Distal-tip portion with valve

An apparatus for use with a guidewire, the apparatus comprising:

• a percutaneous medical device defining a guidewire lumen that extends from a proximal end of the device to a distal end of the device;
• a valve disposed within a distal portion of the guidewire lumen, the valve defining a slit at its proximal end;
• and
• a guidewire guide disposed within the guidewire lumen at a location that is proximal to the valve, the guidewire guide shaped to define a hole therethrough, which narrows in diameter from a proximal end of the guidewire guide to a distal end of the guidewire guide, the shape of the guidewire guide being configured to guide a tip of the guidewire toward the slit at the proximal end of the valve, when the guidewire is inserted from the proximal end of the percutaneous medical device.