WO2011089014A1

WO2011089014A1 - Catheter having spacer holder

Info

Publication number: WO2011089014A1
Application number: PCT/EP2011/000267
Authority: WO
Inventors: Markus Cybulla
Original assignee: Markus Cybulla
Priority date: 2010-01-23
Filing date: 2011-01-24
Publication date: 2011-07-28
Also published as: DE102010005542A1

Abstract

The invention relates to a catheter having a spacer (3). Said spacer (3) spreads or springs open radially to the outside when it is located in the interior of a container. Perfusion of the container is thus ensured, including when the catheter is inserted. According to the invention, it is simultaneously ensured that it only very rarely clogs. In addition, a point (7) of the cannula (1) does not harm the inner wall of the container.

Description

Title: Catheter with Spacer

description

Catheters are used in many areas of medicine and are indispensable there. Examples of this are, above all, venous accesses to the infusion of fluids.

A conventional catheter comprises a cannula and at least one lumen, the cannula having the task, for example, of penetrating a vessel and thus establishing a fluidic connection between the lumen and the vessel. Frequently, once a catheter has been set, it remains in the patient's body for a period of several hours or even several days for access, be it for infusion of medication or infusion, and / or

Removal of liquids, to have.

In the removal or transfusion and exchange

(Dialysis, apheresis, etc.) and measurement of body fluids and their solid and non-solid constituents with the help of vascular catheters or cannulas, punctures and / or lying catheters often cause damage to the vessel walls and the surrounding tissue with the formation of hematomas. The result can be vascular occlusions, infections and irreparable tissue damage, which can be detrimental to the patient. However, properly placed catheters and cannulas may be severely impaired in function, for example if they adhere to the vessel walls, because then the inflow or outflow is obstructed or even completely succumbs. This requires new functions which, in turn, result in the hazards described above.

From US 6,673,042 Bl a cannula is known, which in

Inner has a guide wire. A distal portion of the cannula is a radially expandable wire mesh

educated. When the cannula reaches a desired position in one

CONFIRMATION COPY Vein has reached, then the wire mesh is through

Retracting the guidewire spread and thereby prevents the "collapse" of the surrounding vein.

The invention has for its object to provide a catheter that can remain with high reliability for a longer duration in the body of the patient, without causing obstruction of the cannula or the vessel in which the cannula is located.

This object is achieved according to the invention in a catheter,

comprising a cannula and at least one lumen, wherein the cannula and the lumen fluidly communicate with each other by being loosened coaxially with the cannula

Spacer is arranged and that the spacer is partially resilient in the radial direction.

The present invention describes a catheter and

Cannula system with the help of a spacer

(Basket), which unfolds from the cannula wall, a protection of the surrounding tissue is ensured. This basket is fixed during the insertion process to the target tissue vessel in a second tube or catheter to the

Restrict insertion diameter of the catheter cannula system. Both coaxially mounted tubes and cannulas can be moved against each other to expand the

Spacer to allow in the radial direction. The spacer is preferably made of a

Shape memory alloy (Nitinol) or one

highly elastic material, preferably a highly elastic polymer manufactured.

When the catheter or cannula is accurately placed, the expanded spacer prevents damage to the surrounding tissue. Further, since the lumen of the catheter or cannula is protected by the cup, the adherence of the catheter Catheter to the vessel wall no longer possible, allowing a constant undisturbed fluid flow.

The spacer according to the invention expands in a very small, but nevertheless effective measure the vessel in which the cannula is located in the radial direction, so that the free

Strömungsguerschnitt in the vessel at the point where the cannula opens into the vessel is not significantly reduced. As a result, there is a significant reduction in the risk of the vessel becoming clogged at this most vulnerable point. Another advantage of the spacer according to the invention is that the spacer centers the cannula within the vessel so that the tip of the cannula does not abut the vessel wall. This ensures that the cannula does not inflict injury on the vessel wall. Furthermore, it is ensured that the cannula is always surrounded by liquid and thereby the clogging of the cannula can be minimized.

Through the cannula of the catheter according to the invention either drugs or other liquids can be introduced into the vessel. But it is equally possible to remove liquid from the vessel. Also at

long-lasting treatments that last for hours or even days, it is possible with the help of

catheter according to the invention at the required times to remove body fluid or to introduce a liquid such as a drug or a contrast agent in the vessel.

