Aspiration catheters having adjustable flaps

An aspiration catheter comprising:

• a proximal end region, a distal end region configured to be positioned at an intravascular treatment site;
• a sidewall defining a lumen extending from the proximal end region to the distal end region;
• an aspiration opening in the sidewall in the distal end region;
• and
• a cover releasably disposed over the aspiration opening, the cover having a first end coupled to the sidewall and a free second end, the cover adjustable between a closed configuration and an open configuration.

A method comprising:

• disposing a medical device within a vessel at or adjacent a treatment site, the medical device comprising:
• a tubular member, the tubular member having a plurality of side openings in a distal region of the tubular member, and
• at least one adjustable flap coupled to the tubular member, wherein the adjustable flap is proximate to a one of the plurality of side openings, and wherein the flap has a first configuration in which the flap at least partially covers the side opening and a second configuration in which the flap is biased away from the side opening;
• and
• transitioning the adjustable flap from the first configuration to the second configuration.