Note: Descriptions are shown in the official language in which they were submitted.
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ETH-464
PLASTIC LIGATING CLIPS
BACXGROUND OF THE INVENTION
The present invention relates to hemostatic clips and clip
appliers, and, more particularly, to hemostatic clips
5 fabricated from absorbable or nonabsorbable polymeric
materials and to instruments for applying such clips to
blood vessels and the like.
Hemostatic clips are utilized in surgical procedures to
10 close severed blood vessels and other small fluid ducts.
In the past, hemostatic clips have been narrow U-shaped or
V-shaped strips formed of tantalum or stainless steel
which are capable of being deformed and possess sufficient
strength to retain the deformation when clamped about a
15 blood vessel. The clips are generally applied using a
forceps-type device having jaws channeled or otherwise
adapted to hold the open clip. Representative hemostatic
clips and appliers of the prior art are best illustrated
in U.S. Patents Nos. 3,867,944; 3,631,707; 3,439,523;
20 3,439,522; 3,363,628; 3,312,216; and 3,270,745.
It has been suggested in the prior art, as in U.S. Patent
No. 3,439,523, for example, that hemostatic clips might be
formed of inexpensive plastics or materials which are
25 slowly absorbable in the body. Unfortunately,
conventional U-and V-shaped hemostatic clips do no t
possess the required strength or deformability when
constructed of known plastic materials to be successfully
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clamped about a blood vessel. Thus, although the need and
desirability of providing inexpensive plastic ligating
elips of both absorbable and non-absorbable materials has
been recognized for over ten years, there has been no
practieal way to satisfy this need.
U.S. 3,926,195 describes a small, plastic clip designed
for the temporary or permanent close of the oviduct and
vas deferens in humans. These clips preferably have a
clamping surface of from 6 to 10 mm in length and 3 to 6
mm in width. The size of sueh elips are aeeordingly
considerably larger than is desirable for hemostatic clips.
Additionally, clips of U.S. 3,926,195 require the use of
several complex tools to apply the elips whieh are aeeept-
able for the purposes deseribed in the referenee but would
be unacceptable in a surgical procedure requiring the
rapid placement of a large number of hemostatic clips to
stem the flow of blood from~ severed ~essels.
It is accordingly an object of the present invention to
provide a plastie ligating elip effective for elamping off
small blood vessels and other fluid duets in the body. It
is a further object of this invention to provide plastie
ligating clips of both absorbable and non-absorbable
materials. It is yet a further objeet of this invention to
provide plastie ligating elips whieh are quickly and easily
applied to severed blood vessels and other fluid ducts
with a single forceps-type instrument used in applying
metallic clips.
In accordance with the present invention, there is thus
provided a sterile, hemostatic ligating clip made from
absorbable or non-absorbable polymeric materials for appli-
cation using a clip applying instrument having a pair of
jaws for holding the clip, placing the clip about the vessel
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to be ligated and closing the clip to ligate the vessel.
The clip of the invention comprises first and second leg
members joined at their proximal ends by resilient hinge
means and terminating at their distal ends in latch means,
each leg member having an outer surface and a vessel clamp-
ing innerface. The vessel clamping innerface is in
opposition to a vessel clamping innerface of the other
leg member. The first leg member terminates at the distal
end thereof in a portion of the latch means, which portion
comprises a deflectable hook member extending from the
innerface of the leg member, the hook member having an inner-
face spaced from the innerface of the hook member and
substantially parallel thereto, the end face of the hook
member being beveled so as to form an acute angle with the
innerface of the hook member. The first leg member also
has a boss disposed on a portion of its outer surface
opposite the vessel clamping innerface, the boss having a
cylindrical shape with the axis of the cylinder extending
across the width of the leg member. The boss is adapted
to fit into a first jaw of the clip applying instrument
and is spaced from the opposite side of the leg member. The
second leg member terminates at the distal end thereof in
a complementary portion of the latch means, which portion
comprises an end face of the leg member having a ~evel
complementary on the bevel to the end face of the hook
member, the complementary bevel forming an obtuse angle
with the innerface of the second leg member and adapted to
enter the space between the innerface of the hook member
and the innerface of the first leg member with the end face
of the leg member being enclosed by the hook member. The
second leg member has a boss disposed on a portion of its
outer surface opposite the vessel clamping innerface, the
boss having a cylindrical shape with the axis of the cylinder
extending across the width of the leg member. The boss is
adapted to fit into the second jaw of the clip applying
instrument and is spaced from the proximal end of the leg
member. ~len the pair of jaws of the clip applying
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3a
instrument having the clip therein are closed, the bosses
of the clip rotate with the jaws of the instrument and allow
the first and second leg members to pivot about the hinge
means and the distal end of the second leg member to deflect
and engage the hook member of the first leg member to lock
the clip in a closed position.
