U.S. patent application number 10/945656 was filed with the patent office on 2006-03-23 for method for treatment of an intervertebral disc.
Invention is credited to Ronald J. Podhajsky.
Application Number | 20060064145 10/945656 |
Document ID | / |
Family ID | 36075080 |
Filed Date | 2006-03-23 |
United States Patent
Application |
20060064145 |
Kind Code |
A1 |
Podhajsky; Ronald J. |
March 23, 2006 |
Method for treatment of an intervertebral disc
Abstract
The present disclosure is directed to methods for relieving pain
associated with an intervertebral disc having a disc nucleus
pulposus and an outer annulus fibrosus surrounding the nucleus
pulposus. The method includes the steps of providing an elongated
thermal or electromagnetic probe member having a flexible guidable
region adjacent the distal end thereof; introducing the flexible
guidable region of the probe into the annulus fibrosus of the
intervertebral disc; and supplying thermal or electromagnetic
energy, from an energy source, to heat or induce an electromagnetic
field adjacent to the annulus fibrosus sufficient to produce a
thermal or electromagnetic effect on the intervertebral disc. The
flexible guidable region of the probe may be introduced at a
location which is in relative close proximity to the region of
intervertebral disc to be thermally or electromagnetically
treated.
Inventors: |
Podhajsky; Ronald J.;
(Boulder, CO) |
Correspondence
Address: |
UNITED STATES SURGICAL,;A DIVISION OF TYCO HEALTHCARE GROUP LP
150 GLOVER AVENUE
NORWALK
CT
06856
US
|
Family ID: |
36075080 |
Appl. No.: |
10/945656 |
Filed: |
September 21, 2004 |
Current U.S.
Class: |
607/96 ;
607/100 |
Current CPC
Class: |
A61B 2018/0044 20130101;
A61F 2002/4627 20130101; A61B 18/1492 20130101; A61F 2002/4435
20130101; A61F 2/4611 20130101 |
Class at
Publication: |
607/096 ;
607/100 |
International
Class: |
A61F 7/00 20060101
A61F007/00; A61F 7/12 20060101 A61F007/12; A61F 2/00 20060101
A61F002/00 |
Claims
1. A method for relieving pain associated with an intervertebral
disc having a disc nucleus pulposus and an outer annulus fibrosus
surrounding the nucleus pulposus, the method comprising the steps
of: providing an elongated thermal or electromagnetic probe member
having proximal and distal ends and defining a longitudinal axis,
and having a flexible guidable region adjacent the distal end;
introducing the flexible guidable region of the probe into the
annulus fibrosus of the intervertebral disc, at a location which is
in relative close proximity to the region of intervertebral disc to
be thermally or electromagnetically treated, whereby the flexible
guidable region of the probe bends to follow a generally arcuate
path through the annulus fibrosus without entering the nucleus
pulposus; and supplying thermal or electromagnetic energy, from an
energy source, to heat or induce an electromagnetic field adjacent
to the annulus fibrosus sufficient to produce a thermal or
electromagnetic effect on the intervertebral disc.
2. The method according to claim 1, wherein the step of introducing
includes positioning the flexible guidable region of the probe
adjacent the region of the intervertebral disc to be treated.
3. The method according to claim 2, further including the step of:
positioning a cannula adjacent the region of the intervertebral
disc to be treated; and passing the flexible guidable region of the
probe through a lumen of the cannula.
4. The method according to claim 3, wherein the cannula includes an
arcuate portion adjacent a distal end thereof and wherein, during
the step of introducing the flexible guidable region of the probe,
the arcuate cannula portion guides the flexible guidable region of
the probe adjacent to the region to be treated.
5. The method according to claim 4, further comprising the step of:
angulating the arcuate portion of the cannula to a desired
orientation within the intervertebral disc.
6. The method according to claim 5, further comprising the step of:
monitoring impedance of tissue to detect variations in tissue-type
to thereby facilitate positioning of the flexible guidable region
of the probe.
7. The method according to claim 6, further comprising the steps
of: increasing an amplitude of thermal or electromagnetic energy
supplied to the probe until indications of effect on the
intervertebral disc are obtained; and noting the amplitude at which
the indications of effect of the intervertebral disc are
obtained.
8. The method according to claim 7, wherein when the indications of
effect of the intervertebral disc are obtained for amplitudes below
about 0.75 volts, the method includes the step of applying thermal
energy at about 60.degree. C.
9. The method according to claim 7, wherein when the indications of
effect of the intervertebral disc are obtained for amplitudes
between about 0.75 volts and 1.25 volts, the method includes the
step of applying thermal energy at about 65.degree. C.
