WO2011021191A1

WO2011021191A1 - Method and system for ultrasound-guided biopsy

Info

Publication number: WO2011021191A1
Application number: PCT/IL2010/000666
Authority: WO
Inventors: Alexander Kanevsky; Alexander Burlakov
Original assignee: Alexander Kanevsky; Alexander Burlakov
Priority date: 2009-08-17
Filing date: 2010-08-17
Publication date: 2011-02-24

Abstract

The invention provides a system for obtaining rectal or transrectal biopsies. The system has a probe adapted for insertion into a rectum. The probe contains ultrasound transducers for obtaining images of tissues in the vicinity of the rectum and a massager for massaging a region of wall of the rectum prior to insertion of a biopsy needle. The system may also include a percutaneous electrical nerve stimulation (TENS) device and a massaging device adapted for massaging the sphincter ani externis.

Description

METHOD AND SYSTEM FOR ULTRASOUND-GUIDED BIOPSY

FIELD OF THE INVENTION

This invention relates to medical devices for obtaining a biopsy through the wall of a rectum.

BACKGROUND OF THE INVENTION

A rectal biopsy is a procedure in which sample of rectal tissue is removed and collected for examination. In a transrectal biopsy, a biopsy needle is inserted into the rectum that is made to pierce through the rectal wall to obtain a tissue sample from an organ outside the rectum, such as a prostate gland or urinary bladder.

Prostate biopsy is typically performed when a digital rectal examination or prostate specific antigen (PSA) blood level has indicated the possible presence of prostate cancer. Every year about one million prostate biopsies carried out in the United States alone, of which about 25 percent show the presence of prostate cancer.

In one method of rectal or transrectal biopsy, an ultrasound probe is inserted through the anus into the rectum to image the tissue from which a sample is to be taken. While imaging, the tip of a spring-loaded prostate tissue collection needle is delivered into the rectum to the rectum wall adjacent to a region where a biopsy is to be taken. The needle is then is then shot into the rectum wall, and, in the case of transrectal biopsy, the needle pierces through the rectal wall into the adjacent organ from which an tissue sampel is to be taken. Up to about a dozen biopsies can be collected. US Patent No. 6,443,902 to Sasady discloses an ultrasound probe adapted for insertion into a rectum including a guide for guiding a biopsy needle to the rectum wall while imaging the prostate.

Insertion of the ultrasound probe into the rectum and collection of tissue samples from the rectal wall or adjacent organs, can provoke considerable discomfort and pain. The pain arises from the dilation of the sphincters ani during probe insertion, pressure on the rectal wall and the puncturing of the rectal wall and prostate capsule during collection of the biopsies. Due to the pain, many patients are reluctant to undergo these kinds of biopsies, and often try to postpone or cancel a procedure or ask the physician to perform the procedure under general anesthesia, which is problematic especially for elderly patients.

Several methods are known for reducing the pain or discomfort associated with rectal and transrectal biopsies. Prior to insertion of the biopsy needle, a local anesthetic may be administered into the rectal wall tissue. US Patent 6,416,484 discloses a device in which biopsy material is removed from the biopsy needle without removing the needle from the prostate. The biopsy material is examined for the presence of cancer, and if the examination indicates that the biopsy is not cancerous, a second biopsy can be obtained from the same site in the prostate. In this way, the number of stabs into the rectum wall and prostate can be reduced.

SUMMARY OF THE INVENTION

The present invention is based on the novel and unexpected finding that massaging the wall of the rectum adjacent to the insertion site of a biopsy needle can reduce the pain or discomfort associated with obtaining rectal and transrectal biopsies. Thus, in its first aspect, the present invention provides a system for obtaining rectal and transrectal biopsies. The system of the invention includes an ultrasound probe adapted for insertion into a rectum. The ultrasound probe includes an ultrasound transducer adapted for obtaining images of tissues in the rectal wall or adjacent to the rectal wall, and a massager or vibrator for massaging the walls of the rectum while the biopsies are being obtained. The ultrasound transducer may be provided with a channel for delivering the tip of the needle of biopsy gun to a site on rectum wall prior to activating the gun to obtain a biopsy. The system can also include a biopsy gun. The system of the invention can include other devices for reducing pain. For example, the system can include a percutaneous electrical nerve stimulation (TENS) device comprising one or more electrodes adapted for attachment to the skin surface to generate electric currents in the body while biopsies are obtained. The system can also include a massaging device for massaging the sphincter ani extends prior to insertion of the probe through the anus into the rectum.

