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Claims  |
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We claim:
1. A needle assembly for localization of lesions within the body,
comprising:
a needle cannula having a lumen, a cutting edge at a first end of said
cannula and at least one notch in said cannula forming a cutout
communicating with said lumen, said cutout being located proximate a
second end of said cannula a predetermined distance from said first end; a
marking device positioned within said lumen, said marking device including
a shaft and a helical wire including a first portion helically wound at
said first end about said shaft and extending a predetermined distance
from said shaft in a helical coil, said helical wire having a sharpened
tip, said marking wire being axially slidable and rotatable within said
cannula;
wherein said helical wire of said marking device includes a second portion
which engages into said at least one cutout formed by said notch, whereby
rotation of said marking device effects advancement of said marking device
through said lumen, the advancement of said marking device being
responsive to said helical wire rotatingly engaging into and contacting
said at least one cutout.
2. A needle assembly according to claim 1, wherein said wire is wound about
and secured to said shaft.
3. A needle assembly according to claim 1, wherein said cannula and said
marking device are constructed of biocompatible material.
4. A needle assembly according to claim 3, wherein said cannula and said
marking device are constructed of stainless steel.
5. A needle assembly according to claim 3, wherein said cannula and said
marking device are constructed of a metal alloy.
6. A needle assembly according to claim 1, wherein said helical coil of
said wire has a constant diameter along its length.
7. A needle assembly for localization of lesions within the body,
comprising:
a needle cannula having a lumen, a cutting edge at a first end of said
cannula, and a gripping knob secured at a second end of said cannula, said
knob having a first hole formed therethrough in coaxial alignment with
said lumen, and a second hole formed therethrough offset from said first
hole and having a wire guide passing through and secured within said
second hole in a direction parallel to said cannula, said wire being bent
at a right angle perpendicular to said cannula to practically cover said
first hole;
a marking device positioned within said lumen and including a shaft having
a diameter less than the inner diameter of said lumen, said marking device
further including a first helical wire coiled about a first end of said
shaft and secured thereto, said first wire extending beyond said first end
of said shaft in a helical coil for a predetermined distance and
terminating in a sharpened tip, said marking device further including a
second helical wire coiled about said shaft and secured thereto a distance
from said first helical wire towards a second end of said shaft, said
first and second wires forming coils having an outer diameter
substantially equal to each other and less than or substantially equal to
the inner diameter of said lumen;
wherein said second helical wire of said shaft engages said wire guide of
said knob, whereby rotation of said marking device advances said shaft and
said first and second wires through said lumen, the advancement of said
shaft and said wires through said lumen being assisted by said second
helical wire rotatingly contact said wire guide.
8. A needle assembly according to claim 7, wherein said first and second
helical wires of said marking device are secured to said shaft by
soldering.
9. A needle assembly according to claim 7, wherein said first helical wire
extends past said shaft end a predetermined distance which is equal to the
length of said second helical wire.
10. A needle assembly according to claim 9, wherein an end of said second
helical wire remote from said first helical wire is positioned at a
distance such that when said second end is rotated past said wire guide
into said cannula, said first end of said shaft is positioned coaxial and
adjacent to said cutting edge of said cannula.
11. A needle assembly according to claim 9, wherein said predetermined
distance said first helical wire extends past said shaft end and the
length of said second helical wire is between 0.5 and 2.0 cm.
12. A needle assembly according to claim 11, wherein said predetermined
distance is 1 cm.
13. A needle assembly according to claim 7, wherein said second helical
wire is positioned a predetermined distance from said first helical wire,
such than when an end of said second helical wire closest to said first
helical wire engages said wire guide of said knob, said sharpened tip of
said first helical wire is positioned coaxial and adjacent to said cutting
edge of said cannula.
14. A needle assembly according to claim 7, wherein said first and second
helical wires have a constant diameter along their entire lengths.
15. A needle assembly according to claim 8, wherein said first and second
helical wires have a diameter of approximately 0.02 cm and said shaft has
a diameter of approximately 0.04 cm.
16. A needle assembly according to claim 7, wherein said cannula and wire
marker are constructed of stainless steel.
17. A needle assembly according to claim 7, wherein said first and second
helical wires are wound about said shaft an identical number of turns per
centimeter.
