U.S. patent application number 11/411316 was filed with the patent office on 2006-08-31 for electrosurgical hemostat.
Invention is credited to Mark R. Bilitz, Roderick E. Briscoe, Tom P. Daigle, David E. Francischelli, Jack Goodman, Scott E. Jahns, James R. Keogh, David J.S. Kim, Alison A. Lutterman, William G. O'Neill, Adam A. Podbelski, Stephen J. Roddy, Paul T. Rothstein.
Application Number | 20060195083 11/411316 |
Document ID | / |
Family ID | 32179921 |
Filed Date | 2006-08-31 |
United States Patent
Application |
20060195083 |
Kind Code |
A1 |
Jahns; Scott E. ; et
al. |
August 31, 2006 |
Electrosurgical hemostat
Abstract
A hemostat-type device for ablative treatment of tissue,
particularly for treatment of atrial fibrillation, is constructed
with features that provide easy and effective treatment. A
swiveling head assembly can allow the jaws to be adjusted in pitch
and roll. Malleable jaws can permit curved lesion shapes. A locking
detent can secure the jaws in a closed position during the
procedure. An illuminated indicator provides confirmation that the
device is operating. A fluid delivery system simplifies irrigated
ablation procedures.
Inventors: |
Jahns; Scott E.; (Hudson,
WI) ; Francischelli; David E.; (Anoka, MN) ;
Lutterman; Alison A.; (Minneapolis, MN) ; Keogh;
James R.; (Maplewood, MN) ; Briscoe; Roderick E.;
(Rogers, MN) ; O'Neill; William G.; (Maple Grove,
MN) ; Goodman; Jack; (Ann Arbor, MI) ; Daigle;
Tom P.; (Corcoran, MN) ; Rothstein; Paul T.;
(Maple Grove, MN) ; Podbelski; Adam A.; (St. Paul,
MN) ; Roddy; Stephen J.; (Maple Grove, MN) ;
Kim; David J.S.; (Maple Grove, MN) ; Bilitz; Mark
R.; (Plymouth, MN) |
Correspondence
Address: |
James R. Keogh;Medtronic, Inc.
710 Medtronic Parkway
Minneapolis
MN
55432
US
|
Family ID: |
32179921 |
Appl. No.: |
11/411316 |
Filed: |
April 26, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10621893 |
Jul 17, 2003 |
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11411316 |
Apr 26, 2006 |
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60422330 |
Oct 30, 2002 |
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Current U.S.
Class: |
606/41 |
Current CPC
Class: |
A61B 2018/1861 20130101;
A61B 18/1445 20130101 |
Class at
Publication: |
606/041 |
International
Class: |
A61B 18/14 20060101
A61B018/14 |
Claims
1. A device for performing a surgical procedure, comprising. an
elongated handle; a pair of closeable jaws on a distal portion of
the handle; means on at least one of the jaws for ablative
treatment of tissue; means for closing the jaws on tissue; and
means for adjusting roll and pitch of the pair ofjaws relative to
the handle.
2.-72. (canceled)
Description
RELATED U.S. APPLICATION DATA
[0001] This application claims priority from U.S. Provisional
Patent Application No. 60/422,330 filed Oct. 30, 2002, incorporated
herein by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to surgical tools and
procedures generally and relates more particularly to the use of
electrosurgical ablation to treat atrial fibrillation.
[0003] In patients with chronic atrial fibrillation or having
atrial tachycardia that is resistant to medical treatment, the Maze
III procedure has been employed. This procedure controls
propagation of the depolarization wavefronts in the right and left
atria by means of surgical incisions through the walls of the right
and left atria. The incisions create blind or dead end conduction
pathways, which prevent re-entrant atrial tachycardias from
occurring. While the Maze procedure is successful in treating
atrial fibrillation, the procedure is quite complex and is
currently practiced by only a few very skilled cardiac physicians
in conjunction with other open-heart procedures. The procedure also
is quite traumatic to the heart, as in essence the right and left
atria are cut into pieces and sewed back together, to define lines
of lesion across which the depolarization wavefronts will not
propagate.
[0004] It has been suggested that procedures similar to the Maze
procedure could be instead performed by means of electrosurgical
ablation, for example, by applying radiofrequency (RF) energy to
internal or external surfaces of the atria to create lesions across
which the depolarization wavefronts will not propagate. Such
procedures are disclosed in U.S. Pat. No. 5,895,417, issued to
Pomeranz, et al., U.S. Pat. No. 5,575,766, issued to Swartz, et
al., U.S. Pat. No. 6,032,077, issued to Pomeranz, U.S. Pat. No.
6,142,944, issued to Swanson, et al., U.S. Pat. No. 5,871,523,
issued to Fleischman, et al. and U.S. Pat. No. 6,502,575, issued to
Jacobs et al., all incorporated herein by reference in their
entireties. Hemostat type, electrosurgical or cryo-ablation devices
for use in performing such procedures are described in U.S. Pat.
No. 5,733,280 issued to Avitall, U.S. Pat. No. 6,237,605 issued to
Vaska, et al, U.S. Pat. No. 6,161,543, issued to Cox, et al., PCT
published Application No. WO99/59486, by Wang and in pending U.S.
patent application Ser. No. 09/747,609 filed Dec. 22, 2000 by
Hooven, et al., all incorporated herein by reference in their
entireties. In order for such procedures to be effective it is
desirable that the electrosurgically created lesions are continuous
along their length and extend completely through the tissue of the
heart (i.e. transmural lesions). These goals may be difficult to
accomplish employing dry ablation electrodes or electrodes applied
only to the interior or exterior surfaces of the heart tissue.
Electrosurgical hemostats configured to allow fluid-assisted tissue
ablation are generally described in U.S. Pat. No. 6,096,037, issued
to Mulier, also incorporated by reference in its entirety.
