Vascular embolism prevention device employing filters

A method for preventing embolism and microembolism in a blood flow circuit incident to performance of a treatment at a location in a blood vessel, said method comprising:

• introducing a first filter element into the blood vessel downstream of the location so that the first filter element obturates the blood vessel;
• performing the treatment;
• introducing a second filter element into the blood vessel upstream of the location so that the second filter element obturates the blood vessel;
• and
• after the step of performing a treatment, bringing the first and second filter elements close to one another, radially collapsing the first and second filter elements and withdrawing the first and second filter elements from the blood vessel.

A method for performing angioplasty comprising:

• aligning a first balloon with an obstruction in a blood vessel, the first balloon being radially outwardly expandable;
• interposing a second balloon between the first balloon and the obstruction, the second balloon being annular and radially outwardly expandable;
• expanding the first balloon to support the second balloon;
• and
• expanding the second balloon to dilate the obstruction.

A system for performing angioplasty comprising:

• a first balloon movable into alignment with an obstruction in a blood vessel, the first balloon being radially outwardly expandable;
• a second balloon movable into a position where the second balloon is interposed between said first balloon and the obstruction, said second balloon being annular and radially outwardly expandable;
• means coupled to said first balloon for expanding said first balloon to support the second balloon;
• and
• means coupled to said second balloon for expanding said second balloon to dilate the obstruction.