Note: Descriptions are shown in the official language in which they were submitted.
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PLASTIC LIGATING CLIPS
BACKGROUND 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 which may be applied to blood vessels and
the like with conventional instruments.
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 s teel
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, the very
small conventional U-and V-shaped hemostatic clips do not
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
clips of both absorbable and nonabsorbable materials has
been recognized for over ten years, there has been no
5 practical 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
10 clamping surface of from ~ to 10 rnm in length and 3 to 6
mm in width. The size of such clips are accordingly
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 clips which are
15 acceptable for the purposes described in the reference 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 vessels.
20 It is accordingly an object of the present invention to
provide a plastic ligating clip effective for clamping off
small blood vessels and other fluid ducts in the body. It
is a further object of this invention to provide plastic
ligating clips of both absorbable and nonabsorbable
25 materials. It is yet a further object of this invention
to provide plastic ligating clips which are quickly and
easily applied to severed blood vessels and other fluid
ducts with a conventional single forceps-type instrument
used in applying metallic clips.
SUMMARY
The ligating clips of the present invention comprise two
legs joined at the proximal ends thereof along a line
forming a resilient hinge, with the first leg terminating
35 in a deflectable hook member adapted to engage the distal
end of the other leg. The first leg is provided with an
outside raised rib having a radial curvature over
substantially the entire length thereof which permits the
leg to rotate forward within the jaw of the applier as the
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clip is closed The outer surface of the raised rib is
provided with gear-like teeth at the distal end thereof
which mesh with corresponding teeth in the jaws of a
conventional ligating clip applying instrument.
The second leg is provided with a short raised rib over
the central portion thereof and spaced from the distal and
proximal ends of the leg. This rib is also provided with
gear-like teeth to mesh with corresponding teeth in the
10 jaw of the applier.
The applier for the clips of the present invention is a
conventional, forceps-type instrument wherein each jaw is
channeled and gear-like teeth are provided in the base of
the channel to grip the clip. The width of the raised
ribs of the clip correspond to the width of the channels
in the applier, and the size and spacing of the teeth on
the ribs of the clip correspond to the size and spacing of
the teeth in the channel of the applier.
The clips may be formed of plastic by injection molding or
other suitable technique, and may be composed of a
nonabsorbable 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 to the ends of severed vessels 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.
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.
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FIGURE 4 illustrates the clip of FIGURE 1 retained in the
jaws of a forceps-type clip applier.
FIGURE 5 is an end view of FIGURE 4 illustrating the
5 position of the clip in the jaws of the applier.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring now to ~IGURE 1, there is illustrated hemostatic
clip 10 constructed of two leg segments 11 and 12
10 connected at the proximal ends thereof by hinge section
13. Leg 11 terminates at the distal end thereof in hook
member 14. Inner face 15 of hook member 14 is
substantially parallel to inner face 16 of leg 11 and
forms an acute angle with extension 17 of the hook member.
15 Leg member 12 terminates at the distal end in surface 19
which forms a corresponding acute angle with outer surface
20. Extension 17 further forms an obtuse angle with the
plane of inner face 16 of leg 11, while surface 19 of leg
12 forms a corresponding obtuse angle with the plane of
inner surface 18.
The length and width of faces 16 and 18 are substantially
equal, and face 15 of hook 14 is spaced from face 16 of
leg 11 by a distance corresponding to the thickness of leg
25 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 into opposition, hook 14 is deflected by surface 19 of
leg 12 until the distal end of leg 12 snaps under hook 14
and is thereby locked in place. Front surface 26 of hook
30 14 is preferably rounded and angled as illustrated to
facilitate the passage of leg 12 during clip closure.
When the clip is closed over a tubular vessel as
illustrated in FIGURE 2, surfaces 16 and 18 engage and
35 compress vessel 28 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. The distal end of surface 18 of leg 12 is
preferably beveled as illustrated by broken line a in
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FIGURE 1 to reduce the thickness at the tip of the leg,
thereby compensating for inward deflection of hook 14
during closure which reduces the clearance between
surfaces 15 and 16 and may otherwise interfere with the
5 latching of the clip. Closure is further facilitated by
undercutting leg 11 at the juncture of extension 17 and
surface 16 as illustrated at 27 in FIGURE 1 to increase
the deflectability of hook member 14 and the effective
space between the hook member 14 and leg 11.