18. A needle assembly according to claim 17, wherein said first and second
helical wires are wound about said shaft between 6 and 15 turns per
centimeter.
19. A needle assembly according to claim 18, wherein said first and second
helical wires are wound about said shaft 8 turns per centimeter.
20. A method for marking no-=palpable lesions within the body, comprising
steps of:
puncturing the skin to enter the body with a marking needle assembly, said
needle assembly including a cannula having a lumen, a cutting edge atone
end of said cannula and a gripping mean on said cannula, said needle
assembly further including a marking device positioned within said lumen,
said marking device having a helical wire helically wound at one end a
predetermined distance in a helical coil, and having a sharpened tip; said
marking device being coaxially slideable and rotatable within said
cannula;
tracking said needle assembly inside said body;
advancing said needle assembly to a point within proximity to a lesion
within said body;
rotating said marking device within said cannula to advance said marking
device;
determining the distance said marking device travels by the distance said
marking device is advanced into said cannula;
ceasing rotation of said marking device when said marking device is
positioned within a determined proximal distance of said lesion; and
removing said cannula from said body;
wherein said marking device remains in position with respect to said lesion
to mark said lesion for subsequent medical procedures.
21. A method for marking non-palpable lesions within the body, in
particular the human breast, comprising the steps of:
puncturing the skin to enter the body with a marking needle assembly, said
needle assembly including a needle cannula having a lumen, a cutting edge
at one end and a gripping knob at another end, said gripping knob having a
first hole formed therethrough aligned with said lumen and a second hole
formed therethrough offset and parallel to said first hole for receiving a
wire guide, said wire guide bent at an angle perpendicular to said second
hole and covering a part of said first hole, said needle assembly further
including a marking device positioned within said lumen, said marking
device having a shaft and a least two helically wound wires concentrically
coiled about and secured to said shaft and spaced from each other a
predetermined distance, a first helical wire secured at an end of said
shaft and concentrically extending outwardly a predetermined length from
said shaft and terminating in a sharpened end, and a second helical wire
coiled about said shaft having an equal number of turns per centimeter as
said first helical wire, a first end of said second helical wire engaging
said wire guide while said sharpened end of said first helical wire is
adjacent to said cutting edge of said cannula;
tracking said needle assembly inside said body;
advancing said needle assembly to a point adjacent to a lesion within said
body;
rotating said marking device within the lumen of said cannula to advance
said marking device such that said wire guide draws said marking device
through said lumen by engaging said second helical wire;
determining the distance said first helical wire travels by the distance
said second helical wire has travelled past said wire guide;
ceasing rotation when said first helical wire marks said lesion; and
removing said cannula from said body;
wherein said first helical wire remains in position with respect to said
lesion to mark said lesion for subsequent medical procedures.
22. A method according to claim 21, wherein rotation continues until said
first helical wire is embedded in said lesion and said second helical wire
passes fully into said knob beyond said wire guide. |
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Claims |
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Description |
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to lesion localization needles and devices,
for use in localizing or marking non-palpable lesions and tumors within
the body, and more particularly, the present invention relates to a needle
assembly which includes a wire marker having a helically wound wire tip
for rotatingly anchoring a marker to a lesion within a human breast.
Localization or marking of lesions within the body, such as non-palpable
lesions discovered within the body, and devices such as needles and wires
for marking these lesions, are well known in the art. The devices
generally comprise a hypodermic needle or cannula which is inserted into
the body under local anesthesia to a position adjacent and in contact with
the lesion. The wire marker is then passed through the cannula and is
anchored into the lesion so that the lesion is marked for subsequent
surgical procedures such as excision or biopsy. After marking the lesion
with the wire marker, the. cannula is usually removed from the body,
leaving the wire in place and extending from the body. However, these
markers tend to dislodge and migrate during transport of the patient for
the surgical biopsy procedure.
Increasingly, ultrasonic imaging is being used as a preferred ancillary or
adjunctive imaging method to evaluate breast masses which may be
associated with positive or negative mammographic findings. Currently
available localization and marking devices image poorly, if at all,
ultrasonically, making it difficult to accurately pinpoint the tip of the
localization wire with respect to the lesion. Consequently, a subsequent
surgical biopsy procedure may result in an inaccurate incision causing
unnecessary tissue damage, and may necessitate a second surgical procedure
to properly biopsy the lesion, causing the patient unnecessary pain,
suffering, and expense.
