Note: Descriptions are shown in the official language in which they were submitted.
2170841
"FINGER-LIKE" LAPAROSCOPIC BLUNT DISSECTOR DEVICE
Field of the Invention
The present invention relates to dissector devices for
use in surgical procedures and, more particularly, to an
improved blunt dissector device which is particularly
adapted for use in laparoscopic surgery.
Background of the Invention
Most laparoscopic and open surgical procedures require
some "blunt" anatomical dissection to, for example,
separate the tissue and hold the tissue out of the way of
the operating site. In laparoscopic surgery, dissection is
done most commonly with electrical cautery or, in some
procedures, using thin mechanical dissectors, sometimes
combined with cauterization. Both of these approaches
present the possibility of perforation of the dissected
organ.
A number of different mechanical dissectors have been
used in surgical procedures. Patents of interest or
possible interest in the broad field of medical
manipulators and in other medical fields include the
following: 5,284,128 (Hart); 5,195,968 (Lundquist et al.);
4,998,527 (Meyer); 4,807,626 (McGirr); 4,271,845
(Chikashige et al.); and 3,730,185 (Cooke et al.).
The Hart patent discloses a surgical manipulator
having a long outer tube with a distal end and a proximal
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end. The proximal end is connected to a handle. The
distal end is constructed so that one sidewall of the outer
tube is relatively weak compared to the opposite sidewall.
An inner tube, smaller in diameter than the outer tube, is
positioned longitudinally within the outer tube and the
distal ends of the inner and outer tubes are connected
together while the proximal end of the inner tube is
connected to a finger tab that is slidably located on the
handle. When the finger tab is slid forward or backward in
relation to the handle, the tab creates a compression or
tension in the inner tube. The inner tube translates that
force to the outer tube at the distal connection, and in
response to that force, the outer tube curls in one
direction, either toward or away from the weaker wall,
depending on whether the force is compression or tension.
Thus, the end of the outer tube (as well as the inner tube
encased within) can be made to curl in either of two
directions. The patent discloses that the inner element
could be in the form of a wire rather than a tube. By
using a tube as the inner element, however, the device
allows the insertion of other laparoscopic devices through
the inner opening as well as allowing suction of fluid from
the body cavity back through the opening.
The Lundquist et al patent discloses a steering
mechanism for use with a catheter. The mechanism includes
a hollow tube with a proximal end connected to a handle and
a flexible distal end having a flat lead spring mounted
therewithin. The lead spring serves to provide memory for
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the distal end so that the distal end reverts to its
straightened position when not under tension.
Longitudinally positioned within the hollow tube is a
steering wire that is connected to the lead spring at its
distal end and to one of several tension producing
mechanisms at its proximal end in the handle. When tension
is placed on the steering wire the distal end of the tube
curls in the direction of the side of the spring to which
the wire is connected. In another embodiment, two steering
wires can be used so that the tube can be forced to curl in
either of two opposite directions. Because the device is
designed only to steer a catheter, it is not adapted to
carry other instruments or to allow fluid flow within the
tube.
The Chikashige et al. patent discloses a device for
guiding a medical instrument by bending a shaft that holds
the end of the instrument. The outer shaft is a
cylindrical coil or spring. The distal end of the coil is
coarsely wound and has one sidewall weaker than its
opposing sidewall. The different sidewall strengths can be
accomplished through a number of illustrated methods. A
wire is longitudinally positioned through the center of the
spring and connected to the distal end of the spring.
Tension placed on the wire causes the distal end of the
spring to curl in a direction away from the weaker
sidewall, thus guiding the medical instrument that is
attached to the distal end of the spring. The patent also
provides for a control wire to be longitudinally positioned
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within the spring for operating instruments such as forceps
that may be attached to the distal end of the spring.
The McGirr patent discloses a stone extractor for use
within body cavities which includes a tube with a distal
end connected to a self-closing basket and a control wire
longitudinally positioned within the tube for opening the
basket. The patent provides that fluids can flow through
the interior of the tube. In one embodiment, the tube is
made from a flexible material that has elastic memory and
is formed with a predetermined curvature. A rigid sleeve
is slid over the tube to keep it straight as the tube is
inserted through an endoscope and the sleeve is retraced to
allow the tube to resume its pre-formed curl once inside
the cavity. In this manner the basket is guided to its
desired location.
The Meyer patent discloses an endoscope tissue
removing device performing multiple functions necessary for
viewing and resecting tissue. The distal end of an inner
tube is rotated in relation to an outer tube to aid in
resecting the tissue.
