U.S. patent application number 11/112449 was filed with the patent office on 2005-09-08 for tissue accessing and anchoring device and method.
This patent application is currently assigned to SenoRx, Inc.. Invention is credited to Burbank, Fred H., Louw, Frank, Lubock, Paul, Quick, Richard L., Wardle, John.
Application Number | 20050197594 11/112449 |
Document ID | / |
Family ID | 25375758 |
Filed Date | 2005-09-08 |
United States Patent
Application |
20050197594 |
Kind Code |
A1 |
Burbank, Fred H. ; et
al. |
September 8, 2005 |
Tissue accessing and anchoring device and method
Abstract
The invention provides systems, methods and a node accessing and
anchoring device, comprising an elongated shaft, a tissue cutting
member, at least one anchoring element extending from a position at
or near the distal end of the shaft; and a radiation detector. The
radiation detector is effective to locate and identify sentinel
lymph nodes following injection of radioactive material into a
primary lesion site within a patient. The tissue cutting member,
which may be activated with radio frequency energy, is effective to
allow access of the elongated shaft to a sentinel lymph node. The
anchoring elements are effective to anchor the device to or
adjacent a sentinel lymph node accessed by the device. Anchoring
elements may assume radially, longitudinally, or mixed radially and
longitudinally curved or coiled configurations when deployed.
Inventors: |
Burbank, Fred H.; (Laguna
Niguel, CA) ; Lubock, Paul; (Laguna Niguel, CA)
; Wardle, John; (San Clemente, CA) ; Louw,
Frank; (Carlsbad, CA) ; Quick, Richard L.;
(Mission Viejo, CA) |
Correspondence
Address: |
Edward J. Lynch
DUANE MORRIS LLP
One Market
Spear Tower, Suite 2000
San Francisco
CA
94105
US
|
Assignee: |
SenoRx, Inc.
|
Family ID: |
25375758 |
Appl. No.: |
11/112449 |
Filed: |
April 21, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11112449 |
Apr 21, 2005 |
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10729086 |
Dec 5, 2003 |
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10729086 |
Dec 5, 2003 |
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09880218 |
Jun 12, 2001 |
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6679851 |
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09880218 |
Jun 12, 2001 |
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09146185 |
Sep 1, 1998 |
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6540693 |
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09880218 |
Jun 12, 2001 |
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09356187 |
Jul 16, 1999 |
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6312429 |
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09880218 |
Jun 12, 2001 |
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09477255 |
Jan 4, 2000 |
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6471700 |
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09880218 |
Jun 12, 2001 |
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09727112 |
Nov 29, 2000 |
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6638234 |
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Current U.S.
Class: |
600/564 |
Current CPC
Class: |
A61B 18/148 20130101;
A61B 2018/1407 20130101; A61B 18/1487 20130101; A61B 2018/00577
20130101; A61B 2018/00916 20130101; A61B 2090/3904 20160201; A61B
18/1477 20130101; A61B 2017/3488 20130101; A61B 2018/00333
20130101; A61B 2018/1425 20130101; A61B 90/39 20160201; A61B
2017/00115 20130101; A61B 2090/378 20160201; A61B 2018/00208
20130101; A61B 2018/1475 20130101; A61B 17/00491 20130101; A61B
10/02 20130101; A61B 2017/00867 20130101; A61B 18/1482 20130101;
A61B 2018/00273 20130101; A61B 2010/0208 20130101; A61B 10/0266
20130101; A61B 2018/00601 20130101; A61B 18/1815 20130101; A61B
6/4258 20130101; A61B 2090/3908 20160201; A61B 2090/392 20160201;
A61B 2018/00958 20130101 |
Class at
Publication: |
600/564 |
International
Class: |
A61B 006/00 |
Claims
1. A tissue access and anchoring device, comprising: a. an
elongated shaft having a distal end and a proximal end; b. a tissue
cutting member at the end of the distal shaft; and c. at least one
anchoring element extending from a position at or near the distal
end of the shaft:
2-65. (canceled)
66. A method of positioning a needle in a patient's breast for a
medical procedure, comprising the steps of: providing a needle
having at least one movable indicator for indicating an angular
orientation when viewed along a longitudinal axis of the needle,
the needle having a distal portion and a proximal portion;
positioning the distal portion in a patient's breast with the
proximal portion remaining outside the breast, moving the indicator
to a position which provides an indication of a selected angular
orientation relative to the longitudinal axis to move the indicator
to a position which angularly bounds a tissue area to be removed
from the breast, and performing a medical procedure using
information from the selected angular orientation.
67. The method of claim 66, wherein: the performing step includes
the step of removing breast tissue.
68. A method of positioning a needle in a patient's breast for a
medical procedure, comprising the steps of: providing a needle at
least one movable indicator for indicating an: angular orientation
when viewed along a longitudinal axis of the needle, the needle
having a distal portion that includes at least one anchoring
element and a proximal portion; positioning the distal portion in a
patient's breast with the proximal portion remaining outside the
breast, moving the indicator to a position which provides an
indication of a selected angular orientation relative to the
longitudinal axis, the moving step being carried out by moving the
at least one anchoring element, the at least one anchoring element
being displaced angularly with respect to the longitudinal axis,
and performing a medical procedure using information from the
selected angular orientation.
69. The method of claim 68, wherein: the performing step includes
the step of removing breast tissue.
70. The method of claim 68, wherein: the moving step is carried out
with the at least one anchoring element being a thin, elongate
element which pierces the breast tissue.
71. The method of claim 68, wherein: the moving step is carried out
with the at least one anchoring element being a wire.
72. The method of claim 70, wherein: the providing step is carried
out with the needle having a shaft; and the moving step is carried
out with the anchoring element extending through a slot in the
shaft.
73. The method of claim 70, wherein: the performing step includes
the step of removing breast tissue.
74. A method of positioning a needle in a patient's breast for a
medical procedure, comprising the steps of: providing a needle
having at least one movable indicator for indicating an angular
orientation when viewed along a longitudinal axis of the needle,
the needle having a distal portion and a proximal portion;
positioning the distal portion in a patient's' breast with the
proximal portion remaining outside the breast, moving the indicator
to a position which provides an indication of a selected angular
orientation relative to the longitudinal axis by selecting at least
two different angular positions when viewed along the longitudinal
axis of the needle, and performing a medical procedure using
information from the selected angular orientation.
75. The method of claim 74, wherein: the performing step includes
the step of removing breast tissue.
76. The method of claim 74, wherein: the providing is carried out
with the needle including at least one anchoring element, and the
moving step is carried out by moving the at least one anchoring
element, the anchoring element being displaced angularly with
respect to the longitudinal axis during the moving step.
77. The method of claim 76, wherein: the moving step is carried out
with the at least one anchoring element being a thin, elongate
element which pierces the breast tissue.
78. The method of claim 76, wherein: the moving step is earned out
with the at least one anchoring element being a wire.
79. The method of claim 77, wherein: the providing step is carried
out with the needle having a shaft; and the moving step is carried
out with the element extending through a slot in the shaft.
80. A method of positioning a needle in a patient's breast for a
medical procedure, comprising the steps of: providing a needle
having at least one movable indicator for indicating an angular
orientation when viewed along a longitudinal axis of the needle,
the needle having a distal portion and a proximal portion;
positioning the distal portion in a patient's breast with the
proximal portion remaining outside the breast; moving the indicator
to a position which provides an indication of a selected angular
orientation relative to the longitudinal axis and repeating the
moving step at least once to indicate two different angular
orientations relative to the longitudinal axis; and performing a
medical procedure using information from the selected angular
orientation.
81. The method of claim 80, wherein: the providing is can-fed out
with the needle including at least one anchoring element, and the
moving step is carried out by moving the at least one anchoring
element, the anchoring element being displaced angularly with
respect to the longitudinal axis during the moving step.
82. The method of claim 81, wherein: the moving step is carried out
with the at least one anchoring element being a thin, elongate
element which pierces the breast tissue.
83. The method of claim 81, wherein: the moving step is carried out
with the at least one anchoring element being a wire.
84. The method of claim 82, wherein: the providing step is carried
out with the needle having a shaft; and the moving step is carried
out with the element extending through a slot in the shaft.
85. A needle for introduction into a patient's breast comprising:
an elongate shaft having a longitudinal axis; and a first indicator
for indicating an angular orientation when viewed along the
longitudinal axis of the shaft. the first indicator being movable
by the user to a selected angular orientation and being coupled to
an anchoring element, the anchoring element being displaced
angularly with respect to the longitudinal axis when the first
indicator is moved by the user.
