U.S. patent application number 13/332250 was filed with the patent office on 2012-04-12 for seal assembly for a cannula.
This patent application is currently assigned to SMITH & NEPHEW, INC.. Invention is credited to Richard M. Lunn, David A. Paulk, Julie K. Tripodi.
Application Number | 20120089161 13/332250 |
Document ID | / |
Family ID | 39830393 |
Filed Date | 2012-04-12 |
United States Patent
Application |
20120089161 |
Kind Code |
A1 |
Lunn; Richard M. ; et
al. |
April 12, 2012 |
Seal Assembly For A Cannula
Abstract
The present disclosure relates to a seal assembly for a cannula.
The cannula includes a housing having a proximal portion and a
distal portion. The seal assembly is located in the proximal
portion of the housing and includes a first seal including a first
tri-slit, a second seal disposed co-axially and proximal to the
first seal and including a second tri-slit, and a third seal
disposed co-axially to the first seal and the second seal and
including a central opening. A cap is coupled to the proximal
portion of the housing and adjacent the third seal and includes a
plurality of suture retaining features, such as tabs, for
management of sutures during surgery. Fluid leakage out of the
cannula, during surgery, is substantially reduced due to the
leakage being limited to a channel defined by the first tri-slit,
the second tri-slit, and the central opening.
Inventors: |
Lunn; Richard M.; (Kingston,
MA) ; Paulk; David A.; (Hopedale, MA) ;
Tripodi; Julie K.; (Marlborough, MA) |
Assignee: |
SMITH & NEPHEW, INC.
Memphis
TN
|
Family ID: |
39830393 |
Appl. No.: |
13/332250 |
Filed: |
December 20, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11753094 |
May 24, 2007 |
8092431 |
|
|
13332250 |
|
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Current U.S.
Class: |
606/148 |
Current CPC
Class: |
A61B 17/3462 20130101;
A61B 17/3474 20130101; A61B 17/3415 20130101; A61B 2017/00862
20130101; A61B 2017/349 20130101; A61B 17/0483 20130101 |
Class at
Publication: |
606/148 |
International
Class: |
A61B 17/04 20060101
A61B017/04 |
Claims
1. A seal assembly for a cannula, the cannula comprising a housing
having a proximal portion and a distal portion, the seal assembly
comprising: a first seal including a first tri-slit; a second seal
disposed co-axially and proximal to the first seal, the second seal
including a second tri-slit; and a third seal disposed co-axially
and proximal to the first seal and the second seal, the third seal
including a central opening, wherein the seal assembly is located
in the proximal portion of the housing.
2. The seal assembly of claim 1 further comprising a cap coupled to
the proximal portion of the housing and adjacent to the third
seal.
3. The seal assembly of claim 2 wherein the cap comprises a
plurality of suture retaining features for management of sutures
during a surgery.
4. The seal assembly of claim 3 wherein the suture retaining
features comprise tabs.
5. The seal assembly of claim 1 further comprising a space located
between the second seal and the third seal.
6. The seal assembly of claim 1 wherein the first tri-slit and the
second tri-slit are offset by an angle .alpha..
7. The seal assembly of claim 6 wherein the angle .alpha. is about
180.degree..
8. The seal assembly of claim 1 wherein the first tri-slit, the
second tri-slit, and the central opening define a channel passing
through the seal assembly.
9. The seal assembly of claim 1 wherein the first seal and the
second seal are configured to form a seal against sutures.
10. The seal assembly of claim 1 wherein the third seal is
configured to form a seal against shafted instruments.
11. The seal assembly of claim 1 wherein the central opening
comprises a diameter of between about 0.060 inches to about 0.120
inches.
12. The seal assembly of claim 1 wherein the third seal comprises a
synthetic material.
13. The seal assembly of claim 1 wherein the third seal comprises a
polymer material.
14. The seal assembly of claim 13 wherein the polymer material
comprises polyisoprene.
15. A cannula comprising: a housing having a proximal portion and a
distal portion; a cap coupled to the proximal portion of the
housing; and a seal assembly located in the proximal portion of the
housing and adjacent the cap, the seal assembly comprising: a first
seal including a first tri-slit; a second seal disposed co-axially
and proximal to the first seal, the second seal including a second
tri-slit; and a third seal disposed co-axially and proximal to the
first seal and the second seal, the third seal including a central
opening.