The invention also provides an ultrasound probe for use in the system of the invention. In another aspect the invention provides a method for obtaining rectal and transrectal biopsies using the system of the invention. In accordance with this aspect of the invention, the wall of the rectum adjacent to the biopsy site is massaged while prostate biopsies are obtained. The method of the invention may include applying other means for reducing pain or discomfort while biopsies are obtained, for example, massaging the sphincter ani externis, and applying TENS to the skin surface adjacent to the prostate gland.

Thus, in its first aspect, the present invention provides a system for obtaining rectal or transrectal biopsies, comprising:

(a) a probe adapted for insertion into a rectum, the probe comprising:

(i) one or more ultrasound transducers adapted for obtaining images of tissues in the vicinity of the rectum; and

(ii) a massager or vibrator adapted for massaging a region of wall of the rectum where a biopsy needle is to be inserted;

(iii) a CPU configured to receive signals from the ultrasound transducers and generate one or more images of the prostate gland from the signals, and to display the one or more images on a display screen.

(b) a display screen configured to display images generated by the CPU.

The system of the invention may be adapted to obtain, for example, a prostate biopsy.

The system of the invention may further comprise any one or more of a biopsy gun having a needle, a percutaneous electrical nerve stimulation (TENS) device, or a a massaging device adapted for massaging the sphincter ani externis. The massaging device may have a frequency, for example, of around 200 Hz.

The ultrasound probe may be provided with a channel adapted to receive a needle of a biopsy gun.

The invention also provides an ultrasound probe for use in the system of the invention.

In another of its aspects, the invention provides a method for obtaining a rectal or transrectal biopsy comprising:

(a) inserting an ultrasound probe into a rectum, the ultrasound probe comprising: - A -

(b) activating the massager to massage a region of a wall of the rectum at a site where a biopsy needle is to be inserted;

(c) inserting a needle of a biopsy gun through the massaged region of the wall of the rectum and into the prostate gland; and

(d) activating the biopsy gun to obtain a prostate biopsy.

The method of the invention may further comprise obtaining ultrasound images of the rectal wall or tissues adjacent to the rectal wall. The method may further comprise stimulating the sphincter ani externis. The method may further comprise percutaneous electrical nerve stimulation applied to one or more skin regions over the prostate gland.

The frequency of vibration may be, for example, around 200 Hz, and may be periodically increased.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to understand the invention and to see how it may be carried out in practice, embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:

Fig. 1 shows a system for obtaining rectal and transrectal biopsies in accordance with one embodiment of the invention;

Fig. 2 shows an ultrasound probe for use in the system of Fig. 1; and

Figs. 3a to 3e show a method for obtaining prostate biopsies in accordance with one embodiment of the invention.

