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Description  |
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TECHNICAL FIELD
The present invention relates in general to medical devices and more
particularly relates to an improved trocar sleeve which can be inserted a
short distance into the abdominal cavity and expanded to prevent the
sleeve from sliding in and out of the incision.
BACKGROUND OF THE INVENTION
In the past few years, laparoscopic surgery has become increasingly
important and widespread. In the past, when doing surgery within the
abdominal cavity, a large incision through the abdominal wall was required
to permit the surgeon to adequate view the area to be operated on. The
development of the laparoscope, a small telescope utilizing fiber optic
technology, allows the surgeon to view a cite to be operated on within the
abdominal cavity with an incision only large enough to insert the
laparoscope. With such a small incision required, laparoscopic surgery
reduces the risk of infection to the patient and the extent of trauma to
the body during the surgery. The surgery also reduces the chance of
adhesions resulting from exposure of the interior of the body, a relative
common occurrence in prior surgery.
In conducting laparoscopic surgery, a small incision is typically cut
through the abdominal wall for insertion of a cannula. Pressurized carbon
dioxide gas passes through the cannula to inflate the abdomen to create
voids for passage of the laparoscope. After inflation, the cannula is
removed.
A trocar, or sharp pointed instrument, is then used to form an incision
through the abdominal wall which will be used for insertion of the
laparoscope. A trocar sleeve is concentric with the trocar, with only the
sharp end of the trocar exposed from the trocar sleeve. Thus, when the
trocar is inserted through the abdomen wall, a first end of the trocar
sleeve is pushed through the abdomen wall into the abdominal cavity. The
trocar is withdrawn from both the abdomen and trocar sleeve, leaving the
first end of the trocar sleeve within the abdominal cavity. The
laparoscope, or other suitable apparatus, can then be inserted through the
interior of the trocar sleeve into the abdominal cavity. One example of a
trocar assembly is disclosed in U.S. Pat. No. 4,601,710 issued Jul. 22,
1986.
While such techniques have proven useful, several disadvantages remain. The
trocar sleeve has a tendency to slide in and out of the incision in the
abdominal wall, particularly when the surgeon is trying to move the
laparoscopic instrumentation through the interior of the trocar sleeve
into or out of the abdominal cavity. Further, seals are provided in the
passage through the trocar sleeve to prevent the carbon dioxide gas from
escaping the abdominal cavity. It is often difficult and time consuming to
force the laparoscopic instrumentation or other device past these seals
into the abdominal cavity. Therefore, a need exists for an improved
apparatus and method for performing such laparoscopic surgery.
SUMMARY OF THE INVENTION
An improved trocar assembly is provided for use in inserting a laparoscopic
instrument into the abdominal cavity. The trocar assembly includes a
trocar sleeve having a first end extending into the abdominal cavity
through an incision in the abdominal wall. The first end has a first
external diameter for passage through the incision. The trocar assembly
further has structure for expanding a portion of the first end within the
abdominal cavity so that the external dimension of the first end within
the abdominal cavity is a larger, second external diameter. The expanded
first end of the trocar sleeve abuts the inner abdominal wall about the
incision to resist withdrawal of the trocar sleeve from the abdominal
cavity.
In accordance with another aspect of the present invention, the trocar
sleeve includes a first sleeve portion and a second sleeve portion, the
sleeve portions being concentric. The first sleeve portion has a mushroom
hinge thereon at the first end of the trocar sleeve. The structure for
expanding the portion of the first end causes the first and second sleeve
portions to move relative one another along their longitudinal axes to
expand the mushroom hinge. The structure can include a spring for moving
the sleeve portions relative one another and a latch mechanism for holding
the spring in a compressed state with the first end of the trocar sleeve
having the first external dimension. Release of the latch mechanism allows
the spring to expand, causing the sleeve portions to move and expand the
mushroom hinge.
In accordance with another aspect of the present invention, a trocar sleeve
is provided which has a first end extending into the abdominal cavity
through an incision in the abdominal wall. The trocar sleeve has a passage
formed therethrough which extends from the abdominal cavity to the
exterior, A seal is mounted in the trocar sleeve along the passage. The
seal is formed of a resilient material and has a concave shape facing the
first end of the trocar assembly within the abdominal cavity. A slit is
formed in the seal, forming first and second seal lips on opposite sides
of the slit. In the absence of a laparoscopic instrument, the pressure
within the abdominal cavity urges the first and second lips together to
form a seal at the slit. When a laparoscopic instrument is inserted
through the passage, the first and second lips are resiliently deflected
to permit passage of the instrument.
In accordance with another aspect of the present invention, a method for
inserting a trocar sleeve through the abdominal wall for laparoscopic
surgery is provided. The method includes the step of forming an incision
through the abdominal cavity with a trocar and passing a first end of a
trocar sleeve into the abdominal cavity. The first end of the trocar
sleeve having a first external dimension for passage through the incision.
