Surgical procedures

A method of occluding a vessel including: cinching the vessel with a ligature comprising a flexible elongate base structure having a longitudinal axis, a needle end, and a second end, a collar for receiving a needle and affixed elongate base structure, positioned on the second end, and a node for interacting with the collar, the node positioned on the elongate base structure, between the needle and second ends, transverse to the longitudinal axis and having a proximal and a distal edge with respect to the needle end of the flexible elongate base structure, a portion of the node's proximal edge relative the needle end of the flexible elongate base structure being perpendicular to the elongate base structure's longitudinal axis. The method is ideally suited for performing a tubal (fallopian tube) ligation for reproductive control. In such a case, the fallopian tube is cinched sufficiently to block passage of an ovum through the fallopian tube's lumen, but is insufficiently occluded to unduly restrict blood circulation through the fallopian tube. In such a method, the ligature may be impregnated with contraceptive compound (e.g. a contraceptive steroid such as a progestogen) in order to prevent implantation of an ovum which already passed through the fallopian tube's lumen.

TECHNICAL FIELD 
The invention relates to a suture device useful in surgery in general and 
to processes for using a self-affixing suture assembly in particular. 
BACKGROUND 
Laparoscopic tubal sterilization techniques such as unipolar 
electrocoagulation, bipolar electrocoagulation, tubal ring occlusion, and 
the use of a spring-loaded tubal clip are disclosed in Novak's Textbook of 
Gynecology. 
As described in Novak's, the tubal ring occlusion was first described by 
Yoon et al. in 1974 and uses a silicone rubber band for the occlusion of a 
small knuckle of uterine tube just lateral to the cornu of the uterus. 
The use of a spring-loaded tubal clip involves utilizing a very small inert 
clip modified with a metal spring to provide sustained apposition under 
pressure. This technique is reported to result in minimal destruction of 
the uterine tube. 
All of these techniques have some drawbacks. For instance, as described in 
Novak's, these techniques are all associated with some risk of subsequent 
pregnancy due to, for example, carrying out the procedure in the luteal 
phase at a time when the fertilized ovum has passed through the uterine 
tube into the endometrial cavity. Furthermore, the spring-loaded tubal 
clip can dislodge, leaving a foreign metallic object in the woman's body 
besides subjecting her to a risk of an unintended pregnancy. 
Another problem associated with these techniques is that they are expensive 
to have reversed, and the restoration process is not always successful. 
It would be an improvement in the art to have a tubal sterilization 
technique which was more easily reversible and which would have a smaller 
chance of causing tissue damage and allowing for an unintended pregnancy. 
DISCLOSURE OF THE INVENTION 
The invention includes a method of occluding a vessel. The method includes 
cinching the vessel with a ligature comprising a flexible elongate base 
structure having a longitudinal axis, a needle end, and a second end, a 
collar for receiving a needle and affixed elongate base structure, 
positioned on the second end, and a node for interacting with the collar, 
the node positioned on the elongate base structure, between the needle and 
second ends, transverse to the longitudinal axis and having a proximal and 
a distal edge with respect to the needle end of the flexible elongate base 
structure, a portion of the node's proximal edge relative the needle end 
of the flexible elongate base structure being perpendicular to the 
elongate base structure's longitudinal axis. 
The method is ideally suited for performing a tubal (fallopian tube) 
ligation for reproductive control. In such a case, the fallopian tube is 
cinched sufficiently to block passage of an ovum through the fallopian 
tube's tureen, but is insufficiently occluded to unduly restrict blood 
circulation through the fallopian tube. In such a method, the ligature may 
be impregnated with contraceptive (e.g. a contraceptive steroid such as a 
progestogen) or other (e.g. antibiotic, anesthetic) compound in order, for 
example, to prevent implantation of an ovum which already passed through 
the fallopian tube's lumen. 