DETAILED DESCRIPTION OF EMBODIMENTS

The invention will now be described with reference to obtaining a prostate biopsy. This is by way of example only, and the invention can be used to obtain any rectal or transrectal biopsy. Fig. 1 shows a system 1 for obtaining prostate biopsies in accordance with one embodiment of the invention. The system 1 comprises a control unit 2 including a CPU 4 with an associated memory 6, a power supply 8 and a user input device such as a keyboard 10. The system 1 also includes a probe 12 adapted for insertion into a rectum. As described below, the probe 12 includes an ultrasound transducer adapted for obtaining images of tissues in the vicinity of the rectum, and a massager or vibrator for massaging the walls of the rectum while the biopsies are being obtained. The probe is connected to the control unit via a harness 14. The system 1 also includes a display device, such as a CRT 20 for displaying images obtained by the ultrasound transducer. The system 1 also includes a biopsy gun 25 having a needle 37 for obtaining prostate biopsies through the rectal wall. The system 1 may also include a percutaneous electrical nerve stimulation (TENS) device 15 comprising one or more electrodes 16 adapted for attachment to the skin surface to generate electric currents in the body while prostate biopsies are obtained, as explained below. For example, the TENS device may be the IntelliSTIM produced by BEAC Biomedical Ltd, Italy, or the TENSMED 911, produced by Enraf Nonius, Netherlands. The electrodes 16 are connected to a control unit 17 of the TENS device via cables 18. The system 1 can also include a massaging device 13 adapted for massaging the sphincter ani externis prior to insertion of the probe 22 through the anus into the rectum, as described below. The user input device 10 is used to set various parameters of the treatment such as the ultrasound frequency and amplitude of the ultrasound transducer, the amplitude of the massager and the voltage or current between the electrodes 16. These parameter values may be pre-set and stored in the memory 6. Memory 6 may also store one or more images obtained by the ultrasound transducer.

Fig. 2 shows the probe 12 in greater detail. The probe 12 has a handle 24 at a proximal end 23 and an ultrasound transducer 22 located at the distal end 27 of the probe 12, and adapted for insertion into a rectum. The distal portion 29 of the probe 12 is dimension and shaped to be insertable into a rectum. The ultrasound transducer 12 includes associated electrical components, such as a circuit board 25 on which the transducer 25 is mounted. The transducer 22 may be an array of multiple ultrasound transducer elements 29. The probe 12 also includes a massager 26 that generates vibrations in the distal end portion 29 of the probe 12 for massaging the rectal wall while biopsies are being obtained, hi the embodiment of Fig. 2, the massager 26 is located outside of the probe 12. In another embodiment (not shown) the massager is located inside the probe. A two-layer silicon coating is placed on the handle 24 to protect the user from negative reactions due to vibration of ultrasound probe. The probe 12 is provided with a channel 31 passing obliquely through the distal portion 29 for guiding the biopsy gun 25 to the rectum wall, as explained below.

In its second aspect the invention provides a method for obtaining prostate biopsies using the system of the invention. Fig. 3 shows a method of obtaining prostate biopsies in accordance with one embodiment of this aspect of the invention. As shown in Fig. 3a, the process begins by inserting the massager 13 into the anus 100. The massager 13 is then activated in order to stimulate the sphincter ani externis 102. commences using the massager 13 for about 15 which tends to cause slow extension of the muscular ring of the sphincter 102. The frequency of vibration may be around 200 Hz. The intensity of oscillations can be periodically increased, for example, every 30 seconds.

During or after stimulation by the massager 13, electrical stimulation of one or more skin sites can be performed, as shown in Fig. 3b. Two of the electrodes 16 can be placed on the skin surface over the suprapubic region of the abdominal wall which overlies the prostate gland to. Another two of the electrodes 16 can be placed on the skin over the lower spine area according to innervations of the prostate, anus and rectum by parasympathetic, sympathetic, and somatic nervous systems (dermatomes of L5-S4 spinal cord segments). The electrical stimulation can be started simultaneously with the vibration of the massager 13 (about 15 minutes before penetration into the rectum) and can be maintained during the entire biopsy procedure. The current stimulation of the TENS device 15 may provide a rectangular pulsed current, with a frequency of 100 Hz and a pulse width of 50 ms. The stimulation is preferably performed by all four electrodes simultaneously. The intensity of the current (between 10 and 25 mA) is raised according to the individual sensation of the patient.

For stimulation of myelinized nerve fibers of the A beta and delta types it is suitable to use low frequency currents having a frequency in the range of 50 - 150 Hz (optimum 100 Hz) and an intensity at or above threshold sensitivity. This method is effective especially for acute and segmentally localized pains. For chronic painful syndromes it is most suitable to use low frequencies 2 - 8 Hz and intensity at the highest tolerable level (up to the threshold of pain); thus thin fibers of C type are stimulated (creation of endorphins). For achievement of combination of both above-stated mechanisms of easing of pain use the "burst modulation". The carrier frequency should be about 100 Hz, burst frequency up to 10 Hz (even frequencies lower than 1 Hz are not exceptional). Currents with burst modulation bring the cumulated analgesic effect.

