WO2003105684A1

WO2003105684A1 - Endovascular catheter comprising means to measure the temperature of vessel walls

Info

Publication number: WO2003105684A1
Application number: PCT/GR2003/000024
Authority: WO
Inventors: Christodoulos Stefanadis
Original assignee: Christodoulos Stefanadis
Priority date: 2002-06-17
Filing date: 2003-06-11
Publication date: 2003-12-24
Also published as: GR20020100289A; GR1004471B; AU2003232369A1

Abstract

Catheter, that stops/blocks the blood flow and is used in combination with thermography catheters, -catheters for recording wall temperatures in vessel (arteries - veins)-, comprising two lumens (2,3), one for the introduction of the thermography catheter and one for the controlled inflation of the balloon (8), two exits (4,5), one with a clasp (6) for stabilizing the thermography catheter and one for controlling the means of controlled inflation of the balloon, and a balloon. With the controlled inflation of the balloon, blocking of the blood flow is achieved and consequently, accurate measurement and recording of the vessel wall temperature can be carried out.

Description

ENDOVASCULAR CATHETER COMPRISING MEANS TO MEASURE THE TEMPERATURE OF VESSEL WALLS

The present invention relates to an endovascular catheter specially designed to interrupt the blood flow, and being used in conjunction with catheters designed for temperature measurement of the vessel wall (arteries-veins) or the wall of the concave biological organs.

Thermography is already a well established technique among many medical specialties and still rapidly expanding among others. In the recent years the temperature measurement of the vessel walls especially of the coronary arteries has attracted a worldwide interest both in the research and the clinical field. This is because studies have shown that locally increased temperature of the vessel wall is associated with atherosclerotic plaque being prone to rupture.

In order for any temperature measurement device, as for example a temperature sensor, to accurately measure the temperature of the vessel wall it is necessary to ensure that during measurement the device readings are not affected by the temperature of the blood itself. The blood, as it circulates around, tends to cool down the hot spots by taking away the excess heat so the cooling effect must be somehow eliminated or minimized. In order to avoid incorrect measurement, the blood flow should be interrupted. Accurate temperature measurement of the vessel wall presupposes a catheter having the ability to interrupt the blood flow and at the same time incorporating any other temperature measurement catheter without compromising its operation.

It is an object of the present invention to provide such a catheter that has the ability to interrupt the blood flow and enable the accurate temperature measurement of the vessel wall by a temperature measurement catheter attachable thereto. To this effect the invention provides an endovascular catheter configured to be inserted within a blood vessel for stopping/blocking the blood flow comprising an elongated/longitudinal catheter body made from appropriate non-thrombogenic material for the insertion inside vessels having a proximal and a distal end, a first central inner lumen passing through the whole length of said catheter body allowing the introduction of a thermography catheter via said lumen into a blood vessel, a second inner lumen having proximal and distal ends and running substantially parallel to part of the first central inner lumen, the catheter further comprising a first and second exit at the proximal end of the catheter body , a clasp positioned at said first exit securely fastening the thermography catheter passing through the first inner lumen to the elongated catheter body, a valve at the end of said second exit connected with the second inner lumen and a balloon positioned at the distal end of the catheter body and connected to the second inner lumen in a way such that by controllably inserting a desired amount of gas or liquid through the valve this passes through the second inner lumen and inflates the balloon, thus achieving controllable dilation of the balloon, which by coming into contact with the walls of the blood vessel permits the complete stopping of the blood flow, thus allowing an accurate temperature measurement of the vessel or the vessel wall by the thermography catheter introduced through the first inner lumen.

The catheter is configured to be inserted within a blood vessel. It is made from a non-thrombogenic material and comprises an elongated body where at the distal tip a balloon is placed. The length, the external cross-section of the catheter and the balloon dimensions depend on the specific part of the body where the thermography catheter is to be used. The balloon is made from non-traumatic material in order to avoid causing any damage to the vessel with which it comes into contact.