86. The needle of claim 85, wherein: the first indicator is moved
to a position to provide angular information regarding a tissue
area to be removed from the breast.
87. The needle of claim 85, wherein: the anchoring element is a
thin, elongate element which pierces the breast tissue
88. The needle of claim 85, wherein: the anchoring element is a
wire.
89. The needle of claim 88, wherein: the wire extending through a
slot in the shaft.
90. A needle for introduction into a patient's breast, comprising:
an elongate shaft having a longitudinal axis; a first indicator for
indicating an angular orientation when viewed along the
longitudinal axis of the shaft, the first indicator being movable
by the user to a selected angular orientation, and a second
indicator for indicating another angular orientation when viewed
along the longitudinal axis of the shaft.
91. The needle of claim 90, wherein: the first and second
indicators are moved to positions to provide angular information
regarding a tissue area to be removed from the breast.
92. The needle of claim 90, wherein: the first indicator is coupled
to an anchoring element, the anchoring element being displaced
angularly with respect to the longitudinal axis when the first
indicator is moved by the user.
93. The needle of claim 92, wherein: the anchoring element is a
thin, elongate element which pierces the breast tissue.
94. The needle of claim 92, wherein: the anchoring element is a
wire.
95. The needle of claim 94, wherein: the wire extending through a
slot in the shaft.
96. A method of excising breast tissue, comprising the steps of:
providing a guide element and a cutting device, the cutting device
having a deployable cutting element mounted on a shaft, the cutting
device also having a tissue collection element; introducing the
guide element into a patient's breast; advancing the cutting device
into the patient's breast, the cutting device being slidably
coupled to the guide element so that the guide element guides the
cutting device as the cutting device is advanced into the patient's
breast; deploying a cutting element on the cutting device after the
advancing step, the cutting element moving from a collapsed
position to an expanded position, the cutting element bowing
outwardly from the shaft when being deployed; rotating the shaft so
that the cutting element severs breast tissue, the severed breast
tissue entering the tissue collection element which trails the
cutting element as the cutting element moves through the breast
tissue when the shaft is rotated; and removing the breast tissue
which has been severed by the cutting element and is contained
within the tissue collection element.
97. The method of claim 96, wherein: the providing step is carried
out with the guide element being a needle; and the advancing step
being carried out with the cutting device being advanced over the
needle.
98. The method of claim 96, wherein: the rotating step is carried
out with the shaft rotating less than 180 degrees relative to the
guide element.
99. The method of claim 96, wherein: the providing step is carried
out with the guide element having an indicator for a desired depth
of penetration of the cutting device during the advancing step.
100. The method of claim 96, wherein: the removing step is carried
out with the tissue collection element surrounding and isolating
the severed tissue from the surrounding tissue.
101. A method of excising breast tissue, comprising the steps of:
providing a guide element having at least one indicator for
indicating an angular orientation with respect to a longitudinal
axis of the guide element and a cutting device, the cutting device
having a deployable cutting element mounted on a shaft and;
introducing the guide element into a patient's breast; advancing
the cutting device into the patient's breast, the cutting device
being slidably coupled to the guide element so that the guide
element guides the cutting device as the cutting device is advanced
into the patient's breast; deploying a cutting element on the
cutting device after the advancing step; rotating the shaft so that
the cutting element severs breast tissue; and removing the breast
tissue which has been severed by the cutting element.
102. The method of claim 101, wherein: the rotating step is carried
out with the shaft rotating less than 180 degrees relative to the
guide element.
103. The method of claim 101, wherein: the providing step is
carried out with the guide element being a needle.
104. The method of claim 101, wherein: the rotating step is carried
out using the angular orientation indicated by the at least one
indicator.
105. The method of claim 101, wherein: the removing step is carried
out with the severed breast tissue being contained in a collection
element carried by the cutting device.
106. The method of claim 105, wherein: the removing step is carried
out with the collection element surrounding and isolating the
severed tissue from the surrounding tissue.
Description
RELATED APPLICATIONS
[0001] This application is a continuation in part of copending U.S.
patent application Ser. No. 09/146,185, filed Sep. 1, 1998, by
Burbank et al., U.S. patent application Ser. No. 09/159,467, filed
Sep. 23, 1998, by Burbank et al.; U.S. patent application Ser. No.
09/856,187, filed Jul. 16, 1999 by Burbank et al.; U.S. patent
application Ser. No. 09/477,255, filed Jan. 4, 2000 by Burbank et
al, and U.S. patent application Ser. No. 09/727,112, filed Nov. 29,
2000, by Burbank et al. All of the above copending applications,
and all patents and patent applications referred to below, are
herein incorporated by reference in their entirety.
BACKGROUND OF THE INVENTION
[0002] The invention relates to the field of medical devices and
methods used in the treatment of diseases such as cancer which have
the ability to metastasize within a patient's body. More
specifically, the invention is directed to methods and devices for
accessing sentinel lymph nodes associated with a lesion site within
a patient's body and anchoring devices to these nodes accessed so
that they may thereafter be selectively removed and analyzed to
determine whether disease has spread from the primary lesion site
to the sentinel lymph nodes. In the case of breast cancer patients,
such methods and devices may eliminate the need for complete
axillary lymph node dissection in patients who do not require such
invasive and debilitating procedures.
[0003] Metastasis, or migration of cancerous cells, typically
occurs through lymph ducts. Sentinel lymph nodes are so-called
because, where metastasis occurs, such lymph nodes are often the
first locations to harbor metastatic cancer cells. These lymph
nodes thus serve as sentinels warning of the spread of the
cancerous lesion. A sentinel lymph node may be identified by
injection of radioactive material into a primary lesion site such
as a cancerous tumor. Detection of radiation at a location other
than the injection site indicates that migration of the radioactive
material has occurred. The first lymph nodes into which the
radioactive material migrates are thus identified as the sentinel
lymph nodes.
[0004] With regard to breast cancer patients specifically, the
determination of the severity of the disease or staging is
frequently determined by the level of lymph node involvement in
those lymph nodes which correspond to the primary cancer lesion
site in the breast. The lymph nodes which correspond to the breast
area are typically located in the armpit or axilla of the patient
and are connected to the breast tissue of the patient by a series
of lymph ducts. Other likely areas for sentinel nodes include
inframammary and submammary locations and elsewhere in the
patient's chest. The sentinel lymph nodes can be in fluid
communication with other surrounding lymph nodes, however, lymph
drainage from the lesion site will first flow to the sentinel lymph
nodes. Thereafter, lymph fluid drainage may then continue on to
lymph nodes surrounding the sentinel nodes.
[0005] Studies have shown that by the time a typical breast cancer
lesion reaches the size of 1-2 cm, the cancer will have
metastasized to at least one of the sentinel lymph nodes in about
one third of patients. Malignant cells break off and drain through
the lymph fluid ducts to the lymph nodes and will be apparent in
excised lymph nodes if the malignant cells embed in the lymph node.
In patients with more advanced disease, the likelihood of spread to
sentinel nodes is higher as is the likelihood of spread of the
disease to the lymph nodes surrounding the sentinel lymph
nodes.
[0006] As discussed above, when a tumor lesion is under 1-2 cm,
only about 1/3 of patients will have cancer cells in the
corresponding lymph nodes, and in the patients where the disease
has spread to the lymph nodes, it is often confined to the sentinel
lymph nodes.
[0007] In the past, a breast cancer patient would normally have a
complete axillary lymph node dissection as an adjunct to removal of
the primary lesion in the breast. Thus, the patient's entire lymph
node system in the armpit area is removed and biopsied to determine
the stage of the cancer and what further treatment was required.
However, as discussed above, when the lesion is under 1-2 cm, two
thirds of the patients had no migration of cancer cells to the
lymph nodes at all, and in others, cancer had only migrated to the
sentinel lymph nodes. Thus, total axillary lymph node dissection in
two-thirds of the cases were unnecessary. It should be noted that
total axillary lymph node dissection can be an extremely painful
and debilitating procedure for patients who often suffer from
severe lymph edema as a result of the body's inability to channel
the flow of lymph fluid once most or all of the lymph nodes have
been excised.
[0008] Wires and other devices have been used to anchor devices and
to mark suspected cancerous lesion sites within a breast. Such
wires may have exposed, sharp ends to cut into tissue, and may
expose physicians to accidental injury during excision of tissue.