Massaging of the sphincter by the massager 13 is now terminated, and the massager 13 is removed from the anus. The distal end of the probe 12 containing the ultrasound transducer 22 is now introduced into the rectum 104 (Fig.3 c) which is the terminal portion of the colon 105 adjacent to the anus 100. A balloon filled with an acoustically coupling medium such as degassed water (not shown) may be plaeed over the distal portion 29 of the probe. The massager 26 is then activated in order to massage the wall of the rectum adjacent to the prostate 106. The prostate 106 is located below the urinary bladder 108 and surrounds the urethra 110. The inventors have found that massaging the rectum wall prior to and during the taking of biopsies tends to reduce the discomfort associated with the biopsy procedure. Images of the prostate are obtained using the ultrasound probe. The images are displayed on the display device 20 which are then analyzed to identify regions of the prostate from which a biopsy is to be obtained. Now, as shown in Fig. 3d, the needle 37 of the biopsy gun 25 is inserted into the channel 31 and the tip of the biopsy needle is delivered to the rectum wall adjacent to a prostate region from which a biopsy is to be obtained, with the needle 37 in alignment with the prostate region from which a biopsy is to be obtained. The biopsy gun 25 is then activated so as to insert the needle through the rectum wall into the prostate gland to obtain a biopsy (Fig. 3e). The biopsy can then be collected for laboratory examination. The process may be repeated as many times as required in order to obtain a sufficient number of biopsies from one or more regions of the prostate. After all biopsies have been collected, the vibration by the vibrator 26 and the TENS can be discontinued and the probe 12 and biopsy gun 25 removed from the body, and the electrodes 16 removed from the skin surface.

Claims

CLAIMS:

1. A system for obtaining rectal or transrectal biopsies, comprising:

(a) a probe adapted for insertion into a rectum, the probe comprising:

(b) a CPU configured to receive signals from the ultrasound transducers and generate one or more images of the prostate gland from the signals, and to display the one or more images on a display screen.

(c) a display screen configured to display images generated by the CPU.

2. The system according to Claim 1 further comprising a biopsy gun having a needle.

3. The system according to Claim 1 or further comprising a percutaneous electrical nerve stimulation (TENS) device.

4. The system according to any one of the previous claims further comprising a massaging device adapted for massaging the sphincter ani externis.

5. The system according to Claim 4 wherein the massaging device has a frequency of 200 Hz.

6. The system according to any one of the previous claims wherein the ultrasound probe is provided with a channel adapted to receive a needle of a biopsy gun.

7. The system according to any one of the previous claims adapted for obtaining a prostate biopsy.

8. An ultrasound probe for use in the system of any one of Claims 1 to 7.

9. A method for obtaining a rectal or transrectal biopsy comprising:

(a) inserting an ultrasound probe into a rectum, the ultrasound probe comprising:

(ii) a massager or vibrator adapted for massaging a region of wall of the rectum where a biopsy needle is to be inserted; (b) activating the massager to massage a region of a wall of the rectum adjacent to the prostate gland;

(d) activating the biopsy gun to obtain a prostate biopsy.

10. The method according to Claim 9 further comprising obtaining ultrasound images of the rectal wall or tissues adjacent to the rectal wall.

11. The method according to Claim 7 or 8 further comprising stimulating the sphincter ani externis.

12. The method according to any one of Claims 7 to 10 further comprising percutaneous electrical nerve stimulation applied to one or more skin regions over the prostate gland.

13. The method according to any one of Claims 9 to 12 wherein the frequency of vibration is 200 Hz.

14. The method according to any one of claims 9 to 13 wherein the frequency of the vibration is periodically increased.