A process for occluding a fallopian tube includes providing a ligature 
comprising a flexible elongate base structure having a longitudinal axis, 
a needle end, and a second end, a collar for receiving a needle and 
affixed elongate base structure, positioned on the second end, and a node 
for interacting with the collar, the node positioned on the elongate base 
structure, between the needle and second ends, transverse to the 
longitudinal axis and having a proximal and a distal edge with respect to 
the needle end of the flexible elongate base structure; inserting the 
needle end through mesosalpinx associated with the fallopian tube; 
encircling the fallopian tube with the ligature; placing the needle end 
and affixed elongate base into the collar; and cinching the ligature about 
the fallopian tube to prevent passage of ova therethrough. 
The process can further include cinching a second ligature, in a spaced 
relationship (e.g. 0.5 to three centimeters) along the fallopian tube from 
the first ligature, about the same fallopian tube. The process can still 
further include cutting through the fallopian tube if permanent 
sterilization is desired. 
In one embodiment, the ligature of the process further includes an arced 
portion along the elongate base, such that when the ligature is cinched 
about the fallopian tube, a loop (having a diameter of 0.5 to two 
centimeters), non-contiguous with the fallopian tube, exists in the 
ligature. 
The ligature may be formed of a biodegradable material, which is especially 
useful if the process is to be performed post-partum. 
The method may also be practiced on other vessels such as the vas deferens, 
veins, cystic ducts of a gall bladder, and arteries. 
The process can be conducted laparoscopically or endoscopically. 
In one embodiment, the elongate base structure is at least partially formed 
of a biodegradable material (e.g. PLAGA). 
A hinged flap may be positioned within the collar for allowing 
unidirectional movement of base structure and associated node 
therethrough. 
The process is to be practiced on the vessels of mammals, including women.

BEST MODE OF THE INVENTION 
A preferred ligature for use with the invention includes an elongate base 
structure having a needle end, a collar end, and at least one node for 
interacting with the collar end. The node is positioned on the elongate 
base structure transverse to the base structure's longitudinal axis, and 
has a proximal and a distal edge with respect to the needle end (a 
"leading" and "trailing" edge, respectively). In the invention, a portion 
of the node's proximal edge is perpendicular to the elongate base 
structure's longitudinal axis, thus acting to prevent further cinching of 
the device once it has been finally placed. The distal edge of the node 
may also be wholly or partially perpendicular to the elongate base 
structure's longitudinal axis. 
Between the proximal and distal edges of a single notch is a top surface. 
This top surface will usually be planar or convex. A planar top surface 
can be, but need not be, parallel to the base structure's longitudinal 
axis. 
In one embodiment of the device, the elongate suture has multiple nodes. 
The nodes will then generally be positioned in a spaced relationship along 
the longitudinal axis of the suture cord, thus forming planar notches 
between the nodes. These notches can be sized to allow the collar or other 
structure to move along the longitudinal surface to a very limited extent 
to give the suture some "play", thus preventing possible tissue damage 
when the stitched tissue moves (e.g. by curing into the local tissue 
surrounding the stitches). In such a case, the planar notch will generally 
be parallel to the elongate suture's longitudinal axis. 
A ligature may also have an elongate surface with evenly spaced lateral 
ribs traversing the surface and an aperture, collar or other means, 
associated with one end of the ligature, for impeding movement of the 
ligature in one direction through the aperture while still allowing 
movement in the direction opposite to the impeded direction. Between the 
lateral ribs are notches. The notches will, in cross-section, lay 
substantially parallel to the elongate surface's longitudinal axis. The 
aperture is sized to encase the notch while still allowing limited 
bi-directional longitudinal movement of the aperture in the area of the 
notch between the ribs. 
As shown in FIG. 1, a suture, generally 20, has a base structure 22. This 
base structure 22 may be of various cross-sections, e.g. circular, 
rectangular, square, or elliptical, although a rectangular one is depicted 
(FIG. 2). The suture, generally 20, will typically vary in length from two 
to sixty centimeters, preferably from three to 10 centimeters. The base 
structure will preferably have a width or diameter varying from 0.1 to 
three millimeters, but preferably one to two millimeters. In one preferred 
embodiment, the base structure has a uniform cross-sectional shape and 
dimension along its longitudinal axis. 
