WO2000025851A1

WO2000025851A1 - End piece for a catheter or the like, perfusion catheter and perfusion catheter systems

Info

Publication number: WO2000025851A1
Application number: PCT/AT1999/000259
Authority: WO
Inventors: Werner Mohl; Dirk Peter Claassen
Original assignee: Pro-Med Technology Consult Medizinisch-Technische Geräte Gmbh
Priority date: 1998-11-02
Filing date: 1999-11-02
Publication date: 2000-05-11
Also published as: WO2000025851B1; AU1017900A

Abstract

The present invention relates to an end piece (2, 3) for a catheter (1) or the like, wherein said end piece comprises an inlet opening for a liquid or a gas that results in the widening of a sealing member or area provided on said end piece. The purpose of this invention is to provide a better sealing of the vessel without excessive stress, to reduce as much as possible the overall dimensions and to simplify the apparatus as much as possible while simultaneously ensuring that the operation or intervention site is free from any blood or the like. To this end, the sealing member (8, 12) or the sealing area (6) comprise at least one outlet opening which is different from the inlet opening for the gas or the liquid. This invention also relates to a perfusion catheter comprising at least two distal, flexible and hollow end pieces (2, 3) which are capable of axial sliding movement, which can be displaced individually and which are guided in the catheter so as to be capable of sliding in parallel. Each end piece includes at least one sealing member and the perfusion catheter is provided with such end pieces (2, 3).

Description

END PIECE FOR CATHETER OR SIMILAR, PERFUSION CATHETER AND PERFUSION CATHETER SYSTEMS

The invention relates to an end piece for a catheter or the like, with an inlet opening for a liquid or a gas which causes the expansion of a sealing element or area provided on the end piece, a perfusion catheter with at least two hollow, axially displaceable, flexible distal end pieces, which are individual are adjustable and displaceable parallel to each other in the catheter and which are each provided with at least one sealing element, and a perfusion catheter system

It is known to seal the ends of catheters by means of inflatable balloons, which balloons press against the inner wall of the vessel under the pressure of an introduced gas or a liquid and thus interrupt the blood flow. An example of such a device is described, for example, in WO94 / 22519. However, sealing elements are also used on catheter end pieces with fixed dimensions, the outer diameter of which is larger than the vessel lumen and which, when inserted into the vessel, cause this expansion and thereby the sealing effect. Finally, WO96 / 17644 discloses a catheter system in which several Perfusion catheters are guided through a guide catheter to the site of intervention, each of the perfusion catheters inserted into a vessel being provided at the end with a sealing element.

The above constructions have the disadvantage that, despite the relatively large outlay and large dimensions, also because of the lines for the medium for expanding the sealing balloons, they cannot ensure sufficient clearance of the operation or intervention site. Therefore, for example in the production of apiastomoses Usually a carbon dioxide gas jet is used to keep the surgical site free of blood.This means, of course, additional equipment and a further reduction in the space available for the surgeon to work.In addition, blood is blown away by the relatively strong gas jet, but this also deforms and anastomoses the site anastomosis formation difficult It was therefore the object of the present invention to provide a catheter end piece which, with the best sealing of the vessel, without excessive stress due to clamps or excessive expansion, with the smallest possible space requirement and expenditure on equipment, at the same time keeping the surgical or surgical site largely free of blood , other body fluids or the like. Another task was a perfusion catheter, in particular for use in the manufacture of anastomoses, which enables a secure seal and at the same time keeping the surgical site free while taking up little space.

To achieve this object, it is provided according to the invention that the sealing element or the sealing area has at least one outlet opening that is different from the inlet opening for the liquid or the gas. This configuration of the catheter end piece means that the fluid which is used to expand the catheter end or a sealing element arranged thereon and thus to seal the vessel can also be used for other tasks. For example, a liquid which is to be introduced into the bloodstream could be passed through the catheter end under such a pressure that this liquid expands the material of the catheter and thus brings it into sealing contact with the inner wall of the vessel.

For this purpose, it is particularly advantageous if the outlet opening is oriented essentially in the same direction as the inlet opening. This also facilitates the guidance and exact alignment of the catheter end to the intended site of intervention.

According to a first embodiment it can be provided that the sealing element is formed by at least one sleeve made of hydrophilic plastic on the outside of the end piece.

According to a further advantageous embodiment, the sealing element is itself formed by at least one section of the end piece which can be expanded radially under the pressure flowing through the pressure. Thus, for example when using the end piece according to the invention in a perfusion catheter, the widening of the catheter end for sealing the vessel by the pressure of the Perfusates are possible even in the catheter and further lines that take up additional space can be avoided.