2. Discussion of the Prior Art
In the prior art, several types of lesion localization devices and lesion
markers are disclosed. Currently, the method of detecting and performing a
biopsy on a non-palpable occult lesion within the body, such as
non-palpable breast lesions, has been to radiologically or ultrasonically
locate the lesion and to mark the lesion using a localization needle
assembly, prior to a biopsy procedure. These needle assemblies generally
comprise a hypodermic needle or cannula which is inserted into the body to
an area adjacent to and in contact with the lesion. A marking wire is then
inserted through the cannula into the lesion and anchored in place so that
the cannula may be removed.
Ultrasonic imaging is increasingly being used as the preferred method of
detection and evaluation of lesions and masses within the body due to its
accuracy, and in view of the fact that the patient is not exposed to
potentially harmful radiation for extended periods of time. The prior art
marking devices generally image very poorly ultrasonically, as the tip of
the previous marker shows up as a small, hard to locate dot or spot on the
viewing screen. Depth perception is very limited, and consequently,
accurate, reliable placement of the previous marking device is not
guaranteed.
Nicholson, et al., U.S. Pat. No. 4,616,656, discloses a probe wire and
sheath assembly in which the wire has a J-type memory hook for marking
lesions. The wire probe has a soft flexibility so that when it is enclosed
within the sheath it has a straight configuration. The sheath, or needle,
is inserted into the body, for instance into the breast of a female
patient, and positioned proximate to a lesion. The wire probe is then
pushed further into the lesion so that the memory hook is reformed and
anchors itself within the lesion. The sheath is then removed leaving the
hook embedded in the lesion as a marker.
A similar device is disclosed in Hawkins, Jr., U.S. Pat. No. 4,230,123.
Hawkins, Jr. discloses a needle sheath assembly which consists of a small
gauge needle in which a stylus or wire is positioned within a cannula. A
shorter outer sheath is slidably located over the cannula which is
removable after insertion of the needle into the patient's body. The wire
has a J-type hook which is passed through the cannula to stabilize the tip
of the cannula during biopsy.
Nicholson, et al. and Hawkins, Jr. are subject to several disadvantages
which effect the accuracy and performance of the device. Devices such as
those disclosed in these references image very poorly and are
inconsistently visualized ultrasonically, and consequently may not be
accurately placed. Furthermore, in procedures involving lesions of the
breast, the breast is compressed during the mammographic localization
procedure so that after the needle is in place and compression
discontinued, the needle marker may inadvertently dislodge or migrate to a
different position than that set during the localization procedure. The
needle may also deflect away from the lesion, or if the strength and
resiliency of the wire is less than that required to penetrate the lesion,
the hook may not reform, allowing the marker to migrate or dislodge. This
can result in damaging the tissues of the breast, as well as an inaccurate
surgical incision during the biopsy procedure, usually requiring a second
surgical procedure to properly biopsy the lesion, causing the patient
unnecessary pain, suffering and expense. Devices of this type also
generally require that the breast be stabilized during transport of the
patient from the radiology section of a hospital to the surgical section
for the biopsy procedure in order to prevent dislodgement of the marker.
Simon, U.S. Pat. No. 4,790,329, discloses a biopsy localization device
having a sheath or cannula through which a barbed rod passes. The cannula
is provided with an open side port through which the barb extends upon
positioning within a lesion. In use, the barb is compressed within the
lumen of the cannula and the pointed end of the rod extends from the
cannula. As the device penetrates the patient's body, and into a lesion,
the rod is rotated 180.degree. so that the end of the barb may pass
through the open side port of the cannula. The rod is then drawn back so
that barb and cannula anchor into the lesion to prevent removal. While the
device is relocatable, such as by drawing back the cannula to enclose the
barbed rod after anchoring, it is apparent that some tissue damage will
result due to the barb puncturing the tissue once it is anchored. In
addition, the cannula remains in place while the lesion is marked by the
barb, which results in excessive weight applied to the tissue. The entire
device must be stabilized in order to prevent tearing of tissue and
dislodgement of the marker. As related to breast lesions, as discussed
above, compression of the breast during the procedure provides accurate
anchoring of the barb; however, during transport of the patient, the
additional weight of the cannula as well as the barbed rod will require
stabilization of the breast to prevent migration and dislodgement of the
device. A similar device, facing the same disadvantages, is disclosed in
Hawkins, et al., U.S. Pat. No. 4,799,495.
