Balloon catheter method for reducing restenosis via irreversible electroporation

Abstract

Restenosis or neointimal formation may occur following angioplasty or other trauma to an artery such as by-pass surgery. This presents a major clinical problem which narrows the artery. The invention provides a balloon catheter with a particular electrode configuration. Also provided is a method whereby vascular cells in the area of the artery subjected to the trauma are subjected to irreversible electroporation which is a non-thermal, non-pharmaceutical method of applying electrical pulses to the cells so that substantially all of the cells in the area are ablated while leaving the structure of the vessel in place and substantially unharmed due to the non-thermal nature of the procedure.

Description

CROSS-REFERENCE[0001]This application claims the benefit of U.S. Provisional Application Nos. 61 / 040,110, filed Mar. 28, 2008 and 61 / 156,368, filed Feb. 27, 2009, which applications are incorporated herein by reference.GOVERNMENT RIGHTS[0002]This invention was made with government support under federal grant no. NIH R01 RR018961 awarded by the U.S. National Institutes of Health (NIH). The United States Government has certain rights in this invention.FIELD OF THE INVENTION[0003]The present invention relates to a medical device and method for the prevention of vascular re-stenosis using electroporation. More particularly, the present invention relates to a balloon catheter device with electrodes for electroporating the inner wall of a vascular structure to prevent re-stenosis.BACKGROUND OF THE INVENTION[0004]Catheters, and more particularly, balloon catheters have been used to treat stenosis of a vascular or other anatomical tubular structure. In one such procedure, called percutaneou...

AI Technical Summary

Benefits of technology

[0014]In another embodiment of the invention the device comprises an electrical power source which provides electrical pulses which provide voltage, current and are provided for a duration so as to avoid thermal damage to a target area and surrounding tissues while obtaining the IRE on the target area.

[0019]The IRE is not carried out in order to provide for reversible electroporation of substantially all of the cells. Reversible electroporation is carried out when the pores of the cells are temporarily opened and after the procedure go back to normal size and the cells survive. Others carry out electroporation in a manner so as to prevent excessive cell lysing (see U.S. Pat. Nos. 6,865,416 and 6,342,247). With irreversible electroporation the pores of the cells are opened and are opened to a degree that they do not return to normal size and the cells die, so excessive lysing of cells is desired. Thus, irreversible electroporation requires more voltage, current or time in order to obtain the desired result as compared to reversible electroporation. The amount of current used and the time it is applied must be controlled in accordance with the invention in order to avoid thermal damage. The result sought per the present invention is to have substantially all of the vascular cells of the targeted area of the artery ablated or killed but to not raise the temperature of that area sufficiently to cause thermal damage and denature proteins. By avoiding thermal damage the structure of the artery and surrounding tissue remains in place. However, due to the irreversible electroporation the vascular cells are killed and as such do not form scar tissue (neointimal) in the area thereby reducing or avoiding restenosis.

Problems solved by technology

Notwithstanding the importance of PTA procedures in restoring normal blood flow to an anatomical region, one problem associated with PTA procedures is the undesired re-growth of the lesion, commonly known as re-stenosis.

Although the use of stents has reduced the re-stenosis rate to approximately 30% of the procedures, re-stenosis remains a significant clinical problem, particularly for those patients whose general health is not conducive to repeat interventional procedures.

The main cause of re-stenosis following angioplasty procedures is due to vessel wall trauma created during the procedure.

An overgrowth of endothelial cells triggered by the trauma leads to a re-narrowing of the vessel and eventual re-stenosis of the treated area.

Although it is contemplated that scoring a lesion will lead to less procedural vessel trauma, endothelial cell re-growth and re-stenosis, to date there are no studies that effectively demonstrate this.

Although shown to be effective in further reducing re-stenosis, there are several known problems with drug-eluting stents including an increased risk in some patient populations of localized blood clots after the drug has been completely eluted, usually after six or more months.

Clot formation in the coronary system can lead to heart attack and death.

Other problems include stent fracture and other known risks associated with long-term implants.

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