The base structure is flexible enough to be stitched and is preferably made 
of a material strong enough to hold two pieces of tissue together after 
stitching. Acceptable materials for surgical sutures include those listed 
in the generalized monograph of the United States Pharmacopeia. These 
include absorbable and nonabsorbable sutures. 
Examples of absorbable sutures include surgical gut ("catgut") and 
synthetic absorbable sutures such as thermoplastic polymers derived from 
condensing the cyclic derivative of glycolic acid (glycolide) and mixtures 
of glycolide and cyclicized lactic acid (lactide) (e.g. PLAGA). Materials 
and methods for making polyglycolic and polylactic are disclosed in U.S. 
Pat. Nos. 3,463,158; 3,739,773; 3,772,420; and 3,636,956, the contents of 
which are incorporated by this reference. Other absorbable polymers are 
disclosed in U.S. Pat. Nos. 3,225,766 and 3,883,901 (absorbable 
polyesters), U.S. Pat. No. 2,764,159 (absorbable cellulose glycolic acid 
ethers), and U.S. Pat. Nos. 3,527,841; 3,564,078; and 3,759,264 (esters of 
.alpha.-cyanoacrylic acid), the contents of all of which are incorporated 
by this reference. Examples of nonabsorbable sutures include silk, dermal 
silk sutures (e.g. coated with tanned gelatin), nylon, polyester fiber, 
polyolefin fibers, silver, and stainless steel. PLAGA fibers can be melt 
extruded. 
Positioned on the surface of the base structure 22 is a node 24 (or rib). 
This node 24 has an edge 26 proximate the needle end 28 of the suture. 
This proximal edge 26 sits perpendicular to the longitudinal axis of the 
base structure at the point of its association with the base structure 
(FIG. 3). It also has a distal edge 30 (with respect to the needle end 28 
and any associated needle 32 (FIG. 2)). A rib or node may be integrally 
formed together with the base structure, or may be a separate piece 
affixed or attached to the base structure. 
The diameter or cross-sectional area of the base structure with nodes will 
preferably be as close as possible to that of a conventional ligature to 
prevent unnecessary tissue damage. In a preferred embodiment, the nodes 
add less than half a millimeter to the total diameter of the base 
structure. 
On the end 34 of the base structure 22 distal to the needle 32 is a latch 
collar 36 or other structure for interacting with the node 24 or nodes 24, 
24A (FIG. 3). The latch collar 36 or similar structure acts to prevent 
withdrawal of the needle 32 and base structure 22 once they have been 
inserted into the aperture 38. In order to prevent withdrawal of the base 
structure, a flange, hinged flexible flap or member, latch 40 or similar 
structure is preferably associated with the aperture 38. The height of the 
collar structure is typically chosen to adequately span the wound and 
accommodate the aperture. The use of a flap placed within the aperture or 
collar is especially preferred since it allows for relatively easy 
cinching of the device without the need for undue tension which might 
cause tissue damage during placement. 
The latch collar 36 may be formed of the same material as the base 
structure. This is especially the case when the structure is intended to 
be absorbable. Alternatively, the latch collar, or portions of it (e.g. 
the flap), may be formed of different materials if so desired. When the 
latch collar is made of the same material as the base structure, it can be 
integrally formed with the base structure. 
FIG. 3 depicts another embodiment of the device having two nodes 24, 24A. 
Between the two nodes is a planar notch 44 having a length along the 
longitudinal axis of the base structure 22 at least that of the thickness 
of the latch collar 36. The length of the notch can be selected to provide 
very limited play of the collar about the notch (e.g. from 0.1 to one 
millimeter). In the embodiment depicted in FIG. 3, the nodes 24, 24A have 
a convex top surface to facilitate their entry and placement in the 
aperture 38, although planar, concave, and other shapes will also work. 
