Method of using an aortic dissection septal cutting tool

1. A method of treating an aortic dissection comprising:

providing a medical cutting tool for cutting a tissue wall of a false lumen of a vessel, said medical cutting tool comprising:

a guidewire having opposite first and second ends;

a catheter having a luminal space for receiving said guidewire therethrough;

at least one self-expanding displacement element attached to said catheter;

at least one translatable cutting edge incorporated with said catheter, said translatable cutting edge being actuated with an elongate member; and

a flexible housing coupled to said translatable cutting edge attached to said catheter for protecting the vessel from said translatable cutting edge until said cutting edge is positioned and actuated, said flexible housing being hollow and dimensioned to accommodate said guidewire therethrough, said luminal space of said catheter and said flexible housing defining at least a portion of a continuous path through which one of said first and second ends of the guidewire can be fed,

wherein said flexible housing is generally U-shaped so that said one of the first and second ends is presented along an opposite side of a tissue wall relative to said catheter in order to facilitate location and guiding of said flexible housing into the false lumen thereby positioning said translatable cutting edge for cutting engagement with the tissue wall of the false lumen,

placing said catheter within an arterial system;

advancing said catheter through said arterial system to a location distal to a primary entry tear of said aortic dissection;

contacting aortic tissue with said displacement element;

forming a hole in septal tissue of said aortic dissection;

cannulating a guidewire from said catheter through said hole in tissue of said aortic dissection into a false lumen delimited by said septal tissue;

engaging said at least one cutting edge with said septum; and

advancing said cutting edge along said septum.

2. The method of claim 1 further comprising removing said catheter from said arterial system.

3. The method of claim 1 wherein said cutting edge is translatable.

4. The method of claim 1 wherein said catheter has a flexible atraumatic end portion.

5. The method of claim 1 wherein said displacement element is expandable.

6. The method of claim 5 wherein said expandable displacement element is self-expandable.