U.S. patent application number 10/742217 was filed with the patent office on 2004-07-15 for lateral probe advancement in intervertebral disc tissue.
Invention is credited to Banks, Thomas, Einhorn, Jacob, Lambrecht, Gregory H., Moore, Robert Kevin, Redmond, Russel J., Vidal, Claude A..
Application Number | 20040138673 10/742217 |
Document ID | / |
Family ID | 26693525 |
Filed Date | 2004-07-15 |
United States Patent
Application |
20040138673 |
Kind Code |
A1 |
Lambrecht, Gregory H. ; et
al. |
July 15, 2004 |
Lateral probe advancement in intervertebral disc tissue
Abstract
The present invention relates generally to intervertebral disc
devices and methods and instrumentation for intervertebral disc
procedures. An intervertebral disc repair and diagnostic device
that is minimally invasive, actively guided, and provides direct
and consistent access to the inner surface of the posterior anulus,
which will not unintentionally exit the posterior anulus and cause
harm to the spinal cord, is provided. A method for lateral probe
advancement in bodily tissue, including an intervertebral disc, is
also provided.
Inventors: |
Lambrecht, Gregory H.;
(Natick, MA) ; Moore, Robert Kevin; (Natick,
MA) ; Banks, Thomas; (Santa Barbara, CA) ;
Redmond, Russel J.; (Goleta, CA) ; Vidal, Claude
A.; (Santa Barbara, CA) ; Einhorn, Jacob;
(Brookline, MA) |
Correspondence
Address: |
KNOBBE MARTENS OLSON & BEAR LLP
2040 MAIN STREET
FOURTEENTH FLOOR
IRVINE
CA
92614
US
|
Family ID: |
26693525 |
Appl. No.: |
10/742217 |
Filed: |
December 19, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10742217 |
Dec 19, 2003 |
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10020507 |
Dec 11, 2001 |
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10020507 |
Dec 11, 2001 |
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09642450 |
Aug 18, 2000 |
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6482235 |
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60298605 |
Jun 14, 2001 |
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Current U.S.
Class: |
606/102 |
Current CPC
Class: |
A61F 2002/4435 20130101;
A61F 2002/30131 20130101; A61F 2002/30291 20130101; A61F 2002/444
20130101; A61F 2002/4635 20130101; A61F 2/442 20130101; A61F
2210/0004 20130101; A61F 2230/0091 20130101; A61F 2/4657 20130101;
A61F 2210/0061 20130101; A61F 2310/00023 20130101; A61F 2310/0097
20130101; A61F 2/30723 20130101; A61B 2090/062 20160201; A61F
2/4611 20130101; A61F 2002/4627 20130101; A61F 2310/00017 20130101;
A61B 17/320708 20130101; A61F 2002/2817 20130101; A61B 2017/320044
20130101; A61F 2002/4658 20130101; A61F 2002/30677 20130101; A61F
2002/30785 20130101; A61F 2002/448 20130101; A61F 2310/00365
20130101; A61F 2/30907 20130101; A61F 2230/0013 20130101; A61F
2/2846 20130101; A61F 2002/30777 20130101; A61F 2002/30062
20130101; A61B 5/4514 20130101; A61F 2002/30228 20130101; A61B
2017/3445 20130101; A61F 2002/30589 20130101; A61F 2002/30462
20130101; A61F 2310/00976 20130101; A61F 2220/0075 20130101; A61F
2230/0069 20130101; A61B 17/70 20130101; A61B 2017/22077 20130101;
A61F 2002/30583 20130101; A61B 2090/061 20160201; A61F 2/4601
20130101; A61F 2002/30075 20130101; A61F 2/441 20130101; A61F
2310/00293 20130101; A61F 2210/0085 20130101; A61F 2002/30571
20130101; A61B 5/1076 20130101; A61F 2002/30224 20130101; A61F
2002/4661 20130101; A61F 2310/00029 20130101; A61B 2017/00261
20130101; A61F 2002/4662 20130101 |
Class at
Publication: |
606/102 |
International
Class: |
A61F 002/00 |
Claims
What is claimed is:
1. A method of performing a procedure in a disc in the spine,
comprising the steps of: advancing a device at least part way
through an anulus; and advancing a probe laterally from the device
in a first direction along a portion of the anulus.
2. A method of performing a procedure in a disc as in claim 1,
wherein the advancing a probe step comprises advancing the probe in
between adjacent layers of the anulus.
3. A method of performing a procedure in a disc as in claim 1,
wherein the advancing a probe step comprises advancing the probe
along an interior surface of the anulus.
4. A method of performing a procedure in a disc as in claim 1,
further comprising the step of advancing the probe in a second
direction along a portion of the anulus.
5. A method of performing a procedure in a disc as in claim 1,
further comprising the step of introducing media through the
delivery device and into the disc.
6. A method of performing a procedure in a disc as in claim 5,
wherein the media comprises contrast media.
7. A method of performing a procedure in a disc as in claim 5,
wherein the media comprises a medication.
8. A method of performing a procedure in a disc as in claim 5,
wherein the media comprises a nucleus augmentation material.
9. A method of performing a procedure in a disc as in claim 5,
further comprising the step of introducing a prosthesis into the
disc.
10. A method of performing a procedure in a disc as in claim 9,
further comprising the step of proximally retracting a push rod
from a lumen in the delivery device, and introducing the prosthesis
through the lumen.
11. A method of performing a procedure in a disc as in claim 1,
wherein the advancing a device step comprises percutaneously
advancing the device.
12. A method of performing a procedure in a disc as in claim 1,
wherein the advancing a device step comprises advancing the device
through a skin incision no greater than about two inches in
length.
13. A method of performing a procedure in a disc as in claim 1,
wherein the advancing a device step comprises advancing the device
through a skin incision no greater than about one inch in
length.
14. A method of performing a procedure in a disc as in claim 1,
wherein the advancing a device step comprises advancing the device
through a skin incision no greater than about one half inch in
length.