16. The cannula of claim 15 wherein the cap comprises a plurality
of suture retaining features for management of sutures during a
surgery.
17. The cannula of claim 16 wherein the suture retaining features
comprise tabs.
18. The cannula of claim 15 further comprising a space located
between the second seal and the third seal.
19. The cannula of claim 15 wherein the first tri-slit and the
second tri-slit are offset by an angle .alpha..
20. The cannula of claim 19 wherein the angle .alpha. is about
180.degree..
21. The cannula of claim 15 further comprising a channel defined by
the first tri-slit, the second tri-slit, and the central opening,
wherein fluid leakage during surgery is limited to the channel.
22. The cannula of claim 15 wherein the first seal and the second
seal are configured to form a seal against sutures.
23. The cannula of claim 15 wherein the third seal is configured to
form a seal against shafted instruments.
24. The cannula of claim 15 wherein the central opening comprises a
diameter of between about 0.060 inches and about 0.120 inches.
25. The cannula of claim 15 wherein the third seal comprises a
synthetic material.
26. The cannula of claim 15 wherein the third seal comprises a
polymer material.
27. The cannula of claim 26 wherein the polymer material comprises
polyisoprene.
28. A seal assembly comprising: a first seal including a first
tri-slit and at least one interlocking member; a second seal
disposed co-axially and proximal to the first seal, the second seal
including a second tri-slit and at least one interlocking member;
and a third seal disposed co-axially and proximal to the first seal
and the second seal, the third seal including a central opening,
wherein the interlocking member of the first seal and the
interlocking member of the second seal interlock with each
other.
29. The seal assembly of claim 28 wherein the first seal and the
second seal both include multiple interlocking members.
30. The seal assembly of claim 29 wherein the interlocking members
of the first seal and the interlocking members of the second seal
interlock with each other.
31. The seal assembly of claim 28 wherein the interlocking of the
interlocking member of the first seal and the interlocking member
of the second seal facilitates positioning of the first tri-slit
and the second tri-slit at an angle .alpha. relative to each
other.
32. The seal assembly of claim 31 wherein the angle .alpha. is
about 180.degree..
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present disclosure relates generally to medical and
surgical devices, and more specifically to seal assemblies for
cannulas.
[0003] 2. Related Art
[0004] Arthroscopic or, more generally, endoscopic surgical
procedures enable closed surgery to be performed via portals
through which a variety of elongated instruments may be passed to
gain access to an internal surgical work site. Very often a
disposable cannula is inserted into the portal in order to provide
a convenient passageway through which various instruments may be
passed. Because many arthroscopic procedures require the use of
pressurized fluid to distend and irrigate the joint being operated
upon, the cannula must provide a sealed passageway in order to
enable instruments to be passed into and out of the cannula while
maintaining a fluid seal whether or not an instrument is in the
cannula passageway. The sealing of such cannula passageways is
usually accomplished by one or more elastomeric membranes attached
to the proximal end of the elongated cannula.
[0005] Since the fluid at the work site is pressurized, care must
be taken to avoid leakage during the time the instrument is being
inserted. Current seal assemblies for use in cannulas leak
excessively and improvement on the amount of leakage out of the
cannula is desired. In addition, upon insertion of an instrument
into an opening on the seals of current models, fluid sprays out of
the opening. In order to prevent this from occurring, the seal is
covered by placing a spray shield on the proximal end of the
cannula. FIG. 1 shows a current cannula model 10 that has a spray
shield 11 covering the seal assembly 12 at the proximal end 13 of
the cannula 10. However, the size of the spray shield 11 makes it
difficult for the surgeon to work in tight operative spaces.
Therefore, a sealing assembly that minimizes this problem is also
needed.
[0006] Furthermore, the variety of instruments which must be
inserted through the cannula seal includes instruments of varying
sizes and configurations. While the instrument shafts are usually
cylindrical, some instruments may have unusually large or sharp
distal tips which may cut a seal element upon the insertion or
extraction of the instrument thus making it less suitable for
subsequent instruments which must be inserted during the same
surgical procedure. It is desirable, therefore, to devise a sealing
cannula which minimizes this problem.
