CATHETER WITH CORKSCREW-LIKE BALLOON

Abstract: A helical balloon (18) is attached to the distal end of a catheter (10) to serve when inflated as a therapeutic tool for the removal of blood clots and as a diagnostic tool for physical measurements and the application of treatment and other materials.

Description: The present invention relates to a catheter according to the precharacterizing portion of claim 1. The present invention relates, more particularly, to improved catheters for use as embolectomy catheters and flow-directed diagnostic catheters. In its more specific aspects, the invention is directed to such catheters which employ balloons which may be expanded into a helical configuration. It is well-known in the art to provide embolectomy catheters with annular balloon means for blood clot removal. US-A-3,435,826 to Thomas J. Fogarty, one of the coinventors herein, discloses such a catheter. It is also known in the art to provide embolectomy catheters with a wire or blade in the shape of a spiral helix. Such catheters are rotated to screw the helix into the clot, following which the catheter is removed from the blood vessel without rotation. A catheter of this type is shown in US-A-4,030,503 to Clark. Embolectomy catheters have also been provided with annular balloons having flexible protrusions adapted to bite into the clot upon inflation of the balloons to enable the clot to be pulled free by withdrawal of the catheter. Such a catheter is shown in US-A-3,635,223 to Klieman. Catheters have also been provided with successively inflatable helical balloon sections to render the catheters self-propelling. A catheter of this type is shown in US-A-3,485,237 to Bedford. The US-A-4 608 984 discloses a catheter comprising a flexible tube having a through lumen and an open distal end; an elongate balloon extending longitudinally from the distal end of the tube, said balloon being movable between collapsed and extended conditions and having an open proximal end secured to the distal end of the tube an elongate element extending through the tube and into engagement with the balloon, said element being movable relative to the tube. The WO-83/00997 discloses a catheter where a helically shaped coil spring can be expanded to a state of larger diameter for expanding a blood vessel. The catheter of the present invention is defined according to the characterizing portion of claim 1. The subject catheter comprises a catheter body or tube with a balloon secured to and extending from the distal end of the tube. The balloon contains a wire which may be expanded into a helical configuration to conform the balloon to such a configuration. When used as an embolectomy catheter, the distal end of the catheter is pushed through a blood clot to be removed with the balloon in a deflated or contracted condition. Thereafter, the balloon is expanded into the helical configuration so that it grips or engages the clot. The concept here is to apply an expansionary balloon force to the interior wall of the blood vessel along a helical path such as to avoid the application of diametrically opposed forces, with possible perforation or abrasion effect on the vessel wall. By providing one or both ends of the helical balloon with sealing loops, the flow of blood within the vessel may be utilized to propel the catheter along the vessel. By providing the catheter with a plurality of lumens, a through lumen and one or more side opening lumens, the subject catheter is adapted for use for diagnostic purposes, such as pressure measurements, withdrawal of samples, the injection of medicants, etc. A principal object of the invention is to provide an embolectomy catheter with a balloon which reduces abrasion to the wall of the vessel within which the catheter is used. Another object of the invention is to provide such an embolectomy catheter wherein the balloon is of a helical configuration so as to increase the pulling surface area of engagement between the clot being removed and the balloon. Another object of the invention is to provide such an embolectomy catheter which will not pinch off and separate the clot being removed. Another object of the invention is to provide an inflatable balloon diagnostic catheter which may be placed by inflating the balloon and then permitting blood flow to move the catheter Yet another object is to provide such a diagnostic catheter with multiple lumens to measure pressure Still another object of the invention is to provide such a diagnostic catheter wherein arterial contact is minimized during flow placement and wherein, once placed, the pressure points provided by the balloon are not directly opposite one another. The foregoing and other objects will become more apparent when viewed in light of the accompanying drawings and following detailed description. Fig. 1 is a cross-sectional elevational view of a first embodiment of the subject embolectomy catheter, with the balloon of the catheter in the contracted condition; Fig. 2 is a cross-sectional elevational view of the first embodiment embolectomy catheter, with the catheter shown received within a blood vessel and the balloon in an expanded condition; Fig. 3 is a cross-sectional elevational view of a second embodiment of the subject embolectomy catheter, with the balloon shown in a contracted condition; and Fig. 4 is a cross-sectional elevational view of the second embodiment embolectomy catheter received within a blood vessel, with the balloon of the catheter in an expanded condition. Description of the First Embodiment Embolectomy Catheter This catheter, as shown in Figs. 1 and 2, comprises a balloon element 58 in the form of an elongate cylindrical elastomeric sleeve secured to the distal end of a catheter 10e. The distal end of the balloon element 58 is sealed by a rounded end or tip portion 24e. A helical spring wire 62 extends through the element 58 and is engaged at one end with the distal end of the catheter 10e and at the other end with the end or tip portion 24e. A central core or rod element 64 extends slidably through the lumen of the catheter 10e into secure engagement with the balloon through the end or tip portion 24e. This rod provides means whereby the tip 24e may be held in place while the catheter 10e is drawn away from the tip to elongate the balloon element 58. Fig. 2 shows the first embodiment catheter within a blood vessel 26 in the expanded balloon condition which it normally assumes under influence of the spring wire 62. In this condition, the wire functions to expand the balloon into a helical configuration. Fig. 1 shows the balloon element in the contracted condition which it assumes upon withdrawing of the catheter 10e relative to the core or rod element 64. Such retraction functions to extend the balloon element and the spring longitudinally and, in turn, reduce the overall profile diameter of the assembly. In use, the first embodiment catheter is introduced into a vessel 26 in the reduced profile condition shown in Fig. 1. This is achieved by applying linear tension to the catheter with respect to the core or rod 64, thus necking down the preset balloon. Although not illustrated, it should be understood that the central core or rod could be retained in this tensioned condition through means of a locking mechanism at the catheter hub. After passing the catheter assembly into or through the clot to be removed, the catheter 10e is released to permit the spring wire to expand the balloon element 58 into the helical condition shown in Fig. 2. Thus, the clot is securely engaged. The clot may then be removed by withdrawing the assembly from the blood vessel, designated 26 in Fig. 2. Description of the Second Embodiment Embolectomy Catheter As shown in Figs. 3 and 4, this embodiment is similar to the first embodiment in that the balloon element, designated 58a, takes the form of a resilient sleeve secured to the distal end of a catheter 10f. Similarly to the first embodiment, the distal end of the sleeve 58a is closed by a rounded end or tip portion 24f and the central core or rod element 64a is secured to this portion and extends therefrom through the catheter 10f. A knob 66 is fixedly secured to the proximal end of the rod 64a. A knob 68 having an opening 70 there through in alignment with the catheter 10f is fixedly secured to the catheter. The second embodiment differs from the first embodiment primarily in that it does not employ a preformed helical spring wire, such as the wire 62. Rather, it employs a flexible spring wire 72 of a generally rectilinear configuration secured at its opposite ends to the tip portion 24f and the distal end portion of the catheter 10f. This spring wire is normally extended and the balloon element 58a is in the contracted condition as shown in Fig. 3. Upon twisting of the rod 64a relative to the catheter 10f, through means of the knobs 66 and 68, the spring wire 72 assumes the helical configuration shown in Fig. 18 and elastically deforms the balloon element 58a into this configuration. The second embodiment catheter is introduced into the vessel to be treated (26) in the reduced profile configuration shown in Fig. 3. When the desired location of the assembly is achieved, twisting of the rod 64 relative to the catheter 10f causes the flexible spring wire 72 to wrap around the rod and assume the helical configuration shown in Fig. 4, thus gripping the clot engaged by the assembly. Once so engaged, the assembly is removed, together with the clot. Conclusion From the foregoing description, it is believed apparent that the present invention enables the attainment of the objects initially set forth herein. In particular, it provides an improved embolectomy catheter wherein a clot may be securely engaged and removed, with a minimum of abrasion to the vessel within which it is used. It also provides an ideal diagnostic catheter which may be flow-directed and provides sealed engagement with the vessel within which it is used, with a minimum of friction and abrasion. It should be understood, however, that the invention is not intended to be limited to the specifics of the described embodiments, but rather is defined by the accompanying claims.

