Breast biopsy system and methods
An apparatus and method are provided for precisely isolating a target lesion in a patient's body tissue, resulting in a high likelihood of “clean” margins about the lesion when it is removed for diagnosis and/or therapy. This approach advantageously will often result in the ability to both diagnose and treat a malignant lesion with only a single percutaneous procedure, with no follow-up percutaneous or surgical procedure required, while minimizing the risk of migration of possibly cancerous cells from the lesion to surrounding tissue or the bloodstream. In particular, the apparatus comprises a biopsy instrument having a distal end adapted for entry into the patient's body, a longitudinal shaft, and a cutting element disposed along the shaft. The cutting element is actuatable between a radially retracted position and a radially extended position. Advantageously, the instrument is rotatable about its axis in the radially extended position to isolate a desired tissue specimen from surrounding tissue by defining a peripheral margin about the tissue specimen. Once the tissue specimen is isolated, it may be segmented by further manipulation of the cutting element, after which the tissue segments are preferably individually removed from the patient's body through a cannula or the like. Alternatively, the specimen may be encapsulated and removed as an intact piece.
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The present invention relates to methods and devices for removing tissue samples, and more specifically to improved instruments and methods for acquiring soft body tissue.
BACKGROUND OF THE INVENTIONIt is often desirable and frequently necessary to sample or remove a portion of tissue from humans and other animals, particularly in the diagnosis and treatment of patients with cancerous tumors, pre-malignant conditions, and other diseases or disorders.
Typically, in the case of cancer, particularly cancer of the breast, there is a great emphasis on early detection and diagnosis through the use of screening modalities, such as physical examination, and particularly mammography, which is capable of detecting very small abnormalities, often nonpalpable. When the physician establishes by means of a mammogram or other screening modality, such as ultrasound, that suspicious circumstances exist, a biopsy must be performed to capture tissue for a definitive diagnosis as to whether the suspicious lesion is cancerous. Biopsy may be done by an open or percutaneous technique. Open biopsy, which is an invasive surgical procedure using a scalpel and involving direct vision of the target area, removes the entire mass (excisional biopsy) or a part of the mass (incisional biopsy). Percutaneous biopsy, on the other hand, is usually done with a needle-like instrument through a relatively small incision, blindly or with the aid of an artificial imaging device, and may be either a fine needle aspiration (FNA) or a core biopsy. In FNA biopsy, individual cells or clusters of cells are obtained for cytologic examination and may be prepared such as in a Papanicolaou smear. In core biopsy, as the term suggests, a core or fragment of tissue is obtained for histologic examination which may be done via a frozen section or paraffin section.
The type of biopsy utilized depends in large part on circumstances present with respect to the patient, including the location of the lesion(s) within the body, and no single procedure is ideal for all cases. However, core biopsy is extremely usefull in a number of conditions and is being used more frequently by the medical profession.
A very successful type of image guided percutaneous core breast biopsy instrument currently available is a vacuum-assisted automatic core biopsy device. One such successful biopsy device is shown and disclosed in U.S. Pat. No. 5,526,822 to Burbank et al, expressly incorporated by reference herein. This device, known commercially as the MAMMOTOME® Biopsy System, which is available from Ethicon Endo-Surgery, Inc., a division of Johnson & Johnson, has the capability to actively capture tissue prior to cutting the tissue. Active capture allows for sampling through non-homogeneous tissues. The device is comprised of a disposable probe, a motorized drive unit, and an integrated vacuum source. The probe is made of stainless steel and molded plastic and is designed for collection of multiple tissue samples with a single insertion of the probe into the breast. The tip of the probe is configured with a laterally disposed sampling notch for capturing tissue samples. Orientation of the sample notch is directed by the physician, who uses a thumbwheel to direct tissue sampling in any direction about the circumference of the probe. A hollow cylindrical cutter severs and transports tissue samples to a tissue collection chamber for later testing.