The Cooke et al. patent discloses a method of removing
arteriosclerotic material from an artery. The distal end
of a rod is formed into a loop and is oscillated to cause a
separation of the material from the artery.
Summary of the Invention
According to the invention, a blunt dissector device
is provided which overcomes or reduces the dangers and
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disadvantages associated with prior art dissectors and also
provides positive advantages.
In accordance with one preferred embodiment of the
invention, a blunt dissector device is provided which
comprises: an elongate dissector element including a
movable flexible distal end portion; control means
connected to the dissector element for controlling movement
of the flexible distal end portion so as to control the
curvature (bending or curling) thereof: and mounting means
for rotatably mounting the proximal end portion of the
dissector element so as to enable the dissector element to
be rotated relative to the mounting means so as to control
positioning of the tip of the dissector element. The
latter feature enables the overall device to be held in a
comfortable position while still permitting the tip to be
moved to a desired position or site.
Preferably, the control means includes locking means
for maintaining the desired curvature of said flexible
distal end portion.
In a particularly advantageous implementation, the
control means includes a control rod extending along the
dissector element and comprising a first relatively non-
flexible proximal portion disposed with the proximal end
portion of the dissector element and second, relatively
flexible distal portion disposed within the distal end
portion of said dissector element, the proximal end portion
of the dissector element being substantially non-flexible
and the control means further comprising manually operated
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means connected to the control rod for effecting angular
rotation of the proximal end portion of the dissector
element within the mounting means so as to cause rotation
of dissector element without movement of the mounting
means.
The control means preferably includes a pair of
pivotable control arms pivotably connected together
intermediate the ends thereof, one end of one of the
control arms being connected to the control rod to control
movement thereof and one end of the other of the control
arms being connected to the mounting means. The control
arms advantageously include gripping loops at the other,
distal ends thereof, and, preferably, the device further
comprises a spring means for biasing the gripping loops
away from each other. Advantageously, one control arm
includes, at the one end thereof, a plate member having a
curved (preferably semicircular) slot therein defining end
points and the control rod extends through the curved slot
and includes said manually operated means (e. g., a control
knob) at the proximal end thereof for enabling control of
movement of the control rod within the slot, thereby to
selectively control angular movement of the dissector
element between said end points.
In accordance with an important feature, the dissector
element further comprises a resilient outer covering or
cuff made of a silicone or the like and presenting a smooth
surface.
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In an important implementation, the device further
comprises securing means for releasably securing said
dissector element in a desired angular position.
Advantageously, the securing means comprising a
circumferential groove in the outer surface of the
dissector element at the proximal end thereof, and a set
screw, disposed in the mounting means for the dissector
element, for, in use, engaging in the groove to fix the
angular position of the dissector element.
Preferably, the dissector element includes a non-
pivotable dissector member and plurality of pivotable
dissector members arranged in serial relation and hinged
together to enable pivoting thereof relative to one
another. In this implementation, the relatively non-
flexible portion of the control rod extends through the
non-pivotable dissector member and the relatively flexible
portion of said control rod extends through said pivotable
dissector members and is connected to the most distal
pivotable dissector member.
In accordance with a further feature of the invention,
a tubular member is provided which extends along the length
of the dissector element and terminates at the most distal
dissector member for permitting the insertion of auxiliary
implements through the dissector element.
Other features and advantages of the invention will be
set forth in, or apparent from, the following detailed
description of preferred embodiments of the invention.
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Brief Description of the Drawings
Figure 1 is a perspective view of a preferred
embodiment of the dissector device of the invention, with
the outer covering for the dissector portion or element
removed:
Figure 2 is a perspective view similar to that of
Figure 1 showing vertical flexure or bending of the distal
end of the dissector element in solid lines, and showing
two other possible bending positions in dashed lines;
Figure 3 is a side elevational view, partially broken
away, of the dissector element and a portion of the
remainder of the device and including the outer covering:
Figure 4 is a an exploded cross section view of the
components shown in Figure 3:
Figure 5 is a perspective view of the dissector
element of Figure 1, with parts removed:
Figure 6 is a top plan view, partially broken away, of
the dissector element of Figure 1: and
Figure 7 is a side elevational view of the control rod
or stent for the dissector element.
Description of the Preferred Embodiments
Referring to Figure 1, there is shown a perspective
view of a preferred embodiment of the blunt dissector
device of the present invention. The device, which is
generally denoted 10, basically comprises a handle portion
12, a control portion 14 and a finger-like dissector
portion 16. As will appear, these designations are more or
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less arbitrary since, for example, the handle portion
performs a control function, and are provided here for ease
of description.