15. A method of measuring a dimension within a disc, comprising the
steps of: providing a measuring device, having an elongate body
with a first stop surface thereon and an axially movable element
having a second stop surface thereon; advancing the device through
an opening in an annulus; bringing the first stop surface into
contact with a first surface of the annulus; bringing the second
stop surface into contact with a second anatomical structure; and
determining the distance between the first and second stop surfaces
to measure a dimension within the disc.
16. A method of measuring a dimension within a disc as in claim 15,
wherein the first surface is a proximal, outside surface of the
annulus.
17. A method of measuring a dimension within a disc as in claim 15,
wherein the second surface is an anterior, interior surface of the
annulus.
18. A method of measuring a dimension within a disc as in claim 15,
wherein the second surface is a posterior, interior surface of the
annulus.
19. A method of measuring a dimension within a disc as in claim 15,
wherein the determining the distance step comprises determining the
thickness of the annulus.
20. A method of measuring a dimension within a disc as in claim 15,
wherein the determining the distance step comprises determining the
anterior-posterior dimension of the nuclear space.
21. A method of measuring a dimension within a disc as in claim 15,
wherein the determining the distance step comprises determining the
sum of the anterior-posterior dimension of the nuclear space and
the thickness of the posterior wall of the annulus.
22. A method of measuring a dimension within a disc as in claim 15,
wherein the determining the distance step comprises observing
visual indicia of the distance on the measuring device.
23. A method of measuring a dimension within a disc as in claim 15,
wherein the bringing the second stop surface step comprises
advancing the second stop laterally from the device in a first
direction along the posterior annulus.
24. A method of measuring a dimension within a disc as in claim 23,
wherein the bringing the second stop surface step comprises
advancing the second stop laterally from the device in a second
direction along the posterior annulus.
25. A method of measuring a bodily cavity or tissue comprising:
inserting a probe into the bodily cavity or tissue; extending the
probe tip across or through said bodily cavity or tissue; and
measuring the dimensions of said bodily cavity or tissue.
Description
RELATED APPLICATIONS
[0001] This application is a divisional of co-pending U.S.
application Ser. No. 10/020,507, filed Dec. 11, 2001, which is
continuation-in-part of U.S. application Ser. No. 09/642,450, filed
Aug. 18, 2000, and claims priority under 35 U.S.C. .sctn.119(e) to
U.S. Provisional Appl. No. 60/298,605, filed Jun. 14, 2001, all
herein incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates generally to devices and
instrumentation for intervertebral disc diagnosis and treatment,
and methods thereof.
[0004] 2. Description of the Related Art
[0005] An intervertebral disc performs the important role of
absorbing mechanical loads while allowing for constrained
flexibility of the spine. The disc is composed of a soft, central
nucleus pulposus surrounded by a tough, woven anulus fibrosis.
Herniation is a result of a weakening in the anulus. Symptomatic
herniations occur when weakness in the anulus allows the nucleus to
bulge or leak posteriorly toward the spinal cord and major nerve
roots. The most common symptoms of herniation include pain
radiating along a compressed nerve and lower back pain, both of
which can be crippling for the patient. Herniation, and the
resulting dehabilitating symptoms, are of significant medical
concern in the United States because of the low average age of
diagnosis. Indeed, over 80% of patients in the United States
diagnosed with herniation are under the age of 59.
[0006] Information regarding anular thickness, internal dimensions
of the disc space normally occupied by the nucleus, and the
location of anular apertures and lesions in relation to the
vertebral endplates and lateral walls of the anulus facilitates
accurate diagnosis and treatment of intervertebral disc conditions.
For example, medical procedures involving the implantation of an
artificial nucleus or anular augmentation depend on this
information for accurate sizing of such implants. Also important
are safe, dependable, and minimally invasive methods and devices
for the manipulation of anular and nuclear tissue, especially along
the inner wall of the posterior anulus. For example, tissues in the
anulus and nucleus are commonly removed or manipulated during the
implantation of artificial discs either to clear a path for the
insertion of other types of prosthetic devices or as part of a
discectomy procedure.
[0007] Specialized tools have evolved for the surgical treatment of
intervertebral discs in the lumbar, cervical, and thoracic spine,
which have suffered from tears in the anulus fibrosis or herniation
of the nucleus pulposus. These tools are well-known in the prior
art. The devices of the prior art, however, are designed for
specific procedures, including complete discectomies (as opposed to
partial discectomy or minute removal of tissue) and the
installation of vertebral fusion implants. Accordingly, these
devices cannot be used to manipulate anular and nuclear tissue in a
precise and minimally invasive manner. Moreover, such devices are
typically designed to access the disc using an anterior approach,
i.e., through the abdomen. Although an anterior surgical approach
provides direct access to intervertebral discs, it is highly
invasive to the abdominal organs. Thus, surgery is typically more
complicated and time consuming. A direct posterior approach is not
anatomically practicable because the spinal cord and its
surrounding bony protective sheath lies directly in front of each
vertebral disc. An posterior-lateral aspect approach is the least
invasive of these methods but provides limited and oblique access
to the disc and its interior. Depending upon the surgical
necessities involved, several methods of percutaneous disc tissue
manipulation are available, including chemonucleolysis (e.g., U.S.
Pat. No. 4,439,423), laser (e.g., U.S. Pat. No. 5,437,661), manual,
focused energy, ultrasonic disruption (e.g., U.S. Pat. No.
5,772,661), arthroscopy and endoscopy.
[0008] Endoscopic instrumentation has evolved over the past 25
years and permits viewing, irrigation, suction, and cutting. Probes
that permit automated percutaneous suction such as nucleotomes or
cylindrically housed rotating cutting means, such as debreders,
provide gross but efficient removal of disc tissue. Varying tip
profiles control the amount and direction of tissue resection as
well as the likelihood of damage to surrounding tissue. These
devices tend to be limited by the size of the cannula which houses
the instrumentation and its ability to maneuver around vertebral
bodies and delicate tissues of the spine.