It could be provided according to an additional feature of the invention that the outlet opening on the end piece is initially closed and is evident from a predetermined pressure that is above the pressure required to expand the expandable section. Before the medium that is introduced through the catheter first flows out, a relatively high pressure builds up, which leads to the rapid and secure sealing of the vessel. Only then does the end of the catheter open, and if the vessel section is well sealed, the medium is then introduced into the bloodstream or to the site of the intervention, which can then also take place under somewhat lower pressure, as long as this is sufficient to maintain the sealing effect.

The sealing effect can additionally be supported or maintained in the event of a pressure drop by at least one area consisting of a shape memory material. The end of the catheter is brought into the sealing form by the action of the fluid passed through and securely held in this sealing form by the shape memory effect, even if the fluid pressure should then drop.

According to another advantageous embodiment of the invention, the catheter end piece is characterized in that the or each sealing element is designed as a preferably elastic, expandable sleeve around the end piece, which sleeve is open in the proximal direction. This results in a construction that is very simple to manufacture and that can be made with the smallest diameter, but nevertheless securely seals the operating area by introducing a liquid or better gas flow under the cuff. Through the opening facing the operation area, the greatest possible liquid or gas flow into this area for displacing blood or the like is additionally ensured for the production of the seal of the vessel, wherein the sufficiency is found with only one additional fluid line into the area of engagement.

If the line for supplying fluid advantageously has at least one outlet opening in the area covered by the cuff, the optimum flow rate at the beginning of the supply or with the smallest amounts of gas or liquid Male sealing effect and backflow into the surgical area ensured. The fluid used can be a gas, such as carbon dioxide, which is usually used to keep the site of intervention free of blood and other body fluids, or a liquid, such as saline, for flushing the operating site.

Another embodiment is characterized in that the or each sealing element consists of a preferably elastic, expandable balloon around the end piece. Part of the liquid passed through the end of the catheter can preferably flow into these through suitable outlet openings in the region of the balloon, expand it and bring it sealingly against the inner wall of the vessel. As soon as this process is complete, all of the fluid only flows through the end of the catheter into the patient's blood vessel or bloodstream. Here, too, the fluid to be introduced is used in addition to its actual effect in the body or at the operation site to produce the sealing effect, so that additional effort for a separate sealing system can be avoided.

According to a further feature of the invention, it is provided that the or each balloon has at least one outlet opening which is preferably directed in the proximal direction of the distal end piece. Even with the smallest amounts of liquid or gas, a quick and safe sealing of the vessel is possible, after which the outflow through the outlet openings for introducing the fluid into the body or to the operation site takes place or through the displacement effect keeps it free of blood or the like.

The best possible keeping the surgical area free of blood is possible with this variant if the or each balloon is provided with a group of outlet openings distributed over the circumference.

To achieve the further object, a perfusion catheter described at the outset is characterized according to the invention in that at least one of these end pieces is designed in accordance with one of the preceding paragraphs. This enables perfusion in any vessel into which an end piece of the catheter is inserted, with the formation of at least one of these end pieces for simultaneously effecting the sealing and keeping the point of engagement free, thereby saving considerable space by saving an additional sealing medium. Conduction directly to the catheter ends is possible, which benefits the operating surgeon.

According to a further feature of the invention, the perfusion catheter itself is characterized in that a further lumen is provided, from which a line leads to at least one sealing element or region of an end piece and which can be connected proximally to a gas source or liquid source, or in which one Light source is provided. Since the catheter itself can be made somewhat thicker without major disadvantage, as long as only its end pieces penetrating into the vessels can be kept small due to the double function of the medium flowing through for sealing and its actually intended effect, the formation of a further lumen and the gas supply are necessary additional or supplementary keeping the surgical area free of blood or the like is advantageously possible. A light source in the catheter itself makes external light sources, holders and supply lines unnecessary, so that the space requirement of the overall system remains small.

Preferably, the distal end pieces can also be connected to a gas or liquid source via the catheter, so that in addition to the conventional perfume, which is mostly blood drawn from the patient elsewhere, also gases, for example oxygen or carbon dioxide, and liquids, for example physiological Saline, can be introduced. This allows the composition of the blood downstream of the perfusion site to be adjusted precisely.

In order to be able to adapt the perfusion exactly to the physiological needs, a pressure and / or flow sensor is provided in a perfusion catheter system of the type mentioned at the gas or liquid source and / or in the course of the lumen to the distal end pieces.

To increase comfort and to make it easier for the attending doctor or medical team to concentrate on the actual procedure, it is provided that the pressure and / or flow sensor is connected to a control unit for the gas and / or liquid source.

A program is advantageously stored in the control unit which uses at least one parameter via an algorithm known per se to determine the necessary pressure or flow rate is determined and the gas or liquid source is controlled accordingly.

In the following description, the invention is to be explained in more detail but not in a restrictive manner on the basis of preferred exemplary embodiments illustrated in the drawings.

