REMOTE CONTROLLED CATHETER GUIDE

Abstract: The invention relates to a remote controlled catheter guide provided with a micro-balloon which comprises a head formed of a coil spring (4) mounted at the end of the extremity (2) of a tube (l). When pulling on a flexible traction member (7) fastened to an excentered point inside the end of the head, this head can be curved at will. The remote controlled catheter guide with micro-balloon is thus constituted of the assembly of elements forming a channel through which it is possible to locate the flexible traction member (7) as well as to feed a contrast liquid. Due to the provision of the micro-balloon (8) which is inflatable through its feeding duct (9) it is possible to carry out the pre-dilatation of stenosis so that afterwords a conventional catheter can be slid in place over the catheter-guide.

Description: Field of the invention The present invention relates to a remote controlled catheter guide provided with a micro-balloon which is to be mainly used in the treatment of cardio-vascular deseases, particularly of the level of the coronarian vessels. The treatment of the narrowing of an arteria or stenosis is currently done through dilatation of the balloon of an instrument called catheter. It is not always simple or even possible to place the said inflatable balloon inside the stenosis due to the multiple ramifications of the blood vessels and when the narrowing of the vessel is too important. Nowadays, to be able to put in the right place the inflatable balloon of the catheter one first introduces in the blood vessels and into the stenosis a very thin metallic rod having a curved end. This rod is then used as a guide for a catheter with an inflatable balloon which is slid over said rod up to the locations of the narrowings. This method is currently used but has the drawback to use a guide having a fixe curvature at its end which cannot be modidied in function of the variable successive directions it has to take through the multiple ramifications of blood vessels. It is further impossible to inject through said guide a contrast liquid to control its positioning. The present invention relates to a polyvalent guide for a catheter obviating to the precited drawbacks but which has the further advantage of being provided with a micro-balloon for obtaining the pre-dilatation of very strong stenosis where the remaining passage for the blood has got so narrow that the normal catheter balloon can not be used. In fact the micro-balloon is intended to work within diameters of 0.6 to 2 millimeters for a full expansion with regard to the commonly used balloons the expansion of which starts only at a diameter of about 2 millimeters. When the aperture of the stenosis has been first widened by mean of the micro-balloon of the guide it is then possible to slide in place over said guide a catheter with a normal balloon up to all narrowing zones in order to further expand the stenosis through subsequent dilatation. Description of the drawings. Figure l shows schematically one embodiment of the catheter-guide provided with its remote control for its setting in place. Figure 2 shows the catheter-guide after having been set in place and ready to be used as a guide for a conventional catheter. Description of the prefered embodiment. The remote controlled catheter-guide provided with a micro-balloon comprises a tube (l) the extremity 2 of which is formed of a cylindrical coil spring the coils of which are jointed the ones to the others and covered by a plastic coating. The end of said coil spring is fitted on a sleeve 3 itself fitted into the tube l. The head of the catheter-guide is formed of coil spring 4 having disjointed coils, at least in its central position, fitted on a sleeve 5 itself fitted into the free end of the extremity 2 of the tube l. A cap 6 is fitted in the free end of the spring 4. A flexible traction member 7 is fixed to the cap 6 in an excentered location and extends throughout the head and the tube to enter in a control member. A metallic rod can be provided within the tube l to increase its rigidity, this rod is not shown. An inflatable micro-balloon 8 is located around the extremity 2 of the tube and connected to a feeding tube 9. A control unit l0 is fixed to the other end of the tube l in a removable manner and tightly by mean of an O-ring ll. This unit l0 comprises a cylindrical part l2 fixed to the flexible traction member 7 and sliding tightly, due to O-ring l3, in said unit l0. Said control unit comprises further a cutter l4 and its operating member l5 sliding tightly in the unit l0 by mean of an O-ring l6 and a threaded member l8. The control unit comprises further first l7 and second l9 threaded elements tightly assembled with the unit l0 respectively with the first element l7 by mean of O-rings ll and 20. First of all, before any surgical intervention, one makes sure that the three threaded elements l7,l8 and l9 are fully screwed to secure tightly the control unit l0 with the tube l, the push member l5 and the feeding circuit for the micro-balloon respectively. In order to set in place the catheter-guide in one or the other circulatory ramifications up to the inside of the area to be treated the user has therefore three degrees of movement ; to go back and forth with the whole assembly, to rotate the whole assembly on itself in one direction or the other and to curve or bend the head or to let it straighten again. The said latter function is obtained by pulling the flexible traction member 7, through part l2, bending the coil sprping 4. When the traction is released on member 7 the coil spring straighten due to its elasticity. The displacement of member l2 with respect to the control unit l0 can be obtained manually or by a not illustrated mechanism for example of the micrometric type. A contrast liquid can be introduced into the blood vessel considered to locate by means of a radiological examination the head of the catheter guide. The liquid is injected in channel 23 of the control unit l0, fills the chamber 24 and the tube l as well as its extremity 2 and is let out into the blood vessel through the disjointed coils of the spring 4. Finally to inflate the micro-balloon 8, a pressurized fluid is fed through the channel 25 into the feeding duct 9 and the balloon 8. The channel 26 is provided in care said fluid being a liquid it would be necessary to evacuate the air contained in the duct 9 and the balloon 8. When the catheter-guide is in place and after having pre-expanded the stenosis or the several stenoses with the inflation of the micro-balloon 8, the user unscrews the threaded element l8 to liberate the axis of the push member l5. He then pushes said member l5 actuating the cutter l4 to cut the flexible traction member 7. Thereafter the screwed element l7 and l9 are unscrewed totally liberating the feeding duct 9 and the tube l which can then be withdrawn from the control unit l0. Finally it is possible to replace the control unit l0 by a handle 2l one end of which is fitted into the end of tube l. Then a normal catheter is slid over the handle 2l, and the tube l which are then used as a conventional catheter-guide.