[0009] Hand tools for use in the spine are also well known and can
be inserted through cannulae or freely guided by hand. These tips
may be blades, burs, rongeurs, curettes or forcep-like "graspers"
that are capable of pinching of small amounts of material. To the
extent that these instruments can access the various tissues, these
devices provide good tactical feedback and control. However, if
used in an antero-lateral spinal approach, these tools are
generally limited by the indirect approach necessitated by the
laminae and spinous processes of the adjacent vertebrae, and thus,
access to tissues is substantially hampered.
[0010] Some intervertebral disc devices have been designed with
flexible tips that are designed not to perforate or deflect off of
the interior surface of the disc. Unfortunately, such tips deflect
off of healthy disc tissue only, not the pathological tissue that
caused the need for the surgery in the first place. Thus, such
instrumentation can exit the anulus and cause considerable damage
to the surrounding tissues and spinal cord. Also, the flexible
probe tips on some instruments which permit access to remote
locations within the disc can only do so by sacrificing direct
control because the devices are passively guided or blindly
"snaked" within the disc. Accordingly, delicate and precise work
within a disc is not possible with such instruments.
[0011] Among other disadvantages, the devices and methods of the
prior art are typically invasive and destructive to surrounding
tissue, frequently causing disc infection and nerve root injury.
Moreover, such devices are unable to precisely manipulate disc
material along the posterior anulus in a minimally invasive manner.
Accordingly, there is a need for an intervertebral disc diagnostic
and manipulation device which is capable of performing delicate and
precise work within a disc, especially along the posterior anulus
and between anular lamella.
SUMMARY OF THE INVENTION
[0012] The current invention relates generally to devices and
instrumentation for intervertebral disc diagnosis and treatment,
and methods thereof. In several embodiments, the present invention
provides for a minimally invasive and actively guided
intervertebral disc repair and diagnostic device. This device
provides direct and consistent access to the inner surface of the
posterior anulus and will not unintentionally exit the posterior
anulus and cause harm to the spinal cord. One skilled in the art
will understand that this device is not limited to intervertebral
disc applications, but includes medical procedures in which a
minimally invasive, actively guided device for diagnosis, repair or
treatment is desired. These procedures include, but are not limited
to, arthroscopic, endoscopic, and endovascular applications.
Further, one skilled in the art will appreciate that, in many
embodiments, this invention may be used percutaneously or
intralumenally.
[0013] Various embodiments of the invention may be guided by
tactile feedback or through active viewing. Also, various
embodiments may be used in conjunction with medical imaging
technologies, including MRI, ultrasound, or fluoroscopy. Further,
several embodiments of the invention having radiopacity or
selective radiopacity may be used in conjunction with imaging
methods for guidance and/or to facilitate measurement of organs or
tissues.
[0014] Various embodiments of the current invention are
particularly advantageous because they provide active controlled
direction of the working end of the instrument within the anulus or
nucleus. Further, several embodiments provide access to the
posterior portion of the anulus using a posterior surgical
approach. In various embodiments, access to the posterior anulus,
via circumferential navigation of the instrument as it is deflected
from the lateral, anterior, opposite lateral, and finally to the
posterior anulus, is avoided. This is advantageous because
circumferential deflection of the working end of the instrument
within the anulus can result in the tip of the instrument passing
through a fissure in the posterior anular surface and outward to
the spinal cord. This can occur because the circumferential
navigation from a typical posterior surgical approach eventually
directs the tip perpendicular to the posterior anular surface,
which may contain lesions large enough to allow protrusion of the
tip directly through to the spinal cord.
[0015] There is provided in accordance with one aspect of the
present invention, a device for treating the spine. The device
comprises an elongate guide having a longitudinal axis. An axially
moveable actuator is carried by the guide. A probe is movable with
the actuator, and a deflection surface is carried by the guide.
Axial movement of the actuator causes the probe to advance along
the deflection surface and extend away from the guide at an angle
to the longitudinal access of the guide.
[0016] In one implementation of the invention, the guide comprises
an elongate tubular body having at least one lumen extending
therethrough. The actuator extends through at least a portion of
the guide. The probe may comprise an elongate flexible body,
attached to the actuator. The probe may be biased in a nonlinear
configuration. In one embodiment, the probe comprises a nickel
titanium alloy.
[0017] In accordance with another aspect of the present invention,
there is provided a method of treating a disc in the spine. The
method comprises the steps of advancing a device at least part way
through an anulus. A probe is advanced laterally from the device in
a first direction along a portion of the anulus.
[0018] L In one application of the invention, the advancing a probe
step comprises advancing the probe in between adjacent (anular
lamella) layers of the anulus. In another application of the
invention, the advancing a probe step comprises advancing the probe
along an interior surface of the anulus, between the anulus and the
nucleus. The method may further comprise the step of repositioning
the probe and advancing the probe in a second direction along a
second portion of the anulus.
[0019] In accordance with a further aspect of the present
invention, the method additionally comprises the step of
introducing media through the delivery device and into the disc. In
one application, the media comprises contrast media, to permit
fluoroscopic visualization. The media may alternatively or
additionally comprise a medication, and/or a nucleus augmentation
material. The method may additionally comprise the step of
introducing a prosthesis into the disc. The prosthesis may be
introduced by proximately retracting a push rod from a lumen in the
delivery device, and introducing the prosthesis into the disc
through the lumen.
[0020] As will be appreciated by those of skill in the art, the
present invention, therefore, provides a minimally invasive access
pathway into the anulus and/or nucleus of a vertebral disc. The
pathway may be utilized to perform any of a wide variety of
procedures, including diagnostic and therapeutic procedures, some
of which will be identified below.
[0021] Several embodiments of this invention provide a new
intervertebral disc manipulation and diagnostic device.
[0022] One or more embodiments disclosed herein provide a
convenient, reliable, and accurate way to measure the anular
thickness and the internal dimensions of the disc space normally
occupied by the nucleus pulposus.
[0023] Several embodiments of this invention provide a device
useful in determining various disc dimensions in order to enable a
surgeon to size various implants and tools and facilitate their
guidance within the disc.
[0024] Various embodiments provide for the manipulation through an
opening in the anulus. Manipulation includes, but is not limited
to, dissection, resection or ablation of disc tissue. The opening
may be a single iatrogenic hole, such as an anulotomy, a naturally
occurring hole, or a lesion in the anulus.