In a further advantageous embodiment of the invention, it is provided that the spacer, if it is not prevented by another component from rebounding, at least partially increased in diameter. This means that the spacer has a diameter extension in this rebound state, which leads to a moderate Widening of the vessel wall, in which the spacer is located. This creates space in the vessel so that the body fluid circulating in the vessel can flow past the cannula almost undisturbed. At the same time, it is also ensured that the tip of the cannula does not touch the vessel wall and thus does not hurt from the inside.

In addition, this reduces the risk of adding the cannula.

In a further advantageous embodiment of the invention may be arranged coaxially to the cannula an indwelling cannula (Braunüle) or an introducer sheath. For then it is also possible to inject medication, contrast media and other more into the vessel via this cannula or the introducer sheath. At the same time, it is also possible to remove the catheter when the introducer sheath is inserted, if

for example due to a medical treatment, another catheter or other instrument over the

Introductory lock must be introduced into the vessel. Because a cannula or an introducer sheath can also be placed simultaneously with the catheter according to the invention, the use of the catheter according to the invention is very gentle on the patient.

In a further advantageous embodiment of the invention, the cannula, the indwelling cannula, the introducer sheath and / or the spacer in the axial direction relative to each other

displaceable. This makes it possible, for example, when laying the catheter to pierce the vessel wall using the sharpened cannula and then the

Spacer and, if available, the indwelling cannula or the introducer, to put. Even the fact that both the catheter and an indwelling cannula or an introducer sheath can be set by a puncture by means of the cannula, illustrates how gentle and low risk the use of the invention

Catheter is.

When the introducer sheath is at its destination

It is because of the axial displacement of

Catheter and spacer relative to the introducer sheath possible, then the cannula and with it the

To bring spacers to the desired location. The Kathederspitze can already be withdrawn something, so that in this state, the foremost boundary of the catheter is formed by the spacer. This

Spacer has no sharp edges. This ensures that the vessel wall from the cannula is not

is injured while the catheter is advanced in the vessel until the spacer or cannula has reached the desired location.

If, for example, the introducer sheath over the

Spacer is pushed, then pushes the introducer sheath the radially resilient portion of the spacer together to a minimum diameter, so that the entire assembly in this state has approximately the same diameter as a conventional introducer sheath and thus the insertion of the catheter according to the invention as the introducer sheath or a cannula no major difficulties and

Complications are caused, such as laying a conventional catheter or a conventional cannula.

The resilient property according to the invention in the radial direction is advantageously achieved in that the

Spacer has webs extending in the axial direction of the spacer, and that the webs are resilient in the radial direction. These webs can

For example, in the form of a "leaf spring" can be formed by windows are recessed between the webs.The width of the webs is dimensioned so that they are the desired Have spring rate. About the length of the webs in the axial

Direction can be set even with otherwise the same parameters of the travel of the webs in a simple manner.

Alternatively, it is also possible to make the webs of wire pieces which are parallel and coaxial with the catheter

run. At their ends, the pieces of wire are connected to a tubular portion of the spacer, so that the risk of injury to the vessel wall is minimized here. Of course, all components of the

Spacer, but also the introducer sheath are very carefully rounded and have no sharp edges to minimize the risk of injury to the vessel wall.

It has further proven to be advantageous if the

Spacer is at least partially made of a material having a shape memory (so-called memory effect). For then it is possible that the spacer takes its original shape at body temperature in which it has a diameter-expanded portion. At lower temperatures than the body temperature, the spacer has a cylindrical shape and is thus

minimized in terms of its diameter. In this condition it can be placed together with the catheter. As a result, the spacer assumes the body temperature of the patient.

As soon as it has a sufficient temperature, its shape memory is reactivated and in sections the diameter of the spacer widens. This makes it possible, a spacer according to the invention without

additional protective tube without cannula and without introducer sheath. This achieves a further simplification, but also a reduction in the diameter of the catheter according to the invention when the catheter is laid.

As materials suitable in principle, plastics but also metallic materials, such as NitTiNol, as proved suitable. Further advantages and advantageous

Embodiments of the invention are the following

Drawing, the description and the claims

removable. All features described in the drawing, the description and the claims can be used individually as well as in any combination with one another

be essential to the invention.

drawing

Show it

Figures 1 to 8 different embodiments

inventive catheter in different views.