While this type of system functions very well as a core biopsy device, there are occasions when it may be useful to have the capability of acquiring a relatively large intact tissue sample. One such core biopsy device is disclosed in U.S. Pat. No. 5,111,828, to Kornberg et al., also expressly incorporated by reference herein. In the device disclosed by Komberg et al., the tissue receiving port is disposed at the distal end of the device and is oriented axially rather than laterally. A disadvantage of this type of device, however, is the inability to acquire a tissue sample having a cross-section larger than that of the cannula through which the sample will be removed. Additionally, it is difficult, using such a device, which obtains cylindrical shaped specimens, to determine whether an entire lesion of interest is being removed or whether a further procedure will be necessary. This is particularly true because most lesions of interest are typically spherical in'shape, having a diameter of approximately 1 cm. The only way one can tell whether the entire lesion has been removed using the Komberg technique is to remove and examine the specimen, determining whether each of the margins of the specimen is “clean”, meaning that there is no evidence of lesion, or “dirty”, meaning that lesion is evident right to the edge of the specimen. Of course, if one or more specimen margins is “dirty”, it is almost a certainty that a portion of the lesion remains in the patient, and if the biopsy test results on the lesion are positive, a further surgical procedure will be indicated.
It would be desirable, therefore, to have an apparatus and method for isolating a target lesion, with a sufficient border around and beyond the lesion that the likelihood of “clean” margins is relatively high. It would further be advantageous to have an apparatus and method available for initially isolating the entire target lesion, by cutting a swath completely about the lesion to cut off its blood supply, after which a further procedure is undertaken to remove it from the patient's body. This approach would help to minimize the migration of possibly cancerous cells from the lesion to surrounding tissue or bloodstream during the removal procedure.
SUMMARY OF THE INVENTIONThe present invention addresses the foregoing problems by providing such an apparatus and method for precisely isolating a target lesion, resulting in a high likelihood of “clean” margins. This advantageously will often result in the ability to both diagnose and treat a malignant lesion with only a single percutaneous procedure, with no follow-up percutaneous or surgical procedure required, while minimizing the risk of migration of possibly cancerous cells from the lesion to surrounding tissue or the bloodstream.
More particularly, in one aspect of the invention, a biopsy instrument is provided for retrieving body tissue, which instrument has a longitudinal axis. The instrument comprises a distal end adapted for entry into a patient's body, a shaft disposed along the axis, and a cutting element disposed along the shaft. The cutting element is actuatable between a radially retracted position and a radially extended position. Advantageously, the instrument is rotatable about its axis in the radially extended position to isolate a desired tissue specimen from surrounding tissue by defining a peripheral margin about the tissue specimen. Once the tissue specimen is isolated, it may be segmented by further manipulation of the cutting element, after which the tissue segments are preferably individually removed from the patient's body through a cannula or the like. Alternatively, the specimen may be encapsulated and removed as an intact piece.
In another aspect of the invention, an instrument is provided for retrieving body tissue, having a longitudinal axis and comprising a distal end adapted for entry into a patient's body. The instrument further comprises an element for encapsulating a tissue specimen so that it may be withdrawn as a single unit from the patient's body. The encapsulating element preferably comprises a plurality of bands disposed along the instrument axis, each of which are actuatable between a radially retracted position and a radially extended position.
In yet another aspect of the invention, a method is disclosed for retrieving a tissue specimen from a patient's body, comprising the steps of inserting an instrument having a distal end, a longitudinal axis, and an axially disposed cutting element, into the patient's body, so that a distal end is disposed in a tissue region from which the tissue specimen is to be taken. The cutting element is radially expanded so that a portion thereof is radially outwardly spaced from the axis of the instrument. Once the cutting element is radially expanded, it is rotated about the axis to cut the tissue and create a peripheral boundary about the tissue specimen, to isolate the tissue specimen from surrounding tissue in the tissue region.