Referring again to FIGURE 1, leg 11 of clip 10 includes a
raised rib 21 extending from the tip of hook member 14 to
a point adjacent hinge section 13. The outer surface of
rib 21 defines a radial curve extending from extension 17
15 into the body of leg 11, and a plurality of gear-like
teeth 22 extend across the width of the rib opposite
extension 17. Rib 21 reinforces leg 11, and, since the
rib may have less thickness than inner face 16 of leg 11,
reduces the amount of material required to fabricate the
20 clip.
Leg 12 is likewise provided with a short, raised rib 23
spaced from the distal and proximal ends thereof which
includes a plurality of gear-like teeth 24 extending
25 across the width of the rib. Rib 23 serves to reinforce
the rigidity of leg 12, and also functions as a foot upon
which the clip stands when held in the applier as
hereinafter described.
30 The significance of the clip configuration as illustrated
in FIGURE 1 and described above will be appreciated in
connection with the instrument used to apply and close the
clip as illustrated in FIGURE 3 and FIGURE 4.
35 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
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jaw member 34 while the extension of handle 32 forms jaw
member 35.
FIGURE 4 illustrates the detail of the construction of
jaws 34 and 35 and the interaction of the jaws with the
clip of FIGURE 1. Jaws 34 and 35 are of identical design
and are provided respectively with channels 36 and 37
extending rearwardly from the tips of the jaws. Each
channel is provided with gear-like teeth 38 and 39 across
the bottom of the channel and over an area extending
rearward from the tips of the jaws. The size and spacing
of channel teeth 38 and 39 correspond to the size and
spacing of clip teeth 24 and 22, and when the open clip is
held in the applier, the teeth of the clip mesh with those
15 of the applier as illustrated in FIGURE 4. Since the jaws
of the applier have identical structure, there is no need
to orient the applier to the clip when loading or using
the applier.
20 Clip 10 is initially loaded in applier 30 in the normally
open position as illustrated in FIGURE 4. After moving
the 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
25 as illustrated in FIGURE 2. As the jaws of the applier
are closed, leg 11 of clip 10 rotates in channel 37 until
teeth 22 disengage from the channel. Thereafter, leg 11
moves forward with the curved surface of rib 21 sliding
and rotating in channel 37. Simultaneously, the clip
30 pivots backward on rib 23 of leg 12 until the distal end
of leg 12 is engaged by hook member 14. Once the clip is
fully closed and locked onto the vessel as illustrated in
FIGURE 2, the jaws of the applier are allowed to open and
the applier is withdrawn from the site to be reloaded with
35 another clip.
Referring now to FIGURE 5, there is illustrated an end
view of FIGURE 4 showing clip 10 positioned between jaws
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34 and 35 of the applier with ribs 21 and 23 of the clip
engaging channels 37 and 36 of the jaws, respectively.
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, while the raised
ribs of the clip are illustrated as being narrower than
the clamping surfaces, the entire clip could be
10 constructed of a uniform thickness if desired. The
undercut between extension 17 and surface 16 of leg 11 is
optional and may be omitted, especially if the width of
leg 11 is reduced. Greater or lesser numbers of teeth may
be employed on the raised ribs, or other means may be
15 employed to lock the open clip between the jaws of the
applier without departing from the scope and spirit of the
invention.
The clips of the present invention may be constructed in
20 various sizes according to their intended function.
Hemostatic clips are typically less than 6 mm in length,
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
25 microsurgery. Larger clips for special hemostatic
applications and other functions such as closure of
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
30 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
35 may be absorbable or nonabsorbable. Preferred absorbable
polymers include homopolymers and copolymers of glycolide
and lactide, and poly(_-dioxanone). Preferred
nonabsorbable polymers include nylon and polypropylene.
All these materials have been demonstrated to be
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biologically acceptable when used as sutures or other
implantable medical devices. The clips may also be cast
or machined from solid polymeric materials or from metals
such as aluminum, magne.sium, stainless steel, tantalum,
5 and various alloys of these, some of which may also be
absorbable in biological tissue.