SUMMARY OF THE INVENTION
[0005] The present invention provides an ablation hemostat,
particularly useful in performing a maze type procedure by applying
ablation energy (e.g. RF energy) across the walls of the left and
right atria by means of delivery means located on either side of
the atrial walls. In a preferred embodiment of the invention, the
hemostat is provided with elongated RF electrodes malleable to
assume various straight and curved configurations to produce
lesions that approximate the incisions that would occur during the
Maze III procedure as described in the book `Cardiac Surgery
Operative Technique` by Donald B. Doty, M.D. at pages.. 410-419,
incorporated herein by reference in its entirety, or to allow
creation of lines of lesion corresponding to the incisions that
would be provided by other forms of the Maze procedure. The
hemostat may be useful in conjunction with other procedures as
well.
[0006] The hemostat of the present invention is provided with a
number of useful features, particularly adapted to ease its use in
conjunction with creating elongated lines of lesion. While the
disclosed and most preferred embodiments of the invention employ
all of the improved features, each of the improved features
discussed below is believed valuable in and of itself to improve
the performance and ease of use of prior art electrosurgical
hemostats.
[0007] In order to allow the hemostat to produce straight and
curved elongated lesions, the jaws of the hemostat are malleable to
allow the physician to set the specific jaw configuration. The jaws
are fabricated of a flexible plastic sheath enclosing elongated
bendable or malleable backbones and electrodes to achieve this
result. The backbones and electrodes may be shaped by the
physicians ' fingers into a desired curvature and serve to retain
the curvature imparted to them until reshaped for creation of a
subsequent lesion. The backbones take the form of elongated plates
having thicknesses substantially less than their widths to
encourage bending of the jaws within a single plane so that the
opposed electrodes can more readily be maintained in alignment
along their lengths. The backbones are also preferably tapered
along their length such that the width of the backbones diminishes
as they approach the tips of the jaws, in turn making it easier to
provide the jaws with the curvature extending over the entire
length of the jaws.
[0008] The hemostat includes an elongated handle portion or handle
and a jaw assembly mounted at the distal end of the handle. The jaw
assembly preferably includes two elongated jaws carrying RF
electrodes or other ablation elements, extending along the lengths
of the jaws and arranged so that they are located on opposite sides
of tissue compressed between the jaws. In preferred embodiments,
the electrodes take the form of fluid irrigated RF electrodes,
however, other ablation mechanisms such as cyroablation, direct
current ablation, microwave ablation, and the like may be
substituted for RF ablation electrodes.
[0009] The jaw assembly preferably includes a swiveling head
assembly adapted to allow the jaws to be rotated relative to the
axis of the handle (roll) and allowing the jaws to pivot around an
axis perpendicular to the axis of the handle (pitch). Adjustment of
the jaws relative to the handle (pitch and roll) is made manually
by the physician, and the jaws are retained in their desired
orientation relative to the handle by means of detent
mechanisms.
[0010] The jaws are mounted to one another at a pivot point and are
opened and closed by means of a trigger, mounted to the handle,
which applies. tensile force to a cable or other tension member
extending along the handle. The cable, when pulled, pulls the jaws
toward one another to compress tissue between them. In the
particular embodiments disclosed, the cable is anchored offset from
the pivot point to a first one of the jaws. The first jaw is fixed,
i.e. retains its location during jaw closure regardless of the
pitch and roll adjustment made to the jaw assembly. The second,
pivoting jaw, is mounted to the fixed jaw at a pivot point and the
cable passes around an internal boss within the pivoting jaw, also
offset from the pivot point. Application of tension to the tension
member pulls the internal boss in the pivoting jaw toward the cable
mounting point in the fixed jaw and thereby causes movement of the
jaws toward one another. Tissue placed between the jaws can thus be
engaged by the jaws and compressed between the jaws as the jaws
close.
[0011] The cable enters the jaw assembly along its rotational
(roll) axis, so that rotation of the jaw assembly about the roll
axis does not alter the operation of the cable. The cable extends
around a shoulder internal to the fixed jaw, which shoulder remains
essentially in the same location regardless of the pitch adjustment
of the jaw assembly, so that pitch adjustment of the jaw assembly
does not significantly effect operation of the cable to close the
jaws.
[0012] In preferred embodiments, the trigger mechanism is provided
with a locking detent mechanism which may be engaged or disengaged
and which, when engaged, retains the trigger in its position, in
turn maintaining compression of the jaws against tissue located
there between. The detent mechanism in a preferred embodiment is
activated or deactivated by means of a sliding button, mounted to
the handle.
[0013] In preferred embodiments, irrigation fluid is provided to
the electrodes by means of plastic tubing that is provided with
in-line flow limiters, controlling the delivery rate of irrigation
fluid to the electrodes. This feature allows the use of a
simplified fluid pumping mechanism and also provides balanced, even
fluid flow to the electrodes. In its preferred embodiment, the
trigger, when released, also serves to block fluid flow to the
electrodes, preventing irrigation while the hemostat is not in
use.
[0014] In one embodiment, the RF electrode assembly can take the
form of an elongated porous material coupled to the fluid delivery
lines and carrying elongated electrode wires on their inner, facing
services. The electrode wires may be coupled to the porous material
by means of a series of spikes extending from the electrode wires
into the porous material. Other alternative electrode designs may
of course be substituted, including electrodes comprised of
elongated coil electrodes or perforated tubular electrodes with
porous material located either inside of or surrounding the
electrodes. For example, a perforated tubular electrode can be
seated inside a porous polymeric support such the electrode is
entirely within the support. In this embodiment, conductive fluid
flows through the interior of the electrode, out of perforations in
the electrode and through the porous support to facilitate ablation
such that the polymeric support, not the electrode, is on the
facing surfaces of the jaws to contact the tissue to be
ablated.
[0015] The hemostat may optionally also include a thermocouple,
located along the jaws allowing for temperature controlled feedback
of power provided to the RF electrodes and may also preferably
includes an indicator LED mounted to the handle, activated to
indicate that delivery of RF energy is underway. The hemostat is
usable useable with conventional RF generators. Alternatively, the
hemostat may be used in conjunction with an RF generator system,
which incorporates a transmurality measurement and automatic shut
off of ablation energy.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a plan view of an assembled hemostat according to
one embodiment of the present invention.