The method further includes the step of expanding a portion of the first
end within the abdominal cavity so that the external diameter of the first
end within the cavity is expanded to a larger, second external dimension
to abut the inner surface of the abdominal wall about the incision to
resist withdrawal of the trocar sleeve from the abdominal cavity.
BRIEF DESCRIPTION OF THE DRAWINGS
Further features and advantages of the invention will become more apparent
from the following Detailed Description and illustrated in the
accompanying drawings, in which:
FIG. 1 is a side view of a trocar sleeve forming a first embodiment of the
present invention prior to expansion;
FIG. 2 is a side view of the trocar sleeve after expansion of the mushroom
hinge;
FIG. 3 is a side view of a trocar used with the trocar sleeve;
FIG. 4 is a perspective view of a seal within the trocar sleeve;
FIG. 5 is an illustrative view of a first modification of the trocar sleeve
where an expanding sponge is used; and
FIG. 6 is an illustrative view of a second modification of the trocar
sleeve where an inflatable balloon is used.
DETAILED DESCRIPTION
With reference now to FIGS. 1-3, a trocar sleeve 10 forming a first
embodiment of the present invention is illustrated. With the assistance of
a trocar 12, seen in FIG. 3, a first end 14 of the sleeve 10 is inserted
through an incision 16 in the abdominal wall 18 of a patient. The trocar
12 is inserted through passage 26 in the trocar sleeve so that only the
sharp pointed end 13 extends from the first end 14 of sleeve 10. The
pointed end of trocar 12 then is pushed through the abdominal wall along
with first end 14. The sleeve 10 is secured therein by expansion of a
mushroom hinge 20 which abuts the inside surface 22 of the abdominal wall
about the incision 16 to prevent premature withdrawal of the trocar
sleeve. After removal of trocar 12, laparoscopic instruments and the like
can be inserted into the abdominal cavity 24 through passage 26 in the
trocar sleeve 10.
With reference to FIGS. 1 and 2, the trocar sleeve 10 can be seen to
include an inner cylindrical metal sleeve 28 and a concentric outer
cylindrical plastic sleeve 30 preferably of polypropylene. The sleeves 28
and 30 are bonded or fastened together at the first end 14. Near the first
end 14, the outer plastic sleeve 30 defines mushroom hinge 20 with a
series of living hinges 32 about the circumference of the sleeve 30
separated by elongated slits 34. An outer elastic coating or sleeve 36,
preferably of latex, overlies the living hinges 32 and slits 34 to cover
the mushroom hinge 20. Coating or sleeve 36 insures that no body tissue is
trapped between portions of the mushroom hinge, particularly when
contracting the hinge for removal of the sleeve 10 from the patient.
At end 38 of the trocar sleeve opposite the first end, the metal sleeve 28
has a series of openings 40. A plastic end member 42 is secured to the
metal sleeve 28 at end 38 by latches 44 received in the openings 40.
A plastic seal retaining cap 46 is, in turn, secured to the end member 42
by latches 48 on the cap. An O.D. seal 50, a split seal 52, and a pack
ring 54 are confined between the end member 42 and cap 46 to prevent the
pressurized gas within the abdominal cavity from escaping through the
passage 26 in the metal sleeve 28 as will be described hereinafter. Seals
50 and 52 are preferably of silicon rubber.
A handle 58 is secured to the outer plastic sleeve 30 at end 38. A coil
spring 60 acts between the end member 42 and the handle 58 to urge the
handle 58 toward the first end of the trocar sleeve.
In the configuration illustrated in FIG. 1, the coil spring 60 is held in a
compressed state between the end member 42 and the handle 58 as resilient
latches 62 on the end member 42 are in contact with an end surface 64 of
the handle.
A latch release 66 is received about the outer plastic sleeve 30 for
movement relative the sleeve 30. The latch release 66 can be seen to have
a conical camming surface 68 which can be moved into engagement with the
ends of latches 62 to deflect the latches inward toward the axis 70 of the
trocar sleeve 10. The latch release 66 can be activated by the surgeon
directly, or, as an alternative, by providing a mechanism whereby
withdrawal of the trocar after inserting the sleeve through incision 16
activates the latch release. The latches 62 will be deflected inward
enough to release the handle 58 from the end member 42, which permits the
spring 60 to expand to the position shown in FIG. 2. As the spring
expands, the spring forces the handle 58, and attached outer plastic
sleeve 30, toward the first end relative to the end member 42 and inner
metal sleeve 28. This causes the portions of the plastic sleeve 30 at the
living hinges to bend and expand the mushroom hinge 20, as seen in FIG. 2.
