U.S. patent application number 12/220187 was filed with the patent office on 2010-01-28 for rf intervertebral disc surgical system.
Invention is credited to Alan G. Ellman.
Application Number | 20100023006 12/220187 |
Document ID | / |
Family ID | 41323507 |
Filed Date | 2010-01-28 |
United States Patent
Application |
20100023006 |
Kind Code |
A1 |
Ellman; Alan G. |
January 28, 2010 |
RF intervertebral disc surgical system
Abstract
A spinal surgical system comprising a plurality of surgical
components for cooperating with a electrosurgical handpiece
comprising an elongated tubular member housing an electrode, with
the tubular member configured to fit within and be extended down a
standard sized cannula in a MIS procedure. The system components
comprise one or more cannulas, straight or beveled; one or more
guide wires, with and without pointed ends for piercing tissue; a
tapered dilator; a trephine; and one or more depth control stops
for mounting on the cannula for monitoring its depth. The system is
especially useful for performing a discectomy.
Inventors: |
Ellman; Alan G.; (Oceanside,
NY) |
Correspondence
Address: |
JACK OISHER
200 HIGH POINT DRIVE, SUITE PH2
HARTSDALE
NY
10530
US
|
Family ID: |
41323507 |
Appl. No.: |
12/220187 |
Filed: |
July 23, 2008 |
Current U.S.
Class: |
606/45 ; 604/35;
606/41; 606/48 |
Current CPC
Class: |
A61B 2090/034 20160201;
A61B 18/1482 20130101; A61B 2017/00261 20130101; A61B 2218/007
20130101; A61B 2017/22038 20130101; A61B 17/3421 20130101; A61B
2017/22044 20130101 |
Class at
Publication: |
606/45 ; 604/35;
606/41; 606/48 |
International
Class: |
A61B 18/18 20060101
A61B018/18; A61M 1/00 20060101 A61M001/00 |
Claims
1. A MIS intervertebral disc surgical system for use with an
electrosurgical instrument having an elongated tubular member
housing an electrosurgical electrode for excising of or shrinking
tissue, comprising: (a) one or more straight or beveled cannulas,
the cannulas configured with a lumen to receive the elongated
tubular member of the electrosurgical instrument, (b) one or more
guide wires, at least one of the guide wires having a pointed end
for piercing tissue, each of the guide wires being configured to
fit within the cannula's lumen, (c) a tapered dilator configured to
slide over a guide wire, (d) a trephine configured to slide over a
guide wire, (e) an adjustable depth control stop for mounting on
the cannula for monitoring its depth into the tissue.
2. A disc surgical system as claimed in claim 1, wherein the
cannula has an enlarged head at one end, the enlarged head having
an internally threaded opening.
3. A disc surgical system as claimed in claim 2, wherein the
dilator has an enlarged head at one end, the enlarged head having
an externally threaded extension configured to threadingly engage
the internally threaded opening on the cannula's head.
4. A disc surgical system as claimed in claim 1, wherein the depth
control stop comprises two threaded members that when tightened
lock to the cannula.
5. A disc surgical system as claimed in claim 1, wherein the
dilator has a length such that, when fully engaging the cannula's
lumen, the dilator's end protrudes about 3-5 mm from the end of the
cannula.
6. A disc surgical system as claimed in claim 1, wherein the
trephine has a length such that, when fully engaging the cannula's
lumen, the trephine's end protrudes up to about 10 mm from the end
of the cannula.
7. A disc surgical system as claimed in claim 1, wherein the
dilator has a tapered end.
8. A disc surgical system as claimed in claim 1, wherein the
trephine has a cutting end.
9. A spinal procedure comprising the steps: a. providing a cannula,
a guide wire, a tapered dilator with a lumen, a trephine with a
lumen, a depth control stop, and an elongated electrosurgical
instrument, b. after a spinal needle with a lumen is inserted into
a patient's back toward a spinal disc, the guide wire is threaded
through the needle lumen into the disc nucleus, c. the spinal
needle is then removed leaving the guide wire in place, d. the
cannula and dilator joined together are placed over the guide wire
and advanced toward the annulus, e. the cannula with dilator is
advanced under fluoroscopic guidance into the nucleus, f. the
dilator is removed creating a portal into the disc, g. the depth
stop is mounted on the cannula and advanced to the patient's skin
and secured to prevent advancement of the cannula, h, the
electrosurgical instrument is advanced through the cannula and into
the pulpous to remove, shrink or modulate pulpous tissue.
10. A procedure as set forth in claim 9, further comprising: i.
after step d. and before step e., the dilator is removed from the
cannula, j. the trephine is inserted through the cannula and
advanced toward the outer surface of the disc annulus and an
annulotomy is created by rotation of the trephine 1-3 turns, k. the
trephine is removed and replaced by the dilator.