10. The method according to claim 7, wherein when the indications
of effect of the intervertebral disc are obtained for amplitudes
above about 1.25 volts, the method includes the step of applying
thermal energy at about 70.degree. C.
11. A method for relieving pain associated with an intervertebral
disc having a disc nucleus pulposus and an outer annulus fibrosus
surrounding the nucleus pulposus, the method comprising the steps
of: introducing a thermal or electromagnetic transmitting element
of a thermal probe into the intervertebral disc, at a location in
close proximity to the region of the intervertebral disc to be
treated; and supplying thermal or electromagnetic energy from an
energy source to the thermal or electromagnetic transmitting
element to produce a thermal or electromagnetic effect on the
intervertebral disc.
12. The method according to claim 11, wherein the probe includes a
flexible guidable region, and wherein the method further includes
the step of advancing the probe whereby the flexible guidable
region of the probe follows a generally arcuate path.
13. The method according to claim 12, wherein the step of advancing
the probe includes passing the flexible guidable region along an
arcuate path defined by natural striata of the annulus
fibrosus.
14. The method according to claim 13, wherein the step of advancing
the probe includes extending the flexible guidable region across
the region of the intervertebral disc to be treated.
15. The method according to claim 14, further including the step
of: positioning a cannula adjacent the region of the intervertebral
disc to be treated; and passing the flexible guidable region of the
probe through a lumen of the cannula.
16. The method according to claim 15, wherein the cannula includes
an arcuate portion adjacent a distal end thereof and wherein,
during the step of introducing the flexible guidable region of the
probe, the arcuate cannula portion guides the flexible guidable
region of the probe adjacent to the region to be treated.
17. The method according to claim 16, further comprising the step
of: angulating the arcuate portion of the cannula to a desired
orientation within the intervertebral disc.
18. The method according to claim 17, further comprising the step
of: monitoring impedance of tissue to detect variations in
tissue-type to thereby facilitate positioning of the flexible
guidable region of the probe.
19. The method according to claim 11, further comprising the steps
of: increasing an amplitude of thermal or electromagnetic energy
supplied to the probe until indications of effect on the
intervertebral disc are obtained; and noting the amplitude at which
the indications of effect of the intervertebral disc are
obtained.
20. The method according to claim 19, wherein when the indications
of effect of the intervertebral disc are obtained for amplitudes
below about 0.75 volts, the method includes the step of applying
thermal energy at about 60.degree. C.
21. The method according to claim 19, wherein when the indications
of effect of the intervertebral disc are obtained for amplitudes
between about 0.75 volts and 1.25 volts, the method includes the
step of applying thermal energy at about 65.degree. C.
22. The method according to claim 19, wherein when the indications
of effect of the intervertebral disc are obtained for amplitudes
above about 1.25 volts, the method includes the step of applying
thermal energy at about 70.degree. C.
23. The method according to claim 11, further including the step of
introducing the thermal or electromagnetic transmitting element of
the thermal probe the intervertebral disc from at least one of a
medial direction and a lateral direction.
24. The method according to claim 23, further including the step of
introducing the thermal or electromagnetic transmitting element of
the thermal probe into a nucleus of the intervertebral disc.
Description
BACKGROUND
[0001] 1. Technical Field
[0002] The present disclosure relates to methods for treating
intervertebral disc problems using percutaneous techniques without
the need for major surgical intervention, and more particularly, to
methods for the insertion of a cannula into the intervertebral disc
and the insertion of a thermal probe into the disc material to heat
the intervertebral disc thereby relieving and treating
abnormalities or pain related to the disc.
[0003] 2. Background of Related Art
[0004] The use of thermal therapy in and around the spinal column
is known. Also, the insertion of cannula into the intervertebral
discs is commonly done for injection of contrast mediums to
implement X-ray discograms. This technique is used to detect or
diagnose abnormalities or damage to the intervertebral disc. The
use of heating of an intervertebral disc to relieve pain is
described in U.S. Pat. No. 4,433,739, issued Jul. 18, 1995, and in
U.S. Pat. No. 5,571,147, issued Nov. 5, 1996, the entire contents
of each of which being incorporated herein by reference. In these
patents, electrodes are described for either radiofrequency or
resistive thermal heating of all or a portion of the intervertebral
disc. Straight, curved, and flexible-tipped electrodes are
described for this purpose. The thermal treatment of an
intervertebral disc for the relief of back pain is also described
within the patents cited above.
[0005] The use of a resistively heated probe adapted to be inserted
into the intervertebral disc is described in U.S. Pat. No.