Placement of such marking and anchoring devices is typically
performed in the operating room. However, there is a need for
methods and devices that can be used to determine the location of
sentinel lymph nodes corresponding to a patient's primary lesion
site, in addition to the primary lesion site itself, and a reliable
means of accessing the sentinel lymph nodes to determine whether
they are involved in the disease. If the sentinel lymph nodes are
determined not to have cancer cells within them, then a total
axillary lymph node dissection may be avoided. Anchoring devices
near to such sentinel nodes would be useful if the sentinel lymph
nodes are determined to be involved in the disease.
[0009] Radioactive materials have been used as localizing agents
which can be injected into the area of a primary lesion to monitor
the flow of the materials within the patients body using a variety
of detectors. A pharmaceutically-acceptable solution containing a
radioactive material may be termed a radiopharmaceutical. Suitable
radioactive materials include the radioactive elements Technetium
99, Indium 111, Iodine 123 or Iodine 125.
[0010] Although techniques exist to locate the sentinel lymph nodes
of a patient with such radiopharmaceutical tagging, what has been
needed are methods and devices to precisely access the sentinel
lymph nodes of the patient and to anchor a device adjacent sentinel
lymph nodes should it be determined that axillary node dissection
is necessary.
SUMMARY OF THE INVENTION
[0011] The invention is directed generally to devices, methods and
systems for accessing and anchoring specific target sites within
the body of a patient. More specifically, the invention is directed
to accessing and anchoring a sentinel lymph node of a patient which
corresponds to a lesion site within the patient's body. The
accessing and anchoring device may be used to locate a sentinel
lymph node during a surgical procedure in which a sentinel lymph
node is surgically removed with the anchor device attached.
[0012] The accessing and anchoring device having features of the
invention has an elongated shaft, with a tissue cutting member, one
or more anchoring elements, and may be configured so that at least
a portion of a radiation detector may be disposed at or near the
distal end of the shaft to aid in radioactive node location. The
anchoring element or elements may extend away from the shaft from a
position at or near the distal end of the shaft to form a curved or
coiled structure or structures which may extend through at least
180.degree., preferably through at least 360.degree., and more
preferably through at least 540.degree.. In further embodiments of
the invention, there are at least two, and more preferably at least
three radially extending anchoring elements, which may extend along
a substantial length of the shaft. This substantial length of the
shaft may further have an oblong transverse cross section.
[0013] The tissue cutting member is configured to cut tissue,
having a cutting surface which may have a cutting edge. The tissue
cutting member may be an electrode, and in particular may be an
electrode with an electrosurgical active surface, which may have a
sharp edge. This electrode may be configured to be electrically
connected to an RF energy source. The cutting surface of the
cutting member is preferably spaced from the distal end of the
shaft, and may also have an arcuate shape. The elongated shaft of
the accessing and anchoring device may have an inner lumen in which
an elongated radiation detector may be slidably disposed to an
operative location on the distal section of the shaft to facilitate
receiving radioactive emissions from a patient's node.
[0014] Another embodiment of the tissue accessing and anchoring
device has an elongated shaft with a distal portion having an
oblong transverse cross section. A plurality of anchoring elements
extending along the oblong transverse cross-sectional portion of
the shaft, preferably in a parallel relationship, and may extend
along the long dimension of the oblong transverse cross sectional
portion of the shaft.
[0015] Detection of radiation in order to identify sentinel lymph
nodes may be accomplished by manipulating the shaft and/or the
radiation energy detector to detect the amount of radiation energy
emanating from the tissue along the longitudinal axis of the shaft,
and comparing the amounts of radiation detected from various
portions of tissue. Confirmation that the distal end of the shaft
is within or adjacent to a sentinel lymph node is indicated by
detecting an above-normal amount of radiation energy emanating from
the tissue. Such radiation detection is preferably effected with an
elongate radiation detector disposed within the inner lumen of the
elongated shaft; most preferably, the elongated radiation detector
is slidably disposed within the inner lumen of the elongated shaft.
A gamma camera, ultrasound imaging, stains, dyes, or skin markings
may be used to determine the approximate position of the at least
one sentinel lymph node within the patient's body.
[0016] The method of accessing and anchoring a sentinel lymph node
of a patient which corresponds to a lesion site within the
patient's body generally includes, first locating the approximate
position of a sentinel lymph node that has accumulated radioactive
material using a radiation detector; accessing the sentinel lymph
node; and then anchoring the node. The node may be accessed by
activating the tissue cutting member on the distal end of the
device to ablate tissue while passing the shaft into the patient's
body until the distal end of the shaft is disposed within or
adjacent to the sentinel lymph node. One or more anchoring elements
are extended from the shaft into the sentinel lymph node to secure
the distal end of the device to the sentinel lymph node. The step
of extending an anchoring element may include a radially extending
step, and may further include the step of activating an outer
extremity of an anchoring element to emit radiofrequency (RF)
energy as it extends. The methods may also include locating a
sentinel lymph node using the accessing and anchoring device during
a surgical procedure in which a sentinel lymph node is surgically
removed with the accessing and anchoring device attached.
[0017] The system for accessing and anchoring a sentinel node
within a patient includes the previously described accessing and
anchoring device with an elongated radiation detecting member
slidably disposed within the lumen of the shaft so that radiation
detecting elements are located near enough to the distal end of the
device to detect radiation emitted from a radioactive sentinel
lymph node. The system may further include an electrical lead
electrically coupled to a radially extending anchoring member, and
another electrical lead electrically coupled to the patient. In
this way, RF energy from a RF source can be applied to an anchoring
element during its deployment and extension.
[0018] The devices, methods and systems of the invention provide
the advantages of locating and accessing a desired location within
a patient's body with a single device which may be directly
anchored at the location. Including these capabilities in a single
device avoids the delay and imprecision in anchoring a device at a
proper location that results from the use of multiple devices for
these functions. Moreover, the methods and devices of the present
invention are suitable for use outside of an operating room,
simplifying and reducing the cost of such procedures. In addition,
the coiling of the anchoring elements serves to shield the sharp
tips, protecting physicians from possible injury during excision of
a patient's tissue. The present invention thus provides improved
devices for marking and excising a sentinel lymph node that has
accumulated radiation and is suspected of harboring cancerous
tissue. In addition, the devices provide anchoring elements that
radially extend through a substantial angular extent to provide
improved anchoring and demarcation of a location within a patient's
body.
[0019] These and other advantages of the invention will become more
apparent from the following detailed description when taken in
conjunction with the accompanying exemplary drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1A is a perspective view of a system embodying features
of the invention, with anchoring elements retracted.
[0021] FIG. 1B is a perspective view of a system embodying features
of the invention with anchoring elements deployed.
[0022] FIG. 2 is a side elevation view showing a device embodying
features of the invention with anchoring elements retracted.
[0023] FIG. 3 is a front elevation view of the device of FIG.
2.
[0024] FIG. 4 is a top cross-sectional longitudinal view of the
device shown in FIG. 2.
[0025] FIG. 5A is a front elevation view of the device of FIG. 2
including a transverse cross-sectional view of the shaft of the
device taken along line 5A-5A of FIG. 2.
[0026] FIG. 5B is a rear elevation view of the device of FIG. 2
including a transverse cross-sectional view of the shaft of the
device taken along line 5B-5B of FIG. 2.
[0027] FIG. 5C is a rear elevation view of the device of FIG. 2
including a transverse cross-sectional view of the shaft and
RF-power connector taken along line 5C-5C of FIG. 2.
[0028] FIG. 5D is a transverse cross-sectional view of the shaft of
the device of FIG. 2 taken along line 5D-5D of FIG. 2.
[0029] FIG. 6 is a side elevation view in partial longitudinal
section taken along line 6-6 of FIG. 3.
[0030] FIG. 7 is a perspective view of a portion of a device
embodying features of the invention with anchoring elements
deployed.
[0031] FIG. 8 is a side elevation view of a device embodying
features of the invention with anchoring elements deployed.
[0032] FIG. 9 is a front elevation view of the device of FIG. 8
with anchoring elements deployed.
[0033] FIG. 10 is a top cross-sectional longitudinal view of the
device shown in FIG. 8.
[0034] FIG. 11A is a rear elevation view of the device of FIG. 8
including a transverse cross-sectional view of the shaft and
RF-power connector taken along line 11A-11A.