[0017] FIG. 2 is an exploded view of the jaw assembly of the
hemostat of FIG. 1.
[0018] FIG. 3A is a cross-section view through the jaw assembly of
the hemostat of FIG. 1.
[0019] FIG. 3B is a cross-section view through lines 3B-3B of FIG.
3A.
[0020] FIG. 4 is an end view in partial cross-section of the
proximal end of the knuckle portion of the jaw assembly of the
hemostat of FIG. 1.
[0021] FIG. 5A is a plan view of an elongated tubular electrode
used in the hemostat of FIG. 1.
[0022] Figure 5B is an enlarged cross-section view taken along
lines 5B-5B of the electrode illustrated in FIG. 5A.
[0023] FIG. 6A is an end view of an electrode support as used in
the jaw assembly of the hemostat of FIG. 1.
[0024] FIG. 6B is a cross-section view taken along lines 6A-6A of
FIG. 6A illustrating the electrode support.
[0025] FIG. 7A is an end view of an electrode sheath as included in
the jaw assembly of the hemostat of FIG. 1.
[0026] FIG. 7B is a cross-section view taken along lines 7B-7B of
FIG. 7A illustrating the electrode sheath.
[0027] FIG. 8A is a plan view of the right half of the handle
employed in the hemostat of FIG. 1.
[0028] FIG. 8B is an enlarged plan view of the distal portion of
the right handle half illustrated in FIG. 8A.
[0029] FIG. 8C is a cross-section view taken along lines 8C-8C
through the right handle half of the hemostat of FIG. 1.
[0030] FIG. 9A is a plan view of the left half of the handle
employed in the hemostat of FIG. 1.
[0031] FIG. 9B is an enlarged plan view of the distal portion of
the left handle half illustrated in FIG. 9A.
[0032] FIG. 9C is a cross-section view taken along lines 9C-9C
through the left handle half of the hemostat of FIG. 1.
[0033] FIG. 10 is an enlarged view of the trigger portion of a
hemostat as in FIG. 1 with the left handle half removed.
[0034] FIG. 11A is a perspective view of a trigger lock as employed
in the trigger assembly of the hemostat as in FIG. 1.
[0035] FIG. 11B is a plan view of the trigger lock of FIG. 11A.
[0036] FIG. 12A is a top plan view of a link arm as employed in the
trigger assembly of an assembled hemostat as in FIG. 1.
[0037] FIG. 12B is a side plan view of the link arm of FIG.
12A.
[0038] FIG. 13A is a side plan view from the distal end of the
trigger employed in the trigger assembly of the hemostat of FIG.
1.
[0039] FIG. 13B is a cross-section view taken along lines 13B-13B
through the trigger of FIG. 13A.
[0040] FIG. 14 is a cut-away view of the proximal portion of the
hemostat of FIG. 1 with the left handle half removed. p FIG. 15A is
a sectional view through an alternative embodiment of an upper and
lower jaw for use with a hemostat otherwise as in FIG. 1.
[0041] FIG. 15B is a cross-sectional view taken along lines 15B-15B
of FIG. 15A.
[0042] FIG. 16A is a plan view of an electrode extension employed
in the alternative embodiment of the upper and lower jaw depicted
in FIGS. 15A and 15B.
[0043] FIG. 16B is an expanded view of a barb of the electrode
extension depicted in FIG. 16A.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0044] In reference to FIG. 1, a preferred embodiment of the
hemostat of the present invention generally comprises an elongated
handle assembly or handle 10 having a jaw assembly 90 mounted at
handle distal end 15, a trigger 20 intermediate the handle proximal
and distal ends 95 and 15, and a strain relief 60 located at handle
proximal end 95. An elongated cable is coupled to the strain relief
60 and comprises a fluid conduit 70 extending to a proximal fluid
fitting 75 adapted to be coupled to a source of conductive fluid
and a multi-conductor electrical cable 80 extending to a proximal
electrical connector 85 adapted to be coupled to an electrosurgical
unit. The trigger 20 is employed to move the jaws of the first or
lower jaw assembly 40 with respect to the second or upper jaw
assembly 30 of the jaw assembly 90 together to compress tissue
therebetween to allow for creation of a linear RF ablation by
electrically conductive fluid emitted from electrodes and
contacting tissue or direct contact of the electrodes located along
the upper and lower jaws 35 and 45.
[0045] The jaw assembly 90 includes the upper jaw assembly 30, the
lower jaw assembly 40, and a swivel assembly 50, discussed in more
detail below. The upper jaw and lower jaw assemblies 30 and 40 have
opposed upper and lower jaws 35 and 45, respectively, each
comprising a fluid assisted elongated electrode assembly. The upper
and lower jaw assemblies 30 and 40 support elongated electrodes,
discussed in more detail below, each coupled to one of the
insulated conductors within conduit 70 extending proximately
through the strain relief 60 to electrical connector 85. Each of
the jaws 35 and 40 of respective upper and lower jaw assemblies 30
and 40 are also coupled to fluid conduit 80 enabling delivery of
saline or other conductive fluid from a source coupled to fitting
75 along the lengths of the opposedjaws 35 and 45.
[0046] The swivel assembly 50, provides the physician with the
opportunity to position the jaw assembly 90 in a variety of
orientations relative to the handle 10, to facilitate placing the
35 and 45 jaws against tissue to form desired lines of lesions,
e.g., the heart wall in performance of the above-described Maze
procedure. The physician can manually grasp and rotate the swivel
assembly 50 and the jaw assembly 90 to provide a roll adjustment R,
preferably through an arc of at least 300 degrees, relative to the
axis of the distal end 15 of the handle 10 through interaction of
components of the handle and swivel assembly described further
below. In addition, the physician can grasp the jaw assembly 90 and
adjust it in pitch P relative to the swivel assembly 50 through the
interaction of components of the jaw assembly 90 and the swivel
assembly 50 described further below. Preferably, the available arc
of pitch P adjustment extends over at least 90 degrees. Moreover,
the upper and lower jaws 35 and 45 are malleable as described
further below. The combination of these features and the S-shape
handle 10 make the hemostat highly versatile in use.