6,073,051, issued June 6, 2000, the entire content of which is
incorporated herein by reference. As seen in FIG. 1, U.S. Pat. No.
6,073,051, an apparatus or probe for treating intervertebral discs,
the apparatus including a flexible catheter 14 which is introduced
into the nucleus pulposus "N" and manipulated about (i.e., a
functional element 16 of catheter 14 is introduced from a lateral
side of nucleus pulposus "N", opposite the area to be treated, and
extended around to the opposite lateral side of nucleus pulposus
"N", adjacent to the area to be treated) an inner wall of the
annulus fibrosus along annulus fibrosus/nucleus pulposus interface
28. Accordingly, functional element or intradiscal section 16 of
catheter 14 delivers a therapeutic effect to the area of nucleus
pulposus "N" to be treated, i.e., fissures "F".
[0006] It is desirable to treat the posterior or posterior/lateral
portion of the intervertebral disc for the indication of mechanical
degeneration of the disc and discogenic back pain. Pain can be
derived from degeneration or compression of the intervertebral disc
in its posterior or posterior/lateral portions. There is some
innervation of the intervertebral disc near the surface of the disc
and also within its outer portion known as the annulus fibrosus.
Fissures or cracks within the disc caused by age, mechanical
trauma, or disc degeneration are believed to be associated with
painful symptoms.
[0007] Thus, a configuration of insertion cannula, to approach and
enter the intervertebral disc, and a thermal probe to be built into
or associated with said cannula, to adequately reach the
posterior/lateral and posterior portions of the intervertebral
disc, is desirable. Additionally, a novel method of introducing and
advancing a thermal probe, toward the tissue to be treated, is also
desirable.
SUMMARY
[0008] The present disclosure is directed generally to methods for
the treatment of intervertebral discs. In particular, according to
one aspect of the present disclosure, a method for relieving pain
associated with an intervertebral disc having a disc nucleus
pulposus and an outer annulus fibrosus surrounding the nucleus
pulposus, is provided.
[0009] The method includes the steps of providing an elongated
thermal or electromagnetic probe member. The probe member has
proximal and distal ends and defines a longitudinal axis. The probe
member further includes a flexible guidable region adjacent the
distal end thereof.
[0010] The method further includes the step of introducing the
flexible guidable region of the probe into the annulus fibrosus of
the intervertebral disc. Preferably, the flexible guidable region
of the probe is introduced at a location which is in relative close
proximity to the region of intervertebral disc to be thermally or
electromagnetically treated. The flexible guidable region of the
probe is capable of bending to follow a generally arcuate path
through the annulus fibrosus without entering the nucleus pulposus.
Desirably, the step of introducing includes positioning the
flexible guidable region of the probe adjacent the region of the
intervertebral disc to be treated.
[0011] The method further includes the step of supplying thermal or
electromagnetic energy, from an energy source, to heat or induce an
electromagnetic field adjacent to the annulus fibrosus sufficient
to produce a thermal or electromagnetic effect on the
intervertebral disc.
[0012] The method may further include the step of positioning a
cannula adjacent the region of the intervertebral disc to be
treated; and passing the flexible guidable region of the probe
through a lumen of the cannula.
[0013] It is envisioned that the cannula may include an arcuate
portion adjacent a distal end thereof. Accordingly, during the step
of introducing the flexible guidable region of the probe, the
arcuate cannula portion may guide the flexible guidable region of
the probe adjacent to the region to be treated.
[0014] The method may further include the step of angulating the
arcuate portion of the cannula to a desired orientation within the
intervertebral disc.
[0015] The method may still further include the step of monitoring
impedance of tissue to detect variations in tissue-type to thereby
facilitate positioning of the flexible guidable region of the
probe.
[0016] The method further includes the steps of increasing an
amplitude of thermal or electromagnetic energy supplied to the
probe until indications of effect on the intervertebral disc are
obtained; and noting the amplitude at which the indications of
effect of the intervertebral disc are obtained.
[0017] Desirably, when the indications of effect of the
intervertebral disc are obtained for amplitudes below about 0.75
volts, thermal energy at about 60.degree. C. is applied. When the
indications of effect of the intervertebral disc are obtained for
amplitudes between about 0.75 volts and 1.25 volts, thermal energy
at about 65.degree. C. is applied. When the indications of effect
of the intervertebral disc are obtained for amplitudes above about
1.25 volts, thermal energy at about 70.degree. C. is applied.
