Surgical needle abstract
An improved surgical needle. The needle comprises a plurality of
curves which provide for improved control while suturing.
Surgical needle claims
What is claimed is:
1. A surgical needle comprising a multiple curved body portion
terminating in a blunt end and a stra-ght point end, all curves
of the multiple curves being concave, the curve adjacent the pointed
end of the needle having a radius of curvature of from 0.040 inch
to 0.075 inch and a length of curvature of from 0.063 inch to 0.105
inch, and the curve adjacent the blunt end of the needle having
a radius of curvature of from 0.080 inch to 0.120 inch and a length
of curvature of from 0.081 inch to 0.115 inch the axis of said straight
point end intersecting at an angle the concavity of said concave
curve adjacent said straight point end whereby the straight point
provides a controlled depth during the placement of the needle,
the tighter initial curve provides the desired turnaround of the
needle when the needle is placed and the gentler curved portion
provides ease of gripping of the needle and control of the needle
during placement.
2. A needle according to claim 1 wherein the curve adjacent the
pointed end of the needle is in abuting relationship with the curve
adjacent the blunt end of the needle.
3. A surgical needle comprising a multiple curved body portion
terminating in a blunt end and a straight point end, all curves
of the multiple curves being concave, the curve adjacent the pointed
end of the needle having a radius of curvature of from 0.040 inch
to 0.075 inch, a length of curvature of from 0.063 inch to 0.105
inch and an angle of curvature of from 75 degrees to 90 degrees,
and the curve adjacent the blunt end of the needle having a radius
of curvature of from 0.080 inch to 0.120 inch, a length of curvature
of from 0.081 inch to 0.115 inch and an angle of curvature of from
40 degrees to 60 degrees the axis of said straight point end intersecting
at an angle the concavity of said concave curve adjacent said straight
point end whereby the straight point provides a controlled depth
during the placement of the needle, the curve adjacent the pointed
end of the needle provides the desired turnaround of the needle
when the needle is placed and the curve adjacent the blunt end of
the needle provides ease of gripping of the needle and control of
the needle during placement.
4. The needle of claim 1 2 or 3 wherein a suture is swaged to
the blunt end of the needle.
5. A needle according to claim 4 wherein the straight pointed end
of the needle has a trapezoidal cross-section with the longer parallel
side of the trapezoid being on the inner curve of the needle and
the shorter parallel size of the trapezoid being on the outer curve
of the needle.
6. A needle according to claim 4 or 5 wherein the curve adjacent
the pointed end of the needle has a generally oval cross-section
and the curve adjacent the blunt end of the needle has a generally
circular cross-section.
7. A needle according to claim 6 having flattened sides extending
at least 2/3rds of the distance from the straight point towards
the blunt end whereby said needle may be gripped by a needle holder
substantially closer to said blunt end than to said straight point.
8. A surgical needle according to claim 1 wherein the curve adjacent
the pointed end of the needle has a radius of curvature of 0.055
inch and the curve adjacent the blunt end of the needle has a radius
of curvature of 0.100 inch.
9. A surgical needle according to claim 3 wherein the curve adjacent
the pointed end of the needle has an angle of curvature of 80.degree.
and the curve adjacent the blunt end of the needle has an angle
of curvature of 45.degree..
10. A surgical needle according to claims 4 5 8 or 9 wherein
the length of the pointed end of the needle is from 0.013 inch to
0.028 inch.
11. A surgical needle according to claim 10 wherein the length
of the pointed end of the needle is 0.021 inch.
Surgical needle description
BACKGROUND OF THE INVENTION
The present invention relates to surgical needles and, more particularly,
to specifically curved surgical needles for use in ophthalmic surgery,
microsurgery and similar surgical procedures.
Surgical needles are generally either straight, ski-shaped, or
uniformly curved. For many surgical procedures including eye operations
and microsurgery, the curved needles have gained wide acceptance.
These needles have a uniform radius and the length of the needle
may be from about a quarter of a circle to 2/3rds of a circle; that
is, from about 90.degree. to about 240.degree.. The curve in the
needle is helpful to the surgeon in placing the suture in that the
surgeon usually grasps the body of the needle near its center and
inserts the pointed end into the edge of the tissue to be closed.