[0007] Finally, in addition to instruments, sutures may also be
passed through the seal assembly. In fact, the management of these
sutures has become critical to the technical success of the
surgery. Indeed, tangled sutures can terminate an arthroscopic
procedure. Therefore, an approach to suture management is also
needed.
SUMMARY OF THE INVENTION
[0008] The present disclosure relates to a seal assembly for a
cannula. The cannula includes a housing having a proximal portion
and a distal portion. The seal assembly is located in the proximal
portion of the housing and includes a first seal including a first
tri-slit, a second seal disposed co-axially and proximal to the
first seal and including a second tri-slit, and a third seal
disposed co-axially to the first seal and the second seal and
including a central opening having a diameter of between about
0.060 inches to about 0.120 inches. In an embodiment, a cap is
coupled to the proximal portion of the housing and adjacent the
third seal and includes a plurality of suture retaining features,
such as tabs, for management of sutures during surgery. In another
embodiment, the seal assembly further includes a space located
between the second seal and the third seal. In yet another
embodiment, the first tri-slit and the second tri-slit are offset
by an angle .alpha., which is about 180.degree.. In a further
embodiment, the first tri-slit, the second tri-slit and the central
opening define a channel passing through the seal assembly. Fluid
leakage during surgery is limited to the channel. In yet a further
embodiment, the first seal and the second seal are configured to
form a seal against sutures and the third seal is configured to
form a seal against shafted instruments. In an embodiment, the
third seal comprises a synthetic material. In another embodiment,
the third seal comprises a polymer, such as polyisoprene.
[0009] The present disclosure also relates to a seal assembly
having a first seal including a first tri-slit and at least one
interlocking member, a second seal disposed co-axially and proximal
to the first seal, the second seal including a second tri-slit and
at least one interlocking member, and a third seal disposed
co-axially and proximal to the first seal and the second seal, the
third seal including a central opening. The interlocking member of
the first seal and the interlocking member of the second seal
interlock with each other. In an embodiment, the first seal and the
second seal both include multiple interlocking members, wherein the
interlocking members of the first seal and the interlocking members
of the second seal interlock with each other. The interlocking
between the interlocking member of the first seal and the
interlocking member of the second seal facilitates positioning of
the first tri-slit and the second tri-slit at an angle .alpha.,
which is about 180.degree., relative to each other.
[0010] Further areas of applicability of the present invention will
become apparent from the detailed description provided hereinafter.
It should be understood that the detailed description and specific
examples, while indicating the preferred embodiment of the
invention, are intended for purposes of illustration only and are
not intended to limit the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The accompanying drawings, which are incorporated in and
form a part of the specification, illustrate the embodiments of the
present invention and together with the written description serve
to explain the principles, characteristics, and features of the
invention. In the drawings:
[0012] FIG. 1 shows a perspective view of a prior art cannula
having a spray shield coupled to the proximal end of the
cannula.
[0013] FIG. 2 shows an exploded perspective view of the cannula of
the present disclosure.
[0014] FIG. 3A shows a top view of the first and second seals of
the seal assembly of the present disclosure.
[0015] FIG. 3B shows a top view of the first and second seals of
the present disclosure showing suture coming out of the
tri-slits.
[0016] FIG. 4 shows a cross-sectional perspective view of the
proximal portion of the cannula of the present disclosure.
[0017] FIG. 5 shows a perspective view of the cap of the present
disclosure as located on the proximal portion of the cannula.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0018] The following description of the preferred embodiment(s) is
merely exemplary in nature and is in no way intended to limit the
invention, its application, or uses.
[0019] An embodiment of a cannula of the present disclosure is
illustrated in FIG. 2 and designated generally by reference number
100. The cannula includes a seal assembly for substantially
reducing the amount of fluid leakage from the cannula and
specifically for forming a seal against sutures and shafted
instruments.
