JPH0154058B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention belongs to medical equipment, and relates to an aspiration biopsy needle for aspirating and collecting a piece of tissue from an affected area of a patient's organ, etc.
In particular, the present invention relates to an aspiration biopsy needle that reliably aspirates tissue pieces and makes the aspiration operation using a plunger most efficient.

[Conventional technology]

The present applicant has previously proposed an aspiration biopsy needle 20 as shown in FIG.
It is a double needle consisting of an outer needle 21 and an inner needle 22, and the outer needle 21 has a section A that is slidably in close contact with the inner needle 22 at the needle tip, and an inner needle that follows the section A. It has two sections with different diameters, a section B having a larger inner diameter and having an air chamber space between it and 22.

In the above configuration, the negative pressure generated in the cylinder (not shown) by pulling the plunger (not shown) is communicated to the needle tip through the gap between the outer needle 21 and the inner needle 22 of the double needle. , which creates a suction force at the needle tip. In particular, since this aspiration biopsy needle 20 has the section A, at the beginning of the aspiration operation, while the tip of the inner needle is in the section A, the negative pressure generated in the cylinder will hardly leak and accumulate. Then, the moment the needle tip of the inner needle enters section B, the accumulated negative pressure is rapidly transmitted to the needle tip, resulting in a strong suction force.

[Problem that the invention seeks to solve]

However, with conventional aspiration biopsy needles, the close contact area between the outer needle and the inner needle is short (for example, 5 mm), which is about a fraction of the stroke length of the plunger. This occurs at the tip of the needle and the tissue fragments (liquid) are aspirated.
For this reason, there is a risk of clogging occurring during the retraction operation of the plunger, and even if no clogging occurs, the tip of the inner needle will quickly pass the close contact area, causing negative pressure inside the cylinder to There was a limit to the increase in negative pressure level due to leakage to the outside through the gap between the needles.

[Means and actions for solving problems]

The present invention has been made in view of the above,
To prevent clogging during operation by generating a large level of suction force at the needle tip near the end of the plunger retraction operation, the close contact section between the inner and outer needles is made slightly smaller than the stroke length of the plunger, and the suction force is generated at the needle tip near the end of the plunger retraction operation. The present invention provides an aspiration biopsy needle in which the tip of the inner needle passes through the close contact section and separates.

〔Example〕

Hereinafter, the aspiration biopsy needle according to the present invention will be explained in detail.

Figures 1 to 3 show one embodiment, which includes a thin tubular outer needle 1 and a cylinder 3 fixed to the outer needle 1 as described below.
a cylinder 3 having a notch 4 at an axially symmetrical position in the longitudinal direction and a fixed lid 5 at the rear end; an inner needle 6 having a sharp tip; A slide packing 8 is attached, an inner needle 6 is fixed to the center of the front end, and a handle 9 is slidable along the notch 8 at the rear end.
The plunger 7 has a plunger 7.

As shown in Fig. 3, the outer needle 1 is divided into three sections A, B, and C with different diameters.
21G (outer diameter 0.81mm, inner diameter 0.58mm), 20G in section B
(outer diameter 0.91mm, inner diameter 0.69mm), section C is 19G (outer diameter
1.05mm, inner diameter 0.84mm), from needle tip to needle base 2
The pipe diameter becomes thicker towards the end. The inner needle, on the other hand, has a single diameter of approximately 0.55 mm. Further, the section A has a length of about 30 mm.

Therefore, when the inner needle 6 is housed in the outer needle 1 and the inner needle 6 slides inside the outer needle 1, the two are in close contact with each other in the section A, and there is almost no air circulation in the gap between the two. In an airtight state, in section B, the gap widens a little, allowing air to flow, but with some resistance to the flow, and in section C, the gap widens further and there is almost no resistance to air flow, which can be ignored. Since the section C is provided, the negative pressure inside the cylinder is more easily transmitted to the tip of the outer needle 5 than in the past, and the bending strength is increased by increasing the diameter.

In the above configuration, the operation of extracting a tissue piece of an internal organ using the aspiration biopsy needle of the present invention and its operation will be described below.

First, while inserting the inner needle 6 into the outer needle 1, push the plunger 7 until it hits the bottom of the cylinder 3, so that the tip of the inner needle 6 moves from the tip of the outer needle 1 to the tip of the inner needle 6.
Make it protrude by about mm. In this state, the needle is pierced into the human body, and after the needle tip reaches the target organ, hook the second and third fingers of one hand on both sides of the handle 9 of the plunger 7, and fix it with the first finger. While holding down the lid 5, the plunger 7 is quickly pulled in until the handle 9 comes into contact with the temporary fixing part 4a and stops.