In the embodiment depicted in FIGS. 1-3, the nodes or ribs are generally 
block-shaped and run perpendicular to the longitudinal axis of the suture. 
In cross-section, they will generally be square. The general block shape 
of such a rib is particularly advantageous when biodegradable suture 
material is used to form the ribbed suture. This advantage arises since 
during degradation of the suture material in the body, it will take some 
time for the ribs to erode sufficiently to allow the suture to back out of 
the latch collar end, thus preventing possible premature separation of the 
stitched tissues. In contrast with pointed nodes, the tip of the node can 
erode first, thus freeing, possibly prematurely, the latch collar to slide 
up the base structure and opening the wound. 
FIG. 4 depicts another embodiment of the device. In this embodiment, the 
proximal edges 26, 26A are mounted on the opposite side of the base 
structure 22 than that shown in the previously described embodiments 
(FIGS. 1 to 3). This device also has at the base of the collar a small 
thickening or other structure for abutment 48 against the tissue 46 once 
the suture has been placed (FIG. 5). This structure steadies the suture 
somewhat after placement. 
In embodiments where the device has several nodes, the spacing between the 
distal edge of one node and the proximal edge of the next will typically 
vary from 0.1 to one millimeter, thus forming several notches between the 
spaced ribs. Preferably the nodes will be evenly spaced. 
In one embodiment, the notch portions between the evenly spaced ribs are 
pre-chosen, allowing limited movement of the suture about the latch collar 
end. This movement gives the device some flexibility and decreases 
rigidity, which can result in undue pain or tissue damage when the 
stitched tissue moves. 
To use any of the depicted devices, the surgeon first prepares and orients 
the suture assembly to the extent necessary. The surgeon then pierces the 
tissue to be sutured with the needle 32 and draws it through the tissue 
(e.g. with forceps or a needle holder) with the flexible base structure 22 
following up and cinching the wound. The needle 32 is then inserted into 
the aperture 38 which is sized and shaped to accept the base structure and 
accompanying node(s). In a device having multiple nodes 24, 24A, the 
surgeon passes the collar end by an appropriate number of nodes to firmly 
cinch the tissue together. For a device such as that, this may require the 
surgeon to pull the base structure in a direction opposite to that of 
direction 44 (FIG. 5). The needle and appropriate amount of ligature is 
then cut off. The device, even though flexible, still tends to open, thus 
pushing the base structure in direction 44. Thus when tissue 46 moves, 
potentially driving the base structure further into the aperture 38, the 
proximal edge 26A butts up against the latch collar 36, preventing the 
device from further constricting the healing tissue 46. 
As depicted in FIG. 7, a preferred ligature according to the invention 
includes a base structure 22, a collar 36, and nodes 26, 26A. The ligature 
cinches a vessel 50, and includes a "loop" 52 formed in the base 
structure. This loop 52 is generally a rigid structure which is preferably 
made of a non-biodegradable material (e.g. polypropylene). More than one 
loop may be used (not shown). This ligature may be placed laparoscopically 
about a, for example, fallopian tube. 
After placement (e.g. cinching about a fallopian tube to prevent passage of 
an ovum or sperm through the lumen of the tube 50), the tube may be 
restored by cutting the base structure through the loop 52. Again, such 
cutting may be done laparoscopically. The ligature is then removed from 
the body cavity. Such a ligature may be formed to include a radio-opaque 
substance (e.g. barium sulfate) so that the body cavity may be examined by 
X-ray to ensure that all pieces of the device have been removed. 
After the ligature has been removed, a "tuboplasty" may be performed on the 
fallopian tube in an attempt to open the lumen of the fallopian tube. A 
balloon catheter is inserted up the fallopian tube, and the balloon 
inflated at the portion of the tube whereat the ligature was placed. If 
the tube was cut during placement of the ligature, a stint may be placed 
between the two portions (e.g. by microsurgical techniques). 