[0047] The trigger 20 is employed to open (separate apart) and
close (draw together) the jaws 35 and 45 and to compress tissue
between the jaws 35 and 45 prior to application of RF energy to
create an elongated lesion. A thumb slide 25 is provided in
conjunction with an internal trigger lock, allowing the position of
the trigger 20 and the jaws 35, 45 to be locked. After the trigger
20 is drawn toward the handle 10 to close the jaws 35 and 45, the
thumb slide 25 is moved distally relative to the handle 10 to cause
an internal trigger lock to engage one of a series of ratcheting
lock points that define a set of locking locations for the jaws 35,
45, as described further below. Movement of the thumb slide 25
proximally relative to the handle 10 releases the trigger 20 and
the jaw assembly 90, allowing the jaws 35, 45 to return to a fully
open position. The interaction of the trigger20, thumb slide 25 and
the associated trigger lock mechanism frees the physician from the
need to maintain pressure on the trigger 20 to compress tissue
between the jaws 35, 45 during the ablation, simplifying operation
of the hemostat.
[0048] Referring to FIG. 2, the upper jaw assembly 30 includes a
pivotable, relatively rigid, upper jaw mount 300, an elongated
backbone 310, an elongated insulated electrode sheath 320, an
elongated conductive electrode 330, and an elongated electrode
support 340. Upperjaw mount 300 may be fabricated of plastic or
other insulated material, and in preferred embodiments may be
fabricated of Teflon filled polycarbonate plastic. Backbone 310 is
preferably fabricated of malleable stainless steel or other
malleable metal and is attached at a proximal end to upper jaw
mount 300. An insulated electrode sheath 320 is fitted over spine
310 with its proximal end located adjacent upper jaw mount 300. The
elongated conductive electrode 330 comprises a length of malleable
conductive metal tubing as shown in FIGS. 5A and 5B is fitted into
a lumen of the elongated electrode support 340. The insulated
electrode sheath 320 is formed with a channel that receives the
sub-assembly of the elongated conductive electrode 330 and
electrode support 340 disposed along the jaw 35. Electrode sheath
320 may be fabricated of a flexible, electrically insulating,
material, for example, silicone rubber. Elongated electrode support
340 is preferably fabricated of a porous material, such as
Porex.TM. plastic, allowing for conductive fluid infiltration
through its sidewall along its length and correspondingly delivery
of conductive fluid along the length of jaw 35. The jaw 35 can
therefore be bent laterally with respect to the upper jaw mount 300
to form a curve along the length thereof.
[0049] The lower jaw assembly 40 also includes a relatively rigid,
lower jaw mount 400, an elongated backbone 410, an elongated
insulated electrode sheath 420, an elongated conductive electrode
430, and an elongated electrode support 440 that are all formed of
the same materials as the corresponding elements of the upper jaw
assembly 30. The assembly of the elongated backbone 410, elongated
insulated electrode sheath 420, elongated conductive electrode 430,
and elongated electrode support 440 is also shown in FIG. 3B.
[0050] The jaw 45 can therefore also be bent laterally with respect
to the lower jaw mount 400 to form a curve along the length
thereof. In use, the physician manually forms a lateral curve in
both the upper and lower jaws 35 and 45 to fit the contour of the
tissue, e.g., the heart wall.
[0051] The lower jaw mount 400 is formed with a pair of spaced
apart, parallel, plates or flanges 401 and 403 each bearing a
series of notches 402 and 404, respectively, along the edges
thereof. When assembled, a proximal portion of the upper jaw mount
300 is fitted between the flanges 401 and 403. A pin 480 extends
through aligned holes through the proximal portion of upper jaw
mount 300 and the flanges 401 and 403. The ends of pin 480 are
fixed to the flanges 401 and 403 allowing the proximal portion of
the upper jaw mount 300 to be rotated about the pin 480, thereby
allowing jaws 35 and 45 to open and close. The upper and lower jaws
35 and 45 are separated apart a predetermined distance in the fully
closed positions although the electrically insulated distal ends of
the insulated electrode sheaths 320 and 420 may contact one
another. A spring 450 urges the upper and lower jaws 35 and 45
apart from one another, facilitating opening of the jaws 35 and 45
upon release of the trigger 20 after application of RF energy.
[0052] As shown in FIGS. 2 and 3A, the swivel assembly 50 includes
a swivel 500 that may also be fabricated of Teflon filled
polycarbonate plastic to have a tubular proximal swivel portion
506, a pair of parallel plates or flanges 502 and 504 extending
distally from swivel proximal portion 506 and a extending detent
501 extending laterally between flanges 502 and 504. The jaw
assembly 90 is mounted to the swivel assembly 50 by outwardly and
laterally extending bosses 405 on the outer surfaces of flanges 401
and 403 that are fitted into bores 503 through swivel flanges 502
and 504. The upper jaw mount 300 is mounted to the lower jaw mount
400 by pin 480 as described above, and the lower jaw mount is 400
pivotably mounted relative to the swivel 500. Therefore, the upper
and lower jaw assemblies 30 and 40 may be pivoted together relative
to the swivel 500, allowing for movement of the jaws 35 and 45
together through the range of pitch P adjustment. The selected
pitch P adjustment is maintained by the engagement of the detent
501 into an opposed pair of notches 402 and 404, stabilizing the
upper and lower jaws 35 and 45 in a desired orientation relative to
the swivel assembly 50. In use, the physician adjusts the relative
positions of the jaws 35 and 45 relative to the swivel assembly 50
by simply manually moving the jaw assemblies 30 and 40 in the pitch
P direction around the pivot axis defined by bosses 405 within the
corresponding bores 505 in swivel flanges 502 and 504. The detent
501 simply rides over the ridges separating adjacent notches 402
and 404.
