Axial sharp needle reentry device
A catheter, such as for use for total occlusion crossing and lumen reentry, incorporate a retractable long flexible nitinol curved needle at the catheter distal end. The needle is straight when withdrawn inside the catheter. When pushed forward, the needle is deployed by protruding axially out, directly from the distal tip, through a mechanism used to direct the curved needle into a specific radial direction. When pushed forward, the needle restores its curved shape and can penetrate the plaque or the media and intimal layers to reenter the true lumen.
1 . A method comprising:
providing a catheter device comprising:
a straight catheter shaft comprising a lumen that extends straight through a distalmost end of said catheter shaft, wherein said catheter shaft lacks any side port;
a handle coupled to a proximal portion of said catheter shaft; and
a needle that passes through said lumen in said catheter shaft and said distalmost end, said needle comprising a first straight section coupled to said handle, a curved section that extends distally from said first straight section, a second straight section that extends distally from said curved section, and a sharp distal tip at a most distal end of said needle, wherein said needle is made of an elastic material and, wherein when said needle is inside said lumen, said curved section becomes straight, and when said needle starts to protrude from said distalmost end, said sharp tip protrudes straight through said distalmost end and afterwards said second straight section protrudes straight through said distalmost end, and when said curved section exits said distalmost end, said curved section becomes curved again; and
providing two steps for crossing an occlusion found in a true lumen of a blood vessel, a first step comprising:
advancing said needle without a guidewire in said catheter shaft so that only said sharp tip or said sharp tip and said second straight section protrude straight through said distalmost end; and
using said sharp tip or said sharp tip and said second straight section of said needle to cross the occlusion without entering a sub-intimal space of the blood vessel; and
a second step comprising:
further advancing said needle in said catheter shaft so that said curved section exits said distalmost end and said curved section becomes curved again;
using the curved section of said needle to cross the occlusion if the occlusion is at an angle relative to the catheter axial direction, with or without said curved section entering the sub-intimal space of the blood vessel; and
wherein said needle is selectively advanced to penetrate the occlusion within the true lumen or to cross the occlusion within the sub-intimal space of the blood vessel and to reenter the true lumen.
2 . The method according to claim 1 , further comprising, when said curved section has exited said distalmost end and has become curved again, moving said curved section to advance said needle from the true lumen of the blood vessel into the sub-intimal space and then performing reentry into the true lumen from the sub-intimal space by advancing the catheter shaft distally with the needle fully or partially protruded from said catheter shaft, and moving said catheter, while said needle is fully or partially protruded, following a direction of the curved section, until said tip pierces and reenters the true lumen.
3 . The method according to claim 2 , wherein for reentry into the true lumen, said needle is fully protruded from said catheter shaft, and pulled back proximally if said needle has passed the true lumen, until the distal tip of said needle is positioned in the true lumen.
4 . The method according to claim 2 , wherein if the distal tip of said needle does not reach the true lumen for reentry into the true lumen, further comprising advancing said catheter shaft distally along said needle while fully or partially protruded, such that said catheter shaft follows a direction of said needle until said needle and said catheter shaft pierce and reenter the true lumen.
5 . The method according to claim 1 , wherein for crossing the occlusion, said needle is not fully protruded from said catheter shaft.
6 . A catheter device comprising:
a straight catheter shaft comprising a lumen that extends straight through a distalmost end of said catheter shaft, wherein said catheter shaft lacks any side port;
a handle coupled to a proximal portion of said catheter shaft; and
a needle that passes through said lumen in said catheter shaft and said distalmost end, said needle comprising a first straight section coupled to said handle, a curved section that extends distally from said first straight section, a second straight section that extends distally from said curved section, and a sharp tip at a most distal end of said needle, wherein said needle is made of an elastic material and,
wherein when said needle without a guidewire is inside said lumen, said curved section becomes straight, and when said needle starts to protrude from said distalmost end, said sharp tip protrudes straight through said distalmost end and afterwards said second straight section protrudes straight through said distalmost end, and when said curved section exits said distalmost end, said curved section becomes curved again, and
wherein, said needle is selectively advanceable to penetrate the occlusion within a true lumen of a blood vessel or to cross the occlusion within the sub-intimal space of the blood vessel and to reenter the true lumen.
7 . The catheter device according to claim 6 , wherein a distal portion of said catheter shaft and said needle form a keyed configuration for defining an angular orientation of said needle.
8 . The catheter device according to claim 7 , wherein said keyed configuration comprises a portion of said catheter shaft being formed with a longitudinal slot and said needle comprising a bulge arranged for sliding in said longitudinal slot, or said needle being formed with said longitudinal slot and a portion of said catheter shaft comprising said bulge.