RU94835U1 - NEEDLE DEVICE FOR TRANSRECTAL BIOPSY - Google Patents

Abstract

 A transrectal biopsy needle device comprising a cutter outer tube with a cutting edge on the outer side of the oblique cut on the distal part, a needle located coaxially inside the outer tube, characterized in that the proximal end of the cutter tube is rigidly connected to a cylinder having a thrust ring connected by a thread with a stop nut with a slotted groove, a needle with a guide pin and a fuse strip located in the same diametrical plane on opposite sides of the longitudinal axis of the needle in the guides the slots of the cylinder with a locking recess, made with a groove on the distal cylindrical part, having the form of a single-turn right cylindrical helical surface with a ratio of the diameter of the needle to the pitch of the screw as 1:10, and the thread on the proximal part of the needle is connected to the stopper, and the cut-off spring is located inside the cylinder on the surface of the needle between the end of the inside of the cylinder and the fuse strip.

Description

The utility model relates to medical equipment, namely, to a device for sampling biopsy material for the diagnosis of prostate diseases (RV) associated with the emergence in clinical practice of high-speed automatic devices designed to obtain biopsy samples using various methods, in particular, through the perineum or rectum under local anesthesia.

To reduce unpleasant sensations in patients diagnosing pancreatic cancer by transrectal biopsy of the rectum, devices are used for simultaneous automated sampling of biopsy material with correction of ultrasonic localization of the location of the echogenic tip of the needle in the area of the pancreatic puncture in the absence of needle displacement at the time of tissue collection [Prostate disease. / Ed. Yu.G. Alyaeva. - M. GEOTAR - Media, 2009, - S. 39-43]. Preference is given to reusable biopsy needles in automated sampling systems that provide minimally invasive, atraumatic biopsy sampling, high quality selected material, facilitated stereotactic positioning of the needle in the instrument and easy removal of it from the tissue after completion of the study [Automatic systems for biopsy of reusable and single use. Biopsy needles for automatic systems. Catalog of Nayfeld Corporation 2006, Alameda, CA 94501 USA, 12 p]. Biopsy needle designs are emphasized by the reliable mechanism of safe atraumatic capture of tissue samples, which provides the necessary and sufficient biopsy specimen with a small device size, weight, and simplicity of design [Naya Y et al. Tumor length and location of cancer on biopsy predict for side specific extraprostatic cancer extension. J. Urol 2004; 171; p.1091-1093].

A biopsy needle device with reliable grip and retention of the removed tissue site [AC No. 520976, А61В 10/00], containing a hollow guide needle with a stylet inside it, the working part of the stylet looks like a harpoon with a groove, a hole and a sharp-pointed cutting, was chosen as an analogue. edge, and the opposite end of the stylet has a handle with a guide pin, and in the groove of the harpoon of the stylet, a sharpened curly retainer hidden in the recess of the groove of the harpoon while moving the pin of the guide needle for biopsy relative to the working part of the stylet.

The design disadvantages of the analogue include: turning the latch around its axis with the capture of a portion of the removed tissue, compressing the latter when the harpoon enters the groove, pressing it with the latch on the cutting edge of the harpoon lead to additional mechanical stresses on the tissue sample, which does not allow obtaining a biopsy with stored micro - and macroscopic properties of tissue; additional injuries during surgery; significant dimensions of the outer diameter of the guide needle to ensure reliable operation of the pivotally fixed latch hidden in the recess of the harpoon groove, leading to injury; high ergonomics of the effort to enter the guide needle into the tissue under study, the inability to work with one hand due to the presence of two handles (moving the stylet inside the guide needle to the depth of the alleged pathological focus and moving the needle relative to the working part of the stylet to control the position of the latch), which contribute to fatigue of the clinician's hands.