When the handle 9 is held between the temporary fixing portions 4a and the movement of the plunger 7 is stopped, the inner needle 6
The tip of the needle is adjusted so that it is at a position set back by a distance d from the boundary between section A and section B. Here, the value of d is such that the needle tip of the inner needle 6 crosses section A and reaches section B.
It is sufficient if the value is such that air is securely circulated through the gap between the inner needle 6 and the outer needle 1 by escaping the airtight state in section A. It is necessary that at least d≧0.9 [mm].

This retraction operation of the plunger 7 generates negative pressure in the space surrounded by the cylinder 3 and the slide packing 8 at the tip of the plunger 7, and the space and the outer needle are compressed through the gap between the outer needle 1 and the inner needle 6. Since the opening at the tip of the outer needle 1 is open, a pressure difference with atmospheric pressure is generated, and a suction force is generated from the tip of the outer needle 1 toward the inside of the cylinder 3.

When the inner needle 6 moves backward relative to the outer needle 1 due to the retraction operation of the plunger 7, the inner needle 6
Since the space between the outer needle 1 and the inner needle 6 is almost airtight while the needle tip is present, the negative pressure generated in the cylinder is rapidly accumulated in proportion to the amount of movement of the plunger 7. As shown in FIG. Strong suction power can be obtained at the tip.
Note that when the tip of the inner needle 6 enters section B, the negative pressure within the cylinder 3 continues to leak, so rapid accumulation of negative pressure as in section A can no longer be expected.
Therefore, in this case, continuing to pull the plunger 7 will hardly contribute to the generation of suction force and will be a waste of effort, so the value of d is
If it is too large, it will reduce the efficiency of the suction operation.

Then, at the same time as pulling in the plunger 7,
When the cylinder 3 is advanced toward the organ, the inner needle 6 retreats, and tissue fragments from the organ enter the cavity formed at the tip of the outer needle 1 and are sucked by the above-mentioned suction force. After suction, by pulling out the outer needle 1 from the body, the tissue pieces sucked into the outer needle 1 can be torn into pieces and taken out of the body.

〔Effect of the invention〕

As explained above, according to the aspiration biopsy needle of the present invention, the close contact section of the inner and outer needles is made slightly smaller than the stroke length of the plunger, and the tip of the inner needle passes through the close contact section and separates near the end of the plunger retraction operation. This makes it possible to generate a large level of suction force at the needle tip near the end of the plunger retraction operation, thereby preventing clogging during the operation.

[Brief explanation of drawings]

1 and 2 are configuration diagrams of an aspiration biopsy needle according to an embodiment of the present invention, FIG. 3 is a partial sectional view of an aspiration biopsy needle according to an embodiment of the present invention, and FIG. Partial cross-sectional view of meter reading. Explanation of symbols, 1... Outer needle, 2... Needle base, 3...
Cylinder, 4... Notch split part, 4a... Temporary fixing part, 5... Fixed lid, 6... Inner needle, 7... Plunger, 8... Slide packing, 9...
Handle, 20...Aspiration biopsy needle, 21...Outer needle, 2
1... Inner needle, A, B, C... Each section of the outer needle with a different diameter, d... Distance from the boundary between section A and section B to the tip of the inner needle 6.

Claims (1)

[Scope of Claims] 1. A tubular outer needle fixed to the tip of a cylinder, and an inner needle fixed to the tip of a plunger and moved inside the outer needle based on the movement of the plunger inside the cylinder. an aspiration biopsy needle, which provides a sealed state and a non-sealed state to the aspiration space formed in the cylinder by the relative positional relationship between the outer needle and the inner needle, wherein the outer needle is in contact with the inner needle. A close contact section at the tip that is in close contact and has a length shorter than the stroke length of the plunger by a predetermined minute dimension, and a non-close contact section that is connected to the close contact section with a predetermined gap between the inner needle and the inner needle. the inner needle maintains the sealed state by having its tip located in the close contact area from the start of the retraction operation of the plunger to during the operation;
The aspiration biopsy needle is characterized in that when the plunger leaves the close-contact zone and enters the non-contact zone near the end of the retraction operation of the plunger, the needle is guided into the suction space by providing the unsealed state.