The invention, together with additional features and advantages thereof, may best be understood by reference to the following description taken in conjunction with the accompanying illustrative drawing.
BRIEF DESCRIPTION OF THE DRAWING
Referring now more particularly to
Proximally of the tip 14 is a shaft 18, preferably lying along an axis 19 (
A plurality of cutting wires 20 may be employed if desired, preferably spaced circumferentially about the shaft 18. In some embodiments, it may be preferably to have webs between the cutting elements, to create a “sail” rather than entire distinct separate cutting elements.
Referring now more particularly to
The reusable driver portion 24 comprises a housing 28 within which is disposed a coaxial arrangement comprising an outer sheath 30, the shaft 18, and a rod 32 which is attached at its distal end to the cutter element 20. A knob 34 is rotatably attached to the shaft 18 through a gearing system 35 to rotate the shaft 18 as desired, for the purpose of circumferentially orienting and rotating the cutting element 20. Three levers 36, 38, and 40 extend outwardly through slots 42, 44, and 46, respectively, in the side of the housing 28. The first lever 36 is actuatable to slide the sheath 30 axially both proximally and distally, for a purpose to be described hereinbelow. The second lever 38 is actuatable to move the shaft 18 axially in distal and proximal directions, as desired. The third lever 40 is actuatable to move the rod 32 axially in distal and proximal directions, as desired. Since the rod 32 is attached at its distal end to the proximal end of the wire cutter 20, movement of the rod 32 in an axial direction also causes the proximal end of the wire cutter 20 to move in an axial direction. Since the distal end of the cutter 20 is anchored to the shaft 18, movement of the proximal end of the cutter element 20 in a distal direction causes the midportion of the cutting element 20 to bow radially outwardly to a radially expanded position, as shown in any of
An advantageous feature of the invention is the employment of a series of stops 50 in the second slot 44, and a series of stops 52 in the third slot 46, as illustrated in
With reference now more particularly to
Once the distal tip 14 is generally in the desired position adjacent to or within the target lesion 54, using the stereotactic rail 26, the second lever 38 is actuated to provide fine tuning of the axial position of the distal tip 14 relative to the lesion 54, by moving the shaft 18 axially to a desired position, and securing the lever 38 in an appropriate stop 50 to maintain the desired axial position. This fine axial adjustment of the axial movement of the shaft 18 is performed using appropriate imaging equipment. The objective of this process step is to ensure that the distal end of the cutting wire 20 is disposed distally of the distal peripheral edge of the lesion 54, while at the same time the proximal end of the cutting wire 20 is disposed proximally of the proximal peripheral edge of the lesion 54. This will ensure the ability to isolate the entire lesion 54 during the cutting procedure, with sufficient margins to minimize the chance that any portion of the lesion inadvertently remains behind in the patient's body following removal thereof.
When the distal tip 14 is in the precise position desired by the practitioner, first lever 36, which is normally disposed in a first detent 58 (
After the sheath 30 is retracted as desired, the third lever 40 may then be actuated distally along the third slot 46 to an intermediate stop 52, thereby causing the rod 32, and therefore the proximal end of the cutting element 20, to move axially a distance equivalent to that traversed by the lever 40. This, of course, results in the partial radial expansion of the cutting element 20 to an arched or bowed configuration as shown in
Of course many other mechanisms for radially expanding the cutting element 20 may be utilized as well, within the scope of the invention. For example, since the wire 20 is preferably fabricated of a shaped memory or superelastic material, the proximal retraction of the sheath 30, and resultant release of the wire 20, may be sufficient to cause the cutting wire 20 to radially expand to its desired position.