11. The procedure of claim 10, wherein the electrosurgical
instrument is activated with high frequency currents at a frequency
of about 4 MHz.
Description
[0001] This invention relates to an intervertebral disc surgical
system, and in particular to such a system employing electrosurgery
for performing spinal and related surgical procedures.
BACKGROUND OF THE INVENTION
[0002] Our earlier U.S. Pat. No. 7,137,982, the contents of which
are herein incorporated by reference, describes an electrosurgical
instrument for spinal procedures comprising a generally
scoop-shaped cup whose periphery is electrically active and is
capable of applying RF electrosurgical currents to spinal
tissue.
[0003] While the patented device as explained in that patent is
suitable for many spinal procedures, there is a need in the art for
other instruments that can electrosurgically remove or shrink
tissue, and specifically disc nucleus pulposus, via a cannula for
minimally invasive surgical (MIS) procedures, such as a
discectomy.
SUMMARY OF THE INVENTION
[0004] An object of the invention is an improved surgical system
for performing an MIS discectomy procedure.
[0005] Another object of the invention is an improved procedure for
producing a void or cavity in or reduction of human tissue,
especially in the spinal region.
[0006] In accordance with one aspect of our invention, our novel
system comprises a plurality of surgical components for cooperating
with an electrosurgical handpiece of the type comprising an
elongated tubular member housing an electrode, with the tubular
member configured to fit within and be extended down a standard
sized cannula in a MIS procedure. The system components comprise
one or more cannulas, straight or beveled; one or more guide wires,
with and without pointed ends for piercing tissue; a tapered
dilator; a trephine; and a depth control stop for mounting on the
cannula for monitoring its depth in the patient's tissue.
[0007] The electrosurgical handpiece typically comprises a proximal
end including a handle for the surgeon and may be supplied with
fittings for connection to a source of irrigation fluid and a
source of suction. The distal end of the instrument has an active
end that may comprise a slightly flexible curved wire or straight
electrode, typically bipolar. The tubular member of the handpiece
may be rigid or flexible.
[0008] The system components are designed to provide targeted
access via one of the cannulas, during say a discectomy, to the
disc annulus by the active end of the electrosurgical handpiece
which when energized can provide tissue debulking, ablation or
modulation, as desired. Put another way, the use of the components,
as described below, can provide precise placement and control of
the electrosurgical electrode providing exact pathology
treatment.
[0009] Preferably, the far end of the handpiece tubular member is
constructed of a radio-opaque material such that the instrument end
is visible during fluoroscopic examination while the procedure is
carried out.
[0010] The housed wire electrode is electrically active and is
capable when energized of applying electrosurgical currents to
human tissue with the result that a void or cavity or tunnel can be
formed in the tissue to a considerable depth. The tissue removed to
form the cavity may then be easily aspirated via the suction
port.
[0011] Preferably, radio-frequency (RF) electrosurgical currents,
in a frequency range preferably above 3 MHz, with 4 MHz being
preferred, are employed. It is believed that 4 MHz radiofrequency
energy has been proven to be a self-limiting, minimal penetration
energy source capable of precise tissue interaction. Thus,
electrosurgical instruments that emit 4 MHz radiofrequency currents
will be attractive to spinal surgeons needing to produce a
space-specific nucleotomy efficiently and safely. In combination
with the innovative RF delivery system in a MIS procedure,
radiofrequency energy can result in precision extraction of the
nucleus pulposus and/or the entire disc that will enable a void to
be created that will accommodate a replacement substance or device.
Since lateral heat is typically not a byproduct of 4 MHz RF
currents, damage to endplates can be minimized or avoided, nor will
the RF currents violate the annulus.
[0012] Thus, a MIS electrosurgical procedure using the novel system
components described herein enables physicians to offer to patients
a treatment that is efficiently performed, relatively easily
learned and thus performed at a significantly reduced price, and
with less tissue damage and superior results compared to procedures
done with other voiding devices.
[0013] The system of the invention is especially valuable for
treating patients with contained intravertebral disc herniations or
bulges.