1 shows a perfusion catheter with two distal end pieces in a first embodiment, FIG. 2 is a perfusion catheter with two distal end pieces with sealing elements of another embodiment, and FIG. 3 is a schematic illustration of a perfusion catheter system with separate pressure control in the two perfusion lumens.

In Fig. 1, 1 denotes the guide tube of a perfusion catheter in which two distal and individually displaceable and individually orientable end pieces 2 and 3 are guided and held. The distal end pieces 2, 3 are inserted into the vessel lumen through an incision 4 in the vessel 5, on which an anastomosis is to be made, for example, and penetrate into the vessel 5 on both sides of the incision 4. In order now to seal the site of the anastomosis, i.e. To achieve essentially the incision 4 and to keep this place free of blood and the like, the end pieces 2, 3 are provided with sealing elements or are designed in such a way that they can effect the sealing themselves.

In the example of FIG. 1, the ends of the distal end pieces 2, 3 of the perfusion catheter are provided with at least one expandable section 6. Due to the pressure of the perfusate in the distal end pieces 2, 3, the material in the sections 6 is expanded and lies against the inner wall of the vessel 5 in a sealing manner. This state has already been reached with the right end piece 3, while the left end piece 2 is still at the beginning of the expansion. It can also be seen that advantageously the mouth 7 of the distal end pieces 2, 3 is initially closed, so that a pressure which can be predetermined via the choice of material and the locking mechanism has to build up in the end piece, which widens the section 6 into its sealing position. Only then does the mouth 7 of the distal end piece 2, 3 open and the perfusate can flow into the vessel. Of course, several expandable sections 6 can also be provided in series, or the width of this or each section can be varied as required. As with the variants of the sealing elements described below, these or the sections 6 can also be made from a shape memory material, so that even when the pressure in the distal end piece 2, 3 is released, there is no unintentional reduction in the sealing effect. Alternatively or additionally, one or a group of hydrophilic sleeves can also be provided on the outside of the distal end piece, which swells on contact with liquid and thus seals the vessel 5 against the location of the incision 4.

Sealing elements of somewhat different design are provided in the embodiment of the perfusion catheter of FIG. 2. The left distal end piece 2 carries a sleeve 8 which is open towards the guide catheter 1 and which inflates and presses against the inner wall under the pressure of a gas, preferably carbon dioxide, which is supplied through the additional line 9, preferably attached to the distal end piece 2 or made in one piece therewith of the vessel 5 creates a seal. For this purpose, the line 9 is led into the area of the distal end piece 2 of the catheter, which is covered by the sleeve 8, at least in its position in contact with the end piece 2, and this line 9 has at least one gas outlet opening 10 in this area. The cuff 8 itself is made of an elastic material and / or folded around the end piece 2 in the idle state. The cuff 8 can also be made from a shape memory material and / or with a hydrophilic outside.

The gas blown under the cuff 8, after it has expanded the cuff 8 and pressed against the inner wall of the vessel, flows through the annular gap 11 between the outer edge of the cuff 8 and the end piece 2 in the proximal direction, i.e. to the area of the incision 4 or the anastomosis and thus keeps this area free of blood. Instead of a gas, a liquid could also be supplied through line 9, for example saline solution for flushing the operation site.

In the embodiment of the right distal end piece of FIG. 2, an inflatable balloon 12 is provided at the end of the end piece 3. Again is a provided parallel to the end piece 3 extending line 13 and leads a gas or a liquid into the interior of this balloon 12, whereby this is expanded and brought to bear on the inner wall of the vessel. As a result, the entire amount of gas or liquid is optimally used for sealing the surgical site. In order to keep the surgical site free of blood or the like easily and without additional effort, there are preferably a plurality of outlet openings 15, preferably distributed around the circumference of the end piece 3, in the proximal direction, ie in the direction of the region of the anastomosis to be produced .

In both embodiments, of course, in order for the seal to function, it is necessary that the flow resistance of the outlet openings 11 or 15 of the sleeve 8 or the balloon 12 is greater than the flow resistance of the line 9 or 13.

A gas or a liquid can also be supplied via an additional lumen 16 of the guide catheter 1 in order to further improve the keeping of the surgical site or to rinse it better. On the other hand, a light source can also be provided in this additional lumen, which replaces other external light sources with a larger space requirement. For example, a glass fiber light guide can be provided with the actual light source at the proximal end of the catheter and the light exit at the distal end of the lumen 16. This means that light source brackets, supply lines, etc. can also be avoided and the space requirement of the overall system remains small.