[0053] As noted above, the swivel assembly 50 and the upper and
lower jaw assemblies 30 and 40 can be rotated around the axis of
the distal end 15 of the handle 10 to a desired roll adjustment R
to facilitate positioning the jaws 35 and 45 for creation of
elongated lesions. The proximal portion 506 of swivel 500 is
rotatably mounted within a collar 550 that is mounted fixedly to
the distal end 15 of the handle 10 as shown in FIG. 3A. The collar
550 has a wavy or sinusoidal distally facing surface 551 of collar
550. A washer-shaped insert 510 having a wavy or sinusoidal
proximally facing surface 511 is fitted over the elongated proximal
portion 506 of swivel 500 and attached to the swivel 500 through
notches 514, engaging corresponding bosses 557 and 567 (shown in
FIG. 4) formed on swivel 500. A C-clip 524 mounted in a
circumferential groove formed in the proximal portion 506 of swivel
500 maintains the proximal portion 506 within the lumen of collar
550. A spring washer 522 and a flat washer 520 are interposed
between the C-clip 524 and the proximal end of collar 550. Spring
washer 522 urges the wavy or sinusoidal surfaces of collar 550 and
insert 510 against one another, whereby a plurality of detent
locations are defined that maintain a selected roll R adjustment
relative to the distal end 15 of the handle 10. In use, the
physician adjusts the roll R of the jaw assembly 90 by simply
turning the swivel assembly 50 relative to the handle 10. The
detent mechanism maintains the swivel assembly 50 in the selected
desired roll R adjustment prior to and during closure of the jaws
35, 45 to compress tissue during application of RF energy.
[0054] A cable 390 is also shown in FIGS. 3A and 4 that extends
from the trigger 20 and that is employed to open and close the jaws
35 and 45. Cable 390 passes through the internal lumen of proximal
swivel portion 502, through cable bore 565, around shoulder 404 of
lower jaw mount 400, around boss 303 in upper jaw mount 300 and
then upward into bore 408 in lower jaw mount 400. The distal end of
the cable 390 is maintained within bore 408 by ball 350. When the
cable 390 is pulled proximally by squeezing trigger 25, boss 303 of
upper jaw 300 is pulled toward bore 408 in lower jaw 400, thereby
pulling upper jaw 35 toward lower jaw 45, allowing for compression
of tissue there between. It should be noted that during this
operation, the lower jaw mount 400 remains fixed relative to the
swivel assembly 50 and only upper jaw mount 300 moves relative to
the swivel assembly 50 or the handle 10. Proximal movement of cable
380 does not affect the position of the lower jaw 45 relative to
the handle 10, nor does it affect the selected roll R adjustment of
swivel 500. Rotation of the jaw assembly 90 and swivel 500 about
the roll axis does not affect the operation of the cable 390
because the cable 390 passes through the swivel 500 and enters the
jaw assembly 90 along the roll axis. Pitch P adjustment of the jaw
assembly 90 does not significantly effect operation of the cable
390 in opening or closing the jaws 35, 45 because shoulder 404 is
at the center of rotation of lower jaw mount 400 relative to swivel
500 and remains essentially in the same location regardless of the
pitch P adjustment.
[0055] FIGS. 3A and 4 also internal electrical wiring and fluid
delivery conduits of this embodiment of the invention including,
insulated conductors 360 and 460 and fluid conduits 370 and 470
that both terminate at connections with the proximal ends of the
upper and lower electrodes 330 and 430, respectively. The fluid
conduits 370 and 470 deliver conductive fluid into the lumens of
the tubular upper and lower electrodes 330 and 430, respectively.
As shown in FIG. 4, the upper insulated conductor 360 and the upper
fluid conduit 370 are routed to one side of the cable 390, and the
lower insulated conductor 460 and the lower fluid conduit 470 are
routed to the other side of the cable 390 while passing through the
lumen 534.
[0056] The elongated tubular electrodes 330 and 430 are illustrated
in FIGS. 5A and 5B. The tubular electrodes 330 and 430 are
preferably formed of thin-walled, malleable stainless steel tubing
extending between a proximal open end 331, 431 and a distal closed
end 333, 433. A series of fluid ports 335, 435 are formed, e.g., by
laser drilling, through the sidewall of the tubing from the lumen
339, 439 and extending in a single line, although the fluid ports
could be formed in any selected array extending around the
circumference of the sidewall of the tubing. The proximal ends 331,
431 are notched in alignment with the series of fluid ports 335,
435 to assist in assembly so that the fluid ports 335, 435 are
directed in a particular alignment with the porous electrode
support 340, 440.
[0057] The porous electrode support 340, 440, depicted in FIGS. 6A
and 6B, comprises a length of non-conductive, porous, malleable
tubing having a channeled side 343, 443 adapted to fit within an
elongated channel 323, 423 of the insulated electrode sheath 320,
420, depicted in FIGS. 7A and 7B. The porous electrode support 340,
440 is conically shaped at the support distal end 347, 447 to fit
within a conically shaped terminus 327, 427 of the elongated
channel 323, 423 of the insulated electrode sheath 320, 420. During
assembly, the elongated tubular electrode 330, 430 is inserted into
the elongated lumen 341, 441 of the porous electrode support 340,
440. Preferably, the series of fluid ports 335, 435 are oriented
toward the channeled side 343, 443 so that the conductive fluid
emitted from the lumen through the series of fluid ports 335, 435
then migrates laterally through the pores of the porous electrode
support 340, 440 and around its circumference to thoroughly and
uniformly wet the porous electrode support 340, 440 along the upper
and lower jaws 35 and 45.
[0058] The sub-assembly so formed is fitted into the shaped
terminus 327, 427 and the elongated channel 323, 423 of the
insulated electrode sheath 320, 420 as also shown in FIGS. 3A and
3B. Adhesive is applied to the contacting surfaces 323, 343 and
423, 443 to maintain the sub-assembly of the elongated tubular
electrode 330, 430 inserted into the elongated lumen 341, 441 of
the porous electrode support 340, 440 affixed to the insulated
electrode sheath 320, 420. The adhesive does not block migration of
conductive fluid around the porous electrode support 340, 440.