[0025] One or more aspects of the current invention prepare or
manipulate disc tissue in preparation for the insertion of an
implant or other instruments.
[0026] Several embodiments of the present invention diagnose and
manipulate disc tissue with minimal invasiveness and risk of
unintended passage of the device outside of the posterior anulus in
the direction of the spinal cord or other sensitive areas proximal
thereto.
[0027] Various aspects of this invention permit direct access to
the interior aspect of anulus via an anulotomy.
[0028] Several embodiments of invention provide an intervertebral
disc manipulation and diagnostic device wherein the travel of the
working end of the device is parallel to the lamellae of the
anulus.
[0029] This disclosure utilizes particular orthopedic references,
nomenclature, and conventions. Accordingly, several background
figures and descriptions are included to aid in the understanding
of the environment under which specific embodiments of the
invention may be used. In this description and the following
claims, the terms "anterior" and "posterior", "superior" and
"inferior" are defined by their standard usage in anatomy, i.e.,
anterior is a direction toward the front (ventral) side of the body
or organ, posterior is a direction toward the back (dorsal) side of
the body or organ; superior is upward (toward the head) and
inferior is lower (toward the feet).
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] FIGS. 1A and 1B show the general anatomy of a functional
spinal unit 345. FIG. 1A is a view of a transverse section. FIG. 1B
is a view of a sagittal section. FIG. 1C shows the same functional
spine unit with a defect in the anulus, which may have been created
iatrogenically, as in the performance of an anulotomy, or may be
naturally occurring.
[0031] FIGS. 2A and 2B are front and side views of a device in
accordance with the present invention.
[0032] FIG. 3 is an isometric view of the distal end of the
device.
[0033] FIG. 4 is a side view of the depth stop components of the
device including depth-measuring markings, the depth stop
adjustment knob, and the depth stop body.
[0034] FIG. 5 is a side view of the delivery cannula, cannula
handle and intradiscal tip.
[0035] FIG. 6 is a side view of the advancer, with a
ring-handle.
[0036] FIG. 7 is a cross-sectional view of the device with the
intradiscal tip positioned within an anulotomy. The probe and depth
stop are both retracted, and the distal end of the device has been
inserted to a depth beyond the anterior aspect of the posterior
anulus.
[0037] FIG. 8 depicts the probe of the device advanced relative to
its starting position in FIG. 7 above.
[0038] FIG. 9 depicts the intradiscal tip of the device with the
probe resting on the inner surface of the posterior anulus.
[0039] FIG. 10 depicts the device with the depth stop advanced to
the posterior surface of the posterior anulus.
[0040] FIG. 11A is a side view of the intradiscal tip of the device
showing a variation of the probe tip. In this variation, the
trailing edge of the reverse-curved tip has been sharpened. In FIG.
11B, the same intradiscal tip is shown with the probe advanced from
its initial retracted position.
[0041] FIG. 12 is a top view of the probe from FIGS. 11A and 11B
shown unformed. The probe is shown as it would appear prior to
forming, if it were formed from a flat sheet of material, sharpened
along one edge.
[0042] FIG. 13A is a side view of the intradiscal tip of the
device, showing a variation of the probe tip. In this variation,
the distal end of the reverse-curved tip is spaced further distally
from the distal end of the device than that of the probe depicted
in FIGS. 11a-b. In FIG. 13B the same device is shown with the probe
advanced from its initial retracted position.
[0043] FIG. 14 is a top view of the probe from FIGS. 13A and 13B
shown unformed. The reverse curve that forms the distal tip of the
probe is shown as it would appear prior to forming, if it were
formed from a flat sheet of material.
[0044] FIG. 15A is a side view of a variation of the probe tip. In
this variation, the tip of the reverse curve has two additional
flanges of material on either side of the curve. The combination of
tip elements forms a scoop. In FIG. 15B the same device is shown
with the probe advanced from its initial retracted position.
[0045] FIG. 16 is a top plan view of the probe from FIGS. 15A and
15B shown unformed. The two side flanges and the reverse curve that
forms the distal tip of the probe are shown as they would appear
prior to forming, if they were formed from a flat sheet of
material.
[0046] FIG. 17A is a top view, and FIG. 17B is a side view of the
distal end of the device of an embodiment of the invention. The
probe includes an ablation unit, control wires, and a tube, mounted
to the probe proximal of the distal tip. The anvil of the device
has material removed in its central area to allow the retraction of
the tube and control wires into the device.
[0047] FIG. 18 is a transverse view of the intervertebral disc
wherein the device is being used to measure the anterior to
posterior distance from the anulotomy to the inner aspect of the
anterior anulus.
[0048] FIG. 19 is a transverse view of the intervertebral disc
wherein the probe is advanced from the anulotomy to the far lateral
corner.
[0049] FIG. 20 is a transverse view of the intervertebral disc
wherein the probe is advanced from the anulotomy to the near
lateral corner.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0050] In one aspect of the invention, there is provided a guide
such as a hollow delivery cannula having a distal end and a
proximal end. The guide is dimensioned to fit within a small
anulotomy as might be created by a surgeon or through a naturally
occurring hole or lesion in the anulus. An advancer, push rod, or
actuator is axially moveably carried by the guide, and coupled to a
flexible probe member. The flexible probe member has a proximal end
connected to the advancer and distal end connected to or formed
into a probe tip.
[0051] The probe is advanceable outwardly from the distal end of
the cannula via axial movement of the advancer within the cannula.
In the illustrated embodiment, the probe member exits through a
slot having a curved pathway or deflection surface located at the
distal end of the cannula and can be advanced outwardly therefrom
generally at an angle of between about 30 to about 150 degrees
relative to the cannula's longitudinal axis. Accordingly, when the
distal end of the cannula is properly inserted within the anulotomy
at sufficient depth, the probe travels along a path that is
parallel to and along the surface of or in between the anular
lamellae. The probe may be retracted via reversing the action (e.g.
proximal retraction) of the advancer.
