An intravascular catheter

Claim 1

An intravascular catheter, characterizid by a hub (2) having an axial passage (5) which is open at the forward end and sealed with a sealing member (6) at the base end opposite to said forward end, a first auxiliary passageway (7) branched from the axial passageway (5') near the forward end of the hub (2), and a second auxiliary passageway (8) communicating with the axial passageway (5) at the sealed end thereof; a flexible double-walled tube (3) having an inwardly tapered tip portion (21) and consisting of an inner tube (13) extending into the axial passageway (5) formed in the hub (2) and providing a central passageway (15) and an outer tube (16) disposed in coaxial relation to the inner tube (13), thereby forming an annular passageway (20) between the outer wall of the inner tube (13) and the inner wall of the outer tube (16), the base edge of the inner tube being secured at an intermediate portion between the positions from which the first and second auxiliary passageways (7, 8) extend outward so as to enable the central passageway (15) formed in the inner tube (13) to communicate with the second-auxiliary passageway (8), the base edge of the outer tube (16) being fixed to the forward end of the hub (2) so as to enable the annular passageway (20) to communicate with the first auxiliary passageway (7), and the central passageway (15) having an opening at the tapered tip of the double-walled tube (3) and the forward end of the annular passageway (20) communicating with at least one bore provided at the forward end,portion of the outer tube (16); and a needle (4) removably inserted into the central passageway (15) formed in the inner tube (13) through the sealing member (6) provided at the base portion of the hub (2) such that the tip of the needle (4) extends beyond the tapered. tip (21) of the double-walled tube (3).