It can be readily understood that the expanded mushroom hinge abuts the
inside surface 22 of the abdominal wall 18 to resist removal of the trocar
sleeve.
A dense rubber foam stop 72 can be frictionally engaged with the outer
plastic sleeve 30. When the mushroom hinge has been expanded, the stop 72
can be slid downward along the plastic sleeve 30 toward the first end to
contact the outer surface 74 of the abdominal wall 18 to resist movement
of the trocar sleeve into the abdominal cavity.
It can be readily understood that the trocar sleeve 10 provides a stable
platform for insertion of a laparoscopic instrument or the like through
the sleeve 10 into the abdominal cavity through passage 56. The expanded
mushroom hinge 20 also forms a good seal with the patient's abdominal wall
18 to prevent CO.sub.2 loss. Any tendency for the trocar sleeve 10 to move
relative the abdominal wall as the instrument is being inserted or removed
will be greatly reduced by the expanded mushroom hinge 20 and stop 72.
When the trocar sleeve 10 is to be removed from the patient, surface 46A is
pressed towards the handle 58 at surface 58A in a manner similar to a
syringe to collapse the mushroom hinge 20 and compress the spring 60 until
the latches 62 again latch against surface 64 of the handle 58 to allow
removal of the trocar sleeve. The mushroom hinge 20 can be collapsed and
removed without having to move stop 72.
with reference now to FIGS. 1, 2 and 4, the mechanism for preventing gas
from escaping the abdomen through the sleeve 10 will be described. When no
laparoscopic instrument is inserted through the trocar sleeve 10, a split
seal 52 prevents the escape of gas. The split seal 52 is formed of a
resilient material which has a concave curvature facing the first end 14
of the trocar sleeve. A slit 76 is formed in the split seal which forms a
first seal lip 78 and a second seal lip 80 on opposite sides of the slit
76. With the concave shape, the pressurized gas within the abdominal
cavity acts to force the lips 78 and 80 together to form a tight seal to
prevent the gas escape. When an instrument in inserted in end 38 of the
trocar sleeve 10, the resilient lips 78 and 80 simply deflect away from
the instrument, permitting the instrument to pass through the passage and
into the abdominal cavity.
The O.D. seal 50 forms a seal against the outer cylindrical surface of an
instrument as the instrument is inserted into the passage 26 of trocar
sleeve 10. With the combination of the O.D. seal 50 and split seal 52,
very little gas is lost as instruments are inserted and removed from the
trocar sleeve 10.
With reference to FIG. 5, a first modification of the trocar sleeve 10 is
illustrated. In the first modification, an expanding sponge 90 replaced
the mushroom hinge 20 at the first end of the trocar sleeve 10. The sponge
90 can be expanded in a manner similar to the mushroom hinge 20 to hold
the trocar sleeve within the abdominal cavity.
With reference to FIG. 6, a second modification of trocar sleeve 10 is
illustrated. In the second modification, an inflatable balloon 92 is
mounted at the first end of the trocar sleeve which can be inflated to an
expanded condition to secure the trocar sleeve within the abdominal
cavity.
The sleeve 10 of the present invention reduces the frictional forces
encountered by laparoscopic instruments being inserted into or removed
from the sleeve as compared to prior designs. One reason for this
advantage is that the entire sleeve 10 can be made shorter than past
designs which required a longer length to insert through the abdominal
wall to resist accidental removal of the sleeve from the patient. Another
reason for the friction reduction is the use of efficient seals 50 and 52.
The trocar 12 can be used to automatically expand mushroom hinge 20 as the
trocar is removed from sleeve 10. One possible mechanism for this is
illustrated in FIGS. 2 and 3. A lever 100 can be pivoted to trocar 12
about hinge 106 and urged outwardly by a spring 104, The lever will be
retracted into the trocar 12 as the trocar is inserted into the sleeve 10
to place the sleeve 10 through incision 16. When the trocar is removed
from sleeve 10, the lever extends outward in the direction of arrow 108
through a slot 102 in the sleeve so that the lever 100 contacts latch
release 66. Further movement of trocar 12 would cause the release 66 to
move upward and deploy the mushroom hinge. The lever 100 can be mounted to
retract back into trocar 12 in the direction of arrow 110 after sufficient
force has been exerted on trocar 12 to move release 66 to allow the trocar
to be removed from sleeve 10.
In one possible construction of a sleeve in accordance with the teachings
of the present invention, the inner diameter of the sleeve could be about
5 to 6 mm. with the diameter of the expanded hinge about 0.845 inches. The
stroke of the sleeve 30 to activate the hinge could be 3/8 inches and
sleeve 36 could be 10 mils thick.
While the preferred embodiment of the present invention has been described
in detail and shown in the accompanying drawings, it will be evident that
various further modifications and uses not illustrated are possible
without departing from the scope of the invention.
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