[0052] A means for measuring the distance advanced by the probe is
associated with the probe and cannula. Any of a variety of
measurement indicia may be used, such as calibrated markings on the
advancer visible through or proximal to the cannula. An indicator
for measuring the distance advanced by the cannula within the
anulotomy or lesion may also be included. For example, a calibrated
depth stop may be affixed in a slideably adjustable manner to the
delivery cannula.
[0053] The probe tip at the distal end of the probe member may be
an integral piece of the probe wherein the tip and the probe are of
a unitary construction. Alternatively, the tip may be secured,
either releasably or permanently to the probe. The tip can be blunt
enabling it to forcibly part the tissue without cutting it (blunt
dissection) or be sharpened to present a sharp dissecting blade
surface (sharp dissection).
[0054] The tip may also be constructed in a backwardly curved
manner facing back towards the longitudinal axis of the cannula and
with its reverse facing edge sharpened to facilitate resection or
sharp dissection as it is retracted. This curved shape also serves
to present a blunt profile that is less likely to perforate the
anulus as it is advanced, even in the presence of uneven or
degenerated anular tissue. Alternatively, the curved resection tip
or blade may be formed as a multi-sided scoop with a concave
trailing surface and convex leading surface such that it presents a
blunt frontal profile even when advanced off-angle into the anulus
or toward a vertebral endplate.
[0055] In another embodiment, the tip may be configured to house an
ablation element. This element may be preferentially insulated on
particular surfaces of the probe and/or tip to minimize unwanted
damage to adjacent tissues. For example, the surface of the probe
or tip facing an inner aspect of the anulus may be insulated to
prevent unwanted travel through or harm other portions of the
anulus, nucleus and vertebral endplates. Ablation energy is instead
directed to the targeted tissue adjacent to the probe tip and not
the endplates or tissue facing the insulted side of the probe
tip.
[0056] FIG. 1A is an axial view along the transverse axis M of a
vertebral body with the intervertebral disc 315 superior to the
vertebral body. Axis M shows the anterior (A) and posterior (P)
orientation of the functional spine unit within the anatomy. The
intervertebral disc 315 contains the anulus fibrosus (AF) 310 which
surrounds a central nucleus pulposus (NP) 320. Also shown in this
figure are the left 370 and right 370' transverse spinous processes
and the posterior spinous process 380.
[0057] FIG. 1B is a sagittal section along sagittal axis N through
the midline of two adjacent vertebral bodies 350 (superior) and
350' (inferior). Intervertebral disc space 355 is formed between
the two vertebral bodies and contains intervertebral disc 315,
which supports and cushions the vertebral bodies and permits
movement of the two vertebral bodies with respect to each other and
other adjacent functional spine units.
[0058] Intervertebral disc 315 is comprised of the outer AF 310
which normally surrounds and constrains the NP 320 to be wholly
within the borders of the intervertebral disc space. Axis M extends
between the anterior (A) and posterior (P) of the functional spine
unit. The vertebrae also include facet joints 360 and the superior
390 and inferior 390' pedicle that form the neural foramen 395.
[0059] Referring FIG. 2a, the device 10, a cannula handle 35, and a
ring handle 45 are positioned such that the device 10 may be
operated by one hand, i.e. utilizing the thumb, index, and ring
fingers to position the device 10 and advance and retract the probe
member 20. However, any of a variety of proximal handpieces can
alternatively be used, including triggers, slider switches,
rotatable knobs or other actuators to advance and retract the probe
20 as will be apparent to those of ordinary skill in the art in
view of the disclosure herein.
[0060] In FIG. 5 the cannula handle 35 is secured to the proximal
end 32 of an outer delivery cannula 30. Outer delivery cannula 30
extends from the proximal end 32 to a distal end 34 which is
provided with an intradiscal tip 50. Delivery cannula 30 functions
as a guide for the axial reciprocal movement of a push rod 40 as
will be discussed. Delivery cannula 30 may, therefore, be provided
in the form of an elongate tube having a central lumen for
receiving push rod 40 therethrough. Alternatively, the guide may
comprise a nontubular structure, in an embodiment in which the push
rod travels concentrically over or alongside the guide.
[0061] The delivery cannula 30 may be manufactured in accordance
with any of a variety of techniques well known in the medical
device arts. In one embodiment, the cannula 30 comprises a metal
tube such as stainless steel or other medical grade metal.
Alternatively, the cannula 30 may comprise a polymeric extrusion
such as high density polyethylene, PTFE, PEEK, PEBAX, or others
well known in the medical device arts.
[0062] In general, the axial length of the delivery cannula 30 will
be sufficient to reach the desired treatment site from a
percutaneous or small incision access through the skin. Lengths
within the range from about 10 centimeters to about 30 centimeters
are contemplated, with a length from a proximal end 32 to distal
end 34 within the range of from about 14 to about 20 centimeters
contemplated for most posterior lateral access pathways. The length
may be varied depending upon the intended access pathway and
patient size.
[0063] Preferably, the outside diameter of the delivery cannula 30
is no greater than necessary to accomplish the intended functions
disclosed herein. In general, outside diameters of less than one
centimeter are preferred. In typical embodiments of the present
invention, the delivery cannula 30 has an outside diameter of no
greater than approximately 5 millimeters.
[0064] Referring to FIG. 6, the push rod or advancer 40 comprises
an elongate body 42 having a proximal end 44 and a distal end 46.
Push rod 40 may comprise a solid rod or tubular component as may be
desired, depending upon the construction materials and desired
physical integrity. In one embodiment, the push rod 40 comprises a
solid metal rod, such as stainless steel or other suitable
material. Alternatively, a polymeric extrusion using any of a
variety of known medical grade polymers may be used.
[0065] Push rod 40 is preferably dimensioned to extend throughout
the length of the delivery cannula 30, so that the probe 20 is
fully extended from the intradiscal tip 50 when the ring handle 45
is brought into contact with the cannula handle 35 or other stop
surface.