The present invention's catheter has certain advantages since it has the ability to interrupt the blood flow when the distal balloon is inflated and comes in contact with the vessel wall thus allowing an accurate temperature measurement to be taken by the thermography catheter attached thereto.

An embodiment of the invention will now be described by way of example and with reference to the accompanying figures.

FIGURE 1 illustrates the catheter with the balloon deflated

FIGURE 2 illustrates the catheter with the balloon inflated/ in controlled dilation

In figures 1 and 2 only the distal and the proximal parts of the catheter are displayed.

The catheter of the above example is made of polyurethane has a length of 120 cm, a diameter of 2,5mm and it is used for the interruption of the blood flow in the coronary arteries. The length and the other characteristics of the catheter depend on the needs that arise from the certain usage in conjunction with the design of the thermography catheter and the specific part of the body where temperature measurement is to be recorded.

Figures 1 & 2 illustrate the elongated catheter body (1) comprising two inner lumens (2, 3). The first central inner lumen (2) passes through the whole length of the catheter body (1) and is designed to allow the insertion of a thermography catheter through said first inner lumen (2) within the blood vessel. The second inner lumen (3) has proximal and distal ends and runs substantially parallel to part of the first inner lumen (2).

The catheter body (1) comprises a first (4) and second (5) exit at its proximal end. A clasp (6) is positioned at the first exit (4). This clasp serves to securely fasten the thermography catheter passing through the first inner lumen (2) to the catheter body.

At the end of the second exit (5) of the catheter body a valve (7) is connected to the second inner lumen (3). A balloon made of latex and having a length of 2 cm is (8) positioned at the distal end of the catheter body (1). Said balloon is connected to the second inner lumen in a way such that by controllably inserting a liquid or gas through the valve (7), this passes through the second inner lumen (3) and inflates the balloon. The desired quantity of liquid or gas will depend upon the diameter of the blood vessel within which the catheter will be inserted, while care is being taken so that said quantity will not dilate the balloon in a way which would damage or injure the vessel. Figure 2 illustrates the catheter when the balloon is under controlled dilatation. Balloon diameter is directly proportional to the quantity of the gas or the liquid that inserts the lumen and is determined by that.

In this way when the balloon is controllably inflated, it comes into contact with the walls of the blood vessel and stops the blood flow. Under these conditions the thermography catheter introduced through the first inner lumen (2) at the site of interest, will make an accurate temperature measurement, which is not influenced by the blood flow, since this has been stopped.

Claims

1. Endovascular catheter configured to be inserted within a blood vessel for stopping/blocking the blood flow comprising: an elongated/longitudinal catheter body made from appropriate non- thrombogenic material for the insertion inside vessels having a proximal and a distal end, a first central inner lumen (2) passing through the whole length of said catheter body allowing the introduction of a thermography catheter via said lumen (2) into a blood vessel, a second inner lumen (3) having proximal and distal ends and running substantially parallel to part of the first central inner lumen, the catheter further comprising a first (4) and second (5) exit at the proximal end of the catheter body through which pass the first (2) and second (3) inner lumens respectively, a clasp positioned at said first exit (4) securely fastening the thermography catheter passing through the first inner lumen (2) to the elongated catheter body, a valve (7) at the end of said second exit (5) connected with the second inner lumen (3) and a balloon (8) positioned at the distal end of the catheter body and connected to the second inner lumen (3) in a way such that by controllably inserting a desired amount of gas or liquid through the valve (7) this passes through the second inner lumen (3) and inflates the balloon (8), thus achieving controllable dilation of the balloon, which by coming into contact with the walls of the blood vessel permits the complete stopping of the blood flow, thus allowing an accurate temperature measurement of the vessel or vessel wall by the thermography catheter introduced through the first inner lumen (2)

2. Endovascular catheter for stopping/blocking the blood flow according to claim 1 wherein the size and configuration of said catheter is such that any type of thermography catheter can be incorporate therein.