Exchange method for emboli containment

Abstract

The present invention provides a method for exchanging catheters while containing emboli within a blood vessel such as a saphenous vein graft, coronary artery, carotid artery, or other similar vessels. A guidewire is inserted through the vasculature of a patient until it reaches a desired treatment site. A therapy catheter is then inserted over the guidewire until the distal end of the therapy catheter reaches the treatment site. The guidewire has a distally mounted balloon which is inflated to occlude the blood vessel. Then, the therapy catheter provides means for treating the vessel at the treatment site. After treatment, the therapy catheter is removed from the guidewire and exchanged with an aspiration catheter which rides over the guidewire until the distal end of the aspiration catheter reaches the treatment site. The aspiration catheter applies negative pressure to remove any emboli formed by the treatment procedure.

Description

RELATED APPLICATIONS [0001] This application is a continuation-in-part of application Ser. No. ______, entitled LOW PROFILE CATHETER VALVE AND INFLATION ADAPTOR, filed Nov. 20, 1997 (Attorney Docket No. PERCUS.006CP1), the entirety of which is hereby incorporated by reference.BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to medical catheters used in treating saphenous vein grafts, coronary arteries, and other blood vessels, and more particularly, to a method for exchanging catheters during emboli containment in such vessels. [0004] 2. Description of the Related Art [0005] Guidewires are conventionally used to guide the insertion of various medical instruments, such as catheters, to a desired treatment location within a patient's vasculature. In a typical procedure, the clinician forms an access point for the guidewire by creating an opening in a peripheral blood vessel, such as the femoral artery. The highly flexible guidewire is t...

AI Technical Summary

Benefits of technology

[0019] The present invention satisfies the above needs by providing a method for exchanging catheters during an emboli containment procedure. As described herein, the term “emboli” may refer to any debris, particles, or other objects found, created or placed in a blood vessel. “Emboli containment” may refer to emboli removal, neutralization, disintegration, minimization, or simply to preventing emboli from moving downstream. In essence, “containment” refers to any procedure which reduces the deleterious effects that emboli may have on the patient. The preferred exchange method is particularly useful in angioplasty and similar procedures in smaller blood vessels such as the coronary or carotid arteries or in saphenous vein grafts. The exchange method described herein can be accomplished rapidly to minimize the time that a treated blood vessel is occluded for treatment.

[0020] For example, in most angioplasty procedures, a guidewire is first introduced into the vasculature of a patient until the distal end of the guidewire is near the occlusion or stenosis. The guidewire preferably bears a distal occlusion device, such as a balloon, filter, coil, or combination of these elements. The occlusive device is preferably activated prior to performing therapy to remove or reduce an occlusion or stenosis, to provide a working area and to prevent particles and debris produced during therapy from migrating downstream. The occlusive device may completely or partially occlude the vessel.

[0023] The present invention in a preferred embodiment allows for the rapid and easy exchange of catheters by deploying the occlusive device in stages. For instance, when a guidewire with a distal occlusion balloon is used, the balloon is inflated only when there is danger of emboli moving downstream. Thus, if treatment of the stenosis consists of a dilatation procedure and deployment of a stent, the occlusion balloon will be inflated for a first inflation period during which the dilatation balloon works on the plaque, the dilatation catheter is exchanged with an aspiration catheter, and the aspiration catheter removes emboli from the vessel. After aspiration, the occlusion balloon can safely be deflated to allow blood flow for a period to organs downstream. An exchange can then be performed with another therapy catheter, such as a stent deploying catheter, and the occlusion balloon is reinflated for a second inflation period to deploy a stent to the location of the stenosis. By employing an exchange method with vessel occlusion occurring in stages, the time that blood flow is occluded in the vessel decreases, thereby minimizing the risks to the patient and presenting significant advantages over known technology. The speed of exchange is also improved by using an adaptor which allows for easy and quick handling of the guidewire for inflation and deflation.

Problems solved by technology

As can be readily appreciated, the withdrawal of treatment catheters over a placed guidewire may result in the guidewire being displaced from its position.

Cohen also does not address the problem of emboli containment.

However, many blood vessels where it is desirable to apply catheter treatment are quite narrow.

Similarly, saphenous vein grafts (SVG) and the carotid arteries are also quite small and susceptible to plaque, and could not practically be treated by larger diameter devices.

Human blood vessels often become occluded or completely blocked by plaque, thrombi, other deposits, emboli or other substances, which reduce the blood carrying capacity of the vessel.

Should the blockage occur at a critical place in the circulatory system, serious and permanent injury, or even death, can occur.

The coronary arteries are first narrowed and may eventually be completely blocked by plaque, and may further be complicated by the formation of thrombi (blood clots) on the roughened surfaces of the plaques.

Myocardial infarction can result from atherosclerosis, especially from an occlusive or near occlusive thrombi overlying or adjacent to the atherosclerotic plaque, leading to death of portions of the heart muscle.

Thrombi and emboli also often result from myocardial infarction, and these clots can block the coronary arteries, or can migrate further downstream, causing additional complications.

It can be difficult, however, to treat plaque deposits and thrombi in the coronary arteries, because the coronary arteries are small, which makes accessing them with commonly used catheters difficult.

Each of these methods are not without the risk of embolism caused by the dislodgement of the blocking material which then moves downstream.

In addition, the size of the blocked vessel may limit percutaneous access to the vessel.

In coronary bypass surgery, a more costly and invasive form of intervention, a section of a vein, usually the saphenous vein taken from the leg, is used to form a connection between the aorta and the coronary artery distal to the obstruction.

Over time, however, the saphenous vein graft may itself become diseased, stenosed, or occluded, similar to the bypassed vessel.

Once the plaque and thrombi are dislodged from the vein, they can move downstream, completely blocking another portion of the coronary artery and causing myocardial infarction.

Therefore, balloon angioplasty of vein grafts is performed with the realization that involvement by friable atherosclerosis is likely and that atheroembolization represents a significant risk.

Because of these complications and high recurrence rates, old diffusely diseased saphenous vein grafts have been considered contraindications for angioplasty and atherectomy, severely limiting the options for minimally invasive treatment.

However, such arteries have been very difficult to treat because of the possibility of dislodging plaque which can enter various arterial vessels of the brain and cause permanent brain damage.

Attempts to treat such occlusions with balloon angioplasty have been very limited because of such dangers.

Such surgical procedures have substantial risk associated with them which can lead to morbidity and mortality.

In other procedures, such as in angioplasty and in the treatment of peripheral arteries and veins, there is the possibility that the guide wires and catheters used in such procedures during deployment of the same may cause dislodgement of debris or emboli which can flow downstream and cause serious damage, such as stroke, if they occlude blood flow in smaller vessels.

Moreover, when treating aneurysms, coils or other objects deployed to fill the aneurysm may break free and become lost downstream.

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