[0066] The device 10 may optionally be provided with one or more
axially extending lumens, for placing the proximal end of the
device 10 in fluid communication with the distal end, for any of a
variety of purposes. For example, one or more lumens may extend
through the push rod 40. Alternatively or in addition, the outside
diameter of push rod 40 may be dimensioned smaller than the inside
diameter of the delivery cannula 30 to create an annular space as
is well understood in the catheter arts. A first lumen may be
utilized for introduction of radiopaque dye to facilitate
visualization of the progress of the probe 20 and or distal end of
the device 10 during the procedure. The first lumen or second lumen
may be utilized to introduce any of a variety of media such as
saline solution, or carriers including any of a variety of
medications such as anti-inflammatory agents e.g, steroids, growth
factors e.g., TNf.alpha. antagonists, antibiotics, and functional
proteins and enzymes e.g., chympopapain. A lumen may also be
utilized to aspirate material such as nucleus pulposus, and/or to
introduce nucleus augmentation material during or at the end of the
procedure.
[0067] Referring to FIG. 7, the distal end 34 of device 10 is shown
in cross section. Distal end 34 includes an axially moveable probe
member 20, an outer delivery cannula 30 and an advancer or inner
push rod 40. A curved passage or slot 60 is proximal an intradiscal
tip 50 of the delivery cannula 30. The passage or slot 60 includes
a curved distal deflection surface which acts to deflect the probe
member 20 in a path that is roughly parallel to the lamellae of the
posterior anulus fibrosus 310 as the probe member 20 is advanced
outwardly from the curved slot 60 and into the disc 315 by the
advancer 40.
[0068] The distal end 34 of the cannula 30 may be provided with any
of a variety of constructions, depending upon the mode of
deflection of the probe 20. In the illustrated embodiment, the
distal end 34 is provided with a cap 52 which contains the
deflection surface 62 therein. Cap 52 may be molded from any of the
polymeric materials identified elsewhere herein, and secured to the
distal end 34 by adhesive bonding, interference fit, or other
conventional securing technique. Cap 52 has an atraumatic distal
surface 50, which may comprise the distal end of cap 52, or may
include a coating or layer of an atraumatic material such as
silicone, carried by the cap 52.
[0069] Any of a variety of alternative deflection surfaces may be
used, depending upon the desired distal tip design. For example,
the distal molded cap 52 may be eliminated, and the deflection
surface formed instead by an inside surface of the tubular cannula
30. This may be accomplished by providing two opposing axial slots
extending proximally from the distal end 34 of the cannula 30 to
isolate two opposing axial ribbons on the distal end 34. A first
one of the ribbons is severed and removed, while the second one is
curved across the central axis of the cannula 30 to provide a
curved deflection surface.
[0070] Alternatively, the deflection surface may be eliminated in
certain circumstances. For example, in the procedure illustrated in
FIG. 7, the device is inserted through a defect in the posterior
annulus at an angle relative to the desired treatment plane that
requires the probe 20 to exit the device at a corresponding angle
in order to advance the probe along the surface of or within the
annulus as shown (e.g., within or parallel to the desired treatment
plane). However, by moving the access path through the annulus
roughly 80-90 degrees counterclockwise as viewed in FIG. 7, the
longitudinal axis of the device 10 can be positioned coplanar or
parallel to the posterior interior surface of the annulus or other
desired treatment plane. In this orientation, the probe is
desirably launched axially out of the end of the cannula 30, to
dissect a space for subsequent annulus patch implantation.
[0071] The foregoing axial launch embodiment of the invention may
be utilized through the naturally occurring defect. However, the
axial launch device is more likely to find application through an
iatrogenic access pathway, created through the annulus spaced apart
from the natural defect such that the longitudinal axis of the
iatrogenic access is substantially parallel (e.g., no more than
about +/-20 degrees) from the plane in which the natural defect
resides.
[0072] As a further alternative, the probe 20 may be laterally
deflectable in response to manipulation of a deflection control at
the proximal end of the device 10. For example, the probe 20 in one
construction comprises a flexible metal or polymeric ribbon,
extending from the distal end of the advancer 40 or other axial
support. An axially extending steering element is attached to the
probe 20. Generally the steering element will be attached near the
distal end of the probe 20. Axial proximal or distal movement of
the steering element relative to the advancer 40 will cause a
lateral deflection of the probe 20.
[0073] The radius of curvature of the deflection can be controlled
in a variety of ways as will be apparent to those of skill in the
art in view of the disclosure herein, such as by varying the
lateral flexibility of the probe 20, and the attachment point of
the steering element to the probe 20. Due to the differing physical
requirements of devices under tension compared to compression, the
cross section of the device may be minimized if the steering
element is a pull wire or ribbon such that axial proximal
retraction of the pull wire relative to the probe 20 causes a
lateral deflection of the probe 20. The lateral deflection can be
coordinated with the extent of distal advance to cause the probe to
follow the desired curved path either by mechanics in the proximal
handpiece, or by the clinician. For this purpose, the proximal
handpiece can be provided with any of a variety of controls, such
as slider switches or rotatable levers or knobs to allow the
clinician to control deflection as well as distal (and lateral)
advance.
[0074] In an alternate construction, the probe launches axially
from the distal end 34 of the cannula or other guide 30, but curves
under its own bias to travel in a lateral arc and slide along the
posterior annulus or other desired surface. This may be
accomplished by constructing the probe from a nickel-titanium alloy
such as Nitinol and providing it with a lateral pre bent
orientation. The probe is restrained into an axial orientation
within the cannula 30, but extends laterally under its own bias as
it is advanced distally from an opening in the distal end of the
cannula 30.
[0075] The probe member 20 in the illustrated embodiment may be
formed from a superelastic nickel titanium alloy, or any other
material with suitable rigidity and strain characteristics to allow
sufficient deflection by deflection surface 62 without significant
plastic deformation. The probe member 20 can be formed from an
elongated sheet, tube, rod, wire or the like. Probe 20 may also be
constructed in various cross-sectional geometry's, including, but
not limited to hemicircular, semicircular, hollow, and rectangular
shapes.