The handle portion 12 includes a pair of scissor
elements 18 and 20 comprising a pair of elongate legs 18a
and 20a terminating at one end on finger grips 18b and 20b
and which are pivotably connected together at an
intermediate location along the lengths thereof at a pivot
element 22. A spring 24 disposed between and connected to
the legs 18a and 20a distally of pivot element biases apart
the finger grips or loops 18a and 20a while a locking or
latching mechanism, denoted 26, is used to lock the scissor
legs in position against the biasing force of spring 24.
The locking mechanism 26 comprises, in the illustrated
embodiment, a pair of locking members 28 and 30 disposed on
the respective legs 18a and 18b. Locking member 28
includes a projecting tongue or latch 28a, a portion of
which is visible in Figure 1 and which is adapted to engage
in one of a series of laterally spaced grooves 30a formed
in locking member 30. It will be appreciated that the
pivoting position, i.e., the amount of pivoting, of the
scissor elements 18 and 20 is controlled by the groove 30a
selected and that this position is releasably locked or
latched when tongue or latch 28a is inserted into a
selected groove 30a, as shown in Figure 2. It will also be
understood that the locking or latching mechanism 26 can
take other forms and that, in general, any locking device
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2170841
or mechanism that will retain the scissor elements 18 and
20 in a selected position can be used.
The control portion 14 of device 10 includes a
circular plate member or plate 32 disposed at the other end
of scissor element 18 from finger loop or grip 18b. Plate
32 includes a semicircular aperture 34 therein as well as a
central opening 36. A control member (rod) or stent 38
including a finger control knob 38a extends through
aperture 34 and provides control of the movement of
dissector portion 16, as described below. Further, a
cannula or channel element 40 extends through central
opening 36 and along the dissector portion 16 to permit the
insertion of various instruments required in specific
procedures as well as the insertion of a light guide or
fiber optic element to enable viewing of the operation
site, as is also described below.
Control rod or stent 38 is best seen in Figure 7 and,
as illustrated, includes, in addition to control knob 38a,
a non-flexible portion 38' and a flexible portion 38".
Handle or scissor element 20 terminates at the end
thereof opposite to finger grip or loop 20b in a
cylindrical or barrel member 42 having central cylindrical
opening 42a therethrough (see Figure 4). Barrel member 42
is offset from the plate 32 and receives the proximal non-
flexible end of the dissector portion 16. As illustrated
in, e.g., Figures 3 and 4, the control rod or stent 38 and
the cannula or channel element 40 extend through respective
openings 38b and 40a in dissector portion 16. Unless
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locked in place as described below, the dissector portion
is freely rotatable within barrel 42 under the control of
control rod or stent 38, between the limits defined by
semicircular slot or aperture 34. It will be appreciated
that instead of being integral with scissor element 20,
barrel 42 could be formed by a separate element releasably
secured to scissor element 20 by a cylindrical spring or
the like fitted around the circumference of barrel 42.
As is best seen in Figures 3 and 4, the proximal, non-
flexible end section 16a of dissector portion 16 includes a
circumferential groove 44 therein which enables a set screw
46 received in an threaded bore or aperture 48 in barrel 42
to engage in groove 44 and thus hold end section 16a in
place. In this way the angular position of the dissector
portion 16 can be fixed as desired, between the limits
defined by semicircular slot 34.
Dissector portion 16 includes, in addition to non-
flexible end section 16a, a series of further dissector
elements 16b, 16c, 16d, 16e and 16f of like shape and
distal or terminating element 16g which has the general
shape of the end of a human finger and which includes a
recess 50 in the upper (as viewed in Figures 1 and 2)
surface thereof. Elements 16a to 16g are hinged together
and, as an example, element 16b hinged to the non-flexible
section 16a by a hinge arrangement 52 perhaps best seen in
Figure 5 and Figure 6 (which is partially broken away to
show this). Hinge arrangement 52 includes a tongue 54
extending from element 16a into a slot or groove 56 in
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section 16b and held in place by a pin 58. Similar hinge
arrangements corresponding to hinge 52 and including
tongues 54 and pins 58 are used to connect the remaining
elements together.
