Closed Tip Dynamic Microvalve Protection Device

An endovascular microvalve device for temporary use in a vessel having a vessel wall during an intravascular procedure, comprising:

• a) a flexible outer catheter having a proximal end and a distal end;
• b) a flexible inner catheter having a proximal end and a distal end with an orifice, the inner catheter extending through and longitudinally displaceable relative to the outer catheter;
• and
• c) a filter valve having a proximal end and distal end, the proximal end of the filter valve coupled to the distal end of the outer catheter, and the distal end of the filter valve coupled to the inner catheter adjacent the distal end of the inner catheter, such that longitudinal displacement of the inner catheter relative to the outer catheter moves the filter valve from a non-deployed configuration to a deployed configuration, the filter valve having a proximal portion comprising a braided filamentary structure consisting of a first number of filamentary portions, and distal portion comprising an arrangement of second number of filamentary portions, the second number fewer than the first number, and the distal portion further comprising a porous polymeric material coupled to the filamentary portions of the distal portion, the porous polymeric material defining a pore size not exceeding 500 μm.

A method of a using a microvalve device, comprising:

• a) advancing a microvalve device to a target location, the microvalve device having
• i) a flexible outer catheter having a proximal end and a distal end,
• ii) a flexible inner catheter having a proximal end and a distal end with an orifice, the inner catheter extending through and longitudinally displaceable relative to the outer catheter, and
• iii) a filter valve having a proximal end and distal end, the proximal end of the filter valve coupled to the distal end of the outer catheter, and the distal end of the filter valve coupled to the inner catheter adjacent the distal end of the inner catheter, such that longitudinal displacement of the inner catheter relative to the outer catheter moves the filter valve from a non-deployed configuration to a deployed configuration, the filter valve having a proximal portion comprising a braided filamentary structure;
• b) infusing a therapeutic agent through the inner catheter and out of the distal end of the inner catheter;
• c) retracting the inner catheter relative to the outer catheter to invert at least a portion of the filter valve into the outer catheter;
• and
• d) withdrawing the microvalve device from the target location.