Claims: A catheter comprising a flexible tube (10e;10f) having a through lumen and an open distal end; an elongate balloon (58;58a) extending longitudinally from the distal end of the tube (10e;10f), said balloon (58;58a) being movable between collapsed and extended conditions and having an open proximal end secured to the distal end of the tube (10e;10f); and an elongate element (64;64a) extending through the tube (10e;10f) and secured to the balloon (58;58a) distally, said element (64;64a) being movable relative to the tube (10e;10f) characterized in that means (62;72) are provided to expand the balloon (58;58a) into a helical configuration in response to movement of the element (64;64a) relative to the tube (10e;10f). A catheter according to claim 1 characterized in that said means (62;72) comprises a flexible wire within the tube (10e;10f) said wire having one end secured in engagement with the tube (10e;10f) and another end secured in engagement with the balloon (58;58a) in spaced relationship to the distal end of the tube (10e;10f); and said movement of the element relative to the tube functions to force the wire into an expanded helical configuration. A catheter according to claim 2 characterized in that said wire assumes an elongate helical configuration when the balloon (58) is in the contracted condition and the elongate element (64) is moved axially relative to the tube (10e) to force the wire into an expanded helical configuration. A catheter according to claim 2 characterized in that said wire assumes an elongate generally straight configuration when the balloon (58a) is in the contracted condition and the elongate element (64a) is rotated and moved axially relative to the tube to force the wire into an expanded helical configuration.

Inventors: FINN, JAMES C., III, FOGARTY, THOMAS J., KINNEY, THOMAS B.
Applicants: FOGARTY, THOMAS J.
Application year: 1988
Main classification: A61M25
IPC codes: A61M25, A61B17