As a prototype, a device for biopsy of muscle tissue was selected that improves the quality of the sample by reducing deformation of muscle tissue [AS No. 707576 A61B 10/00], containing a telescopic handle consisting of two parts - the upper and lower, a tube fixed to the upper part of the handle, having a cutting edge at the end with a bevel, and inside the probe, made in the form of a needle with a recess, which is an irregular trapezoid at the end. A return spring located inside the handle allows the probe to reverse movement relative to the tube, cutting off the biopsy tissue preparation in the recess of the needle after sampling.

The disadvantages of the design of the prototype include:

- a manual method of introducing and removing a device for sampling muscle tissue, in which both hands of the clinician are occupied at the same time, the inability to work with one hand due to the presence of the handle and stop held by both hands when moving the probe inside the tube to the depth of the alleged pathological focus and repeated movements of the working parts of the probe relative to the tube for cutting and fixing in the recess of the probe of the selected tissue sample;

- the absence of the expected reduction in muscle tissue deformation due to the location of the cutting edge of the tube on the opposite side of the probe side due to the possibility of uncontrolled rotation of the tube relative to the working part of the probe during surgery, the absence of stabilization of the relative position of the probe and tube relative to the longitudinal diametrical plane of the device when moving relative to each other;

- additional trauma to muscle tissue at the site of biopsy sampling due to longitudinal movements of the working part of the probe relative to the tube to close the cut out tissue sample.

We first proposed a needle device for a transrectal biopsy containing a needle with a groove that looks like a single-turn right cylindrical helical surface [Mathematical Encyclopedia. 1977. T. 1 - M., "Sov. Encyclopedia ", - P.706] with the ratio of the diameter of the needle to the pitch of the screw as 1:10. A needle with a fuse strip, a guide pin to prevent the needle from rotating relative to the cutter tube and a cutter stopper at the proximal end is placed coaxially in the cutter tube rigidly connected to the cylinder having a thrust ring on the distal end of the outer surface of the cylinder and guide slots for the fuse and guide a needle pin with a locking recess of the socket. The proximal end of the cylinder is connected by a thread with a limiter nut having a slot in the form of an annular groove on the outer surface of its proximal part, which regulates with the help of a cutter stopper and a cutter spring located inside the cylinder on the outer surface of the cylindrical part of the needle between the end inner surface of the distal part of the cylinder and the strap fuse, the position of the cutter tube relative to the groove of the needle.

The proposed device is shown in figure 1, where:

1 - needle;

2 - cutoff tube;

3 - cylinder;

4 - a persistent ring of the cylinder;

5 - cutter spring;

6 - a directing pin;

7 - fuse strip;

8 - nest;

9 - a stopper of a course;

10 - limiter nut;

11 - slotted groove.

The device (Figure 1) consists of a needle (1) with a groove having the form of a single-turn right cylindrical helical surface with a ratio of the diameter of the needle to the pitch of the screw as 1:10. A needle (1) with a fuse strip (7) and a guide pin (6) is connected by a thread at the proximal end to the stopper of the cutter (9), placed coaxially in the tube of the cutter (2), rigidly connected to the cylinder (3) having a thrust ring (4), slots for the fuse strip (7) and the guide pin (6), the socket (8) is the fixing recess for the guide pin (6) of the needle (1). The outer surface of the stopper of the cutter (9) is connected in a sliding fit to the inner cylindrical surface of the limiter nut (10), which has a threaded connection with the cylinder (3), an end hole for the exit of the proximal end of the needle (1), and a slot groove (11) in the form an annular recess of a rectangular profile on the outer surface of the proximal part of the limiter nut (10) for fixing the device in the drive mechanism (not shown in FIG. 1). The position of the cut-off tube (2), rigidly connected to the cylinder (3), relative to the groove at the working end of the needle (1), is regulated by the position of the stop-cutter (9) on the needle (1) using the cut-off spring (5), the latter in the cocked state the needle (1) is compressed between the distal end of the inner surface of the cylinder (3) and the fuse strip (7), and the cut-off tube (2) opens the groove on the working end of the needle (1).