A special, advantageous example for the implementation of a perfusion catheter system according to the invention can be seen in FIG. 3. The distal end pieces 2, 3 can be connected to a gas or liquid source 17 via the guide catheter 1. This will mostly be the source of perfusate, ie a source of blood taken from the patient or a blood supply. However, additionally or alternatively, it can also be a gas source, for example for carbon dioxide, nitrogen or oxygen, or for a liquid, for example blood plasma, physiological saline or the like. This allows the composition and various parameters of the blood to flow downstream the perfusion catheter has been inserted can be specifically changed or adjusted.

Advantageously, at least one pressure and / or flow sensor is further provided on the gas or liquid source 17 and / or in the course of the lumen to the distal end pieces 2, 3. The embodiment shown in FIG. 3, with one pressure and / or flow sensor 18 per lumen of each end piece 2, 3, is particularly advantageous. The optimal pressure of the perfume can then be applied to the pump 19, which is also advantageously provided separately for each lumen , the gas or the liquid from the source 17 can be set. In the operation, which is particularly simple and convenient, and which also makes it easier for the attending physicians to concentrate on the operation, in the particularly advantageous embodiment of the perfusion catheter system according to FIG. 3, the pressure and / or flow sensors 18 are connected to a control unit 20 for the Gas and / or liquid source 17 is provided. A perfusion pressure or flow rate can thus be set, monitored and automatically maintained once. On the other hand, a program can also be stored in the control unit 20, which uses at least one parameter, for example the arterial blood pressure, to determine the required pressure or flow through an algorithm and to determine the gas or liquid source 17 or the pumps 19 or other flow or Controls pressure controls accordingly. The aortic pressure can be used for interventions on coronary vessels, where the optimal perfusion pressure is calculated from an algorithm for a value between systolic and diastolic pressure. The pressure in the coronary vessel itself can also be used for regulation, preferably in diastolic application due to the coronary flow taking place in the diastole, a maximum value resulting from the resistance in the coronary vessel itself. But the normal value of blood flow in the vessel can also be used as a control parameter.

Claims:

Claims

Claims:

1. End piece for a catheter or the like, with an inlet opening for a liquid or a gas, which causes the expansion of a sealing element or area provided on the end piece, characterized in that the sealing element (8, 12) or the sealing area (6) at least has an outlet opening different from the inlet opening for the liquid or the gas.

2. End piece according to claim 1, characterized in that the outlet opening (7) is oriented essentially in the same direction as the inlet opening.

3. End piece according to claim 2, characterized in that the sealing element is formed by at least one sleeve made of hydrophilic plastic on the outside of the end piece (2, 3).

4. End piece according to claim 2, characterized in that the sealing element is itself formed by at least one radially expandable medium flowing through the pressure section (6) of the end piece (2, 3).

5. End piece according to claim 4, characterized in that the outlet opening (7) at the end piece (2, 3) is initially closed and is evident by a predetermined pressure which is above the pressure required to expand the expandable section (6).

6. End piece according to claim 4, characterized in that at least one area consists of a shape memory material.

7. End piece according to claim 2, characterized in that the or each sealing element is designed as a preferably elastic, expandable sleeve (8) around the end piece (2), which sleeve is open in the proximal direction.

8. End piece according to claim 7, characterized in that the line (9) for fluid supply has at least one outlet opening (10) in the area covered by the sleeve (8).

9. End piece according to claim 2, characterized in that the or each sealing element consists of a preferably elastic, expandable balloon (12) around the end piece (3).

10. End piece according to claim 9, characterized in that the or each balloon (12) has at least one preferably in the proximal direction of the distal end piece (3) towards the outlet opening (15).

11. End piece according to claim 10, characterized in that the or each balloon (12) is provided with a group of outlet openings (15) distributed over the circumference.

12. Perfusion catheter with at least two hollow, axially displaceable, flexible distal end pieces, which are individually adjustable and displaceable parallel to each other in the catheter and which are each provided with at least one sealing element, characterized in that at least one of these end pieces (2, 3) according one of the preceding claims is formed.

13. Catheter according to claim 12, characterized in that a further lumen (16) is provided, which can be connected proximally to a gas source or liquid source or in which a light source is provided.

14. Catheter according to claim 12 or 13, characterized in that the distal end pieces (2, 3) via the catheter (1) with a gas or liquid source (17) can be connected.

15. Perfusion catheter system with a catheter according to one of claims 12 to 14, characterized in that at the gas or liquid source (17) and / or in the course of the lumen to the distal end pieces (2, 3), a pressure and / or flow sensor (18) is provided.

16. System according to claim 15, characterized in that the pressure and / or flow sensor (18) with a control unit (20) for the gas and / or liquid source (17) is connected.

17. The system according to claim 16, characterized in that a program is stored in the control unit (20) which determines the required pressure or flow rate from at least one parameter via an algorithm known per se and the gas or liquid source (17) accordingly controls.