[0018] According to another aspect of the present disclosure, the
method includes the steps of introducing a thermal or
electromagnetic transmitting element of a thermal probe into the
intervertebral disc, at a location in close proximity to the region
of the intervertebral disc to be treated; and supplying thermal or
electromagnetic energy from an energy source to the thermal or
electromagnetic transmitting element to produce a thermal or
electromagnetic effect on the intervertebral disc.
[0019] Desirably, the probe includes a flexible guidable region.
Accordingly, the method further includes the step of advancing the
probe whereby the flexible guidable region of the probe follows a
generally arcuate path. The step of advancing the probe may include
passing the flexible guidable region along an arcuate path defined
by natural striata of the annulus fibrosus. The step of advancing
the probe may include extending the flexible guidable region across
the region of the intervertebral disc to be treated.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The features of the apparatus and method of the present
disclosure will become more readily apparent and may be better
understood by referring to the following detailed description of
illustrative embodiments of the present disclosure, taken in
conjunction with the accompanying drawings, wherein:
[0021] FIG. 1 is a cross-sectional view of an intervertebral disc
with a portion of an intervertebral apparatus inserted therein
according to a prior art method;
[0022] FIG. 2 is a cross-sectional plan view of a cervical disc and
vertebra;
[0023] FIG. 3 is a side view of a portion of the spine;
[0024] FIG. 4 is an enlarged side view of the area indicated as "4"
of the spine of FIG. 3;
[0025] FIG. 5 is a schematic illustration of an intervertebral
apparatus, in a disassembled condition, depicting an insertion
cannula, a thermal or EMF probe and associated auxiliary electronic
components;
[0026] FIG. 6 is a cross-sectional plan view of an intervertebral
disc with a portion of an intervertebral apparatus inserted therein
according to a method of the present disclosure;
[0027] FIG. 7 is a cross-sectional plan view of an intervertebral
disc with a portion of an intervertebral apparatus inserted therein
according to another method or another step of the present
disclosure;
[0028] FIG. 8 is a cross-sectional plan view of an intervertebral
disc with a portion of an intervertebral apparatus inserted therein
according to yet another method or another step of the present
disclosure; and
[0029] FIG. 9 is a cross-sectional plan view of an intervertebral
disc with a portion of an intervertebral apparatus inserted therein
according to still another method or another step of the present
disclosure.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0030] The present disclosure provides for an alternate and/or
improved method of positioning an apparatus (e.g., a thermal probe)
in an intervertebral disc targeted for treatment of intervertebral
disc disorders. Such disorders include but are not limited to
degenerative discs with (i) localized tears or fissures in the
annulus fibrosus, (ii) localized disc herniations with contained
extrusions, and (iii) chronic, circumferential bulges.
[0031] It will be readily apparent to a person skilled in the art
that the apparatus and method of use of the apparatus may be used
to treat/destroy body tissue in any body cavity or tissue locations
that are accessible by percutaneous or endoscopic catheters or open
surgical techniques, and is not limited to the disc area.
Application of the apparatus and method in all of these organs and
tissues are intended to be included within the scope of the present
disclosure.
[0032] In the drawings and in the following description, the term
"proximal", as is traditional, will refer to the end of the
apparatus, or component thereof, which is closest to the operator,
and the term "distal" will refer to the end of the apparatus, or
component thereof, which is more remote or further from the
operator.
[0033] Prior to a detailed discussion of the apparatus and method
according to the present disclosure, a brief overview of the
anatomy of the intervertebral disc is presented. Accordingly, as
seen in FIG. 14, intervertebral disc "D" includes an annulus
fibrosus "A" and a nucleus pulposus "N" disposed within annulus
fibrosus "A". Annulus fibrosus "A" includes a tough fibrous
material which is arranged to define a plurality of annular
cartilaginous rings "R" forming the natural striata of annulus
fibrosus "A". Nucleus pulposus "N" is made up primarily of an
amorphous gel having a softer consistency than annulus fibrosus
"A". Nucleus pulposus "N" usually contains 70%-90% water by weight
and mechanically functions similar to an incompressible hydrostatic
material. The juncture or transition area of annulus fibrosus "A"
and nucleus pulposus "N" generally defines, for discussion
purposes, an inner wall "W" of annulus fibrosus "A". Disc cortex
"C" surrounds annulus fibrosus "A". Posterior, anterior, and
lateral aspects of intervertebral disc "D" are identified as "P",
"AN" and "L", respectively, with the opposed posterior-lateral
aspects identified as "PL". In FIG. 2, a portion of intervertebral
disc "D" has been cut away so that half of the vertebral body may
be seen.
[0034] When mechanical stress is put upon a disc or when a disc
degenerates with age, fissures, illustrated by cracks "F" in FIG.