Provided the surgeon keeps a general forward motion along the direction
of the shape of the curve of the needle, the needle will tend to
place the suture at the desired depth and take the desired "bite"
by a controlled emergence of the needle from the tissue. The smaller
and more fragile the material being sutured the more difficult it
is to suture. Also, the tighter the area in which the surgeon is
working, the more difficult it is to suture. These problems are
very prevalent in eye surgery. The placing of the suture is critical
to success in many eye operations. For example, in a corneal transplant
operation, the sutures must be uniformly placed as to depth and
length of bite so that the suture loops attain substantially equal
tension around the entire transplant circumference. If some sutures
have more or less tension than other sutures, or some sutures have
been placed at different depths or lengths of bite than others,
the results of the operation may not be as successful. Also, the
standard curved needle when gripped in the center portion by the
needle holder, if gripped too tightly, the area gripped will tend
to be straightened. This slight straightening of the center portion
increases the difficulty the surgeon has in placing uniform suture
loops.
The prior art shows various surgical needle configurations to improve
specific suturing techniques. In U.S. Pat. No. 3556953 there is
disclosed a microminiature suture needle which may be either straight,
ski-shaped or curved. In U.S. Pat. No. 3877570 there is disclosed
a specifically curved needle specifically designed for attaching
hair pieces to the human scalp.
Other various shaped surgical needles for improved suturing are
described in U.S. Pat. Nos. 3918455 4128351 and 4237892.
It is also known that a specifically curved needle for opthalmic
surgery is being sold for corneal scleral closures by the Alcon
Company. This needle is more fully disclosed in an article which
appeared in the Am. Intra-Occular Implant Soc. J. 6 282-284 (1980).
Though many of these prior art surgical needles solve some of the
problems with regard to the specific procedure for which they were
designed, none of them solve all of the problems involved in the
suturing techniques required in ophthalmic surgery or in microsurgery
or other similar surgical procedures. In ophthalmic surgery, as
well as in other surgery, it is important the needle be as sharp
as possible. The sharper the needle the less the damage or trauma
the needle causes to the tissue being sutured. However, the sharper
the needle the less the "feedback" or response the surgeon
feels when using the needle and the more difficult for the surgeon
to know exactly where the suture is being placed and the depth to
which the suture is placed. Also, when the needle is extremely sharp
and there is little "feed-back", it is difficult for the
surgeon to be certain that each placement of the suture is the same
as the previous placement. When using a standard smoothly curved
needle in ophthalmic surgery, the surgeon places some torque on
the needle to bring the needle appropriately through the tissue.
With the desired very sharp needle and, hence, little "feedback",
it is very difficult for the surgeon to place the same amount of
torque on each placement of the needle and, hence, it is extremely
difficult to produce the uniformly tensioned suturing desired in
ophthalmic surgery.
What we have discovered is a new and improved surgical needle which
reduces the trauma to the patient and provides the needle be placed
to the right depth in the tissue and grabs or sutures the right
amount of tissue as the suture is being placed. Also, our newly
configured needle requires minimal manipulation in placing the suture
through the tissue. Furthermore, our newly configured needle allows
for improved suturing of fine fragile tissue and allows such suturing
to be conducted in very tight and confined places while reducing
the possibility of injury to adjacent tissue.
Our new needle may be made as sharp as possible because "feedback"
is surprisingly no longer required with our new needle. The specific
geometry of our new needle eliminates the requirement of "feedback"
because it unexpectedly automatically controls the placement of
the suture and surprisingly places each suture in an identical manner.
Our new needle has less tendency to be straightened by the needle
holder. Our new needle allows for the suturing of delicate corneal
tissue accurately and consecutively in a very uniform manner with
the desired bite and grasp of the tissue being sutured.
SUMMARY OF THE PRESENT INVENTION
The improved surgical needle of the present invention comprises
a multiple curved body portion. The body portion terminates at a
blunt end and at a pointed end. The pointed end is straight to provide
a self-depth seeking portion. The curve adjacent the pointed end
has a radius of curvature of from about 0.040 inch to 0.075 inch
and the length of that curvature is from 0.063 inch to 0.105 inch.
The curve adjacent the blunt or distal end of the needle has a radius
of curvature of from about 0.080 to 0.120 inches and the length
of curvature is from 0.081 inch to 0.115 inch. Both curves are in
substantially the same concavity. In certain embodiments of the
present invention, the two curves abut one another in a smooth manner
while in the embodiments of the needle of the present invention
there may be a small area of graduated curvature that connects the
two critical curves. Though it is necessary that the needle have
at least two curves, in certain embodiments of the present invention
additional intermediate connecting curves may be used.