An additional type of prior art lesion localization and biopsy device is
commonly referred to as the "Nordenstrom Screw Diagnostic Instrument",
which was developed by Bjorn Nordenstrom (Radiology, November 1975, Volume
117, Page 474). The Nordenstrom screw is generally a biopsy device and not
a lesion localization and marking device. A cannula is provided which is
inserted into the body, having a screw-tipped rod within the lumen of the
cannula. When the cannula is positioned proximate a lesion, the rod is
rotated to screw the tip into the lesion. The screw tip is integral with
the rod itself, and is a finely machined device in which the screw threads
define grooves which taper to the tip of the device. After the screw tip
is rotated into the lesion, the cannula is then rotated in an opposite
direction using slight forward pressure to a position over the screw
threads. Tissue from the lesion is captured in the grooves of the screw
tip and the entire device is withdrawn so that the tissue may be examined.
The Nordenstrom screw device, as stated above, is not a marking device,
but instead allows the physician to immediately biopsy the lesion in
question.
An additional marking device using a screw tip is disclosed in Hawkins, et
al., U.S. Pat. No. 4,799,495. In this device, the cannula may be provided
with a tapering screw tip to anchor the cannula in the tissue while the
needle marker penetrates the lesion. The cannula and wire are used to mark
the lesion, and Hawkins et al. also discloses the use of the cannula alone
for marking the lesion. Furthermore, Hawkins et al. discusses a helical
screw needle marker, similar to the Nordenstrom screw device, which may be
inserted through the cannula to mark the lesion. However, the tapering
screw tip of Hawkins et al. is a finely machined device which is quite
expensive to manufacture, and which also is subject to the disadvantage
that the tapered end may result in the loosening or "backing off" of the
screw tip which will dislodge the marker during transport of the patient,
or upon discontinuation of compression of the breast during the marking
procedure. Furthermore, the precise machining of the tip of this device,
and in particular a hollow screw-tipped cannula, would be a difficult and
very expensive procedure from a manufacturing standpoint, and would
necessitate that the device be reusable due to these cost considerations.
In view of this, and in light of current health risks and concerns for
patient safety as related to blood products and invasive surgical
procedures, sterilization procedures would be required prior to and after
each use, thereby making the procedure more elaborate and expensive then
normally necessary.
The novel, disposable lesion localization and marking device of the present
invention obviates the problems associated with the prior art lesion
localization devices by providing an inexpensive, simple to manufacture
lesion marking device having a helically wound marking wire attached to a
wire shaft which passes through a hypodermic needle comprising a cannula.
The helically wound marking wire extends concentrically outward from the
shaft and maintains a substantially uniform diameter so that once the wire
is rotated or screwed into a lesion, it remains anchored in the tissue
without the possibility of backing off and dislodging.
In a preferred embodiment, a second helically wound wire is provided on the
shaft remote from the first helically wound wire at the tip which, in
conjunction with a wire guide provided on a gripping knob of the cannula,
assists in the forward advancement of the shaft so that excessive forward
pressure is not required, and the second helix also acts as a depth guide
to provide an accurate indication of the depth to which the first helix is
embedded in a lesion. The helically wound wires are secured to the shaft
by means such as soldering, or may be wound as part of the shaft itself,
so that the entire device is simple to manufacture and relatively
inexpensive, thereby making the device disposable following the biopsy
procedure.
SUMMARY OF THE INVENTION
The present invention eliminates or substantially ameliorates the
disadvantages encountered in the prior art through the provision of a
lesion localization and marking device having a helically wound wire tip
attached to a shaft which is inserted within the lumen of a cannula into
the body and then rotated into a lesion to anchor the marker within the
lesion tissue. The device is simple to manufacture and inexpensive thereby
making it a disposable unit, which may be packaged in a sterile packaging
unit for one time use.