The tapered shapes provided by the angled end faces of
elements 16b to 16f (perhaps best seen in Figures 1, 2 and
5), and the hinging together of the elements described
above, enable the elements to pivot about the respective
hinges 52 and thus curl or bend away from the straight line
or axial position shown in Figure 1 to the curved position
shown in solid lines in Figure 2 wherein the flexible part
of dissector element 16 is curved or curled upwardly. This
movement is controlled by control rod or stent 38 and more
particularly, by handle portion 12. Specifically, by
closing handle 12, i.e., by bringing finger grips or loops
18b and 20b closer together, plate 32 pivots away from
barrel 42 and thus causes the fixed end of the flexible
portion of control rod 38 to exert a force on the distal
end element 16g of dissector portion 16, and to also cause,
in the orientation of control rod 38 that is illustrated,
elements 16b to 16g to pivot in the same vertical plane to
produce the curling or bending effect described above and
illustrated in Figure 2.
It will be appreciated that the amount of curvature of
the flexible section of dissector portion 16 can be
controlled by controlling the amount of closure or
squeezing together of scissor elements 18a and 20a.
Moreover, in accordance with an important feature of the
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invention, the desired curvature can be "locked in" by
virtue of the action of locking mechanism 26 described
above.
It will also be understood that, in accordance with a
further important feature of the invention, by rotating
knob 38a, and thus control rod 38, within the semicircular
aperture 34, dissector 16 can also be caused to rotate.
Accordingly, if the knob 38a is moved to the endmost
portion on the left (as viewed in Figures 1 and 2) defined
by aperture 34, the flexible portion of dissector element
16 is caused to curl or bend to the left in a horizontal
plane containing the fixed portion 16a, as indicated in
dashed lines in Figure 2, and if knob 38a is moved to the
right endmost position, the dissector element 16 is caused
to bend the to the right in the same plane, as is also
indicated in dashed lines. As discussed above, the angular
position of the dissector element 16 can be fixed using set
screw 46 which can be screwed into threaded bore 48 to
engage in groove 44 in the proximal end of fixed dissector
portion 16a and hence inhibit further rotation of the
dissector element 16. Again, intermediate angular
positions can, of course, be selected as well, depending on
the amount of rotation of control rod 38 and thus of
dissector 16.
As illustrated in Figure 3 but is not shown in the
other figures, an outer covering or cuff 60, made of
silicone or a like material, is used to cover the non-
flexible and flexible parts of the dissector element 16 to
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create a smooth surface and to eliminate or reduce
abdominal insufflation in use of the dissector device 10.
It will be appreciated from the foregoing that flexing
of the flexible part of dissector 16 (elements 16b to 16g)
can be carried out without any rotation of the handle
portion 12, i.e., with handle portion 12 held stationary.
Thus, the handles 18 and 20 can be held by the surgeon in a
comfortable position when the dissector portion 16 is
rotated so as to direct the tip to the desired angle for
dissection. Dissection of the anatomical tissue is
achieved by suitable flexing (and unflexing) of the
flexible part of dissector element 16 through the action of
the scissor-like handles 18 and 20, when unlocked. This
action is assisted by spring 24 which makes this movement
very simple. Although the length of the flexible part of
dissector element 16 can be made longer or shorter to fit
the dissection required with a particular procedure or
operation, an exemplary length of the flexible part of
dissector 16 is about 9 to 10 cm. Advantageously, the
length can vary from 2 to 5 or more centimeters.
As discussed above, the dissector of the invention
serves to reduce the possibility of unintended perforation
of dissected organs such as can occur with prior art
devices and procedures and to assist in this, the diameter
of the dissector is made relatively large as compared with
dissectors presently in use. In accordance with a specific
non-limiting example, the diameter of the dissector is on
the order of 10 mm. Of course, the diameter of the
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dissector can be increased if the procedure to be
undertaken demands this whereas, on the other hand, the
diameter can also be decreased depending on the procedure.
However, with a small diameter (e.g., less than about 7
mm.) some of the features of the larger diameter,
embodiments may have to be eliminated. For example, the
cannula or channel tube 40 provided in the center of the
dissector 16 may have to be dispensed with because of size
considerations. In general, the diameter of the dissector
element 16 is on the order of 5mm to 12 or more mm.
As briefly discussed above, the channel tube 40 can be
used to insert a fiber-optic light element, a specifically
designed small diameter video camera or various instruments
needed for dissection such as scissors, cantering devices,
"grasps" and the like. The end of channel tube 40 is
caused to puncture the outer cuff 60 at the distal end to
permit this to be done.
The opening 40b at the tip or distal end of the
dissector 16 can be used to enable placement of ("bucking"
in) the conventional device or drain that is placed around
the dissected organ for traction or side manipulation.
Although the present invention has been described
relative to specific exemplary embodiments thereof, it will
be understood by those skilled in the art that variations
and modifications can be effected in these exemplary
embodiments without departing from the scope and spirit of
the invention.