The clips of the present invention may be applied by using
a forceps-type instrument which constitutes a further aspect
of the invention, wherein each jaw is channeled to receive
the width and length of the clip and a cylindrical recess
is provided across the base of each channel to receive
the boss on each leg of the clip. The depth of the channel
in each jaw forward of the cylindrical recess (between the
cylindrical recess and the tip of the jaw) is greater than
to the rear of the cylindrical recess. When the open clip
is placed between the jaws of the applier, it is held firmly
in place with the boss of each leg in the recess of each
jaw. As the jaws are closed, the boss of each leg rotates
in the recess of the jaw until the distal end of the second
leg bypasses and locks under the hook member of the first
leg.
The clips may be formed of plastic by injection molding or
other suitable technique, and may be composed of a non-
absorbable material such as polypropylene or an absorbable
material such as a homopolymer or copolymer of lactide
and glycolide. The clips are formed in a normally open
position and constructed with a small amount of material
to minimize tissue reaction. The clips are readily applied
with a forceps-type applier using conventional surgical
techniques.
DESCRIPTION OF DRAWINGS
FIGURE 1 is a greatly enlarged view in perspective of a
surgical clip according to the present-invention.
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FIGURE 2 illustrates the clip of FIGURE 1 clamped about a
blood vessel.
FIGURE 3 illustrates a forceps-type applier useful with
the clips of the present invention.
FIGURE 4 illustrates the open clip of FIGURE 1 retained in
the jaws of a forceps-type clip applier.
10 FIGURE 5 illustrates the clip of FIGURE 4 closed and
locked over a blood vessel in the jaws of the applier.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring now to FIGURE 1, there is illustrated hemostatic
clip 10 constructed of two leg segments 11 and 12
connected at the proximal ends thereof by hinge section
13. Leg 11 terminates at the distal end thereof in hook
20 member 14 having inner face 15 substantially parallel to
inner face 16 of leg 11 and forming an acute angle with
end face 17. Leg member 12 terminates at the distal end
in end face 19 which forms an obtuse angle with inner face
18 of leg 12. End face 19 is offset at 23 to form a notch
25 approximately midway between surfaces 18 and 20, and
additionally is squared off at face 25 to form a
substantially right angle with surface 20.
The length and width of faces 16 and 18 are substantially
30 equal, and face 15 of hook 14 is spaced from face 16 of
leg 11 by a distance corresponding to the thickness of leg
12 between the plane of face 18 and surface 20. When legs
11 and 12 are pivoted about hinge 13 to bring faces 18 and
16 i,nto opposition, hook 14 is deflected by surface 19 of
35 leg 12 until the distal end of leg 12 snaps under hook 14
and is thereby locked in place. End face 17 of hook 14
and end face 19 of leg 12 are angled as illustrated to
facilitate the passage of leg 12 past hook 14 during clip
closure.
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When the clip is closed over a tubular vessel as
illustrated in FIGURE 2, surfaces 16 and 18 engage and
compress vessel 27 to close the lumen thereof. Surfaces
16 and 18 may be smooth as illustrated in FIGURE 1, or may
be provided with ridges or grooves to increase vessel
holding power. Leg 11 may also be undercut at the
juncture of hook member 14 and surface 16 as illustrated
at 26 in FIGURE 1 to increase the deflectability of hook
member 14 and increase the space between the hook member
14 and leg 11, thereby compensating for any inward
deflection of hook 14 during closure which might reduce
the clearance between surfaces 15 and 16 and otherwise
interfere with the latching of the clip.
Referring again to FIGU~E 1, leg 12 of clip 10 includes an
outside cylindrical boss 21 extending across the width of
the leg near the distal end thereof. Boss 21 is spaced
from surface 25 a distance sufficient to permit full
engagement of hook member 14 by leg 12 when the clip is in
a closed and latched position. Cylindrical bosses 21 and
22 are equidistant from hinge means 13 so that when the
clip is closed, bosses 21 and 22 define a line
perpendicular to the major axis along the length of the
clip as best illustrated in FIGURE 5.