[0035] FIG. 11B is a rear elevation view of the device of FIG. 8
including a transverse cross-sectional view of the shaft taken
along line 11B-11B.
[0036] FIG. 11C is a cross-sectional view of the shaft of the
device of FIG. 8 taken along line 11C-11C elevation also showing
the deployed anchoring elements.
[0037] FIG. 12A is a side elevation view in partial longitudinal
section taken along line 12A-12A of FIG. 9.
[0038] FIG. 12B is a side cross-sectional view of the portion of
the device of FIG. 12A within circle 12B.
[0039] FIG. 12C is a cross-sectional view of a portion of an
elongated shaft of a device having an oblong cross-section
embodying features of the invention.
[0040] FIG. 12D is a perspective view of a portion of an elongated
shaft of a device having anchoring elements deployed from positions
proximal to the tip of the shaft embodying features of the
invention.
[0041] FIG. 13A illustrates an anchoring element and anchoring
element sheath embodying features of the invention following
deployment of the anchoring element from a stationary sheath.
[0042] FIG. 13B illustrates an anchoring element and anchoring
element sheath embodying features of the invention following
deployment of the anchoring element from a retracting sheath.
[0043] FIG. 13C illustrates an anchoring element and anchoring
element sheath embodying features of the invention following
deployment of the anchoring element from a sheath that was first
held stationary and then retracted.
[0044] FIG. 14A illustrates an anchoring element embodying features
of the invention having a blunt tip.
[0045] FIG. 14B illustrates an anchoring element embodying features
of the invention having a barbed tip.
[0046] FIG. 15A illustrates a device embodying features of the
invention having anchoring element sheaths shown in an extended
position.
[0047] FIG. 15B is a perspective view of the handle portion of the
device of FIG. 15A showing the configuration of extension tabs and
extension slots when the anchoring element sheaths are in an
extended position and anchoring elements retracted.
[0048] FIG. 15C is a longitudinal cross-sectional view of the
handle portion of the device of FIG. 15A showing the configuration
of extension tabs and extension slots when the anchoring element
sheaths are in an extended position.
[0049] FIG. 15D is a transverse cross-sectional view taken along
line 15D-15D of the tip portion of the device of FIG. 15A.
[0050] FIG. 15E is a transverse cross-sectional view taken along
line 15E-15E of the device of FIG. 15A.
[0051] FIG. 15F is a transverse cross-sectional view taken along
line 15F-15F of the device of FIG. 15A.
[0052] FIG. 16A illustrates a device embodying features of the
invention having anchoring element sheaths retracted and anchoring
elements deployed.
[0053] FIG. 16B illustrates a distal portion of the device of FIG.
16A showing deployed anchoring elements.
[0054] FIG. 16C is a perspective view of the handle portion of the
device of FIG. 16A showing the configuration of extension tabs and
extension slots when the anchoring elements are deployed and the
sheaths retracted.
[0055] FIG. 16D is a longitudinal cross-sectional view of the
handle portion of the device of FIG. 16A showing the configuration
of extension tabs and extension slots when the anchoring elements
are deployed and the sheaths retracted.
[0056] FIG. 16E is a transverse cross-sectional view taken along
line 16E-16E of the device of FIG. 16A.
[0057] FIG. 16F is a transverse cross-sectional view taken along
line 16F-16F shown in FIG. 16C.
[0058] FIG. 16G is a transverse cross-sectional view taken along
line 16G-16G shown in FIG. 16C.
DETAILED DESCRIPTION OF THE INVENTION
[0059] FIGS. 1A and 1B show a system 10 embodying features of the
invention, which includes a sentinel node accessing and anchoring
device 11, and an elongated radiation detector 12. The accessing
and anchoring device has a shaft 13 with a proximal portion and a
distal portion 14 with a cutting wire 15 at its tip 16; and a
source of radio frequency (RF) power 24 connected to the cutting
wire 15 via RF connector 22. The shaft 13 and radiation detector 12
lie generally along longitudinal axis 30. As shown in FIGS. 1A and
1B, cutting wire 15 is a tissue cutting member that may be
activated by RF energy and is configured to ablate and penetrate
tissue. It is shown as an arcuate wire spaced distally from the tip
16 of shaft 13. In alternative embodiments, cutting wire 15 may
take other shapes and may be in contact with or form part of tip
16.
[0060] Radiation energy detector 12 includes an elongated probe 31,
shown in FIGS. 4 and 6, and may be, e.g., a gamma probe. Radiation
energy detector probe 31 is effective to detect, locate and
identify a lymph node within a patient's body that has accumulated
radioactive material and is emitting radiation. Detection of
radiation by detector 12 is communicated via cable 35 to signal
processor 37 and thereby to an operator. The electrical circuit
pathway from RF power source 24 to cutting wire 15 is completed by
ground connector 26 and ground pad 28, which may be placed in
contact with a patient. As shown in FIGS. 1A and 1B, the RF
electrode (cutting wire 15) may lie in substantially the same plane
as the longitudinal axis 30 of the elongate shaft of the node
accessing and anchoring device 11, although it need not do so in
every embodiment.
[0061] As shown more clearly in FIG. 1B, anchoring elements 20 may
be deployed from anchor sheaths 18 at tip 16 to anchor the device
11 in position within a patient's body. In the embodiment shown in
FIG. 1B, anchoring elements 20 extend in a radial direction from
the tip 16 of shaft 13. By "radial" is meant a direction that is
angled, and may be generally orthogonal, to a longitudinal axis 30
of the shaft 13 or an axis of an anchoring sheath 18, so that a
line passing within the coils is angled with respect to such a
longitudinal axis. Anchoring elements 20 are deployed by movement
of the thumb rest 36 towards finger rest 34 (note changed positions
of tab 32 and thumb rest 36 between FIGS. 1A and 1B). Anchoring
elements 20, when deployed, are effective to secure device 11 in a
desired location within a patient's body, as, e.g., when a sentinel
lymph node has been located using the radiation energy detector
12.
[0062] FIG. 2 shows a sentinel node accessing and anchoring device
11, with anchoring elements 20 retracted within anchor sheaths 18.
Radiation energy detector 12 is attached by latch 38 to shell 40.
Latch 38 fits snugly under shell tabs 39 which hold latch 38 and so
hold radiation energy detector 12 to the rest of the device.
Transition bushing 42 aligns shaft 13 with shell 40.
[0063] FIG. 3 shows the device 11 from the front, showing cutting
wire 15 lying in a plane aligned with RF connector 22 and in
substantially the same plane as the longitudinal axis 30 of the
shaft 13.
[0064] The positioning of radiation energy detector 12 and its
elongated probe portion 31, which is slidably disposed within shaft
13 and extends within shaft 13 to the distal portion 14 and may
extend up to tip 16, adjacent a patient's lymph nodes allows the
detection of radiation (such as gamma radiation), if any, emitted
from material collected within a sentinel lymph node of a patient,
and so allows the identification of sentinel lymph nodes in a
patient at risk of cancer metastasis. Radiation energy detector 12
detects radiation energy emanating from the tissue along
longitudinal axis 30 in a proximal direction relative to radiation
energy detector probe 31. The hollow shaft 13 or the radiation
energy detector probe 31 within the shaft 13 can be manipulated
while within a patient to detect the amount of radiation energy
emanating from various portions of the tissue as they pass in front
of the tip 16 and into the radiation energy detector 12 during the
manipulation.
[0065] The amount of radiation detected from the various portions
of tissue adjacent the longitudinal axis 30 of the device 11 and
shaft 13 can be used to determine the position of the radiation
energy detector 12 that produces the maximum radiation signal
strength. The output of a radiation energy detector such as a
detector 12 is carried by cable 35 to provide, e.g., a visual or
audio signal or the like generated by a signal processor 37. Such
an output may be observed and used by an operator of the system to
determine the relative or the absolute amounts of radiation
detected at a particular position within a patient's body. The
input of the radiation energy detector probe 31 within the tip 16
of the shaft 13 can be configured so as to maximize output signal
strength when a sentinel lymph node that emits a relatively large
amount of radiation ("hot" sentinel lymph node) is disposed
directly distal of the tip 16 of the shaft 13 and radiation energy
detector probe 31. Thus, by maximizing the output signal from the
detector 12, the operator can determine the precise location of a
hot sentinel lymph node and effectively discriminate surrounding
non-radioactive tissue and non-radioactive nodes.