The lesion localization and marking device of the present invention
consists of a marker having a shaft constructed of stainless steel or
other biocompatable material which has secured to its distal end, or
formed integrally thereon, a stainless steel wire which is helically wound
about the end of the shaft. The helically wound wire extends outwardly in
a concentric manner from the end of the shaft and overhangs the shaft a
predetermined distance. The end of the helix is sharpened to facilitate
insertion into a lesion within the body. The helical wire is secured to
the shaft by conventional means such as soldering.
The marking device, when used in conjuction with the needle assembly of the
present invention, may be provided with a second helically wound wire
which is secured to the shaft of the marker remote from the end having the
first helically wound wire. The second helically wound wire is secured to
the shaft by soldering, or integrally formed as part of the shaft, and is
dimensioned to have the same number of turns per centimeter as the first
helically wound wire, thus having the same pitch or angle for each turn of
coil. The marking device is positioned within a hypodermic needle or
cannula which essentially comprises a stainless steel tube having a
cutting edge at one end and a thermoplastic gripping knob at its other
end. The gripping knob has a hole bored through the center which
preferably aligns with the lumen of the cannula, and a second hole is
bored through the knob parallel to the first hole and offset from the
center of the lumen. Through the second hole is positioned a wire guide
which is bent perpendicular to the hole and placed to partially cover the
first hole, leaving an opening which is substantially equal to the
diameter of the shaft of the wire marker plus the diameter of the wire
which forms the helix.
In use, the needle assembly is inserted into the body, such as into the
breast of a female patient, until the tip of the cannula is proximate to a
lesion which has been discovered during a mammographic or ultrasonic
imaging procedure. The marking device is positioned within the cannula so
that the sharpened tip of the first helical wire is adjacent to the
cutting edge of the cannula, and the second helical wire is positioned a
predetermined distance such that the end of the second helical wire
closest to the first helical wire is adjacent to and engages the wire
guide of the thermoplastic knob of the cannula. As the marking device is
rotated, the second helical wire is guided along the wire guide so as to
stabilize the shaft while drawing the marker into the cannula due to the
interaction of the second helix and the wire guide during rotation, and
the first helical wire is rotated into the lesion. The wire guide assists
the forward advancement of the marker during rotation.
The length of the second helical wire is identical to the length of the
first helical wire from the end of the shaft to the sharpened tip, and
both helical wires have an identical number of turns per centimeter. As
the first helical wire is embedded into the lesion, the physician can
accurately gauge the depth to which the first wire enters the lesion by
the distance the second helical wire extends outwardly from the gripping
knob of the cannula. When the second helical wire is fully rotated within
the cannula the physician will know that the first wire is fully extended
outside the cannula and is in position with respect to the lesion. The
cannula is then removed from the body leaving the marking device in place.
As ultrasonic imaging is increasingly being used as the preferred method of
evaluation of breast lesions in localization procedures, it is very
important the marker used in the localization procedure provide consistent
visualization and clean imaging with a recognizable acoustic pattern.
Prior art markers do not provide adequate ultrasonic imaging and
consequently do not contribute to accurate localization of a lesion. The
present invention, however, due to the helical tip, provides excellent
imaging characteristics compared to prior art markers, such that each turn
of the helix images distinctly, as opposed to the single spot or dot
appearing from the prior art markers. As a result, the present marker
provides an unambiguous ultrasonic image allowing for accurate marking of
the discovered lesion under the same conditions as mammography, thus
reducing the patient's exposure to X-rays as well as decreasing the number
of repositions required to accurately mark the lesion.
Accordingly, it is a primary object of the present invention to provide an
inexpensive, simple to manufacture, and disposable marking device for
localizing lesions within the body, particularly breast lesions.
It is a further object of the present invention to provide a lesion
localization device which substantially eliminates the possibility of
dislodgement or migration of the needle marker after placement.
It is yet another object of the present invention to provide a lesion
localization device which may be relocated or repositioned within the body
which minimizes or substantially eliminates damage to tissue during
repositioning.
A still further object of the present invention is to provide a lesion
localization device which presents an unambiguous echo when exposed to
ultrasonic sound waves, allowing placement of the device to be carried | | |