[0076] A probe tip 80 at the distal end of the probe member 20 can
be used to dissect between the anulus 310 and nucleus 320, to
dissect between layers of the anulus 310, or to dissect through the
nucleus. The probe tip 80 can be constructed of the same material
as the probe member 20 or another suitable material for the
purposes of cutting or presenting a blunt rounded surface. A
sharpened surface on the distal edge of the probe member 20 forming
the probe tip 80 can be used to dissect a path to enable the
insertion of an implant in the created space. Similarly, a blunted
tip profile may be used to separate or disrupt anular lamella and
create an open space between the anulus 310 and nucleus 320 or
within the nucleus 320 itself.
[0077] The probe tip 80 may also be provided with a backward curve
as shown in FIGS. 11A and 11B. In this construction, a concave
surface faces the longitudinal axis of the device when deployed
within the disc. The tip 82 may be sharpened to facilitate
resection or sharp dissection as it is retracted. This curved shape
will also serve to present a blunt profile to reduce the risk of
perforating the anulus 310 as it is advanced, even in the presence
of uneven or degenerated anular tissue. The curved tip 80 may be
formed in any of a variety of radii or shapes depending on the
amount of material one desires to remove on each pass of the probe
member 20 into the disc, as shown in FIGS. 13A and 13B.
Alternatively, the resection tip 80 or blade may be formed as a
multi sided concave scoop 81 having a cavity therein such that it
presents a blunt convex frontal profile even when advanced
off-angle into the anulus 310 or toward a vertebral endplate 350,
as shown in FIGS. 15A and 15B. Also, the increased surface area of
such a scoop 81 would serve to further facilitate removal of disc
tissue.
[0078] The distal end of device 10 is shown in FIG. 7 as inserted
through a defect in the posterior anulus 300. Alternatively, the
device 10 could be inserted through defects in the
posterior-lateral, lateral, or anterior anulus 300. In these
alternate positions, the probe tip 80 can be advanced parallel to
the lamellae of different regions of the anulus 310. One of the
many advantages of the curved, distal probe tip 80, as represented
in several embodiments of the current invention, is its minimal
profile when the probe is in its retracted state relative to the
outer cannula 30. In this state, depicted in FIG. 7, the curved tip
80 fits around the distal end of intradiscal tip 50, only minimally
increasing the size or profile of device 10. This minimizes the
size of the defect in the anulus 300 necessary to allow proper
insertion of the distal end of device 10.
[0079] As demonstrated in FIGS. 11 and 13, various geometry's of
the tip 80 can be employed without increasing the necessary anular
defect or anulotomy 300 size for insertion of the intradiscal tip
50 of the device 10. For example, the larger radius of the probe
tip 80 in FIG. 13 presents a blunter dissection profile when
advanced from the intradiscal tip 50 without necessitating a
correspondingly larger anulotomy 300 for proper insertion of the
device 10 into the disc. As the bluntness of probe tip 80 is
increased, it may be desirable to increase the stiffness of the
probe 20. This increased stiffness may be achieved in a variety of
ways which can include, but is not limited to using a thicker or
more rigid material for forming probe 20, or by using a curved
cross-sectional shape along the length of probe 20. These
techniques may be used to stiffen all or a portion of the length of
probe 20.
[0080] The probe tip 80 may also be coupled to an ablation unit for
ablating tissue, as shown in FIGS. 17A and 17B. The ablation unit
can be attached to the probe member 20 preferably on the side
facing the interior of the disc and proximal to the probe tip 80.
In this configuration, the probe member 20 acts as a mechanical and
thermal barrier minimizing unwanted ablation in the direction
opposite the ablation unit, i.e. in the direction facing the
interior aspect of the anulus. Ablation may be achieved using any
of a variety of energy delivery techniques including, but not
limited to light (laser), radio-frequency or electro-magnetic
radiation in either unipolar or bipolar configurations, resistive
heating of the probe, ultrasound or the like.
[0081] An embodiment of a bipolar radio-frequency unit is depicted
in FIG. 17. Power and control wires 91 may be deposited directly on
to the probe member 20 as is known in the art. These wires act to
connect RF elements 90 to an external power source and control unit
affixed to or in communication with the advancer 40 and cannula 30.
These elements 90 serve to allow the conduction of current
therebetween, resulting in a resistive heating of the tissue in the
region of the probe tip 80. These elements 90 are shown proximal to
the distal probe tip 80 of device 10, but may be positioned at any
location along probe 20 and/or on probe tip 80. Only two elements
90 are shown, however numerous elements may be positioned at
various locations along the entire length of the probe 20 and be
activated individually or multiplexed in pairs or groups to produce
a desired temperature profile or ablation within the disc
tissue.
[0082] Tube 92 is shown attached to probe 20 to provide an escape
path for vapor and material ablated or for the infusion of fluids
or gasses. These fluids or gasses may be added to alter the
conductive characteristics of the tissue or may include various
drugs, medications, genes or gene vectors or other materials to
produce a desirable therapeutic affect. Tube 92 is shown with a
single distal orifice. It may alternatively comprise any number of
side holes or channels to increase the spread of fluids or gasses
within the tissue or similarly to remove such materials as required
by the procedure. Axial lumen are provided as needed to place the
side holes or other apertures in communication with the proximal
end of the device 10. The ablation unit could be activated as the
probe member 20 is advanced through the tissues to create a cavity
or activated as the probe member 20 is retracted after it has been
advanced to a desired distance. Moreover, the power supplied to the
ablation unit 90 could be varied according to the instantaneous
velocity of the probe member 20 in order to ablate a more uniform
cavity within the disc.
[0083] Whether used to dissect, resect or ablate tissue within the
disc, device 10 may be used as part of an implantation procedure by
creating a cavity or dissected region into which any of a variety
of intradiscal implants or medications may be inserted. This region
may be between or within anular layers 310, within the nucleus 320,
or between the anulus 310 and nucleus 320. It may include a portion
or the entirety of the nucleus. Increasing amounts of disc tissue
may be removed by advancing and retracting the probe tip repeatedly
at different depths within the disc. Intradiscal implants may be
inserted independently using separate instrumentation or along,
through, or around probe 20. Suitable implants include, among
others, those disclosed in U.S. patent application Ser. No.