[0066] As illustrated in FIGS. 4 and 5, at least a portion of the
radiation energy detector 12 fits inside shaft 13. The device 11,
shaft 13, and elongate portion 31 of radiation energy detector 12
may all share a common longitudinal axis 30. In embodiments or the
invention, elongate portion 31 fits slidably within shaft 13. The
diameter of an elongate portion 31 of the radiation energy detector
12 configured to fit within shaft 13 can be about 1 to about 6 mm,
specifically about 3 to about 5 mm, and more specifically about 4.0
to about 4.4 mm. A detector body is disposed within the elongate
portion 31 of radiation energy detector probe 12 which is
configured to receive radiation energy at an angle of up to about
30.degree., preferably about 10.degree. to about 20.degree., from a
longitudinal axis 30 of the elongate portion 31 of the radiation
energy detector probe 12. The detector body can be designed to
encompass the radiation emitted from a 1 cm node at a distance of 1
cm. The detector body can be configured to have enhanced reception
of radiation energy from the distal end 14 of the device 11 as
opposed to side impingement of radiation energy. The detector body
is coupled by the cable 35 to the signal processor unit 37. The
detector body can be configured to specifically detect gamma
radiation or any other suitable form of radiation energy including
alpha or beta radiation. Radiation energy detector 12 may have a
preamplifier within it to increase the signal from the detector
body to the signal processor unit 37. The length of the radiation
energy detector probe 31 is typically configured to access
radiation emitted from a patient's tissue through a hollow shaft
that can be, e.g., about 5 to about 15 cm long.
[0067] The signal processor unit 37 connected to the radiation
energy detector 12 can be configured to emit an audible signal to
be detected by a user of the detector which has a volume and/or
frequency which increases in relation to an increase in the amount
of radiation energy being detected. Alternatively, the signal
processor unit 37 can produce a visual signal to be detected by a
user of the detector which is proportional in amplitude to the
amount of radiation energy being detected. For example, a signal
processor 37 may provide a digital readout of counts per second and
total counts for given time period. It will be understood that
other methods for communicating a signal from signal processing
unit 37 to an operator may also be used. The radiation energy
detector 12 can typically detect radiation at useable levels from a
hot lymph node from a distance of up to about 10 to about 12 cm or
more, but is more accurate at shorter distances, such as distances
less than about 8 cm to about 10 cm, and is most accurate at
distances of about 2 to about 3 cm.
[0068] Preferably, the location of a sentinel lymph node identified
by radiation detector 12 must be marked so that it may be excised.
As shown in FIG. 1B, anchoring elements 20 may be deployed from
anchor sheaths 18 at tip 16 to anchor the device in position,
thereby marking the proper location. In the embodiment shown in
FIG. 1B, anchoring elements 20 extend in a radial direction from
the tip 16 of shaft 13. In embodiments of the invention, anchoring
elements 20 deploy from positions at or very near to tip 16; in
further embodiments, anchoring elements may deploy from positions
proximal of tip 16.
[0069] Anchoring elements 20 are deployed by movement of the thumb
rest 36 towards finger rest 34 (note changed positions of tab 32
and thumb rest 36 between FIGS. 1A and 1B). As illustrated in the
figures, in preferred embodiments, a sentinel node accessing and
anchoring device 11 is configured to be easily held in one hand by
an operator. The anchoring elements may be deployed by squeezing
and moving the thumb (on the thumb rest 36) towards the fingers (on
the finger rest 34). The fingers remain stationary as the thumb and
thumb rest 36 approach the fingers and finger rest 34, insuring
that the tip 16 remains stationary as the anchoring elements are
deployed.
[0070] Thus, the node accessing and anchoring device 11 may be used
to access a lymph node with anchoring elements 20 retracted within
anchoring element sheaths 18, the presence or absence of radiation
detected with radiation energy detector 12 which extends within
shaft 13 to tip 16, and, when a sentinel node containing radiation
emitting material is detected, the position may be marked by
deployment of anchoring elements 20 to fix the device in place for
excision of the sentinel node lymph.
[0071] Anchoring elements 20 may be formed at least in part from a
metal, alloy or compound having shape memory, including a
nickel-titanium shape-memory alloy such as nitinol. In preferred
embodiments, anchoring elements 20 are formed at least in part from
super-elastic nitinol. Alternatively, or additionally, anchoring
elements 20 may also include stainless steel or other
bio-compatible materials with suitable spring-like properties.
Anchoring element sheaths 18 may be made with, among other
materials, stainless steel or polymer tubes, such as hypodermic
tubes or other sheath material suitable for enclosing and guiding
an anchoring element 20 which may assume a fairly linear
configuration within the sheath but which, upon deployment from the
sheath, assumes a coiled configuration. Anchoring element sheaths
18 may have ends that are flat, rounded, beveled, sharpened,
flared, tapered, or that have other configurations. Anchoring
elements 20 may extend from the tip 16 by about 1 to about 35 mm,
specifically by about 5 to about 30 mm, and more specifically by
about 15 to about 25 mm when deployed fully.
[0072] The anchoring elements curve and coil as they are deployed,
to assume a configuration having a curved structure. In embodiments
of the invention, the curved structure of the anchoring elements 20
extends through at least 180.degree. of curvature; in further
embodiments, the curved structure extends through at least
360.degree.; and in yet further embodiments, it extends through at
least 540.degree.; and in still further embodiments, the curved
structure of the anchoring elements 20 extends through more than
540.degree.
[0073] FIGS. 4 and 6 show the cylindrical portion of thumb rest 36
in contact with push sleeve 44. Connected to push sleeve 44 is push
sleeve tab 32 which slides within slot 41 in shell 40 and shows the
location of push sleeve 44. Housing 58 is located between and
separates thumb rest 36 and push sleeve 44 providing support and
guidance as push sleeve 44 advances to push anchoring element
bushing 48 and so to deploy anchoring elements 20 by causing them
to move within anchoring element sheaths 18 located in anchoring
element support sleeves 46.
[0074] FIGS. 5A-D provide illustrations of cross-sections of the
device 11 at the locations indicated by lines 5A-5A (for 5A), 5B-5B
(for 5B), 5C-5C (for 5C) and 5D-5D (for 5D) of FIG. 2. Shown in
these figures are support sleeves 46 in which anchoring element
sheaths 18 slide. Support sleeves 46 and anchoring element sheaths
18 together enclose anchoring elements 20 in a variable-length
enclosure. Sleeves 46 and sheaths 18 fit together with part of one
inside part of the other so that they may slide and telescope to
maintain an enclosure around anchoring elements 20 regardless of
the total length of the enclosure. Support sleeves 46 and anchoring
element sheaths 18 are configured to support and encase anchor wire
20 along its length, and to prevent buckling of anchor wire 20.
[0075] In further embodiments of the invention, the shaft 13 has an
oblong transverse cross-section. The anchoring elements 20 may
further include or contact conductors connected to a source of RF
power 24, and an actuator coupled to the conductors or directly to
the anchoring elements 20 for extending the anchoring elements 20.
Conductors for connecting anchoring elements 20 and/or cutting wire
15 with a source of RF power 24 are termed "inner conductors" since
they may extend along an inner portion of the shaft 13 or within
anchoring element sheaths 18, or within other elements of devices
embodying features of the invention. For example, cutting wire
connector 60 is an inner conductor. An inner conductor may contain
an inner lumen, which may contain a shaft. Anchoring elements may
be deployed by an actuator that is coupled to the inner
conductor.
[0076] In embodiments where anchoring elements 20 are operably
connected to an RF power source 24, anchoring elements may be
insulated, by being coated with an insulating coat or being
sheathed with an insulating sheath so as to cover most but not all
of the surface of the anchoring element that may come into contact
with body tissue. Application of RF power to an anchoring element
20 having an uninsulated tip and insulation along most of its
length is effective to ease the entry of the anchoring element into
body tissue as the anchoring element 20 is deployed. Any
biocompatible insulating material, such as a polymer (e.g.,
polyimide) is suitable for insulating an anchoring element 20.
[0077] In embodiments of the invention, the source of RF power 24
is switchable, and the connection may be a switchable connection.
Thus, in embodiments of the invention, RF power source 24 may be
capable of providing different levels of RF power, and may be
switched between the different levels by the operator. A switchable
power source 24 and switchable connections to RF power source 24
thus provide the ability, for example, to provide one amount of
power to the cutting wire 15 and another amount of power to
anchoring elements 20 as desired. For example, an RF power source
24 may be switchably connected to an inner conductor. In addition,
a switchable RF power source 24 provides the capability to deliver
different amounts of power to cutting wire 15 at different times.