[0014] The various features of novelty which characterize the
invention are pointed out with particularity in the claims annexed
to and forming a part of this disclosure. For a better
understanding of the invention, its operating advantages and
specific objects attained by its use, reference should be had to
the accompanying drawings and descriptive matter in which there are
illustrated and described preferred embodiments of the invention,
like reference numerals or letters signifying the same or similar
components.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a plan view of the components of one form of
surgical system of the invention, the system in this case being
shown with an electrosurgical handpiece shown schematically
connected to an electrosurgical generator;
[0016] FIG. 2 is a plan view of a dilator assembled to a cannula of
the surgical system of FIG. 1;
[0017] FIG. 3 is a plan view of a dilator assembled to a different
cannula of the surgical system of FIG. 1;
[0018] FIG. 4 is a plan view of a trephine assembled to a cannula
of the surgical system of FIG. 1;
[0019] FIG. 5 illustrates operation of depth stop for use in the
surgical system of FIG. 1;
[0020] FIGS. 6-17 are schematic views illustrating different steps
in a surgical procedure using the surgical system of FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] FIG. 1 illustrates the components for one form of discectomy
system 10 in accordance with the invention. It comprises one or
more cannulas, in this instance one 12 with a straight end and one
14 with a beveled end. Each cannula comprises an elongated straight
tube, about 3.4 mm in outer diameter, length about 16.5 cm
connected to a cannula head 18. The free end of the cannula head 18
has an internally-threaded opening 17. A common bore or lumen
typically of about 3 mm extends through the tube and head. Two
guide wires are provided, one small 20 in a removable plastic tube
21 and one large 22. Each guide wire is solid with an outer
diameter of 1 and 1.3 mm respectively, about 40 cm long. Each guide
wire preferably has pointed ends for piercing tissue. A dilator 24
is provided with a tapered tip 26 and a dilator head 28 with a
forwardly projecting threaded end 19 for removable connection to
the backward extended threaded opening 17 in the cannula head. When
threaded together, a cannula and the dilator can be operated
together as a single unit, or separated can operate as separate
units. The system also comprises a trephine 32 having a straight
tube terminating in a beveled cutting edge. The dilator has an OD
of about 2.8 mm tapering down to about 2.2 mm. The trephine has
about the same OD. Their lengths are about 19.5 cm. A depth control
stop is shown at 34 for mounting on the cannula for monitoring its
depth in the tissue. The depth stop comprises two threaded parts
(see FIG. 5) that can separate when on the cannula to adjust their
position on the cannula, and when tightened will lock to the
cannula.
[0022] One procedure in accordance with the invention using these
components is now described in connection with FIGS. 6-17 which
show schematically a patient's back with a spinal disc comprising
an annulus 4 surrounding the nucleus pulposus 6.
[0023] The patient may be positioned on a radiolucent table on a
curved spinal frame in prone position, the lumbar spine area
prepped and draped in the usual sterile fashion, and the entry site
marked, using, for example, a sterile marking pen 8-10 cm from
midline on the affected side using fluoroscopic guidance. The skin
is then anesthetized with local anesthetic using a 25-gauge needle.
A standard 18 guage, 8-inch long spinal needle 40 is inserted
through the marked entry point at a 45-degree angle to the skin
(FIG. 6). The needle is advanced toward the foramen while the
position is checked using both anterior/posterior (AP) and lateral
fluoroscopy. The needle is then advanced into the disc using
standard discography technique. The final position is verified
using fluoroscopy. Discography is performed using 3 cc of contrast
dye containing antibiotics and indigo carmine. The discogram is
performed to verify concordant pain and visualize disc morphology.
One of the guide wires 20 (FIG. 7) is threaded through the lumen of
the needle 40 into the disc nucleus 6. Two different sizes of guide
wires are provided for use with spinal needles with different sized
lumens. A 3-4 mm skin incision is made at the needle site using a
#11 scalpel. The needle 40 is subsequently removed leaving the
guide wire 20 in place (FIG. 8). The working cannula 12 and dilator
24 joined together are placed over the guide wire 20 and advanced
toward the annulus (FIG. 9). FIGS. 2 and 3 show a dilator 28
screwed and assembled to the head of a cannula 12, 14. The
respective lengths are such that the tapered end 26 of the dilator
protrudes about 4 mm from the free end of the cannula. The dilator
24 (FIG. 10) is removed from the working cannula 12. The trephine
32 (FIG. 11) is inserted through the cannula 12 and advanced toward
the outer surface of the disc annulus. The trephine protrudes about
1 cm from the free end of the cannula An annulotomy is created by
applying slight pressure and a 360 degree rotation of the trephine
1-3 turns. The trephine 32 is then removed and replaced by the
dilator 24. The cannula 12 with dilator 24 is advanced under
fluoroscopic guidance into the nucleus (FIG. 12). When the dilator
24 is then removed, a portal into the disc is created (FIG. 13).
The depth stop 34 (shown only in FIG. 12) mounted on the cannula 12
is advanced to the patient's skin and secured to the cannula to
prevent advancement. A standard 2.5 mm diameter endoscopic grasping
forceps (FIG. 14) can be used to manually extract nucleus material.
A bipolar electrosurgical handpiece 50 as described in U.S. Pat.