The device can be used for various surgical procedures. When a 
bioabsorbable material is used, the procedure is temporary and may not 
require surgery to reopen the tubes. When the suture is not made of a 
bioabsorbable material, the device is especially useful for a 
Marshall-Marquette bladder suspension, bowel surgery, or for fastening a 
mesh during e.g. a hernia operation (see, e.g. U.S. Pat. No. 4,548,202 for 
a description of mesh having flexible filaments). 
Various changes to the device can be made without departing from the spirit 
of the invention. For example in the case of a base structure having a 
circular cross-section, concentric ridges having a leading edge at least 
partially perpendicular to the longitudinal axis of the base structure, of 
preferably uniform height and dimension and evenly spaced from each other 
may extend around the surface of the base structure. 
A kit according to the invention may contain an eyed needle together with 
several ligatures according to the invention. Alternatively, a kit 
according to the invention can contain several sutures to which respective 
needles have been attached together with a device for cutting off the 
needle and excess suture material (e.g. using a suture cutter such as that 
described in U.S. Pat. No. 4,271,838 to Lasner et at. (Jun. 9, 1981)) at a 
point within the subject's body. 
A needle for use with the invention is preferably an eyeless needle. An 
eyeless needle may be manufactured with an open channel into which the 
ribbed suture is placed, and the channel swaged around the suture. 
Alternatively, a "seamless" needle may be used, which has a very delicate 
hole drilled in the shank, and the shank is pressed firmly about the 
suture. In one embodiment, the eyeless needle can be removed from the 
strand by gently tugging on it. Needles such as those disclosed in U.S. 
Pat. No. 4,981,149 to Yoon et at. (Jan. 1, 1991) and U.S. Pat. No. 
4,901,722 to Noguchi (Feb. 20, 1990) may be used. 
A preferred device for cutting off the needle and unused portion of the 
suture includes a barrel sized to accept the length of excess suture being 
used and associated with two separate sets of levers which, when actuated, 
provide the mechanical action necessary to collect the needle and snip off 
the base structure of the suture. 
At the end of the barrel of such a cutting device (distal to the user), 
there is an orifice or opening sized to receive a needle of the size being 
used. This distal end of the cutting device is inserted into a cavity in 
the subject and, after the suture has been cinched, the needle is placed 
within the orifice. Actuating a first set of levers causes two rubber type 
geared wheels to rotate in opposite directions drawing the needle in and 
accepting it and the associated suture material into the barrel. A 
sufficient amount of suture material is, of course, left behind to provide 
sufficient tension for the stitched tissue to keep in apposition and heal. 
Alternatively, the cutting device may employ a series of trapping flaps to 
enclose and contain the needle or needles and excess suture material. A 
second set of levers actuates two scissor blades just inside the orifice 
(and distal to the set of wheels) which cut the suture at the desired 
length, releasing the remaining portion of the suture. The procedure can 
be repeated, and the excess suture material and attached needles remain 
within the device until disposal occurs. When the device is full of 
needles and excess suture material or when the surgery is over, it is 
discarded. 
The ligature may be impregnated with various biologically active substances 
such as contraceptive steroids (e.g. progestogens, estrogens or mixtures 
thereof), antibiotics, local anesthetics, heparin, anti-thrombin agents, 
and other substances. 
EXAMPLES 
Example I 
Two devices, made as depicted in FIG. 7 (of a non-biodegradable material), 
are laparoscopically placed on each of the fallopian tubes of a healthy, 
fertile female. 
Example II 
Four devices, made as depicted in FIG. 3 (and of a biodegradable material), 
are cinched about both fallopian tubes (two per fallopian tube) of a 
healthy, human female one day post-partum. The needle ends of the devices 
are clipped from the base structure and removed from the body cavity. 
Contraception is provided for several months. 
Example III 
A device made according to FIG. 4 (made of a non-biodegradable material) is 
cinched about the vas deferens of a healthy male. 
Although the invention has been described with regard to certain preferred 
embodiments, the scope of the invention is defined by the appended claims.