6, may occur in the posterior or posterior/lateral portions of disc
"D". Problems with nerves, fissures "F" and degenerative discs may
give rise to various patient problems, such as back or leg pain
originating from the irritation or occurrence of these
abnormalities. Moreover, these conditions may ultimately result in
conditions such as bulging or herniated discs. By heating and/or
using electromagnetic field (EMF) therapy on intervertebral disc
"D", preferably, annulus fibrosus "A" in posterior "P" or
posterior-lateral "PL" portions, will result in denervation of
nerves and/or alterations and thermal ablation of disc structures,
which will in turn produce alleviation of pain and healing of the
disc. Thus, it is desirable to have a practical and efficient
method of placing a thermal or electromagnetic probe in posterior
"P" and/or posterior-lateral "PL" portion of disc "D" where these
neural and aberrant structures occur for the relief of pain and
other disc related problems.
[0035] With reference to FIG. 5, an apparatus according to the
present disclosure is shown and is generally designated as 100.
Apparatus 100 includes outer insertion or introducer cannula 102,
thermal or EMF probe 104 which is positionable within cannula 102,
and a power source 106 which is connected to thermal probe 104.
Introducer cannula 102 preferably includes a rigid tubular shaft
108 defining a longitudinal axis "X" and having a rigid curved or
arcuate portion 110 adjacent it distal end, angularly offset with
respect to the longitudinal "X" axis at an angle ranging from about
15 to about 45.degree., preferably, about 23.degree.. Shaft 108 is
preferably composed of a conductive material such as stainless
steel or other suitable composition and is insulated with
insulation along most of its length as indicated by the hatching of
FIG. 5. Alternatively, shaft 108 may be fabricated from a suitable
polymeric material and formed by conventional injection molding
techniques. The distal end portion 112 of shaft 108 may be left
uninsulated or exposed to permit electrical connection (e.g., for
impedance measuring, etc.) to or contact with the tissue as cannula
102 is placed in the tissue. Alternatively, exposed portion 112 may
be connected to power source 106 to heat stimulate or micro-thermal
generate the tissue to facilitate passage through the tissue.
[0036] An extreme distal tip 114 of shaft 108 is preferably
sharpened to facilitate penetration into the disc tissue, i.e.,
through the bone of the cortex "C" and into annulus fibrosus "A". A
handle or housing 116 is connected to the proximal end of cannula
shaft 108 to facilitate manipulation of cannula 102. Handle 116 may
include an index marker 118 to indicate the direction of arcuate
portion 110 of cannula 102 such that when thermal or EMF probe 104
is introduced within cannula 102, the surgeon may determine in
which azimuthal rotational direction the curve is oriented.
[0037] Cannula shaft 108 may have a diameter ranging from a
fraction of a millimeter to several millimeters and a length of a
few centimeters up to about 20 centimeters or more. Alternatively,
cannula shaft 108 may be fabricated from an MRI compatible
material, including cobalt alloys, titanium, copper, nitinol, etc.
Arcuate portion 110 of cannula 102 may assume a variety of angular
orientations depending on the surgical procedure to be performed.
In an embodiment for thermal or EMF therapy of the intervertebral
disc, arcuate portion 110 is arranged such that thermal or EMF
probe 104 is generally delivered from cannula 102 in a
substantially orthogonal relation to the longitudinal "X" axis.
[0038] Power source or generator 106 may be, for example, a
radiofrequency generator providing energy at frequencies between
several kilohertz to several hundred megahertz. Power source 106
may have a power output ranging from several watts to several
hundred watts, depending on clinical need. Power source 106 may
have control devices to increase or modulate power output as well
as readout and display devices to monitor energy parameters such as
voltage, current, power, frequency, temperature impedance 109,
etc., as appreciated by one skilled in the art. Other types of
power sources are also contemplated, e.g., including resistive
heating units, laser sources, or microwave generators.
[0039] Apparatus 100 may preferably include an imaging system (not
shown) for potentially monitoring, controlling or verifying the
positioning of cannula 102 and/or thermal probe 104. Imaging
systems contemplated include X-ray machines, fluoroscopic machines
or an ultrasonic, CT, MRI, PET, or other imaging devices. Several
of these devices have conjugate elements (not shown), on the
opposite side of the patient's body, to provide imaging data. For
example, if the imaging system is an X-ray machine, the conjugate
element may be a detection device, such as an X-ray film, digital
X-ray detector, fluoroscopic device, etc. Use of imaging machines
to monitor percutaneously placed electrodes into tissue is commonly
practiced in the surgical field.