Nos. 6,231,571 and D562,978, the contents of which are herein
incorporated by reference, an example of which is known
commercially as the Trigger-Flex Bipolar System and available from
Elliquence LLC of Oceanside, N.Y., is connected to an RF
electrosurgical generator 52, also available commercially from
Elliquence LLC of Oceanside, N.Y. set to a relatively low power in
the bipolar HEMO mode. The electrosurgical handpiece 50 may be
included in the package with the other components or provided
separately. The lowest power setting to achieve desired tissue
effect should be used. The RF energy is activated using footswitch
activation while the handle is squeezed to extend and retract the
electrode (FIG. 15), the active bendable electrode end 54 being
deployed and retracted into the nucleus to create tracks of nucleus
removal. Preferably, the electrode tracks are directed into the
11:, 12:, 1:, 5:, 6: and 7: o'clock positions in order to
accomplish nucleus pulposus decompression. At a lower power
setting, an annuloplasty can be performed at the annulus (FIG. 16).
The electrosurgical handpiece is extracted from the cannula at the
conclusion of the procedure. While stabilizing the skin around the
cannula with the fingers of one hand, the other hand should slowly
withdraw the cannula and dilator together if added. 2-3 sutures are
used to close the surgical site and a sterile bandage applied. The
patient is provided with post-procedural instructions. FIG. 17
illustrates while the cannula is still in position that suction 56
can be provided to extract tissue.
[0024] Certain cautions are advisable. The procedure may be
performed under local anesthesia and/or conscious sedation to allow
for patient monitoring for signs of nerve root irritation.
Continuous fluoroscopic imaging in A/P and lateral views should be
performed throughout the procedure to verify device positioning.
Irrigation should be permitted to flow continuously during the
procedure to ensure proper cooling of the disc space. Care should
be taken to make certain that the active electrode remains within
the confines of the disc during activation.
[0025] Either the small-guide wire or the large guide wire is
inserted directly through the musculature toward the symptomatic
disc. Once the guide wire is in the correct position within the
disc, the chosen cannula and the tapered dilator, completely
attached via the threaded proximal head, is inserted. See FIG. 6
for component orientation. The depth stop 54 can be added to the
selected cannula in the open depth stop position by
counter-rotation of its two ends. After positioning upon cannula
shaft, it is secured by rotation of its ends in opposite
directions. See FIG. 5. The cannula and tapered dilator are passed
together over the guide wire and inserted down to the annulus,
whereupon the tapered dilator is removed from the cannula.
[0026] Performing an annulotomy with the trephine is relatively
straightforward. To incise the annulus, the trephine 32 is placed
over the guide wire and extended through the cannula 12. See FIG.
4. The trephine should be rotated with light pressure in a
clockwise motion to incise the annulus. Once the incision is made,
the trephine and guide wire are removed from the cannula and the
cannula is advanced into the disc nucleus. The depth stop should be
used and secured at the patient's skin upon the cannula shaft to
prevent inadvertent advancement, even though with continuous
fluoroscopic monitoring.
[0027] With the cannula confirmed in optimum position, the cannula
is in place to perform a discectomy procedure.
[0028] The RF electrosurgical handpiece called Trigger-Flex System
has on its shaft two etched markings (not shown) near the handle to
aid in surgical depth monitoring: [0029] Position 1: When the
proximal (top) of the cannula head is flush to the distal etched
marking, the cannula tip will be flush to the Trigger-Flex shaft.
[0030] Position 2: When the proximal (top) of the cannula head is
flush to the proximal etched marking, the Trigger-Flex shaft will
be exposed 1.0 cm beyond the cannula tip. [0031] Position 3: When
the proximal (top) of the cannula head is flush to the distal edge
of the Trigger-Flex handle, the Trigger-Flex shaft will be exposed
3.3 cm beyond the cannula tip. The shaft has an overall length of
about 23 cm and an OD of about 2.3 cm.
[0032] To perform nucleoplasty, with the Trigger-Flex System in
position at or in the nucleus, the handle is squeezed for full
electrode advancement then retraction. This technique should be
repeated for at least 5 passes in the disc while rotating the
device. For annuloplasty; the Trigger-Flex System should be
directed toward the inner annular wall in a sweeping motion.
[0033] While the Trigger-Flex System is preferred, other elongated
electrosurgical handpieces can be substituted.
[0034] While the instrument of the invention is especially useful
for spinal procedures, it is not limited to such uses and it will
be understood that it can be employed in any electrosurgical
procedure employing a cannula in MIS.
[0035] While the invention has been described in connection with
preferred embodiments, it will be understood that modifications
thereof within the principles outlined above will be evident to
those skilled in the art and thus the invention is not limited to
the preferred embodiments but is intended to encompass such
modifications.
* * * * *