For example, it may be desirable to provide cutting wire 15 with
different amounts of power depending upon different types of tissue
encountered within the body of a patient.
[0078] FIG. 6 illustrates the linkage between RF connector 22 and
cutting wire contact 54. This linkage is also illustrated in FIGS.
11 and 12. RF connector 22 is held in contact with compression
spring 56 within sliding pin 50. This assembly is retained within
shell 40 by retainer 52. Sliding pin 50 is pressed against cutting
wire contact 54 by the action of compression spring 56 to make an
effective electrical connection between RF power source 24 and
cutting wire 15 via RF connector 22, compression spring 56, sliding
pin 50, cutting wire contact 54 and cutting wire connector 60.
Cutting wire connector 60 bends within transition bushing 42 as
shown in FIG. 12B to extend along the length of shaft 13 to contact
cutting wire 15 at tip 16.
[0079] In addition to providing electrical contact between RF cable
22 and cutting wire contact 54, sliding pin 50 also provides a
mechanical connection between shell 40 and the probe assembly that
includes shaft 13 and housing 58. Depression of latch 38 to release
tabs 39 allows the removal of the radiation energy detector 12.
[0080] As shown in FIG. 5, thumb ring 36 has a slot 59 having a
chamfer 61 along a portion of the wall of slot 59. Sliding pin 50
has a bevel 51 near its contact tip 53 that mates with slot wall 61
(in slot 59) that has a chamfer, or an angle with respect to the
surface of thumb ring 36. Sliding pin 50 is held in secure
electrical contact with cutting wire contact 54 by compression
spring 56 when inserted into those portions of slot 59 with a slot
wall 61 having a chamfer. The most proximal portion of slot 59 has
a slot wall 61 with no chamfer, instead having a slot wall 61 that
joins the surface of thumb ring 36 in a configuration that is
substantially perpendicular to that surface, as shown in FIG. 11A.
Sliding thumb ring 36 forward towards finger rest 34 moves the
position of contact tip 53 of sliding pin 50 towards more proximal
portions of slot 59. Contact between contact tip 53 and cutting
wire connector 60 is maintained as long as sliding pin 50 is within
a portion of slot 59 that has a chamfer 61. However, electrical
contact between sliding pin 50 and cutting wire connector 60 is
lost as thumb ring 36 nears its most forward position, causing
sliding pin 50 to move to a position where bevel 51 contacts a slot
wall 61 that has no chamfer. There, contact between bevel 51 and
the outer surface of thumb ring 36 lifts sliding pin 50 as slot 59
is moved distally with respect to sliding pin 50. Raising or
removal of sliding pin 50 allows the removal of shell 40, thumb
ring 36, finger rest 34, and other associated elements from housing
58 (including radiation energy detector probe 12 if still attached
to shell 40 with latch 38 connecting to tabs 39). Removal of these
elements may be desirable, for example, after the deployment of the
anchoring elements to allow marking of the sentinel lymph node for
an extended period of time without the weight, bulk and possible
discomfort to the patient of the radiation energy detector probe
12, shell 40, and other elements. Such an extended period of time
may be up to a few minutes, a few hours, or several hours,
depending upon the length of time necessary to effect a full
diagnosis of the patient's condition and, where desirable, to
effect the removal of the sentinel lymph node and optionally any
surrounding structures.
[0081] FIG. 7 illustrates the shaft 13 and housing 58 of a sentinel
node accessing and anchoring device embodying features of the
invention after detachment of shell 40 and other elements from the
shaft 13 and housing 38. The anchoring elements 20 are shown
deployed; accordingly, push tab 32 within slot 59 is shown in a
forward position. Cutting wire contact 54 is shown in connected
with cutting wire connector 60 which runs along shaft 13 to connect
with cutting wire 15.
[0082] FIG. 8 shows a sentinel node accessing and anchoring device
with anchoring elements 20 deployed. Thumb rest 36 is positioned
adjacent shell 40 and push sleeve tab 32 is in a forward position
in slot 41 when anchoring elements 20 are deployed. This is in
contrast to the configurations of thumb rest 36 and push sleeve tab
32 shown in FIG. 1A and in FIGS. 2-5 with anchoring elements
retracted. During use, after location and identification of a
sentinel lymph node, and positioning of the tip 16 of the shaft 13
adjacent to the sentinel lymph node, anchoring elements 20 are
deployed to fix the device in position. When the device has been
fixed in a proper location within a patient's body, there is no
longer need for radiation energy detector 12, and it may be
removed. For example, latch 38 may be depressed at its distal end
to disengage the radiation energy detector 12 from shell tabs 39
and elongated portion 31 of radiation energy detector 12 withdrawn
from within shaft 13. Accordingly, no radiation energy detector 12
is shown in FIGS. 8-12, which depict a device embodying features of
the invention as it may be used after anchoring elements 20 have
been deployed.
[0083] FIG. 9 shows the device illustrated in FIG. 8 viewing along
a longitudinal axis towards cutting wire 15. The anchoring elements
20 are shown in their deployed configuration.
[0084] FIG. 10 is a cross-sectional longitudinal view of the device
shown in FIG. 8, taken along a plane perpendicular to a line
running along RF power connector 22, showing the configuration of
the push sleeve 44 within housing 58 and shell 40 when anchoring
elements 20 are deployed.
[0085] FIG. 11 illustrates sectional views of portions of the
device shown in FIG. 8. Lines 11A-11A, 11B-11B, and 11C-11C shown
in FIG. 8 indicate the lines along which cross-sections are taken
and illustrated in FIGS. 11A, 11B and 11C. FIG. 11 illustrates the
configuration of elements of a device embodying features of the
invention when anchoring elements 20 are deployed. Anchoring
elements 20 illustrated in FIG. 11C have sharp tips 64 effective to
aid their deployment into tissue of a patient's body. FIGS. 11A and
11B show cross-sections of the shaft 13 and, in FIG. 11A, show the
RF power connections and some of its constituent elements in
greater detail.
[0086] The broken line 12A-12A in FIG. 9 indicates the section
illustrated in FIG. 12A. FIG. 12A is a view of the device of FIG. 8
showing RF connections between RF connector 22, and elements 50,
52, 54, 56 and 60 with cutting wire 15. Circle 12B in FIG. 12A
indicates the portion of the figure that is shown in greater detail
in FIG. 12B. The RF power connections, as well as the anchoring
element bushings 48, are shown in greater detail in FIG. 12B. Also
shown in FIG. 12 is a telescoping junction 62 between an anchor
element sheath 18 and a support sleeve 46.
[0087] The elongated shaft 13 of a device embodying features of the
invention may have other than a circular cross-section. For
example, as illustrated in FIG. 12C, the elongated shaft 13 of a
device 11 embodying features of the invention may have having an
oblong cross-section. In the portion of the device 11 illustrated
in this figure, multiple anchoring elements 20 are housed within
anchoring element sheaths 18 extending along the oblong transverse
cross-sectional portion of the shaft 13. Anchoring elements 20 and
sheaths 18 are preferably situated in a parallel relationship as
shown in FIG. 12C. Elongated portion 31 of radiation energy
detector 12 also extends along the long dimension of the oblong
transverse cross-sectional portion of the shaft 13 in the
embodiment shown.
[0088] Anchoring elements 20 may exit from anchoring element
sheaths 18 for deployment into a patient's body from positions
anywhere along the elongated shaft 13. For example, as illustrated
in FIG. 12D, anchoring elements 20 may be deployed from positions
proximal to the tip 16 of the shaft 13. In embodiments of the
invention, anchoring elements 20 may deploy from positions of up to
about 2 cm to 3 cm from the tip 16. In preferred embodiments,
anchoring elements 20 deploying from positions proximal of tip 16
may deploy from positions up to about 0.5 cm to about 2 cm proximal
of the tip 16. Note that some anchoring elements 20 may be deployed
from sheaths 18 at a different distances from tip 16 than other
anchoring elements 20.