[0020] The cannula 100, which is plastic, but could be made from
other material known to one of ordinary skill in the art, includes
a housing 101 having a proximal portion 102 and a distal portion
103. Near the proximal portion 102, an outflow tube 112 provides a
means for removing fluid from the inner lumen of the distal portion
130 during surgery. Although, it is also within the scope of this
disclosure that the tube 112 may be used as an inflow tube for
supplying fluid to the inner lumen of the distal portion 130 during
surgery. A cover 121 is detachably coupled to the inflow tube 112
for closing off the inflow tube while the cannula 100 is not in
use. Located in the proximal portion 102 is a seal assembly 103.
The seal assembly 130 includes a first seal 104 having a first
tri-slit 105, a second seal 106 that is disposed co-axially and
proximal to the first seal 104 and includes a second tri-slit 107,
and a third seal 108 that is disposed coaxially and proximal to the
first seal 104 and the second seal 106 and includes a central
opening 109. The first seal 104 and the second seal 106 both have
four sides (104a-d, 106a-d). The seals 104,106 also have openings
110,111 that extend through the seals 104,106. The second seal 106
sits proximal to the first seal 104 such that no space exists
between the seals 104,106, the openings 110,111 of both seals
104,106 are aligned, and the tri-slits 105,107 are offset by an
angle .alpha., or about 180.degree., as is further shown in FIG.
3A. Sides (104a-b, 106a-b) and sides (104c-d, 106c-d) of the seals
104,106 are made to interlock with each other. For example, as
shown in FIG. 3A, the seals 104,106 include interlocking members,
such as tabs 122 and detents 123, which interlock with one another.
The tabs 122 and detents 123 alternate with regards to the seals
104,106 that they are located on. This interlocking feature
facilitates positioning of the tri-slits 105,107 at an angle, about
180.degree., relative to each other each time the seals 104,106 are
assembled together. Other interlocking features, known to one of
ordinary skill in the art, may be used.
[0021] Also shown in FIG. 3A, the tri-slits 105,107 are of a
Y-shaped configuration with each slit 105,107 defining a pair of
slit arms (105a-b, 107a-b) joined together at one end 105c,107c and
forming an obtuse angle as shown. Thus, they each define an arrow
pointing in an opposed direction to each other and also define a
pair of intersection points 113, forming a channel, as further
discussed below, that that extends completely through both seals
104,106. Added to each pair of arms (105a-b, 107a-b) are slit legs
105d, 107d, which are located at an angle .alpha., or about
180.degree., from each other. As is shown in FIG. 3B, the tri-slits
105,107 provide a seal against the sutures 200 by having a channel,
as further discussed below, that has the smallest possible opening
to the sutures 200 and substantially reduces the amount of fluid
leaving the cannula. For the purposes of this disclosure, both the
first 104 and the second 106 seals are made from silicon. However,
other material known to one of ordinary skill in the art could be
used, including, but not limited to, rubber, vinyl, polyurethane
elastomers, or a combination of components, including
styrene-ethylene-butylene-styrene (SEBS) block co-polymers,
polyolefins, mineral oils, and silicone oils.
[0022] The third seal 108 is located proximal to the first 104 and
second 106 seals and includes a central opening 109, along with
four other openings 114 that are located around the outer diameter
of the seal 108. The seal 108 is in a co-axial relationship with
the first 104 and second 106 seal such that the central opening 109
is aligned with the center 113 of the tri-slits 105,107 and the
openings 114 on the outer diameter are aligned with the openings
110,111 on the first and second seals 104,106. As shown in FIG. 4,
the central opening 109, which is between about 0.060 inches to
about 0.120 inches in diameter, is configured to form a seal
against shafted instruments 140 that have a diameter that is larger
than the opening 109. The instrument 140 is first inserted into the
central opening 109, and then through the Y-slit channel of the
second seal 106. Once the instrument is inserted into the opening
109, the walls 150 of the opening 109 push outward toward the
second seal 106, yet remain against the shaft of the instrument 140
to create a seal against any fluid that may flow through the
tri-slits 105,107 and towards the third seal 108. For the purposes
of this disclosure, the central opening 109 is round, but it could
be of another shape. The third seal 108 is manufactured from a
polymer material, specifically polyisoprene, to substantially
reduce the amount of tearing or wear as a result of insertion
and/or withdrawal of sharp instruments. Other natural or synthetic
materials known to one of ordinary skill in the art, and that would
substantially reduce the amount of tear or wear, could also be
used. These materials include, but are not limited to, silicone,
rubber, vinyl, polyurethane elastomers, or a combination of
components, including styrene-ethylene-butylene-styrene (SEBS)
block co-polymers, polyolefins, mineral oils, and silicone
oils.