09/642,450 filed Aug. 18, 200 entitled Devices and Methods of
Vertebral Disc Augmentation, the disclosure of which is
incorporated in its entirety herein by reference.
[0084] FIGS. 7, 8, 9, and 10 depict an embodiment of the device 10
placed within an anulotomy or defect of anulus 300, which can be
used to measure the thickness of anulus 310. In FIG. 7, the distal
portion of the cannula 30 defined by the intradiscal tip 50 is
inserted through the anulotomy or defect 300 to a depth wherein the
probe 20 is inserted just beyond the anterior border of the
posterior anulus 310. In FIG. 8, the probe member 20 is advanced
out of cannula 30 and deflected by the deflection surface in curved
passage 60 of the intradiscal tip 50 at an angle nearly
perpendicular to device 10, causing the probe member 20 to advance
parallel to the inner surface of the posterior anulus 310. In this
use, the probe 20 need only be advanced outward several
millimeters.
[0085] In FIG. 9, device 10 is proximally retracted from the
anulotomy 300 until the probe 20 contacts the posterior anulus 310.
In FIG. 10, a slideably adjustable depth stop 70 is carried by the
cannula 30 and advanced distally (anteriorly) until it contacts the
exterior surface of the posterior anulus 310 and the probe member
20 is in contact with the interior surface of the posterior anulus
310. The depth stop 70 functions by abutting anular tissue or
surfaces of the vertebral body adjacent to the anulotomy 300 which
impede further entry of the cannula 30 into the disc, such as may
be determined by tactile feedback or under fluoroscopic
visualization. FIG. 4 shows the depth stop adjustment knob 105,
calibrated measurement marks 100 and depth stop 70. The cannula 30
or depth stop 70 may be marked with calibrated measurements 100 so
that the distance between the intradiscal tip 50 at the point where
the probe member 20 exits and the depth stop 70, can be determined.
This distance corresponds to the thickness of the anulus adjacent
to the anulotomy 300.
[0086] FIG. 18 depicts an embodiment of the device 10 placed within
an anulotomy or defect in anulus 300 and being used to determine
the anterior-posterior dimension of the nuclear space as defined by
the distance between the inner surfaces of the posterior anulus and
the anterior anulus. Here, the probe member 20 and the adjustable
depth stop 70 are fully retracted. The probe 20 and advancer 40 may
be eliminated entirely in an embodiment intended solely for the
anterior-posterior measurement described herein. The intradiscal
tip 50 of the device 10 is advanced through the anulotomy or defect
in anulus 300 until the inner surface of the anterior anulus is
reached and impedes further travel of the intradiscal tip 50. In
this manner the device 10 is used to provide tactile feedback of
the disc's internal geometry. The adjustable depth stop 70 is then
advanced distally toward the proximal exterior surface of the
anulus or vertebral body and reading of the maximum depth reached
can be obtained via calibrations on the proximal end of the device
such as on the cannula. Electronic or other means could also be
employed to measure and display this distance. The posterior anular
thickness value can be subtracted from this to yield the distance
between the inner aspects of the posterior and anterior anulus.
[0087] FIGS. 19 and 20 depict an embodiment of the device 10 placed
within an anulotomy or defect in anulus 300 and being used to
determine the distance between the left and right lateral interior
surfaces of the anulus. In measuring the distance between the left
and right lateral surfaces of the anulus 310 the intradiscal tip 50
is inserted just beyond the interior wall of the posterior anulus,
the probe tip 80 is advanced out of the curved passage 60 in the
plane of the disc, i.e. parallel to the endplates, until tactile
feedback from the advancer 40, indicates that lateral surface is
resisting further advancement. Calibrated makings on the advancer
40 visible through or proximal to the cannula can then be used to
determine this distance.
[0088] By rotating the device 10, while the probe member 20 is
fully retracted, 180 degrees and performing the same action in the
lateral direction, as shown in FIG. 20, one can obtain the total
distance between the interior lateral surfaces. This method may be
repeated at various depths within the disc by adjusting the depth
stop 70. A similar method of using the probe member 20 to
tactically interrogate the interior of the disc may be employed to
dimension the distance between the vertebral endplates and relative
distances from the anulotomy 300 to the endplates. All of the
foregoing measurements may be taken either using a scoop shaped
distal tip as shown, or a blunt, atraumatic tip without a scoop to
minimize disruption of the nucleus.
[0089] Depth stop 70 may also be used to coordinate the dissection
or resection of a space within the disc with the placement of
another intradiscal instrument or implant. This method may be
particularly useful for placing an implant along an inner surface
of the anulus fibrosus. The thickness of the anulus as determined
by any of the measurement techniques described above may be used
for setting depth stops on other implantation instruments used to
place an implant along the anulus. As an example, if the posterior
anulus is measured to be 7 mm thick using device 10, a depth stop
may be set on an implantation instrument to limit the penetration
of this instrument into the disc to 7 mm or another depth that is
relative to 7 mm. This would allow for an implant placed by this
instrument to be inserted into a space previously dissected within
the disc by device 10 along the inner surface of the posterior
anulus.
[0090] Probe 20 may be used as part of the placement of an
intradiscal implant in any of a variety of ways. One advantageous
use of the probe 20 can be achieved by detaching it from advancer
40 once probe 20 is in a desired position within the disc space.
Implants may then be passed along, behind or in front of probe 20
into this desired position. Probe 20 may then be removed from the
disc space.
[0091] The measurement techniques described above may also be used
to achieve the complete resection of the nucleus from the disc
space. For example, a resection or ablation tip as described above
may be passed repeatedly into the disc to the lateral borders of
the nucleus. This process may be repeated at varying depths within
the disc from the inner aspect of the posterior anulus to the inner
aspect of the anterior anulus as determined by the depth stop.
[0092] While this invention has been particularly shown and
described with references to preferred embodiments thereof, it will
be understood by those skilled in the art that various changes in
form and details may be made therein without departing from the
scope of the invention encompassed by the appended claims.
* * * * *