Endoscopic tri-point biopsy needle
A tri-point tissue-collection needle configured similarly to a fine-needle-aspiration needle is configured to excise intact tissue cores for collection. The distal tip is configured with three beveled points separated by cutting edges, where a single longer/more distal point is trailed by and circumferentially separated from a symmetrical pair of points, providing a bilaterally symmetrical needle cannula distal end. A stylet may be provided through a lumen of the needle during introduction into a patient body, where the distal end surface of the stylet may be configured to complement the tri-point needle end configuration.
1. A tri-point tissue-sampling needle device, comprising:
an elongate tubular cannula including a cannula wall defining a longitudinal cannula lumen constructed to receive a tissue sample;
a distal beveled tubular terminal end of the cannula including a long side and a short side;
where the short side includes two beveled distal-terminal pointed tips symmetrically disposed opposite of, and proximal from, a longer beveled terminal end tip defining a distalmost terminus of the cannula;
where beveling across a thickness of the cannula wall is angled from a thicker, more proximal, wall thickness to a thinner, more distal, wall thickness between the two beveled points; and
where the distal beveled tubular terminal end of the cannula is bilaterally symmetrical.
2. The device of claim 1 , where the beveling across the thickness of the cannula wall provides a uniform inner diameter of the cannula lumen and provides an outer diameter that decreases proximally to distally.
3. The device of claim 1 , further comprising a notch through the cannula wall, open to the cannula lumen;
where the notch is disposed proximally of, and adjacent to, the beveled distal cannula end and is generally centered radially on the short side; and
where a proximal end of the notch includes a distally-extending generally parabolic distal lip defined by a portion of the cannula wall, including a distal-facing edge that extends distally from a proximal-most end of the notch such that a central distal lip portion including the edge is disposed more distally than lip end portions that transition around a radiused curve from the lip to, and that are continuous with, generally longitudinal lateral sides formed by a parabolic distal boundary of the notch.
4. The device of claim 1 , further comprising a solid stylet disposed through, and occupying substantially an entire cross-sectional area of, at least a lengthwise portion of the cannula lumen.
5. The device of claim 4 , where a distal end of the stylet is beveled to align with the distal beveled cannula end tips.
6. The device of claim 1 , comprising a first operating state for introducing the needle to a target, with said first operating state including a solid stylet disposed through, and occupying substantially an entire cross-sectional area of, at least a lengthwise portion of the cannula lumen, and a second operating state for collecting a sample with the stylet completely removed from the cannula lumen.
7. The device of claim 1 , where a major bevel angle is inclusively between about 7.5 degrees and 15.5 degrees, said major bevel angle disposed between an edge leading to the longer beveled terminal end tip and a longitudinal axis along an outer diameter of the cannula, which longitudinal axis is parallel with a central longitudinal axis of the cannula.
8. The device of claim 7 , where a first minor bevel angle is about 10 degrees across a complete thickness of the cannula wall between the two beveled distal terminal pointed tips and the longer beveled terminal end tip.
9. The device of claim 8 , where a second minor bevel angle is about 9 degrees across a complete thickness of the cannula wall immediately adjacent of and extending proximally and radially externally from the longer beveled terminal end tip.
10. The device of claim 1 , further comprising a solid stylet disposed through, and occupying substantially an entire cross-sectional area of, and an entire distal length, of the cannula lumen without extending substantially beyond a distalmost end terminus of the cannula.
11. The device of claim 1 , wherein the cannula is configured as sufficiently flexible for passage through a working channel of a peroral surgical visualization device.
12. The device of claim 1 , where the cannula comprises a selected one of a 18-gauge needle, 19-gauge needle, 20-gauge needle, 22-gauge needle, or 25-gauge needle.
13. The device of claim 1 , where a major bevel angle is about 10 degrees between the longer beveled terminal end tip and a point on the cannula intermediate the two beveled distal terminal pointed tips, where a first minor bevel angle is about 10 degrees across a complete thickness of the cannula wall between the two beveled distal terminal pointed tips and the longer beveled terminal end tip, and where the longer beveled terminal end tip is configured as a wedge.
14. The device of claim 1 , comprising a consistent inner diameter and outer diameter of the cannula along an entire length of the cannula lumen extending proximally from the distalmost end.
15. A notched tri-point endoscopic biopsy needle, comprising:
a flexible elongate tubular cannula sized no larger than 18-gauge, including a cannula wall defining a cannula lumen configured to communicate with a proximal source of suction;
wherein the cannula lumen extends longitudinally through the cannula;
a distal beveled end of the cannula with a long side including a single, longer extended tip defining a distalmost cannula terminus and a short side including a substantially symmetrically disposed pair of distal-pointed tips;
a notch through the cannula wall, open to the cannula lumen;
wherein the notch is disposed proximally adjacent to the beveled distal cannula end and is generally centered in longitudinal alignment with a short beveled end and opposite a long beveled end; and
wherein the notch includes a cutting edge defined by a distal-facing portion of the cannula wall, where the cutting edge is both longitudinally and radially arcuate such that a center-most portion of the cutting edge is more distally disposed than are lateral-end portions of the cutting edge.
16. The needle of claim 15 , further comprising a stylet disposed through, and occupying substantially an entire cross-sectional area of, at least a distalmost lengthwise portion of the cannula lumen, and where a lateral side of the stylet fully obscures the notch when a distal end of stylet is distal of the notch.
17. A tri-point needle and stylet system comprising:
an elongate cylindrically tubular cannula with a cannula wall defining a coaxial longitudinal cannula lumen between a proximal end and a distal end of the cannula;
a solid stylet disposed removably through, and occupying substantially an entire cross-sectional area of, at least a distalmost lengthwise portion of the cannula lumen; and
where the distal end of the cannula and the distal end of the stylet include three coincident concave parabolic beveled surfaces converging at a common distalmost end terminus of the cannula and the stylet.
18. The system of claim 17 , where the common distalmost end terminus of the cannula and the stylet coincide with a longitudinal axis along an inner diameter wall of the cannula lumen.
19. The system of claim 18 , where each beveled surface is at an angle that is the same relative to a longitudinal axis along an outer diameter wall of the cannula lumen, which longitudinal axis bisects a proximalmost end of said beveled surface.
20. The system of claim 19 , where the angle is about 10 degrees.