Patent Application
20130331733
1. Field of Invention
Aspects of the present invention relate to methods and devices for performing vacuum assisted biopsies. More particularly, aspects of the current invention relate to methods and devices for performing vacuum assisted spring-loaded biopsies.
2. Description of Related Art
A variety of biopsy devices having sampling needles as part of their structure are available in the medical field. Typical biopsy devices include those that are designed to obtain samples from hard tissues, such as bone, and those that are designed for sampling of softer tissues. Soft tissue biopsy devices can include a structure whereby a sampling needle resides within an outer cannula and moves relative thereto during sampling. In particular, the operation of the device involves extending the distal end of the sampling needle beyond the distal end of the outer cannula to expose and introduce a portion of the needle to the tissue sampling site.
For example, U.S. Pat. No. 7,018,343 describes a spring-loaded biopsy device, described herein with respect to
However, the samples obtained by the above devices generally do not fill the entire space enclosed in the notch within the biopsy device, and the collected samples are not as large as they could possibly be, which could sometimes lead to inaccurate diagnoses obtained from the sample.
There is a need in the art, therefore, for biopsy devices capable of obtaining samples that fill the entire space enclosed in the notch and that ensure the collected samples are as large and contiguous as possible.
In light of the above described problems and unmet needs, aspects of the current invention provide biopsy systems and devices with a modified handle and stylet through which a vacuum is delivered to the targeted tissue prior to being severed by a cannula for removal. The biopsy needle, which is capable of penetrating skin and/or tissue to collect biopsy samples, may include a pointed stylet. A distal portion of the stylet may include a notch capable of receiving tissue that has been severed by the cutting cannula. According to various aspects, the vacuum may draw the sample into the notch to fill a larger amount of the notch, after which the tissue may be severed via the cannula. Alternatively, the tissue that is severed via the stylet and the cannula may be deposited within the notch, and the vacuum may be used to maintain the severed tissue within the notch while the biopsy device is extracted from the body of the patient. For example, the vacuum may be used to draw a larger amount of tissue into the notch than would otherwise be collected in the notch if no vacuum was used before the tissue sample is severed by the biopsy device, thus providing a larger sample through the same size access point within the patient.
According to various aspects, the vacuum also provides more assurance that the desired tissue is captured by clinician. Diseased tissue has varied densities when compared to non-diseased tissue, and the use of vacuum to pull the tissue of various densities into the notch provides clinical advantages compared to biopsy needles without vacuum. In addition, vacuum can be applied to needles of very small gauges, which results in improving the biopsy procedure with respect to smaller lesions or calcifications.
There are many benefits of using a spring loaded cannula in combination with vacuum assistance. For example, the cannula provides a sharp cutting edge that cleanly severs the tissue within the notch in a fraction of second. The weight and size of the device are also clinical aspects of the proposed invention because the clinician needs to position the tip of the notch in exactly the right location, which is typically done under ultrasound, and once the tip is placed, the clinician needs to manipulate the stylet tip and vacuum in order to maximize the clinical benefit. The size and weight of the device generally hinder the ability of the clinician to position the biopsy device in the desired location. The visibility of the device under ultrasound is also a clinical factor. Markings on the tip of the stylet, including a small grove around the entire diameter of the stylet, may provide significant improvements of the visibility of the stylet tip from any direction with respect to the ultrasound probe. According to various aspects, surface texturing also improves the overall image.
According to various aspects, the vacuum applied to the biopsy device may be controlled and provided in a variety of ways in order to ensure adequate suction of the tissue into the notch of the stylet of the biopsy device. The vacuum may be controlled by restricting flow through a valve mechanism where the clinician can control the total amount of vacuum being applied. Alternatively, the device may provide the clinician with the ability to turn on or off the vacuum at a predetermined level. According to various aspects, both options may provide varying clinical advantages depending on the type of tissue being biopsied, the size of the lesion or calcification, and the presence of potential clinical complications such as blood vessels, bone, membranes, etc. According to various aspects, the size of the vacuum pump, location of the trigger and amount of vacuum may also be clinically relevant. The pump can be small enough to fit within the clinician's hand or to stand alone on the table. Typical battery powered pumps may provide cost effective benefits to using vacuum as an assist for spring loaded biopsy devices.
