WO2003077782A1

WO2003077782A1 - Catheter for radio frequency induced hyperthermia treatment

Info

Publication number: WO2003077782A1
Application number: PCT/IT2003/000028
Authority: WO
Inventors: Andrea Venturelli
Original assignee: Fogazzi Di Venturelli Andrea & C. S.N.C.
Priority date: 2002-03-20
Filing date: 2003-01-27
Publication date: 2003-09-25
Also published as: WO2003077782A8; ITBS20020040U1; AU2003208604A1

Abstract

The invention concerns an active electrode for the treatment of tumours or other affections using hyperthermia induced by radio frequency. The active electrode (11) is made of a material such as conductive ceramic or graphite (12), positioned in a distal end of a catheter body. The electrode is connected to a radio frequency generator and has at least one longitudinal duct continuing into a corresponding duct in the body of the catheter to allow the passage of a guide wire or arbour.

Description

CATHETER FOR RADIO FREQUENCY INDUCED HYPERTHERMIA TREATMENT"

Field of the Invention

This invention concerns in general devices for therapeutic and surgical use in the treatment of tumours and other affections using hyperthermia, that is to say thermal ablation, induced by radio frequency, and refers in particular to a catheter with an electrode for this use. Prior Art

There are already some well known catheters for the purpose mentioned, among which one using a metal plaque as an active electrode positioned along a tubular body of the catheter in close proximity to a possible distal anchoring balloon. The plaque can be copper, steel or some other metal, it encircles the tubular body it is attached to and in order to avoid too high treatment temperatures induced by radio frequency, which could cause burns, it is usually cooled. For this reason the plaque has to be structured so as to allow a cooling fluid to circulate in it, usually water, fed from a suitable source. Object and summary of the Invention

One object of this invention is provide a catheter with an active electrode for radio frequency treatment made so as not to require cooling while ensuring efficiency and functionality.

Another object of the invention is to provide an active electrode for catheters for therapeutic or surgical treatment using hyperthermia which is simple and not costly to make and which has improved characteristics as regards to smoothness due to its inconsequential tendency to adhere to

tissues.

These objects are achieved by providing a catheter for the

mentioned purposes and use characterised with an active electrode made

of active ceramic or graphite, positioned at a distal end of the catheter and

having at least one longitudinal duct to receive a guide wire or arbour.

Brief Description of the Drawings

Greater details of the invention will become more evident in the

following description made with reference to the indicative and non-

limiting drawings enclosed, in which:

Fig.1 is a side of a portion of the catheter complete with active

electrode;

Fig. 2 is an enlarged longitudinal section of the electrode; and

Fig.3 is a cross-section of the electrode in direction of the arrows A- A in Fig. 2.

Detailed Description of the Invention

As researched and shown, the catheter comprises a body 10 which

can be a tubular element with several longitudinal conduits or made up of

several tubes positioned lengthwise and enclosed externally, for example,

in a flexible insulating sheath.

The body of the catheter 10, in one distal part, houses an active

electrode 11 connectable to a radio frequency generator - not shown,

whereas in a proximal part it is connectable to control devices for the

various functions the catheter is required to carry out.

The active electrode 1 1 is an integral part of, or attached to, the body of the catheter 10 and it is connected in the usual way to a radio frequency generator by a radio frequency lead extending in said body towards the proximal end of the same.

Such an electrode 11 is advantageously made up of a substantially cylindrical element 12 terminating or not terminating in a conically tapered end 13 which may or may not be attached to an inflatable anchoring balloon - not shown. Furthermore the end of the electrode may be inserted to form a metal point of its own.

The element 12 making up the electrode 11 is advantageously made of conductive ceramic or graphite, materials which warrant the functional efficiency of the electrode in treatments using hyperthermia induced by radio frequency even without the need for it to be cooled by a fluid.

The material making up the electrode, whether it is conductive ceramic or graphite, can also contain additives suitable for reducing adhesion to tissue it comes into contact with and at the same time improving its smoothness when the catheter id introduced unto the body through vessels or natural ducts.

The body of the catheter 10 and the active electrode 11 have at least one longitudinal duct 14 to receive the usual guide wire or arbour 15 which extends beyond the other end of the electrode, that is to say its tapered end.

The catheter body also houses a thermistor needle 16 which can be moved longitudinally to extend and to protrude, and be retracted, from one side of said body in close proximity to the electrode. The thermistor needle contains, as is own, the leads of a thermocouple for measuring the temperature around the electrode during heating and use of the latter in the treatment to be carried out.

The catheter described above may also receive other means for other functions without this departing from the field of the invention, as long as the electrode has the aspects and is realised with the means referred to above.

Claims

"CATHETER FOR RADIO FREQUENCY INDUCED HYPERTHERMIA TREATMENT"C L A I M S

1. A catheter with an active electrode for the treatment of tumours or other affections using hyperthermia induced by radio frequency, characterised in that the active electrode (11) is made of a material such as a conductive ceramic or graphite (12), placed at a distal end of a catheter body, the electrode being connected to a radio frequency generator and having at least one longitudinal duct continuing into a corresponding duct in the body of the catheter to allow the passage of a guide wire or arbour.

2. The catheter according to claim 1 , wherein said active electrode is made up of a cylindrical conductive ceramic or graphite element (12), an integral part of or tapered and attached to the distal end of the catheter body and without a cooling system.

3. The catheter according to claims 1 and 2, wherein said element forming the active electrode is equipped either with an inserted metal point or an integral tapered part.

4. The catheter according to any of the previous claims, wherein the electrode works in conjunction with at least one thermistor for the control of the temperature in close proximity to the electrode itself.

5. The catheter according to any of the previous claims, wherein said material making up the electrode contains additives to reduce adhesion and improve smoothness when in contact with body tissues.