[0089] FIG. 13 illustrates anchoring elements 20 and their sheaths
18 in various configurations. FIG. 14 illustrates different tip
configurations: anchoring elements 20 may have flat or rounded tips
64, or may have barbs on their tips (66) as shown in FIG. 14B. It
will be understood that anchoring elements 20 may have any of a
variety of tip shapes and configurations, including but not limited
to flat, rounded, beveled, pointed, barbed, or other configuration,
and may be configured to assume tighter or looser coil
configurations as well. Anchoring elements 20 may be made with any
material having suitable spring-like properties. In preferred
embodiments, anchoring elements 20 are made with super-elastic
nitinol wire configured to assume a coiled configuration upon
release from enclosure within a sheath. The alignment of the
anchoring elements 20 within anchoring element sheaths 18 is an
important factor in obtaining a desired coil configuration upon
deployment.
[0090] Anchoring elements 20, particularly anchoring elements 20
made with materials including super-elastic nitinol, may be
configured and deployed so as to assume different coiled
configurations upon exiting from anchoring element sheaths 18
depending upon the relative motions of the anchoring element 20,
the sheath 18, and the tissue into which the anchoring element is
deployed. In one deployment mode, advancing the anchoring elements
20 out of the anchoring element sheaths 18 into surrounding tissue
lets the anchoring elements 20 assume their natural and restrained
coil shapes. However, in an alternative deployment mode, the
anchoring element sheaths 18 are pulled back while the anchoring
elements 20 are left in a substantially static position. In this
case, the tips 64 of the anchoring elements 20 do not move forward
as they uncoil upon release from the restraint of the anchoring
element sheaths 18, but instead remain relatively stationary or
move backward, so that the final coil shapes of the anchoring
elements 20 are substantially dictated by the composition of the
surrounding tissue. The coil radius of an anchoring element 20 that
is deployed into a region of harder or denser tissue will, in
general, be smaller than the coil radius of an anchoring element 20
deployed into a region of softer or less dense tissue. In general,
the wider the coil radius, the more the backward movement of the
anchoring element tip 64 as an anchoring element 20 uncoils during
retraction of an anchoring element sheath 18.
[0091] The following definitions are useful in describing the
different anchoring element deployment configurations of devices
and methods embodying features of the invention. An imaginary line
following a path down the central axis of a helical coil is termed
a "coil axis"; similarly, an imaginary line following a path down
the central axis of a sheath is termed a "sheath axis." A coil axis
and a sheath axis may be aligned in a substantially parallel
alignment, or may not be similarly aligned. The alignment of a coil
axis is termed to be "radial" to a sheath axis when the coil axis
and the sheath axis are not substantially parallel, but instead,
either meet at an angle, or a projection of the coil axis onto a
plane including the sheath axis forms an angle with the sheath
axis. A forward direction is defined as the direction along the
sheath axis leading from the interior to the exterior of the
sheath; a rearward direction is the direction along the sheath axis
from the exterior to the interior of the sheath, and is opposite to
a forward direction. Rearward movement is also termed
"retraction."
[0092] When an anchoring element 20 made with material having
suitable spring-like properties, such as super-elastic nitinol
wire, is deployed into a tissue from a stationary anchoring element
sheath 18, the anchoring element 20 will assume a coiled
configuration with the coil axis substantially radial to the sheath
axis. However, a different coil configuration is obtained when a
super-elastic nitinol wire is deployed forward into a tissue from a
sheath that is moving in a rearward direction. In this latter case,
the coil, as it extends, will assume a configuration with the coil
axis substantially parallel to the sheath axis. This property is
useful for anchoring medical devices in a proper location within a
patient's body.
[0093] FIG. 13A illustrates the configuration of an anchoring
element 20 and an anchoring element sheath 18 embodying features of
the invention following deployment of the anchoring element 20 with
the sheath 18 held stationary. The anchoring element 20 assumes a
radial configuration having a coil axis substantially perpendicular
to the sheath axis. In embodiments of the invention, anchoring
elements 20 may be configured to deploy from stationary sheaths
into radial configurations having coil axis orientations at other
angles with respect to the sheath axis as well. In FIG. 13B, an
anchoring element 20 and an anchoring element sheath 18 are
illustrated following forward deployment of the anchoring element
20 while the sheath 18 was moving in a rearward direction. In this
case, the anchoring element 20 assumes a configuration with a coil
axis substantially parallel to the sheath axis.
[0094] FIG. 13C illustrates an anchoring element 18 having a coil
configuration produced by utilization of both methods of coiled
wire deployment. The anchoring element 20 illustrated in FIG. 13C
has a coiled portion having a coil axis oriented substantially
perpendicularly with respect to the sheath axis, and a coil portion
having a coil axis oriented substantially parallel to the sheath
axis. This complex configuration may be produced by first deploying
a super-elastic nitinol anchoring element 20 from a stationary
anchoring element sheath 18, and then moving the anchoring element
sheath 18 in a rearward direction while deploying the anchoring
element 20 in a forward direction.
[0095] The anchoring element configurations illustrated in FIGS.
13A, 13B and 13C are effective to anchor a medical device in a
desired location within a patient's body. At least one anchoring
element is effective to anchor a medical device in a desired
location within a patient's body. The use of at least two, or
preferably at least three anchoring elements is believed to be more
effective than the use of a single anchoring element. In
particular, since lymph nodes are small, mobile, and difficult to
identify and localize, use of an anchoring element or use of at
least one, and preferably multiple anchoring elements, as disclosed
herein, is effective to fix a medical device adjacent to a sentinel
lymph node and to aid in the removal of sentinel lymph nodes,
cancerous tissues, and of other tissues.
[0096] The anchoring element sheaths 18 may be configured for
forward and rearward movement effective to deploy anchoring
elements 20 into any desired configuration. FIGS. 15 and 16
illustrate an embodiment of a sentinel node accessing and anchoring
device embodying features of the invention having sheaths and
anchoring elements that may be deployed and retracted. FIG. 15A
illustrates a device embodying features of the invention having
anchoring element sheaths shown moved forward in an extended
position. Anchoring elements 20 are contained within anchoring
element sheaths 18. FIG. 15B illustrates the handle portion of the
device of FIG. 15A to show the configuration of extension tabs and
extension slots corresponding to the configuration of the anchoring
element sheaths 18 and anchoring elements 20 shown in FIG. 15A.
Slotted sleeve 68, having anchoring element slot 70 for controlling
the configuration of anchoring elements 20 and sheath slot 72 for
controlling the configuration of sheaths 18, is mounted on handle
barrel 76. Push sleeve tab 32 and sheath push tab 74 are shown
engaged within anchoring element slot 70 and sheath slot 72,
respectively. FIG. 15C provides a cross-sectional view of the
handle portion of the device of FIGS. 15A and 15B, showing push
sleeve tab 32 and push sleeve 44, and sheath push tab 74 and sheath
push sleeve 78, engaged with slotted sleeve 68 within anchoring
element slot 70 and sheath slot 72, respectively. Slotted sleeve 68
is shown here within rotating handle 80 which is a deployment
actuator and also serves as a cover for slotted sleeve 68 in the
embodiment illustrated in FIG. 15C. FIGS. 15D, 15E and 15F show
transverse cross-sectional views of the device, taken along the
lines 15D-15D, 15E-15E, and 15F-15F shown in FIG. 15A.
[0097] As illustrated in FIG. 13, forward deployment of anchoring
elements while sheaths move rearward results in anchoring elements
configured with coil axes substantially parallel to the sheath
axes. Thus, in order that anchoring elements 20 will assume the
configurations shown in FIG. 16A, anchoring elements 20 are
deployed forward, and sheaths 18 moved rearward, during deployment
of the anchoring elements 20 from the device shown in FIG. 15A. The
configurations of the anchoring elements 20 are shown in greater
detail in FIG. 16B. As is also more readily seen in FIG. 16B,
sheaths 18 have been fully retracted within tip 16 and shaft 13
into anchoring element support sleeve 46. Support sleeve 46 and
anchoring element sheath 18 together form a telescoping tubular
sleeve configured to extend and retract while retaining an
anchoring element 20 within a restraining enclosure effective to
avoid buckling of the enclosed anchoring element 20.
[0098] FIG. 16C shows the handle portion of the device of FIGS. 15
and 16. With sheaths 18 retracted and anchoring elements 20
deployed, sheath tab 74 and push sleeve tab 32 are located in the
positions near to each as shown in FIGS. 16C and 16D. FIGS. 16E,
16F, and 16G show transverse cross-sectional views of the device of
FIG. 16A, taken along the lines 16E-16E, 16F-16F, and 16G-16G in
the figures. Also shown in FIGS. 16A-16D are RF connection 22 and
electrical connector 82 for the radiation energy detector 30.