[0040] With continued reference to FIG. 5, apparatus 100 may
further include a stylet 148 which is to be used in conjunction
with cannula 102. Stylet 148 is positionable within the lumen of
cannula 102 and preferably occludes the front opening of cannula
102 to prevent entry of tissue, fluids, etc., during introduction
of cannula 102 within intervertebral disc "D". Stylet 148 may
include a proximally positioned hub 150 which mates with handle 116
of cannula 102 to lock the components together during insertion.
Such locking mechanisms are appreciated by one skilled in the
art.
[0041] An impedance monitor 152 may be connected, as shown by
connection 154, to stylet 148 and therefore communicates
electrically with the exposed portion 112 of cannula 102 into which
stylet 148 is introduced to monitor impedance of the tissue
adjacent the distal end of cannula 102. Alternatively, connection
of the impedance monitor may be made directly to the shaft of
cannula 102 whereby impedance measurements are effectuated through
the exposed distal end of cannula 102. Once the combination of
stylet 148 and cannula 102 are inserted into the body, impedance
monitoring assists in determining the position of cannula tip 112
with respect to the patient's skin, cortex "C" of disc "D", annulus
fibrosus "A", and/or nucleus "N" of disc "D". These regions will
have different impedance levels which are readily quantifiable.
[0042] For example, for a fully insulated electrode or cannula with
an exposed area of a few square millimeters at the cannula end, the
impedance will change significantly from the position of the tip
near to or contacting cortex "C" of disc "D" to the region where
the tip is within annulus fibrosus "A" and further where the tip is
within nucleus "N" of disc "D". Differences of impedance may range
from a few hundred ohms outside disc "D", to 200 to 300 ohms in
annulus fibrosus "A", to approximately 100 to 200 ohms in nucleus
"N". This variation may be detected by the surgeon by visualizing
impedance on meters or by hearing an audio tone whose frequency is
proportional to impedance. Such a tone may be generated by monitor
109. In this way, an impedance means is provided for detecting
placement of the curved cannula within disc "D". Thus, for example,
in an application where the EMF probe 104 is to be inserted between
adjacent layers of annular tissue, undesired penetration of the EMF
probe 104 and tip portion 112 of cannula 102, through the inner
wall "W" of annulus fibrosus "A" and into nucleus pulposus "N", can
be detected via the impedance monitoring means.
[0043] Stylet 148 can be made from a rigid metal tubing with either
a permanent bend 156 at its distal end to correspond to the
curvature of arcuate portion 112 of cannula 102 or may be a
straight guide wire to adapt to the curvature of cannula 102 when
it is inserted within cannula 102. Hubs 116, 120, 150, and
connector 154 can take various forms including luer hubs,
plug-in-jack-type connections, integral cables, etc.
[0044] With reference now to FIGS. 5 and 6, use of apparatus 100,
in accordance with a preferred procedure, for thermal treatment of
an intervertebral disc, will now be discussed. With reference to
FIG. 6, the targeted intervertebral disc "D" is identified during a
pre-operative phase of the surgery. Access to the intervertebral
disc area is then ascertained, preferably, through percutaneous
techniques or, less desirably, open surgical techniques.
[0045] Cannula 102, with stylet 148 positioned and secured therein,
is introduced within intervertebral disc "D", preferably from a
posterior or posterior-lateral location, most preferably, a
location which is in relative close proximity to, preferably
adjacent to, the region of intervertebral disc "D" to be thermally
or electromagnetically treated (e.g., fissure(s) "F"), as seen in
FIG. 6. It is envisioned that cannula 102 may be utilized without
stylet 148.
[0046] Impedance monitoring is desirably utilized to determine the
position of cannula tip 114 with respect to the patient's skin,
cortex "C" of disc "D", annulus fibrosus "A" and/or nucleus "N" of
disc "D". As discussed above, these regions have different and
quantifiable impedance levels thereby providing an indication to
the user of the position of cannula tip 114 in the tissue.
Monitoring of the location of cannula 102 may also be confirmed
with an imaging system (not shown). In a preferred procedure,
cannula tip 114 of cannula 102 is positioned within annulus
fibrosus "A" of intervertebral disc "D" at a posterior lateral "PL"
location of disc "D" without penetrating through inner wall "W" and
into nucleus "N". As appreciated, a sharpened cannula tip 114
facilitates entry into annulus fibrosus "A".
[0047] Thereafter, cannula 102 is angulated to position arcuate end
portion 110 of cannula 102 at the desired orientation within
annulus fibrosus "A". Confirmation of the angular orientation of
arcuate end portion 110 of cannula 102 is made through location of
index marker 118 of cannula 102. In one preferred orientation,
arcuate end portion 110 is arranged to deliver thermal probe 104
within the posterior section of the intervertebral disc "D".