Electrode sheathe 320, 420 is also formed having an elongated
tapered internal recess 421 441 that receives the malleable
backbone 310,410 as shown in FIGS. 2 and 3. Again, adhesive may be
applied to the contacting surfaces of the backbone 310, 410 and the
elongated tapered internal recess 421 441.
[0059] The handle 10 is formed of a right handle half 600 depicted
in FIGS. 8A-8C and a left handle half 700 depicted in FIGS. 9A-9C.
Trigger sections 620 and 720 of the respective right and left
handle halves 600 and 700 include downwardly opening recesses 621
and 721 in which trigger 20 is mounted (as shown in FIGS. 1 and 10)
to pivot inward to apply tension on cable 390 or outward to release
tension on cable 390. Upward openings 627 and 727 in respective
right and left handle halves 600 and 700 receive the thumb slide
25. Inwardly extending projections 630 and 730 are also formed in
respective right and left handle halves 600 and 700 that function
to constrict the fluid conduits 370 and 470 to prevent conductive
fluid flow therethrough when the trigger 20 is released as
described further below.
[0060] A set of circular matching, laterally opposed, sockets 623
and 723 are formed in the interior surfaces of the respective right
and left handle halves 600 and 700. The set of sockets 623, 723,
receive a pair of pivot bosses 206, 206' of trigger 20 (shown in
Figure. 13A) about which the trigger 20 pivots as described further
below. A set of matching, laterally opposed, and slightly elongated
or oblong, sockets 624 and 724 are formed in the interior surfaces
of the respective right and left handle halves 600 and 700. The set
of sockets 624, 724 receive and guide a trigger lock 27 (shown in
FIGS. 11A and 11B) that interacts with trigger 20 as described
further below. The oblong shape of the set of sockets 624, 724
assists in allowing the trigger 20 to ratchet along the trigger
lock 27 when trigger is drawn inward to tension the cable 390
during closing of the jaws 35, 45 as described further below.
[0061] A further set of matching, laterally opposed, elongated
sockets 625 and 725 are also formed in the interior surfaces of the
respective right and left handle halves 600 and 700. The set of
sockets 625, 725 receive and guide a link arm 26 (shown in FIGS.
12A and 12B) that interacts with trigger 20 as described further
below.
[0062] As shown in FIGS. 8B and 9B, the distal portions of right
and left handle halves 600 and 700 are formed with internal
cylindrical recesses or sockets 612 and 712 that receive the
laterally extending bosses 552 of collar 550 (FIG. 2). Internal
grooves 611 and 711 are also formed within the distal portions of
right and left handle halves 600 and 700 in which the c-clip 524,
flat washer 520 and spring washer 522 (FIGS. 2 and 3A) are
fitted.
[0063] As shown in FIGS. 8C and 9C, the right and left handle
halves 600 and 700 are also provided with a series of laterally
extending, perpendicular internal walls 628 and 728 that include
slots and recesses for routing the fluid conduits or tubes 370 and
470, the cable 390 and the insulated wire conductors 360 and 460
that extend through the length of handle 10.
[0064] The trigger 20, thumb slide 25, and the associated link arm
26 and trigger lock 27 are shown assembled to the right handle half
600 in FIG. 10 with the trigger 20 in the released position and the
thumb slide 25 in the unlocked distal or retracted position. The
trigger lock 27 is shown in greater detail in FIGS. 11A-11B, the
link arm 26 is shown in greater detail in FIGS. 12A-12B, and the
trigger 20 is shown in isolation in FIGS. 13A-13B.
[0065] Trigger 20 is provided with laterally extending cylindrical
pivot bosses 206, 206' that are mounted into sockets 723 and 623,
respectively. When released, trigger 20 extends outward through
downwardly opening recesses 621 and 721. When pulled, trigger 20 is
pivoted inwardly into the handle recesses 621 and 721 about pivot
bosses 206, 206' to apply tension to the cable 390 that draws the
upper and lower jaws 35 and 45 together. Cable 390 is mounted
within a lubricious tube 391, extending from the proximal wall 628
to the distal end 15 of the handle 10, to allow the cable 390 to
move freely within the handle 10 when trigger 20 is pulled or
released.
[0066] Trigger 20 is coupled to the proximal end of cable 390
through link arm 26, illustrated in isolation in FIGS. 12A and 12B.
Link arm 26 is provided at a distal end with two laterally
extending bosses 262 and 262' that are received in circular sockets
204 (one of which is shown in FIG. 13B) formed on the interior
walls of the internal chamber 202 of trigger 20 to thereby
pivotally mount the distal end of the link arm 26 to the trigger
20. Link arm 26 is formed with a longitudinally extending slot 266,
allowing compression of the distal end of the link arm 26 to
facilitate positioning of cylindrical bosses 262 and 262' within
the corresponding sockets 204 within the trigger 20. As also shown
in FIG. 13B, longitudinal slots 215 are provided in the interior
202 to assist insertion of the bosses 262, 262' on link arm 26 into
sockets 204 in trigger 20 during assembly. Link arm 26 is provided
at its proximal end with two laterally extending, circular bosses
264 and 264' that are received within the elongated slots 625 and
725, respectively, in the respective right and left handle halves
600 and 700. When trigger 20 is released, the circular bosses 264
and 264' are disposed at the distal ends of the opposed elongated
slots 625 and 725, respectively. When trigger 20 is pulled inward,
the proximal end of the link arm 26 is moved proximally within the
opposed slots 625 and 725, applying tension to cable 390.