[0099] Sentinel node accessing and anchoring devices embodying
features of the invention find use in the detection, marking and
removal of lymph nodes and other tissues that may harbor metastatic
cancer cells. A patient, such as one having a cancerous lesion, may
be injected with radiation-emitting material at the primary lesion
site. Radioactive materials may be bio-compatible fluids
containing, e.g., Technetium 99, Indium 111, Iodine 123 or Iodine
125, which emit gamma radiation, or may be bio-compatible fluids
containing materials emitting alpha-radiation or beta-radiation.
Detection of radiation by radiation energy detector probe 30 at a
location other than the injection site indicates that migration of
the radioactive material has occurred, typically via the lymphatic
system.
[0100] Identification and removal of sentinel lymph nodes is an
important part of cancer treatment, particularly the treatment of
breast cancer. By correctly timing the observation of the radiation
energy signals coming from the patient's body after injection of
radioactive material, it is possible to locate and identify the
sentinel lymph nodes corresponding to a lesion site. Alternatively,
lack of gamma radiation emission from a lymph node, at a time after
injection sufficient to allow lymph drainage into a sentinel lymph
node, indicates that the node is not in communication with the
cancerous lesion and so is not at high risk of harboring metastatic
cancer cells. The lymph nodes which correspond to the breast and
surrounding areas are typically located in the armpit of the
patient, connected to breast tissue by a series of lymph ducts.
[0101] As described in copending, co-owned U.S. patent application
Ser. No. 09/727,112 "Sentinel Node Location and Biopsy" to Burbank
and Lubock, monitoring of a patient following injection of
radioactive material may be accomplished by hand held radiation
detector, gamma camera, or other radiation detector. Detection of
an accumulation of radioactive material at a time after the
injected radioactive material has migrated through the lymph ducts
to the sentinel lymph nodes but prior to dispersion of the
radioactive material to nodes surrounding the sentinel nodes
indicates that a sentinel lymph node has been located. "Hot"
sentinel lymph nodes are clearly distinguishable from surrounding
non-radioactive lymph nodes using radiation energy detectors from
outside the patient's body, sufficient to indicate an approximate
position of sentinel lymph nodes in a non-invasive manner. A mark
may be made on the skin of the patient to identify the approximate
location of the sentinel lymph node identified in this way by an
external radiation detector such as a hand-held radiation detector
or gamma camera.
[0102] However, knowledge of only the approximate location of a
sentinel lymph node is insufficient for its accurate and complete
removal. Use of a sentinel node accessing and anchoring device 11
embodying features of the invention allows location of the sentinel
lymph nodes with greater precision, and allows their precise
marking for their accurate and complete removal. Thus, the
invention provides an improved method for accessing and anchoring a
sentinel lymph node corresponding to a lesion site within a
patient's body that makes use of the devices and systems of the
invention to access a sentinel lymph node and to anchor the device
in or adjacent the sentinel lymph node.
[0103] An improved method for accessing and anchoring a sentinel
lymph node corresponding to a lesion site within a patient's body
includes the step of locating the approximate position of at least
one sentinel lymph node by detecting radiation accumulated within a
lymph node with a radiation detector. For example, the radiation
detector may be a radiation energy detector probe 30 having an
elongated portion 31 configured to slidably fit within shaft 13.
Then, the device 11 may be used to access the sentinel lymph node
by activating cutting wire 15 to ablate tissue while passing shaft
13 into the patient's body until the distal end 14 of the shaft 13
or the tip 16 is disposed adjacent the sentinel lymph node.
Anchoring elements 20 may then be extended into the patient's body
tissue to anchor the device 11 into the sentinel lymph node or into
tissue adjacent the sentinel lymph node. The extension of the
anchoring elements is effective to secure the distal end 14 of
shaft 13 or the tip 16 to the sentinel lymph node or adjacent to
the sentinel lymph node.
[0104] The anchoring elements 20 may be extended radially or
longitudinally. Anchoring elements 20 may assume a curved or coiled
configuration when extended, as shown in FIGS. 1B, 7-11, 12A, 13,
14, and 16A and B. Once the device 11 is secured to or adjacent a
sentinel lymph node by anchoring elements 20, the patient can be
transferred to a surgical suite and the lymph node surgically
removed, with the device 11 attached and serving as a locating
device.
[0105] A sentinel node accessing and anchoring device 11 may be
introduced into a patient's body at a location corresponding to the
approximate location of a sentinel lymph node identified by
external radiation detectors. Ultrasonic imaging can be used while
the device 11 is being inserted to aid its guidance to a desired
location and to help avoid the large arteries and nerves that are
generally located in the same area as the axillary lymph nodes of a
patient.
[0106] Cutting wire 15 may be spaced distally from tip 16, as
illustrated in the figures, or may be partly or completely in
contact with tip 16. Cutting wire 15 readily cuts through tissue
upon activation with RF power from RF power source 24, allowing
insertion of tip 16 and shaft 13 into a patient. When cutting wire
15 is activated with RF energy and applied to tissue, tissue is
ablated along the length of the cutting wire 15 and displaced by
tip 16 of device 11 as it is advanced through the tissue. Because
RF tissue ablation frequently interferes with ultrasonic imaging
and the like, it may be desirable to use a system for reduction of
such interference such as is taught by copending U.S. patent
application Ser. No. 09/527,868, by Dabney et al., filed Mar. 17,
2000, which is hereby incorporated by reference herein in its
entirety.
[0107] The RF power source 24 for the cutting wire 15 can be any of
a variety of standard electrosurgical units generating
radiofrequency energy in a range of about 300 to about 6,000 kHz,
specifically, about 350 to about 1,000 kHz. Power output for the RF
power source 24 can be about 25 to about 150 watts, preferably
about 75 to about 125 watts. The cutting wire 15 can be made of a
variety of materials, including stainless steel, tungsten, nitinol
and the like. Cutting wire 15 may have a cross section that is
round, rectangular, oval or any other suitable configuration and
generally has a transverse dimension of about 0.001 to about 0.020
inch, specifically about 0.006 to about 0.015 inch. As illustrated
in FIG. 1 and other figures, the cutting wire is spaced distally
from tip 16, although in embodiments of the invention cutting wire
15 is not spaced distally from the tip 16.
[0108] The cutting element at the tip of devices embodying features
of the invention may have a sharp cutting surface, point or edge
for use without electrical power. In preferred embodiments, the
cutting element is an electrode, such as cutting wire 15,
configured for use with RF power to cut through tissue. In addition
to the application of RF energy to cutting wire 15 as described, in
embodiments of the invention anchoring elements 20 may receive RF
energy from RF power source 24 or other RF power source in order to
apply RF power to tissue to aid their deployment. Thus, RF energy
may be applied to the cutting wire 15 to effect insertion and
movement of tip 14 and shaft 13 of devices of the invention, and
may also be applied to anchoring elements 20 during their
deployment to aid in their advancement through tissue. In
embodiments of the invention, anchoring elements 20 may be
insulated along their lengths except for at the tips 64.
[0109] Shaft 13 and tip 16 may be made from any bio-compatible
materials, such as bio-compatible polymers, ceramics, composites,
or metals (the metal preferably having an electrically insulated
outer surface or coating). Preferably, shaft 13 is made from a
disposable polymer sleeve configured to fit over the elongated
portion 31 of radiation detector probe 30. Tip 16 is preferably
formed, at least in part, from high density polyethylene
(HDPE).
[0110] The invention also provides systems for accessing and
anchoring a sentinel node within a patient, including a device 11,
having a shaft 13, a tissue cutting member such as cutting wire 15,
a radiation energy detector probe 30, the device 11 having at least
one anchoring element 20 having a retracted and having an extended
configuration, and a rotating handle 80 configured to deploy an
anchoring element 20 from the retracted configuration to the
extended configuration. In embodiments of the invention, rotating
handle 80, which serves as a deployment actuator, may be configured
to both extend the anchoring elements 20 and to activate the anchor
elements 20 with RF energy. In addition, the system may include a
housing, an inner conductor, a main shaft disposed within an inner
lumen of the inner conductor, an actuator coupled to the inner
conductor for extending the anchoring elements 20 and an RF energy
source switchably coupled to the inner conductor.
[0111] While particular forms of the invention have been
illustrated and described, it should be apparent that various
modifications can be made without departing from the spirit and
scope of the invention. Accordingly, it is not intended that the
invention be limited, except as by the appended claims.
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