Once the cutting element 20 is partially radially expanded as described supra, an inner portion of the target lesion 54 is isolated from surrounding tissue. To complete this step, the cutting element 20 is energized by the electrosurgical generator (not shown), after which the knob 34 is rotated, either manually or via a motorized drive mechanism, to rotate the cutting element 20 through a 360 degree arc. This rotational cutting action functions to completely sever the inner portion of the tissue sample from the surrounding tissue, thereby cutting off all blood supply to the inner tissue sample. Alternatively, if desired, the cutting element 20 may be simultaneously rotated and moved axially, by moving the shaft 18 axially, in order to create a “corkscrew”—shaped tissue segment.
Once this initial isolation step is completed, the cutting element or wire 20 is preferably further radially extended to the position shown in
These steps may be repeated as many times as desired, in order to ensure that the tissue sample is segmented for efficient removal from the patient's body. Ultimately, however, a final cut is preferably made, by fully retracting the outer sheath 30, using the slide lever 36, and fully extending the cutting wire 20, using the slide lever 40, so that the cutting element 20 extends radially beyond the periphery of the target lesion 54, as illustrated in
During the foregoing segmentation process, if the cutting element 20 remains charged by RF energy during the stepwise radial extension process, the outer tissue rings will be further segmented radially.
Other segmentation approaches may be advantageously utilized as well, if desired. For example, rather than segmenting the tissue sample circumferentially, from the inside out, the tissue sample may be segmented circumferentially from the outside in, i.e. by making an outer circumferential cut (
An alternative approach to segmenting the tissue specimen to be retrieved is illustrated in the embodiment shown in
In operation, once the instrument 10a has been positioned so that the distal tip is adjacent to a lesion to be removed, in the manner described supra with respect to the embodiment of
Once segmentation of the tissue sample has been completed, whichever embodiment has been employed, each tissue segment can be withdrawn using a suitable retrieval apparatus. Preferably, the tissue segments are withdrawn through a cannula, such as the sheath 30, using such means as a suction grasper, flexible mechanical graspers, an auger conveyor, a prickly bristle or brush grasper, a wire retrieval basket, or the like.
The foregoing procedure and apparatus may be used for either a diagnostic or a therapeutic purpose. It is particularly advantageous for a diagnostic procedure because the resultant incision from the procedure will not substantially exceed in length the diameter of the cannula. On the other hand, a second preferred embodiment, illustrated in
Referring now to
The proximal end of the instrument 10b may be substantially the same as that for the instrument 10, illustrated in
In operation, as with the first embodiment of
Once the distal tip 14b is generally in the desired position adjacent to the target lesion, using the stereotactic rail 26, the second lever 38 is actuated to provide fine tuning of the axial position of the distal tip 14b relative to the lesion, by moving the shaft 18b axially to a desired position, and securing the lever 38 in an appropriate stop 50 to maintain the desired axial position. This fine axial adjustment of the axial movement of the shaft 18b is performed using appropriate imaging equipment. The objective of this process step is to ensure that the distal end of the cutting wire 20b is disposed distally of the distal peripheral edge of the lesion, while at the same time the proximal end of the cutting wire 20b is disposed proximally of the proximal peripheral edge of the lesion. This will ensure the ability to isolate the entire lesion during the cutting procedure, with sufficient margins to minimize the chance that any portion of the lesion inadvertently remains behind in the patient's body following removal thereof.
When the distal tip 14b is in the precise position desired by the practitioner, first lever 36, which is normally disposed in a first detent 58 (
Once the cutting element 20b and associated encapsulation elements 72 are radially expanded as described supra, it is time to isolate the target lesion from surrounding tissue. Advantageously, a spherical or toroidal tissue sample having a radius of at least 15 mm may be defined and isolated by rotating the cutting element 20b about the axis of the shaft 18b. The encapsulation elements 72 will also be rotated during this process, but their function is not yet important. To complete the isolation step, the cutting element 20b is energized by the electrosurgical generator (not shown), after which the knob 34 is rotated, either manually or via a motorized drive mechanism, to rotate the shaft 18b, and thus the cutting element 20b through a 360 degree arc. This rotational cutting action functions to completely sever the tissue sample from the surrounding tissue, thereby cutting off all blood supply to the tissue sample (and thus from the lesion, which should be completely contained within the tissue sample).
