Endovascular electrolytically detachable wire and tip for the formation of thrombus in arteries, veins, aneurysms, vascular malformations and arteriovenous fistulas

Abstract

An artery, vein, aneurysms vascular malformation or arterial fistula is occluded through endovascular occlusion by the endovascular insertion of a platinum wire and/or tip into the vascular cavity. The vascular cavity is packed with the tip to obstruct blood flow or access of blood in the cavity such that the blood clots in the cavity and an occlusion if formed. The tip may be elongate and flexible so that it packs the cavity by being folded upon itself a multiple number of times, or may pack the cavity by virtue of a filamentary or fuzzy structure of the tip. The tip is then separated from the wire mechanically or by electrolytic separation of the tip from the wire. The wire and the microcatheter are thereafter removed leaving the tip embedded in the thrombus formed within the vascular cavity. Movement of wire in the microcatheter is more easily tracked by providing a radioopaque proximal marker on the microcatheter and a corresponding indicator marker on the wire. Electrothrombosis is facilitate by placing the ground electrode on the distal end of the microcatheter and flowing current between the microcatheter electrode and the tip.

REEAXMINATION RESULTS The questions raised in reexamination request 90/007,231, filed Oct. 4, 2004 have been considered and the results thereof are reflected in this reissue patent which constitutes the reexamination certificate required by 35 U.S.C. 307 as provided in 37 CFR 1.570(e), for ex parte reexaminations, or the reexamination certificate required by 35 U.S.C. 316 as provided in 37 CFR 1.99(e) for inter partes reexaminations.

Description

[0001]This application is a continuation of application Ser. No. 08 / 801,795 filed Feb. 14, 1997, issued as U.S. Pat. No. 5,885,578, which in turn wasis a continuation of application Ser. No. 08 / 485,821, field Jun. 6, 1995, now abandoned, which is a divisional of application Ser. No. 08 / 311,508, filed on Sep. 23, 1994, issued as U.S. Pat. No. 5,540,680, which is a continuation application of application Ser. No. 07 / 840,211 filed on Feb. 24, 1992, issued as U.S. Pat. No. 5,354,295, and which in its turn wasis a continuation-in-part application of application Ser. No. 07 / 492,717, filed Mar. 13, 1990, issued as U.S. Pat. No. 5,122,136.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The invention relates to a method and apparatus for endovascular electrothrombic formation of thrombi in arteries, veins, aneurysms, vascular malformations and arteriovenous fistulas.[0004]2. Description of the Prior Art[0005]Approximately 25,000 intracranial aneurysms rupture every year in No...

AI Technical Summary

Benefits of technology

[0031]The invention is still further characterized as a microcatheter system for use in formation of an occlusion within a vascular cavity comprising a microcatheter having a distal end adapted for disposition in the proximity of the vascular cavity. The distal end has an electrode disposed thereon. A conductive guidewire is disposed in the microcatheter and longitudinally displaceable therein. The guidewire comprises a core wire, and an elongate tip portion extending the

Problems solved by technology

Because of the mortality and morbidity rate expected, the surgical procedure is often delayed while waiting for the best surgical time with the result that an additional percentage of patients will die from the underlying disease or defect prior to surgery.

While endovascular balloon embolization of berry aneurysms is an attractive method in situations where an extravascular surgical approach is difficult, inflation of a balloon into the aneurysm carries some risk of aneurysm rupture due to possible over-distention of portions of the sac and due to the traction produced while detaching the balloon.

While remedial procedures exist for treating a ruptured aneurysm during classical extravascular surgery, no satisfactory methodology exists if the aneurysm breaks during an endovascular balloon embolization.

This may not lead to a satisfactory result and further increase the risk of rupture.

Still further, balloon embolization is not always possible.

If the diameter of the deflated balloon is too great to enter the intracerebral arteries, especially in the cases where there is a vasospasm, complications with ruptured intracranial aneurysms may occur.

The procedure then must be deferred until the spasm is resolved and this then incurs a risk of rebleeding.

However, eac

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