Additional advantages and novel features of these aspects of the invention will be set forth in part in the description that follows, and in part will become more apparent to those skilled in the art upon examination of the following or upon learning by practice of the invention.
Various example aspects of the systems and methods will be described in detail, with reference to the following figures, wherein:
These and other features and advantages of this invention are described in, or are apparent from, the following detailed description of various example aspects.
In operation, the vacuum pump 130 may create a vacuum and transmit the vacuum via the vacuum line 120 to the stylet tip 110. Accordingly, when the stylet tip 110 penetrates the skin/tissue of the patient, the vacuum provided through the vacuum line 120 may draw an amount of tissue in the notch 150 that is larger than if no vacuum was provided, and the tissue sample may then be severed via, for example, firing a cutting cannula. Alternatively, the tissue sample that is first severed via the stylet tip 110 may be deposited in the notch 150, and the vacuum may be used to maintain the severed tissue sample within the notch 150 while the biopsy device is extracted from the body of the patient. As a result, when the stylet tip 110 is removed from the body of the patient, larger tissue samples can be collected by the biopsy device 100 because of the action of the vacuum that maintains a large amount of tissue inside the notch 150.
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In operation, the vacuum pump 230 may create a vacuum and may transmit the vacuum via the vacuum line 220 to the stylet tip 210 via the additional valve 270. Accordingly, when the stylet tip 210 penetrates the skin of the patient, the vacuum provided through the vacuum line 220 may draw an amount of tissue in the notch 250 that is larger than if no vacuum was provided, and the tissue may then be severed via, for example, firing a cutting cannula. Accordingly, a larger amount of tissue sample may be collected in the notch 250 of the biopsy device 200 as compared to a biopsy performed without vacuum.
According to various aspects, the circumference of the body of the stylet, which may correspond to a back portion of the stylet tip 310 and which is typically covered by the cannula 340, may be altered such as to provide enough space for the vacuum to travel inside the cannula and around the outer surface of the stylet. For example, portions of the circumference of the stylet may be machined away so as to leave an uneven cylindrical shape with enough space to allow circulation of vacuum or air around the circumference of the stylet.
According to various aspects, the outside surface 325 of the vacuum line 320 may include asperities and other surface features to provide, for example, space for a lubricant to provide adequate lubrication during insertion and operation of the biopsy device. In addition, the lubricant may prevent a vacuum leak during operation of the biopsy device. According to various aspects, the outside surface 325 of the vacuum line 320 may also be covered with a lubricant 335 such as, e.g., silicone grease, to facilitate movement of the stylet tip 310 and the vacuum line 320 inside the wall of the outer tube or cannula 340 of the biopsy device 300, and thus to facilitate movement of the stylet tip 310 in and out of the outer tube or cannula 340 to penetrate the skin/tissue of the patient, to remove tissue sample(s), or to rotate inside the outer tube or cannula 340 to remove tissue sample(s). In addition, the lubricant 335 may also act as a vacuum membrane to prevent vacuum from escaping through other portions of the biopsy device 300 and to constrain the path of the vacuum to the paths shown in
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In operation, when the stylet tip 310 is inserted into the target tissue, the cannula 340 may be moved forward at a relatively high speed to cover the stylet tip 310, and as a result sever a tissue sample from the body of the patient. For example, the cannula 340 may be fired forward via a spring which, when activated, may fire the cannula 340 forward to cover the stylet tip 310 and sever a tissue sample. According to various aspects, there are three different types of cannula firing mechanisms: i) manual, where the operator manually pushes the stylet tip 310 forward in the target tissue, and then manually pushes the cannula 340 forward to sever a tissue sample, ii) semi-automatic, where the operator manually pushes the stylet tip 310 forward in the target tissue, and then fires the cannula 340 forward via the spring or firing mechanism, and iii) automatic, where the operator fires both the stylet tip 310 and the cannula 340 forward into the target tissue via the spring or firing mechanism.
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While aspects of this invention have been described in conjunction with the example features outlined above, various alternatives, modifications, variations, improvements, and/or substantial equivalents, whether known or that are or may be presently unforeseen, may become apparent to those having at least ordinary skill in the art. Accordingly, the example aspects of the invention, as set forth above, are intended to be illustrative, not limiting. Various changes may be made without departing from the spirit and thereof. Therefore, aspects of the invention are intended to embrace all known or later-developed alternatives, modifications, variations, improvements, and/or substantial equivalents.