In the preferred embodiments of the present invention the needle
has a suitable suture swaged or otherwise attached to the blunt
end of the needle. In certain embodiments of the present invention
the pointed end has a trapezoidal cross-section with the longer
parallel side of the trapezoid being on the inside of the curve
and the shorter parallel side of the trapezoid being on the outside
of the curve. The needle point geometry may also be triangular,
taper, taper cut or other geometrics commonly used in surgical needles.
The curve adjacent the pointed end has an oval or elliptical cross-section
while the curve adjacent the blunt end has a circular cross-section.
Other cross-sectional shapes may also be used such as triangular,
trapezoidal and the like. Our new and improved needle configuration
has a straight point which provides a controlled depth seeking feature
when the needle is placed. The initial tight curve provides the
relative turnaround desired in ophthalmic or other fine microsurgery
and the gentler curve allows for ease of gripping and control of
the needle while the suture is being placed. The gentler curve reduces
distortion of tissue on withdrawing the needle from the tissue.
Our new needle is gripped by the needle holder closer to the blunt
end of the needle. As our new needle has a gentler curve in this
area, there is less tendency for the needle holder to straighten
the needle.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be further described in conjunction with the
accompanying drawings wherein:
FIG. 1 is a plan view of the surgical needle of the present invention;
FIG. 2 is a cross-sectional view taken along line 2--2 of FIG.
1;
FIG. 3 is a cross-sectional view taken along line 3--3 of FIG.
1;
FIG. 4 is a cross-sectional view taken along line 4--4 of FIG.
1;
FIG. 5 is a cross-sectional view taken along line 5--5 of FIG.
1; and
FIG. 6 is a plan view of another embodiment of the surgical needle
of the present invention.
DETAILED DESCRIPTION OF THE DRAWINGS
Referring to the drawings in detail, FIG. 1 shows a surgical needle
10 of the present invention.
The needle has a straight pointed end 11 having a cross-section
as shown in FIG. 2. Adjacent this pointed end is a curved body portion
12 of the needle. The curved body portion has the cross-sectional
shape as shown in FIG. 3. Adjacent this curved portion is a second
curved portion 13 which is a gentler or less of a curve than the
first curved portion. This curved portion of the needle has the
cross-sectional shape as shown in FIG. 4. The second gentler curved
portion terminates in a blunt or distal end 14 in which preferably
a suitable suture 15 is swaged into a drilled hole or a channel
or may be attached to the needle by any of the ways well known in
the art. The swaged end portion is more clearly shown in FIG. 5.
The straight portion of the needle has a distance `a` of from about
0.013 to 0.028 inches. We have found 0.021 inch to be most suitable
in our new compound curved needles. The straight point cutting blade
and the following curvature provide the needle with its self-depth
seeking feature so that it will enter the tissue to the desired
depth and then curve to place the suture correctly with a minimum
of trauma while insuring that a sufficient amount of tissue has
been grasped to close the wound. The straight point should be blended
or gently curved at a radius of curvature of from 0.010 to 0.020
inch into the body of the needle.
The tighter curve adjacent the pointed end, has a radius of curvature
of from about 0.040 to 0.075 inch. We have found a curvature of
about 0.055 inch to be most suitable. The length `b` of this curve
is preferably from about 75 degrees to 90 degrees. We have found
approximately an 80.degree. length of the angle of this curve to
be most suitable.
The gentler curve adjacent the blunt end of the needle has a radius
of curvature of from 0.080 inch to 0.120 inch. We have found a curvature
of 0.100 inch to be most suitable. The length `c` of this curve
is preferably from about 40 to 60 degrees with 45.degree. being
most acceptable.
The two curves may abut each other as shown in FIG. 1 or if desired
there may be a short gradually curved area between the two curves
to provide for an even smoother transition from one curve to the
other.
The needle may be made from any of the materials used in surgical
needles although the preferred material is stainless steel. We have
found that stainless steel wire having a diameter of from 0.003
inch to 0.017 inch to be most suitable in making needles of the
present invention. The needles are manufactured by any of the techniques
well known in the art.
As may be seen in the cross-sectional views of FIGS. 3 and 4 our
new needle is flattened more than 2/3rds of the distance from the
pointed end towards the blunt end. Our new needle is meant to be
gripped by the needle holder approximately where the center 1/3
and the distal 1/3 of the needle meet; i.e., in the gentler curved
portion of the needle. By gripping in the gentler curved portion
there is less possibility of straightening the needle caused by
gripping the needle too tightly. Also, because our new needle is
meant to be gripped close to the blunt end of the needle, the overall
needle length may be reduced and consequently the tissue trauma
caused by the needle is reduced.