[0023] As mentioned above in FIG. 1, upon insertion of an
instrument into an opening on the seals of current cannulas, fluid
sprays out of the opening. In order to prevent this from occurring,
the seal is covered by placing a spray shield on the proximal end
of the cannula. This additional step is eliminated in the present
disclosure by integrating the spray shield, which in this
disclosure is the third seal 108, into the cannula. Without the
spray shield covering the proximal portion of the cannula, the
overall size of the cannula 100 is smaller, thereby making it
easier for the surgeon to work in tight operative spaces.
[0024] In addition to eliminating the step of adding a spray shield
onto the proximal portion, the cannula 100 of the present
disclosure also substantially reduces the amount of fluid spray
that occurs outside of the cannula 100. FIG. 4 shows a space 160
that is located between the second seal 106 and the third seal 108.
This space 160 allows for a substantial reduction in the amount of
fluid spray that occurs outside of the cannula 100 by causing some
of the fluid that would otherwise be sprayed outside of the cannula
100 to be reflected back toward the second seal 106. In addition to
causing a reflection of the fluid, the space 160 also substantially
reduces the force required to insert surgical instruments 140 by
allowing the walls 150 of the opening to have the space needed to
push outward toward the second seal 106. If this space wasn't
present and the third seal 108 was against the second seal 106,
there would be no space to allow the walls 150 to push outward and
a greater amount of force would therefore be required to insert the
instrument 140.
[0025] The seal assembly 130 is placed in the proximal portion 102
of the housing 101 such that the openings (110,111,114) of the
seals (104,106,108) are placed over columns 115 that are located
along the inside perimeter 116 of the proximal portion 102. These
columns 115 provide support for the seals (104,106,108).
[0026] A plastic cap 118 is coupled to the proximal portion 102 of
the housing 101 and is adjacent to the third seal 108. The cap 118
may be made from another material known to one of ordinary skill in
the art. Having the cap 118 on the proximal portion 102 of the
housing 101 compresses the seal assembly 130 and limits fluid
leakage during surgery to a channel 117 defined by the first
tri-slit 105, second tri-slit 107, and central opening 109, thereby
substantially reducing the amount of fluid leakage out of the
cannula 100. The cap 118 includes a central opening 119 and a
plurality of suture retaining features 120, or tabs, for the
management of multiple strands of sutures during surgery.
[0027] There are several advantages for having the tabs 120 on the
cap 118. As shown in FIG. 5, having multiple tabs 120 on the cap
118 allows for different strands of suture 201, 202 to be
simultaneously arranged in separate positions. In addition, the
tabs 120 are molded into the cap 118, which avoids the need for an
accessory device and/or a modification to the housing 101 by the
surgeon to manage the sutures 201,202. Furthermore, the tab length
extends past the proximal portion 102 of the housing 101 to allow
the capture of a suture 201,202 that is placed behind the tab 120
and drawn upwards. Additionally, the tabs 120 are tapered to
maintain secure contact with suture strands of various sizes, such
as strands 201 and 202. Finally, a suture 201,202 is easily removed
once it is secured to the tab 120 without damage to the suture
201,202 or housing 101. It is within the scope of this disclosure
that the number, size, shape, length, orientation, and thickness of
the tabs 120 could be adjusted to make for alternative
embodiments.
[0028] As various modifications could be made to the exemplary
embodiments, as described above with reference to the corresponding
illustrations, without departing from the scope of the present
disclosure, it is intended that all matter contained in the
foregoing description and shown in the accompanying drawings shall
be interpreted as illustrative rather than limiting. Thus, the
breadth and scope of the present disclosure should not be limited
by any of the above-described exemplary embodiments, but should be
defined only in accordance with the following claims appended
hereto and their equivalents.
* * * * *