[0067] Cable 390 is coupled to the link arm 26 by means of a swaged
retainer 24, mounted within a coil spring 28. Coil spring 28 is
fitted within a generally cylindrical chamber 266 formed extending
at 90 degrees to the proximal end of link arm 26. Cable 390 passes
through an upwardly facing slot 270 in link arm 26 and through the
interior of spring 28 to retainer 24. Spring 28 is normally
extended within chamber 266 but is compressed to provide protection
against over tensioning of the cable 390, if the upper and lower
jaws 35 and 45 encounter significant resistance to further movement
toward one another. The configuration of the trigger 20, link arm
26 and slots 625 and 725 provide a mechanism whereby, the cable 390
is pulled proximally relatively quickly during initial upward
movement of the trigger 20 to facilitate initial rapid closing of
the jaws 35 and 45. The cable 390 is pulled relatively more slowly
during further upward movement of the trigger 20 to provide
increased control to the physician during final compression of the
jaws 35 and 45 against the tissue to be ablated.
[0068] Trigger 20 is also provided with a distally extending
projection 208 terminating with a laterally extending, generally
cylindrical, boss 210 shown best in FIG. 13B. As illustrated in
FIG. 10, when the trigger 20 is released and in its most downward
position (corresponding to the point of maximum jaw opening), the
fluid conduits or tubes 370 and 470 are disposed side by side and
compressed between cylindrical boss 210 and the inwardly extending
projections 630 and 730. This compression of the fluid conduits or
tubes 370 and 470 prevents flow of conductive fluid from the fluid
source and out of the electrodes 330 and 430 and the electrode
mounts 340 and 440 when the hemostat is not in use.
[0069] The trigger 20 is also formed with a laterally extending
slot 212 having an array of teeth 214 formed along one side of the
slot 212. A trigger lock mechanism is provided involving the
interaction of the thumb slide 25 with the trigger 20 through a
trigger lock 27 that is coupled at one end with the thumb slide 25
and selectively engages the teeth 214 to retain the upper and lower
jaws 35 and 45 at a fixed position adjacent tissue to be ablated
without requiring the physician to continually apply pressure to
trigger 20. Distal or forward movement of the thumb slide 25 causes
the trigger lock 27 to engage the teeth 214, and proximal or
rearward movement of the thumb slide 25 releases the engagement.
The trigger 20 can be operated freely by the physician to open or
close the upper and lower jaws 35 and 45 when the thumb slide 25 is
in the rearward position. With the thumb slide 25 in the forward
position, the trigger 20 can be moved inward ratcheting over the
teeth 214 to close the upper and lower jaws 35 and 45, but the
trigger 20 will not move outward upon release by the physician.
[0070] The trigger lock 27 depicted in isolation in FIGS. 11A and
11B comprises an elongated link arm 275 having rods 272 and 278
laterally extending parallel to one another from opposed ends of
the link arm 275. As shown in FIG. 10, the rod 272 is inserted
through the slot 202 so that the link arm 275 extends alongside the
trigger 20 within the recess 721. The rod 278 extends into a
generally centrally located notch 252 of a resilient beam section
250 of the thumb slide 25. Cylindrical pivot bosses 276 and 276'
extend laterally on either side of the link arm 275 in alignment
with rod 272 and are inserted into sockets 724 and 624,
respectively.
[0071] The rod 272 inserted through the slot 212 extending through
the trigger 20 is formed with a laterally extending ramped tooth
274 that is selectively engagable with one of the ramped teeth 214
formed along the proximal edge of slot 212, when the trigger lock
27 is pivoted forward from the position illustrated in FIG. 10 by
distal or forward movement of the thumb slide 25 by the physician.
Movement of the trigger 20 inwardly into the handle recess with the
trigger lock 27 advanced forward from the position illustrated in
FIG. 10 causes the interaction of the tooth 274 on the trigger lock
27 with the teeth 214 to retain the trigger 20 in position when
pressure is released. The oblong configuration of sockets 624 and
724 that receive bosses 276' and 276 of the trigger lock 27 allow
the trigger lock 27 to move slightly forward during inward movement
of the trigger 20 so that the tooth 276 on trigger lock 27 may
ratchet along the ramped teeth 214 of trigger 20. Interaction of
the teeth 214 with the ramped tooth 274 on the trigger lock 27
prevents outward movement of the trigger 20 as long as the thumb
slide 25 remains in the forward position in the slot formed by
openings 627 and 727.
[0072] Release of the trigger 20 is accomplished by proximal or
rearward movement of thumb slide 25, pivoting the ramped tooth 274
out of engagement with a tooth of the teeth 214 along slot 212
which allows the upper and lower jaws 35 and 45 to open unless the
physician holds the trigger 20 in position. The trigger 20 is urged
outwardly out of the recess in handle 10 by spring 23 upon release
of the trigger 20 and rearward movement of the thumb slide 25. When
the trigger 20 reaches its full outward position, flow of
conductive fluid through fluid conduits 370 and 470 is terminated
as the tubing is compressed between the laterally extending boss
210 and the inwardly extending projections 630 and 730, as
discussed above.
[0073] The thumb slide 25 is provided with a resilient beam section
250, having a generally centrally located notch 252 which engages
the laterally extending rod 278 on trigger lock 27, coupling the
thumb slide 25 to the trigger lock 27. The thumb slide 25 is
preferentially retained at either the proximal, rearward or distal,
forward point of its travel, without the necessity of the physician
manually maintaining pressure on the thumb slide 25 due to the
resilience of the beam 250 and the arcuate path of travel of the
rod 278.
[0074] FIG. 14 illustrates a proximal portion of the assembled
hemostat of FIG. 1 with the left handle half 700 removed to show
the multi-conductor cable 80 and fluid conduit 70 extending through
the strain relief 60 and their joinder to the wire conductors 360,
460 and the fluid conduits 370, 470.
[0075] The distal end of the fluid conduit 80 is coupled through a
fitting 802 to proximal end of flexible tubing 804. The distal end
of flexible tubing 804 is coupled to the trunk of a Y-connector
806, and the distal legs of the Y connector 806 are coupled to arms
of a D-connector 810. The D connector 810 is formed of a flexible
plastic; e.g., silicone rubber, providing spaced apart fluid
channels that are coupled to the proximal ends of the fluid
conduits 370 and 470.
