can be fused onto unitary catheter tube 60. The distal end tubes are formed so that each has a respective longitudinal passage (lumen) extending longitudinally therethrough, and may also be formed to include a plurality of holes either prior to connection to the distal end of the catheter tube. unit 60 or after connection to the unit catheter tube 60. The distal end tubes can be shaped in various cross-sectional shapes, as desired, with some general and specific aspects described above.

Each formed distal end tube is then connected to the distal end of unitary catheter tube 60 by a suitable heat molding process, or by another form of connection, such as adhesive, ultrasonic welding, or other methods known in the art, such that the first passage in the first distal end tube is in fluid communication with the first lumen of the unitary catheter tube and the second passage in the second distal end tube is in fluid communication with the second lumen in the catheter tube unitary. In one aspect of the present invention, heat fusion is used to connect the distal end tubes, and the fusion can be accomplished using heat applied to the unitary catheter tube and female cavity mold distal end tube lengths to create a smooth fused part in which the tube and end tube lengths meet.

Making the catheter assembly 6 of Figure 4 would require a slightly modified process if fusing individual distal end tubes to a unitary catheter tube were employed. The unitary catheter tube 60 with an exterior having an oval cross section could still be split, prior to fusing round distal end tubes to the distal end of the divided unitary catheter tube, as part of the catheter assembly 6 of Figure 4 between transition point 36 and attachment point 48 (arrow portion "B1") have an exterior having two semi-circular cross sections (double "D"), as shown in Figure 4b. Therefore, prior to fusing individual distal end tubes to the distal end of the unitary catheter tube, the unitary catheter tube would need to cut (split), as described above, at that desired distance for the arrow portion "B1" of the catheter assembly 6. Alternatively, it is possible to perform two tube fuses of different cross-sections, such as fusing a tube and then grinding and polishing a part of it, as described above.

ES 2 559 622 T3

Generally, the extension tubes 20, 22 can be provided either by extrusion or molding of the extension tubes initially when the unitary catheter tube 60 is formed using techniques similar to those used to form the distal end tubes as described above. .

However, it is preferred to connect the extension tubes to a proximal end of the unitary catheter tube using a hub.

Another alternative to the methods described above for making the present invention includes arranging a first catheter tube and a second catheter tube in a substantially longitudinal parallel arrangement, preferably so that they are juxtaposed with each other; however, a slack may be present between the catheter tubes. In addition, more than two catheter tubes can be used and similarly arranged. Each of the catheter tubes is preferably a single lumen catheter; however, for some applications multi-lumen catheters can also be used. Each of the first and second catheter tubes has a respective distal end, distal end portion, and at least one lumen in each catheter tube extending longitudinally therethrough.

An outer layer (sheet) is formed around at least a portion of the length of the outer surfaces of the first and second catheter tubes proximal to the distal end portions of the catheters. The outer layer is preferably extruded around the catheter tubes. However, the catheter tube arrangement and the outer layer formation can also be formed by extruding the catheter tubes simultaneously through dies while the outer layer is coextruded around the catheter tubes. However, the outer layer is coextruded only over a portion of the length of the outer surfaces of the catheter tubes proximal to the distal end portions.

Once the outer layer is formed, sufficient thermal moldability can be applied to heat mold the first and second catheter tubes together. The lumens / passages within the catheter tubes are generally longitudinally parallel, and the catheter tubes are heat molded together in juxtaposed relationship and fixed within the outer layer.

The distal end portions of the catheter tubes extend outwardly and distally from those portions of the lengths of the outer surfaces of the first and second catheter tubes that are within the outer layer. Since the distal end parts are not connected, they can perform independent free-floating movement. It is also within the scope of the invention to heat mold a filler material between the first and second catheter tubes to ensure that an oval smooth outer surface is formed around the catheters once the outer layer is formed.

As previously described, extension tubes can be provided at the ends of the catheter tubes if the outer layer is formed to expand to the proximal ends of the catheter tubes. Alternatively, the outer layer can be formed only a portion of the length of the catheter tubes, leaving separate and independent proximal ends extending from the area within the outer layer to form extension tubes. In this case, the proximal end portions serving as extension tubes, in the manner of the extension tubes 20, 22 shown in Figure 1, extend proximally from a proximal end of the outer layer formed around the catheter tubes. to provide the unitary catheter 12 of Figure 1.

A concentrator is then molded around the proximal end of the outer layer and the distal end of catheter tubes that extend proximally adjacent the outer layer. Preferably, to hold the unitary catheter and extension tubes in place, the concentrator mold has cavities to receive the tubes or metal rods inserted through the extension tubes and lumens within the unitary catheter portion formed, to keep the shape of the lights and hold the tubes in place. A plurality of holes may also be provided for the distal end portions of the catheter tubes.

Those skilled in the art will appreciate that changes can be made to the embodiments described above without departing from the broad inventive concept thereof. Therefore, it is understood that this invention is not limited to particular embodiments included, but is intended to encompass modifications within the sphere and scope of the present invention as defined in the purported claims.