After the isolation step is completed, the isolated tissue sample may be retrieved from the patient's body 56. This retrieval step may be accomplished in a number of ways, but it is the objective in connection with the illustrated embodiment to encapsulate and remove the isolated tissue sample in one piece. Accordingly, as is illustrated in
Once the tissue sample has been fully encapsulated, the tissue sample may be removed from the patient's body. Advantageously, since the tissue sample is larger in cross-section than the cross-section of the sheath 30b, the inventors have developed an inventive approach for removal thereof which results in minimum trauma and incision size for the patient while still permitting the removal of an intact specimen. To remove the specimen, the sheath 30b is retracted proximally, following which the cutting element 20b is again energized by the electrosurgical generator. The shaft 18b, with the tissue specimen encapsulated thereabout, is then proximally withdrawn by the practitioner, with the cutting element 20b functioning to cut through the tissue necessary to create a passage for exit of the sample. Once the unit, including the shaft and encapsulated tissue mass, is completely withdrawn from the body, the incision created by the cutting element 20b upon withdrawal from the body may be adhesively closed, with minimal required follow-up care and scarring.
Many alternative embodiments may be used to accomplish the method outlined supra, which essentially involves isolating the tissue mass from surrounding tissue, encapsulating the tissue mass in place about a shaft, then removing the encapsulated tissue mass and shaft from the body by energizing an RF electrosurgical cutter to cut its way out, without the need for a cannula or pre-existing incision. For example, a plurality of cutting elements could be employed, or a separate cutting element could be disposed on the shaft. An important aspect of the invention, of course, is a relatively high likelihood of acquiring the entire lesion of interest in a single therapeutic procedure, without the need for follow-up surgery.
While this invention has been described with respect to various specific examples and embodiments, it is to be understood that the invention is not limited thereto and that it can be variously practiced within the scope of the following claims.
Claims
1. A biopsy instrument for retrieving body tissue, having a longitudinal axis and comprising:
- distal end adapted for entry into a patient's body; and
- a cutting element disposed on said instrument, said cutting element being actuatable between a radially retracted position and a radially extended position, relative to said axis, and being movable in said radially extended position to isolate a desired tissue specimen from surrounding tissue by defining a peripheral margin about said tissue specimen.
2-31 (Cancelled)
32. The method as recited in claim 40, wherein said at least one encapsulating element comprises a plurality of bands which are disposed axially along said instrument.
33. The method as recited in claim 40, and further comprising the step of proximally withdrawing said instrument, with the encapsulated tissue specimen, from the patient's body, said step including the step of cutting tissue as the instrument is withdrawn.
34. The method as recited in claim 40, further comprising the step of segmenting s the tissue specimen.
35. The method as recited in claim 34, further comprising withdrawing each segment of a the tissue specimen through a cannula lumen.
36. The method as recited in claim 34, wherein the segmenting the tissue specimen includes the stop of radially retracting the cutting element so that the tissue specimen is segmented radially.
37. The method as recited in claim 34, wherein the step of segmenting said tissue specimen includes the steps of partially radially retracting said cutting element from its fully radially expanded position and rotating the instrument about its axis to cut said tissue and create a circumferential tissue segment.
38. The method as recited in claim 37, wherein the segmenting step is repeated at differing partially radially expanded positions of the cutting element, so that a plurality of circumferential tissue segments are created.
39. The method as recited in claim 40, and further comprising the step of simultaneously moving the cutting element axially as it is rotated about said axis to cut said tissue.