[0076] The fitting 804 supports a proximal flow controller or
regulator 820 that has a precisely sized orifice that limits
conductive fluid flow into the Y-connector 806. The flow regulator
820 establishes a fixed flow rate and pressure within the
Y-connector 806 regardless of the pressure of the fluid source that
is available in the surgical theatre. The flow rate is established
depending upon the upper and lower electrode area and design.
[0077] The D connector 810 supports a pair of downstream flow
regulators 822 and 824 that have equal, precisely sized orifices
that further reduce the fluid flow rate and pressure of the
conductive fluid entering the fluid conduits 370 and 470. The
downstream flow regulators 822 and 824 ensure that an even flow of
conductive fluid is provided from within the Y connector 806 into
the fluid conduits 370 and 470. By this mechanism, the hemostat may
be operated without the necessity of an associated pressurized
fluid source and still provide controlled and even fluid flow to
the upper and lower jaws 35 and 45 that contact the tissue to be
ablated.
[0078] An optional light emitter, e.g., an LED 830, is depicted in
FIG. 14 located within the strain relief 60 and coupled through an
electrical junction 832 with the insulated wire conductors 360 and
460. The wire conductors 360 and 460 can take the form of a twisted
wire cable that extends distally from the electrical junction 832
through the length of the handle to the swivel assembly 50 where
they are separated as shown in FIGS. 3A and 4. Separate wire
conductors within a cable 834 extend from the electrical junction
832 to the LED 830. In use, the LED 830 is illuminated in response
to activation of an associated RF electrosurgical generator, and
the LED illumination illuminates the strain relief 60, which is
preferably fabricated of a translucent flexible material, such as
silicone rubber or the like. The physician will typically hold the
handle 10 in orientations that make the strain relief 60 visible,
and illumination of the LED 830 indicates to the physician that RF
energy is being applied to the electrodes
[0079] The proximal portion of the handle 10 may also optionally
carry other electronic components including circuitry containing
calibration information, for example calibrating a thermocouple if
provided to sense electrode or tissue temperature. Circuitry
containing identification information or providing re-use
prevention may also be included, however such features are not
believed to be essential to or a part of the present invention.
[0080] FIGS. 15A and 15B illustrate an alternative embodiment of
the electrode described above that can be employed in modified
upper and lower jaw assemblies 30A and 40A corresponding generally
to upper and lower jaw assemblies 30 and 40. The upper and lower
jaw assemblies 30A, 40A have a malleable backbone 310, 410 and a
sheath 320, 420 as described above that are attached to the
respective upper and lower jaw mounts 300 and 400 as shown in FIGS.
2 and 3. However, electrode 330A, 430A incorporates an exposed
elongated electrode extension 350A, 450A extending to the outer
surface of porous electrode support 340A, 440A and along the jaw
35, 45 that is intended to directly contact the tissue to be
ablated. In this embodiment, conductive fluid is delivered as
described above into the lumen of the internal tubular electrode
330A, 430A, which may be substantially the same as the tubular
electrodes 330, 430. An elongated electrode surface 352A, 452A of
the electrode extension 350A, 450A and the contacted tissue are
irrigated by conductive fluid emitted through the fluid ports of
the internal tubular electrode 330A, 430A and conducted through the
pores of the electrode support 340A, 440A.
[0081] The electrode extension 350A, 450A is depicted prior to
assembly with the electrode support 340A, 440A and the elongated
tubular electrode 330A, 430A in FIGS. 16A and 16B. As formed, the
electrode extension 350A, 450A includes an elongated straight
portion 352A, 452A that is mounted against the exposed to the
exterior of the electrode support 340A, 440A. A distally extending
portion 360A, 460A is adapted to be inserted into the lumen of the
electrode support 340A, 440A to extend alongside the elongated
tubular electrode 330A 430A as shown in FIG. 15B.
[0082] A series of barbed projections 354A, 454A extend laterally
away from the elongated straight portion 352A, 452A. The electrode
extension 350A, 450A is adapted to be bent back at junction 356A,
456A to enable insertion of the series of barbed projections 358A,
458A into the electrode support 340A, 440A. The proximal end 362A,
462A is electrically connected to the proximal ends of the tubular
electrodes 330A, 430A and the distal ends of the wire conductors
360, 460.
[0083] This alternative exposed electrode embodiment can be formed
by modifying the tubular electrode 330, 430 to have a conductive
electrode band extending from the tubular electrode along the
surface of the electrode support 340, 440. Alternatively, this
alternative electrode design can be accomplished without use of the
tubular electrode 330, 430, whereby conductive fluid is delivered
to a lumen of the electrode support 340, 440 or to a fluid channel
between the electrode support 340, 440 and the sheath 320, 420, and
the exposed electrode band is supported by the electrode
support
[0084] The embodiments of the electrosurgical hemostat described
above contain a number of valuable features and components, all of
which contribute to provide a hemostat, which is convenient to use
while providing substantial flexibility in use. However, many of
the features of the hemostat could be employed in hemostats of
other designs. For example, the trigger mechanism and/or the
trigger lock mechanism of the above-described hemostat would
certainly be of use in conjunction with cable activated hemostats
having jaws of alternative designs to that described above.
Similarly, the jaw assembly of the present hemostat might well be
employed in conjunction with alternative trigger mechanisms. And/or
in conjunction with alternative electrode designs, including
electrodes which might not include provision for fluid irrigation
and/or in the context of the hemostat having jaws that are rigid
and not malleable by the physician to assume desired
configurations. Further the specific electrode design employed in
the hemostat design described above would be of significant use in
conjunction with other hemostat types, including hemostats having
jaws which are moved toward one another by alternative mechanisms.
Similarly, a strain relief of the type described above including an
LED indicator is believed to be of value in conjunction with any
number of electrosurgical tools, particularly those in which the
strain relief is within the physician's field of view, during
normal operation of the hemostat. As such, the above description
should be taken as exemplary, rather than limiting, with regard to
the claims which follow.
* * * * *