Description of the embodiments

1 shows a first embodiment of a

catheter according to the invention with spacers in

presented different views. In FIG. 1a, the essential components of the catheter according to the invention, namely a cannula 1 and a spacer 3, are in one

Exploded view arranged. The inner diameter of the spacer 3 is slightly larger than the outer diameter of the cannula 1, so that the spacer 3 is pushed in the axial direction over the cannula 1 or relative to the cannula 1 is displaceable. Optionally, a Braunüle or indwelling cannula (5) can be pushed over the spacer 3. In FIG. 1b, the components described are cannula 1,

Spacer 3 and Braunüle 3 pushed together

shown. In this state, the inventive

Catheter set by the tip 7 of the cannula 1 the

Vascular wall pierces and thus penetrates into the interior of a vessel (not shown). As soon as the tip 7 of the cannula 1 has penetrated into the interior of the vessel, the spacer 3 according to the invention is displaced forward in the axial direction until it covers the sharp tip 7 of the cannula 1. This ensures that the tip 7 causes no damage or injury to the vessel wall. The front end 9 of the spacer 3 is of course very well rounded and has no sharp edges or projections.

Spaced slightly in the axial direction from the front end 9 are a plurality of circumferentially distributed webs 11 on the

Spacer formed. The webs 11 run in

Essentially in the axial direction of the spacer 3. In the circumferential direction 11 windows (without reference numerals) are recessed between the webs.

In the figure lc, the first embodiment of a catheter according to the invention according to Figure lb is shown in longitudinal section and in various side views. From these

Representations it becomes clear that in the in FIG

illustrated state of the spacers 3 has a certain extent the shape of a thin-walled tube, wherein spaced from the front end 9 webs 11 have remained. In this state, with the catheter according to the invention, comprising the cannula 1, the spacer 3 and, if desired, the

Braunüle or indwelling cannula (5) can be created access to a vessel of a patient.

When the indwelling cannula 5 is subsequently withdrawn, the webs 11 spring out and occupy a larger diameter than the remainder of the spacer 3, as shown in FIG. 2b. This situation is sought when the catheter has been set and consequently both the cannula 1 and the spacer 3 with its front end 9 are located in the vessel of the patient, not shown in FIG. Subsequently, the spacer 3 and, if desired, the cannula 1 advanced into the vessel. Once the webs 11 of the spacer 3 is no longer through the Braunüle or indwelling cannula 5 in the illustrated in Figure 1

closed position to be pressed, the webs 11 spring radially outward. This causes surrounding

Vascular wall (not shown) is slightly widened and, as is particularly well visible in particular from the longitudinal section of Figure 2c, the tip 7 of the cannula 1 is effectively protected by the radially outwardly resilient webs 11. This means that the tip 7 of the cannula 1 can not cause injuries to the vessel wall. At the same time, however, a sufficiently large flow cross-section of the

feathered webs 11 kept free, so that circulating in the vessel body fluid can circulate almost undisturbed. At the same time can also be a drug, a

Contrast agent or other more introduced into the vessel or the interior of the vessel or removed via the cannula 1. Because the tip 7 of the cannula 1 of the

webs 11 according to the invention is held at a certain distance at a distance to the vessel wall, is also the risk that the cannula 1 added significantly reduced.

By the webs 11 according to the invention, it is ensured that the tip of the cannula 1 is always flowed around optimally and as a result the risk of clogging is minimized. As can be seen from the lower part as shown in FIG. 2 a, the cannula 1 can also be withdrawn and replaced by a different cannula or another instrument, for example, when the cannula is inserted and fixed to the patient and the spacer 3 inserted according to the invention. The resiliently spread webs 11, even when the cannula 1 has been pulled, ensure that the patient's vessel is kept open and slightly widened, so that when subsequently a cannula 1 again passes over the indwelling cannula 5 or the cannula 1

Spacer 3 is inserted into the vessel of the patient, the access is not blocked and thus without complications and without inconvenience, the desired new cannula 1 or the required new instrument can be introduced.

In the embodiment according to FIGS. 3 and 4, instead of an indwelling cannula 5, an introducer sheath 13 is provided

available. The introducer sheath 13, like the indwelling cannula 5 also, has the task of introducing the invention

Catheter compress the webs 11 radially inwardly, so that the entire arrangement as small as possible

Diameter receives and thus the laying of the catheter according to the invention is facilitated. Similar to a

Indwelling cannula 5 remains the introducer sheath 13 together with the spacer 3 of the invention attached to the patient and the cannula 1 can be pulled out as needed and replaced by another cannula or another instrument. Otherwise, the statements made with regard to FIGS. 1 and 2 apply correspondingly.

In FIGS. 5 and 6, a third variant of a

Spacer according to the invention shown. In this third variant, the spacer 3 is arranged inside the cannula 1 when the catheter to which the cannula 1 belongs is placed. This situation is shown in FIG. In this case, the cannula 1 takes on the task to press the webs 11 of the spacer 3 in the radial direction inwards, so that the diameter of the entire assembly

is minimized. In this position of the spacer shown in Figure 5, the catheter is placed, in which the tip 7 of the cannula 1, the vessel wall is pierced.