The distal end of leg 12 forward of lug 21 is of reduced
thickness relative to the thickness immediately to the
rear of lug 21, thereby forming step 24 between lug 21 and
surface 20. The significance of this clip configuration
30 will be appreciated in connection with the instrument used
to apply and close the clip as illustrated in FIGURES 3
through 5.
FIGURE 3 illustrates a forceps-type ligating clip applier
30 comprising two handle members 31 and 32 crossing at
hinge point 33 and maintained in a normally open position
by spring 38. Handle 31 extends beyond hinge 33 forming
jaw member 34 while the extension of handle 32 forms jaw
member 35.
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FIGURE 4 illustrates the detail o~ the construction of
jaws 34 and 35 and the interaction of the jaws with the
clip of FIG~RE 1. Jaws 34 and 35 are of identical design
and are provided respectively with channels 36 and 37
5 extending rearwardly from the tips of the jaws. Each
channel is provided with a cylindrical recess 38 and 39
rèspectively across the width of the channel and near the
distal end thereof. Recesses 38 and 39 are in alignment
when the jaws of the applier are closed and are sized to
10 receive the cylindrical lugs 21 and 22 of the clip.
Channels 36 and 37 forward of recesses 38 and 39 are
deeper than to the rear of the recesses as illustrated in
FIGURE 4. When the open clip is held in the applier, the
cylindrical lugs on the clip extend into the cylindrical
15 recesses in each jaw. Due to the angle of the clip in the
applier, the distal ends of legs 11 and 12 extend into the
deeper forward channel section of each jaw. The reduced
thickness of leg 12 at the distal tip prevents
interference between the tip and the channel of the
20 applier when the clip is held in the open position as
illustrated in FIGURE 4.
Clip 10 is initially loaded in applier 30 in the open
position as illustrated in FIGURE 4. After moving the
25 jaws of the applier and the clip into position over the
vessel to be ligated, the jaws of the applier are closed
and the clip is locked in position over the vessel as
illustrated in FIGURE 5. As the clip is closed, the
cylindrical lugs of legs 11 and 12 rotate in the
30 cylindrical recesses of jaws 37 and 36 until the outer
surface of leg 12 rests on the base of channel 36 as
illustrated in FIGURE 5. At this point, the distal end of
leg 12 has rotated away from the base of the channel and
sufficient space exists for hook 14 to bypass leg 12 and
35 latch over the outer surface thereof. After the clip has
been securely latched over the~vessel to be ligated, the
jaws of the applier are opened to release the clip and
vessel and a new clip is loaded in the applier. Since the
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jaws of the applier are identical, it is not necessary to
orient the applier to the clip when loading the applier.
Many variations in the clip design other than the
5 embodiments disclosed herein will be apparent to those
skilled in the art and are contemplated within the scope
of the present invention. For example, the undercut at
the juncture of hook 14 and surface 16 of leg 11 may be
omitted, and the inner surface of leg 12 may be beveled at
10 the distal end as indicated by bro~en line a in FIGURE 1
to compensate for downward deflection of hook 14 during
closure which might reduce the clearance under face lS and
interfere with the latching of leg 12. Offset 23 in end
face 19 of leg 12 provides an intermediate latching
15 position and effectively increases the length of face 18
at the distal end of leg 12, but may be omitted if
desired. These and other modifications in the
configuration of the clip may be employed without
departing from the spirit and scope of the present
20 invention.
The clips of the present invention may be constructed in
various sizes according to their intended function.
Hemostatic clips are typically less than 6 mm in length,
25 about 1.5 mm in width, and have a vessel clamping surface
about 3 mm in length. The dimensions of the clip may be
reduced by about 50 percent for certain applications in
microsurgery, Larger clips for special hemostatic
applications and other functions such as closure of
30 oviducts or vas deferens may have dimensions of about
double those of a typical hemostatic clip. The various
sizes of clips are preferably matched with individual
appliers having jaws tailored to the size of the clip for
best performance.
The clips of the present invention are most conveniently
molded of biologically acceptable plastic materials which
may be absorbable or nonabsorbable. Preferred absorbable
polymers include homopolymers and copolymers of glycolide
, ~ . .
.
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1 1573~4
and lactide, and poly(2-dioxanone). PreSerred
nonabsorbable polymers include nylon and polypropylene.
All these materials have been demonstrated to be
biologically acceptable when used as sutures or other
5 implantable medical devices. The clips may also be cast
or machined from solid polymeric materials or from metals
such as aluminum, magnesium, stainless steel, tantalum,
and various alloys of these, some of which may also be
absorbable in biological tissue.