Referring to FIG. 6 there is shown another embodiment of the surgical
needle of the present invention. In this embodiment, the needle
25 has a straight pointed end 26. Adjacent this pointed end is a
first curved body portion 27 and adjacent this first curved body
portion is a second curved body portion 28. The radius of curvature
of both these curves is between 0.040 inch and 0.075 inch and the
total length of these curves should be between 0.063 inch and 0.105
inch. A third curved portion 29 is adjacent the blunt end 30 of
the needle. By using these multiple curves you are able to obtain
even greater control in the use of the needle in certain instances.
Any of the standard absorbable or nonabsorbable sutures may be
used with the surgical needles of the present invention. The preferred
absorbable sutures may be made from catgut or lactide and/or glycolide
polymers and copolymers. The preferred non-absorbable sutures may
be made from silk, nylon polypropylene, or the polyesters.
The surgical needles of the present invention may be sterilized
by any of the well known techniques such as ethylene oxide, irradiation,
etc. and are placed in suitable suture holding packets to provide
sterile packaging as is well known in the art.
In use, the needle is gripped by a needle holder at the juncture
of the middle and distal thirds of the needle. The straight pointed
end of the needle is directed vertically at the tissue to be penetrated.
The vertical position is maintained until the desired tissue depth
is reached. The needle is abruptly turned (approximately 90 degrees)
so that the point assumes a horizontal trajectory and the needle
passed through the tissue. The needle is then turned approximately
another 90 degrees so that it exits vertically on the opposite side
of the incision thereby establishing the bite the suture has taken.
The needles of the present invention may be manufactured by any
of the methods well-known in the art of needle manufacture. A preferred
method for manufacturing the needles of the present invention is
to first straighten a length of wire from a coil. The diameter of
the wire may be 4 mil, 6 mil or other diameter as desired. The straightened
wire is cut to length as is well-known to provide a cut piece of
straight wire. One end of the straight wire is ground by standard
techniques to provide a tapered configuration and a generally pointed
end. The unground end or blunt end is treated to provide a means
for attaching a suture material to that end. This treatment may
comprise drilling the end of the needle to provide a hole in the
end as is well-known. The treatment may also comprise placing a
channel in this end portion as is known. In certain embodiments
of the method of the present invention, longitudinal portions of
the wire are flattened to provide a generally oval cross-section
at this flattened portion to aid in handling the needle during the
surgical procedure. Also in this forming step the tapered end of
the wire may be provided with a triangular, trapezoidal or similar
cross-sectional shape as desired. The edges of the formed configuration
may be further ground to provide sharp cutting edges in the formed
portion.
The wire is then bent to place a plurality of curves in the wire.
This is accomplished by a continuous bending operation wherein the
curve adjacent the unground end or blunt end of the wire is placed
first and then the bending operation continued to place the curve
adjacent the pointed end in the wire. It is important to the present
invention that the gentler curve be placed in the wire first and
then the tighter curve be placed in the wire and that the curves
be placed in the wire in a continuous operation; for example, by
bending the wire around a mandrel whose surface contains the desired
curves. It is believed that by placing the curves in the wire as
described and in a continuous operation produces a smooth transition
from one curve to the next which is important in order to provide
a uniform, smooth needle which can be used and causes a minimum
of trauma to tissue. The straight point at the ground end of the
wire is placed in the wire by continuing to bend the wire about
the mandrel. Appropriate suture material is attached to the unground
end of the wire as is well-known.
If longitudinal portions of the needle are flattened to aid in
the handling of the needle by an appropriate instrument during the
surgical procedure, these flattened areas should be on the inside
of the curve and the outside of the curve.
Because the needles are made of steel or similar springy materials,
the mandrel used should have tighter curves than those desired in
the final needle to allow for some springback after the bending
operation. In some embodiments of the method of the present invention
where the suture material must be placed in a straight portion of
the needle, a short portion of the left straight until the suture
material is attached and that short portion then bent to the appropriate
gentler curve. Also in various embodiments of the present invention
the wire may also be heat treated and/or electropolished as is well-known
in the art.
Clearly, various other modifications in the described invention
may be made without departing from the spirit of the invention and
the foregoing description is to be considered merely exemplary and
not in the limiting sense. The scope of the invention is indicated
by reference to the following claims. |