Subsequently, as shown in Figure 6, the

Spacer 3 in the axial direction relative to the cannula 1 pushed forward. As soon as the webs 11 of the spacer 3 are no longer surrounded by the cannula 1, they spread outward in the radial direction and thereby create the space according to the invention for the removal or insertion of Liquids in the vessel. Here, too, the radially outwardly projecting webs 11 have the function of expanding the vessel wall somewhat outwards so that the vessel is not blocked by the catheters according to the invention. On the other hand, it is also ensured that the tip 7 of a cannula 1 does not reach the vessel wall with the advantages already described several times previously.

FIGS. 7 and 8 show a further exemplary embodiment of a spacer 3 according to the invention. This spacer can also be used in the catheters described above with reference to FIGS. 1 to 6. FIG. 7a shows the spacer 3 in an open state in a side view. FIG. 7b shows the spacer 3 in the open state in longitudinal section.

In this embodiment, spring elements 15 are still formed between the webs 11, which support the spreading of the webs 11. In the illustrated embodiment, the spring elements 15 from the originally tubular

Spacer 3 worked out. This condition is shown in FIG.

In order to increase the bias of the spring elements 15 and also of the webs 11, the blank of an inventive

Spacer 13 are compressed in the axial direction, so that the webs 11 and the spring elements 15 deform in the radial direction outwards and they permanently assume the shape shown in Figure 7. The spring elements 15 serve to support the spreading of the webs 11 in the radial direction or to allow at all.

In this state, the spacer 3 can then be assembled with a cannula 1 and an indwelling cannula 5 to form a catheter according to the invention. The indwelling cannula 5 then presses the webs 11 and the spring elements 15 against their Spring force radially together. In the embodiments according to Figures 1 to 8, the webs 11 are made of a resilient material. When placing the catheter, the webs 11 are radially compressed by the cannula 13 or the cannula 1 so that the catheter can be inserted as easily as possible into the vessel. As soon as the spacer 3 is pushed forward out of the cannula 1, the webs 11 spring outward in the radial direction and thereby cause the expansion of the

Vascular wall and provide a space for the tip 7 of the cannula ready.

Alternatively, it is also possible to make at least the webs 11 of the spacer 3 from a shape memory material, wherein the rebounded state, i. with radially outwardly bent webs is then taken when the material has approximately assumed the body temperature of the patient, t. Previously, i. at lower temperatures, that is

Spacer formed as a cylindrical tube and thus can be easily and without complications together with the cannula into the vessel. As soon as the spacer 3 is inside the vessel, it assumes the temperature of the patient. As a result, the shape memory of the material is activated and the webs 11 springs in the radial direction to the outside, as shown in Figures 2, 4 and 6.

Claims

claims

A catheter comprising a cannula (1) and at least one

Lumen, wherein the cannula (1) and the lumen fluidly communicate with each other, characterized in that coaxial with the cannula (1) a spacer (3) is arranged, and that the spacer (3)

partially resilient in the radial direction.

2. Catheter according to claim 1, characterized in that the spacer (3) in the rebounded state

at least partially enlarged in diameter.

3. A catheter according to claim 1 or 2, characterized in that coaxial with the cannula (1) an indwelling cannula (5) or an introducer sheath (13) is arranged.

4. Catheter according to one of the preceding claims, characterized in that the cannula (1), the indwelling cannula (5), the introducer sheath (13) and / or the spacer (3) in the axial direction are displaceable relative to each other.

5. Catheter according to one of the preceding claims, characterized in that the spacer (3) webs (11), that the webs (11) extend in the axial direction of the spacer (3), and that the webs (11) in the radial Direction are designed resilient.

6. Catheter according to claim 5, characterized in that on the webs (11) spring elements (15) engage.

7. Catheter according to one of the preceding claims, characterized in that the cannula (1) as a

Having piercing aid serving tip (7).

8. Catheter according to one of the preceding claims, characterized in that the spacer (3) is at least partially made of a material with shape memory (memory effect).

9. A catheter according to claim 6, characterized in that the spacer (3) is activated at about 37 ° C its shape memory and its diameter is at least partially increased.

Catheter according to one of the preceding claims, characterized in that the spacer (3) consists of a plastic, in particular of polyurethane, polyamide and / or polymer, or metal, in particular nitinol, titanium, so-called memory metals, or compositions thereof.