40. A method of cutting, isolating and removing a specimen of tissue from a site within a patient's breast, comprising:
- a. providing an excisional device that includes a shaft, a cutting element coupled to the shaft which is movable from a retracted position to an expanded position and which is configured to cut the specimen from the breast tissue and at least one tissue collection element which is movable from a retracted configuration to an expanded configuration and which is configured to encapsulate at least part of the cut specimen;
- b. introducing the excisional device into the patient's breast tissue with the at least one tissue collection element and the cutting element in retracted configurations;
- c. expanding the cutting element to an expanded configuration after the excisional device is introduced into the patient's breast tissue and the cutting element is located at the site within the patient's breast;
- d. moving the cutting element in the expanded configuration to cut the specimen from the patient's breast tissue at the site;
- e. encapsulating at least part of the cut specimen with the at least one tissue collection element; and
- f. removing the excisional device from the site while at least part of the specimen remains encapsulated within the at least one tissue collection element.
41. The method of claim 40, wherein the cutting element is a flexible element which bows outwardly when moving to the expanded configuration.
42. The method of claim 40, wherein the moving step includes rotating the cutting element about a longitudinal axis.
43. The method of claim 40, wherein the moving step is carried out with the cutting element moving along an arcuate path.
44. The method of claim 42, wherein the moving step includes moving the cutting element toward the retracted configuration after the specimen is cut.
45. The method of claim 40, wherein the moving step is carried out with the cutting element being energized with RF energy.
46. The method of claim 40, wherein the encapsulating step is carried out to physically isolate at least part of the tissue specimen from the surrounding tissue so that the specimen does not contact the surrounding tissue from which the specimen is cut.
47. The method of claim 40, wherein the encapsulating step is carried out with the at least one tissue collection element expanding to a size at least as large as the tissue specimen.
48. The method of claim 40, wherein the introducing step includes positioning the shaft so that the tissue cutting element is adjacent to the specimen to be cut.
49. A method of cutting, isolating and removing a specimen of breast tissue, comprising:
- a. providing an excisional device that includes a shaft, a cutting element coupled to the shaft and a tissue collection element, both the cutting element and the tissue collection element being movable from a retracted position to an expanded position, the cutting element being configured to cut the specimen from the breast tissue, the tissue collection element being configured to encapsulate the cut specimen;
- b. introducing the excisional device into the breast tissue with the tissue collection and cutting elements both retracted;
- c. expanding the cutting element to an expanded position after the introducing step;
- d. moving the cutting element to cut the specimen from the breast tissue;
- e. encapsulating the cut specimen with the tissue collection element, the tissue collection element being expanded to an expanded shape that is sufficiently large to enclose the specimen cut during the moving step; and
- f. removing the excisional device while the specimen remains encapsulated within the tissue collection element.
50. The method of claim 49, wherein the tissue collection element includes a flexible membrane and wherein the flexible membrane isolates the specimen from the breast tissue in the encapsulating step.
51. The method of claim 49, wherein the cutting element is a flexible element which bows outward when moving to the expanded position and wherein the expanding step is carried out with the cutting element bowing outward.
52. The method of claim 49, wherein the moving step includes rotating the shaft.
53. The method of claim 52, wherein the moving step is carried out with the cutting element moving along an arcuate path.
54. The method of claim 56, wherein the moving step is carried out by moving the cutting element toward the retracted position after the cutting element moves along the arcuate path.
55. The method of claim 52, wherein at least some of the moving steps are carried out with the cutting element energized.
56. The method of claim 58, wherein the cutting element is energized with RF energy.
57. The method of claim 52, wherein the encapsulating step is carried out to physically isolate at least part of the tissue specimen from the surrounding tissue so that the tissue specimen does not contact the surrounding tissue from which the specimen is cut.
58. The method of claim 52, wherein the introducing step includes positioning the shaft so that the cutting element is adjacent to the specimen to be cut.
Type: Application
Filed: Aug 6, 2004
Publication Date: Jan 13, 2005
Applicant:
Inventors: Fred Burbank (San Juan Capistrano, CA), Michael Jones (Capistrano Beach, CA), Paul Lubock (Laguna Niguel, CA)
Application Number: 10/913,747