[0048] According to another method, as seen in FIG. 7, cannula 102
may be angulated to position arcuate end portion 110 of cannula 102
in another desired orientation within annulus fibrosus "A". In this
other desired orientation, arcuate end portion 110 is arranged to
deliver thermal probe 104 within the posterior-lateral "PL" section
of intervertebral disc "D". When so positioned, as will be
described in greater detail below, advancement of thermal probe 104
through cannula 102 results in placement of guidable region 128 in
the posterior-lateral "PL" section of intervertebral disc "D".
[0049] According to yet another method, as seen in FIG. 8, cannula
102 may be positioned so as to place arcuate end portion 110 of
cannula 102 in yet another desired location and orientation within
annulus fibrosus "A". In the other desired orientation and
location, arcuate end portion 110 is positioned in close proximity
to inner wall "W" of annulus fibrosus "A". When so positioned, as
will be described in greater detail below, advancement of thermal
probe 104 through cannula 102 results in placement of guidable
region 128 in the nucleus "N" of the intervertebral disc "D".
[0050] Stylet 148 is then removed from cannula 102. Thermal or EMF
probe 104 is positioned within the internal lumen of cannula 102
and advanced through cannula 102. Preferably, the pre-bent
orientation of guidable region 128 is arranged to coincide with the
arcuate end portion 110 of cannula 102. Confirmation of this
orientation may be made with the location of the indexing element
121 of handle 120 (see FIG. 5). Preferably, arcuate end portion 110
is angulated to directly access the posterior-lateral "PL" section
of annulus fibrosus "A" without entering nucleus "N". Thermal or
EMF probe 104 is thereafter advanced to position guidable region
128 thereof medially through the posterior "P" section of annulus
fibrosus "A", desirably adjacent and/or across fissure(s) "F", as
seen in FIG. 6. Guidable region 128 of probe 104 is extended by
approximately 1.5 cm or less from the distal end of cannula
102.
[0051] Alternatively or additionally, as seen in the method of FIG.
7, advancement of thermal or EMP probe 104 results in placement of
guidable region 128 thereof laterally along the posterior-lateral
"PL" section of annulus fibrosus "A" (e.g., in a direction away
from fissure "F". It is further envisioned, as seen in the method
of FIG. 8, that thermal or EMF probe 104 may alternatively or
additionally be advanced so as to place guidable region 128 thereof
into nucleus "N" of intervertebral disc "D".
[0052] As seen in FIG. 9, should disc "D" have bilateral fissures
"F1, F2" then guidable region 128 of probe 104 may be extended
through the posterior "P" section into the contralateral side of
the disc "D" in order to place probe 104 adjacent to the secondary
fissure "F2". Confirmation of the orientation of arcuate end
portion 110 is provided through an index pin or marker adjacent to
cannula 102 and can be also monitored through the imaging
system.
[0053] Following the confirmation that guidable region 128 of probe
104 is properly placed, "Simulation Mode" is selected on power
source 106. First, the "Sensory Range" is activated and the
amplitude of the simulation is increased until indications of
effect and/or stimulation, of the region to be treated, are
obtained. The amplitude at which the indications of effect and/or
stimulations are obtained, of the region to be treated, is then
noted. In the event that the "Sensory Range" does not provide a
sufficient effect, the "Motor Range" is activated and the amplitude
is increased. The noted amplitude dictates the temperature which is
selected on the "Automatic Temperature Control" for the treatment
of disc "D". Accordingly, the heating cycle for each position of
guidable region 128 of probe 104 is dictated by the threshold of
the stimulations. For example, if stimulation of the region to be
treated occurs below about 0.75V, then a temperature of
approximately 60.degree. C. is applied. If, for example,
stimulation of the region to be treated occurs between about 0.75V
and 1.25V, then a temperature of approximately 65.degree. C. is
applied. If, for example, stimulation of the region to be treated
occurs above about 1.25V, then a temperature of approximately
70.degree. C. is applied.
[0054] Once guidable region 128 of probe 104 is positioned within
annulus fibrosus "A" as desired, power source 106 is activated
whereby thermal or EMF probe 104 delivers thermal energy and/or
creates an electromagnetic field through guidable region 128
adjacent intervertebral disc "D" to produce the thermal and/or EMF
therapy in accordance with the present disclosure. Appropriate
amounts of power, current or thermal heat may be monitored from the
external power source 106 and delivered for a certain amount of
time as determined appropriate for clinical needs.
