Half cannula full core biopsy needle
View Patent ↗There is disclosed, among other things, embodiments of a biopsy needle for taking a full core sample through soft tissue. In the illustrated embodiments, an inner tubular member having a semi-cylindrical distal end is within and slidable with respect to an outer tubular member. A semi-cylindrical channel is in the distal end, as well as a planar end surface. The channel has a set of one or more protrusions or texture, and a complementary set of protrusions or texture are placed on the inside of the outer member so that the sets of protrusions or texture face each other when the distal ends of the members are adjacent each other. Methods for using these embodiments are also described.
1. A biopsy needle for use in sampling soft tissue, comprising:
an inner tubular member having a lumen and being within an outer tubular member so that said members are slideable with respect to each other along the longitudinal axis of the inner tubular member,
said inner tubular member having an external wall and a semi-cylindrical distal portion that subtends an arc of between about 160 to 200 degrees about the longitudinal axis so that said lumen is a semi-cylindrical channel in said distal portion, said distal portion having a planar end surface that is U-shaped and a sharpened edge along the intersection of said planar end surface and said external wall having a sharpened forwardmost portion adapted to puncture tissue;
said outer tubular member having a central passage through which said inner tubular member extends, and a distal portion having a planar end surface and a sharpened edge at the intersection of said planar end surface of said outer tubular member and a wall surrounding said central passage, said wall surrounding said central passage that is proximal of the planar end surface of said outer tubular member and opposite said semi-cylindrical distal portion of said inner tubular member having no opening therethrough communicating with said central passage;
said biopsy needle further comprising a first textured section in said channel of said inner tubular member, said first textured section having an inward facing surface with one or more raised protrusions extending from the inward facing surface toward the lumen, said first textured section facing a second textured section in said central passage of said outer tubular member, said second textured section having a continuous unbroken external surface.
2. The needle of claim 1 , wherein said inner tubular member and said outer tubular member have a first relative position in which said planar end surface of said inner tubular member is adjacent or coplanar with said planar end surface of said outer tubular member, and wherein said second textured section is positioned in said outer tubular member so that all of said second textured section faces only said channel when said tubular members are in said first relative position.
3. The needle of claim 2 , said second textured section having an inward facing surface opposite the external surface with one or more raised protrusions extending from its inward facing surface toward the lumen, wherein the one or more raised protrusions of said first textured section and the one or more raised protrusions of said second textured section each comprise a respective plurality of round projections, said projections of said first textured section projecting into said channel of said inner tubular member, and said projections of said second textured section projecting into said central passage of said outer tubular member without extending through the external surface of the second textured section.
4. The needle of claim 1 , wherein said first textured section and said second textured section each comprise a same type of texture.
5. The needle of claim 1 , further comprising a handle fixed respectively to said inner tubular member and said outer tubular member to allow said tubular members to slide with respect to each other, said handle having a pair of finger holds on opposite sides of said tubular members and a plunger operatively connected to the inner tubular member to move the inner tubular member within the outer tubular member.
6. The needle of claim 1 , wherein said inner tubular member is adapted to cut a first part-circular profile and said outer tubular member is adapted to then cut a second complementary part-circular profile to provide a substantially circular profile through tissue.
7. The needle of claim 1 , wherein the entire edge along the intersection of said planar end surface and said external wall of said inner cannula is sharpened.
8. The needle of claim 3 , wherein the one or more raised protrusions of said first textured section and the one or more raised protrusions of said second textured section face each other.
9. The needle of claim 1 , wherein the one or more raised protrusions of said first textured section comprise a rounded ridge.
10. The needle of claim 9 , wherein the rounded ridge extends along the inward facing surface of the inner tubular member in a helical path.
11. The needle of claim 1 , wherein the one or more raised protrusions of said first textured section comprise a set of zig-zagging ridges.
12. The needle of claim 11 , wherein adjacent ones of the set of ridges are evenly spaced along a longitudinal distance within the inner tubular member.
13. The needle of claim 1 , wherein the one or more raised protrusions of said first textured section comprise criss-crossing ridges.
14. The needle of claim 1 , wherein the one or more raised protrusions of said first textured section comprise one or more ridges concentric with a longitudinal axis of the the inner tubular member.