The device operates as follows: after the needle (1) is inserted into the prostate tissue to a predetermined depth under the influence of the piston-pusher of the input device (not shown in Fig. 1) through the hole in the limiter nut (8), the fuse strip (7) for the device to function the needle (1) in the automatic operation of the input device moves along the guide slot of the cylinder (3), diametrically opposite the slot for the guide pin (8), preventing the rotation of the needle (1) relative to the cutoff tube (2). The spring of the shut-off valve (5) is straightened, and the guide pin (6) together with the needle (1) moves along the guide slot of the cylinder (3) until it engages in the recess of the socket (8). In this case, the cutter tube (2) closes the working end of the needle (1) with a groove in which a piece of tissue (biopsy) of the prostate is fixed, cut off by the cutting edge on the outer side of the distal part of the oblique cut of the cutter tube (2) at the position of positioning the groove of the needle (1) ) in the biopsy site. The spring of the cutter (5) is straightened to a size determined by the relative position of the end surfaces of the limiter nut (10) and the stopper of the cutter (9) relative to the distal part of the needle (1). A needle (1) with a fixed cut-off tube (2) by a prostate biopsy is automatically removed from the prostate tissue when the return spring of the input device (not shown in Figure 1) is straightened, abutting against the cylinder thrust ring (4).

The proposed design of the device eliminates the disadvantages of the prototype, since the actuation of the return spring allows you to automate the controlled process of taking biopsy samples, regardless of the manual actions of the clinician, to reduce the sampling time due to the high speed of insertion and removal of the needle, to achieve positioning of the groove of the needle in the biopsy sampling zone, and to reduce the injuries of the diagnosed organs with multiple consecutive introduction of the needle to a predetermined depth. In the proposed device, there is no rotation of the cutter tube relative to the working part of the needle due to stabilization of the relative position of the needle and the tube relative to the longitudinal diametrical plane of the device when they are moved relative to each other. The material for the study is safely captured and cut off from the muscle tissue of the prostate, not with the translational movement of the needle with a recess on the end part relative to the tube, but with the edges of the groove of the needle when the cutting edge is fed forward on the outer side of the distal part of the oblique section of the cut-off tube, ensuring a stable positioning position the groove of the needle in the biopsy site. The proposed device of the needle allows for uniform sampling and fixation of samples of the investigated prostate tissue inside the groove of the latter without leading to their fragmentation during longitudinal movements of the needle. The groove in the needle, having the form of a single-turn right cylindrical helical surface with a ratio of the diameter of the needle to the pitch of the screw as 1:10, determined on the basis of empirical data of multiple sampling, allows you to take the volume of a tissue sample 30% more than a hole-shaped one of the same size, while maintaining high mechanical strength of the needle in the cross section of the groove. After removing the biopsy needle, the groove is closed by the cutter tube with the guide pin fixed in the recess of the cylinder slot, which ensures the safety of the sample, and is released only when the pin is removed from the recess of the cylinder slot. The biopsy procedure can be repeated several times during the diagnostic process for detecting prostate cancer without causing any inconvenience to the patient with minimal injury to the prostate tissue.

Claims (1)

A transrectal biopsy needle device comprising a cutter outer tube with a cutting edge on the outer side of the oblique cut on the distal part, a needle located coaxially inside the outer tube, characterized in that the proximal end of the cutter tube is rigidly connected to a cylinder having a thrust ring connected by a thread with a stop nut with a slotted groove, a needle with a guide pin and a fuse strip located in the same diametrical plane on opposite sides of the longitudinal axis of the needle in the guides the slots of the cylinder with a locking recess, made with a groove on the distal cylindrical part, having the form of a single-turn right cylindrical helical surface with a ratio of the diameter of the needle to the pitch of the screw as 1:10, and the thread on the proximal part of the needle is connected to the stopper, and the cut-off spring is located inside the cylinder on the surface of the needle between the end of the inside of the cylinder and the fuse strip.