Claims: 1. Remote controlled catheter-guide comprising a thin and flexible tube, one extremity of which is fixed to the head of the catheter-guide, formed by a coil spring closed out its fore end and provided with a central zone having disjointed coils ; whereas the other end of the tube is removably fixed to a control unit ; and comprising further a control device formed of an operating member sliding in the control unit and connected to an excentered point of the free end of the head of the catheter-guide through a flexible traction member ; characterized by the fact that the extremity of the tube carrying the head is constituted by a coil spring having jointed coils and provided with a tight coating ; and by the fact that this terminal position of the tube is surrounded by an inflatable micro-balloon connected through a duct to a channel provided in the control unit. 2. Catheter-guide according to claim l characterized by the fact that the extremity of the tube formed by the coil spring contain a metallic rod giving it a greater rigidity against bendings. 3. Catheter-guide according to claim l characterized by the fact that the tube is outwardly coated with a plastic envelope on a part at least of its length. 4. Catheter-guide according to claims l and 2 characterized by the fact that the extremity of the tube formed by the coil spring is fit on a sleeve, this latter being partly driven in the end of the tube. 5. Catheter-guide according to claim l and 2 characterized by the fact that the extremity of the tube formed by a spring is welded on the end of the tube. 6. Catheter-guide according to one of the claims l to 4 characterized by the fact that the coil spring of the head is fit on a sleeve, said latter being partly driven into the end of the tube. 7. Catheter-guide according to one of claims l to 5 characterized by the fact that the coil spring of the head is welded onto the spring extremity of the tube. 8. Catheter-guide according to one of claims l to 6 characterized by the fact that the coil spring of the head and the coil spring forming the extremity of the tube are made of one piece of manufacture. 9. Catheter-guide according to one of claims l to 8 characterized by the fact that the control unit has a cutter intended to cut the flexible traction member. l0. Catheter-guide according to claim l characterized by the fact that the channel is formed by an envelope concentric to the tube the end of which the micro-balloon. 11. Catheter-guide according to claim l0 characterized by the fact that the rear end of the envelope is tightly mounted on the control unit whereas the fore end of the micro-balloon is tightly mounted on the plastic coating of the coil spring forming the extremity of the tube.

Inventors: BONELLO, PHILIPPE, JEANMONOD, MAURICE
Applicants: SARCEM SA
Application year: 1987
Main classification: A61M25
IPC codes: A61B17, A61M25