[0055] For example, if denervation of nerves surrounding disc "D"
is the objective, the tissue adjacent the probe end is heated to a
temperature of from about 45.degree. C. to about 60.degree. C. If
heating of fissures "F" in disc "D" is the surgical objective, the
temperature in the tissue is raised to about 60-75.degree. C. As
appreciated, the degree of extension of guidable region 128 from
cannula 102 controls the volume of disc tissue heated by probe 104.
A thermal sensor (not shown), provided on thermal or EMF probe 104
can provide information concerning the temperature of tissue
adjacent the distal end. In an embodiment, the impedance means
associated with cannula 102 can provide impedance measurements of
the tissue thereby providing an indication of the degree of
dessication, power rise, or charring, that may be taking place near
tip 134 of thermal probe 104. This indicates the effectiveness of
the treatment and guards against unsafe contraindications of the
therapy.
[0056] Following thermal treatment at this location, cannula 102 is
repositioned so that guidable region 128 of thermal probe 104 is
guided laterally in annulus fibrosus "A" toward the
posterior-lateral "PL" section. Again, following the confirmation
that guidable region 128 of probe 104 is properly placed,
"Simulation Mode" is selected on power source 106 and the heating
cycle is dictated by the threshold of the stimulations. On
completion of thermal treatment in this position, cannula 102 is
once again adjusted or repositioned so that guidable region 128 of
thermal probe 104 may be placed within nucleus "N" of disc "D". A
temperature approximately equal to the boiling point of the nucleus
"N" and up to approximately 90.degree. C. is applied if stimulation
occurs above about 1.5V when the guidable region 128 of thermal
probe 104 is placed within nucleus "N".
[0057] The apparatus and method of the present disclosure provides
significant advantages over the prior art.
[0058] Cannula 102 and thermal or EMF probe 104 permits the probe
to be inserted through the body, preferably, on the same side as
the tear or fissure "F" formed in annulus fibrosus "A" of disc "D".
The present method reduces the distance guidable probe 128 must be
steered through annulus fibrosus "A".
[0059] Additionally, the site of injury and/or the region to be
treated receives a higher level of directed RF energy. As a result,
the likelihood of effective treatment of the site of injury and/or
the region to be treated is increased. This increased effective
treatment may include, and is not limited to, for example, multiple
RF treatments that ablate the nerve fibers that have grown into the
site of injury, as well as the nerve fibers in the outer annulus
fibrosus "A" that may be the source of discogenic pain. The
increased effective treatment may also include directed RF energy
denaturing of the biochemical constituents of the nucleus pulposus
to thereby reduce their contribution as a source of pain.
Additionally, the directed RF energy may also create a local area
of reduced pressure and higher viscosity in the nucleus "N", in the
immediate vicinity of the fissure(s) to thereby reduce the
likelihood of further extravasations of nuclear material.
[0060] In addition, spinal cord and spinal nerve roots are critical
tissues that must be spared during thermal treatments. Accordingly,
the present method and/or procedure enables a surgeon to identify
if these critical structures are in jeopardy of being injured by
the procedure.
[0061] A further advantage of the present apparatus and method is
that by using a curved introduction cannula, a more efficacious
direction of the probe may be achieved in the difficult lumbar or
lumbar-sacral intervertebral discs. In these approaches, nearby
heavy bone structure, such as the iliac crest, can often obscure a
placement of a curved probe parallel to the end plates or bony
margins of adjacent intervertebral discs. By appropriate angulation
and rotation of a curved cannula, the extension of a thermal probe,
parallel to the so-called end plates of the intervertebral discs,
is made possible with minimal repositioning and manipulation of the
introduction cannula.
[0062] A further advantage of the present apparatus and method is
that it enables simple, minimally-invasive, percutaneous,
out-patient treatment of intradiscal pain without the need for open
surgery as for example discectomies or spinal stabilization using
plates, screws, and other instrumentation hardware. A further
advantage of the present disclosure is that it is simple to use and
relatively economical. Compared to open surgery, the treatment of
the disc by percutaneous electrode placement represents only a
procedure of a few hours with minimal hospitalization, and with
minimal morbitity to the patient. On the other hand, open surgical
procedures often require full anesthetic, extensive operating room
time, and longer hospital and home convalescence.
[0063] While the above description contains many specific examples,
these specifics should not be construed as limitations on the scope
of the disclosure, but merely as exemplifications of preferred
embodiments thereof. Those skilled in the art will envision many
other possible variations that are within the scope and spirit of
the disclosure as defined by the claims appended hereto.
* * * * *