CA1141915A - Elastomeric surgical sutures-comprising segmented copolyether/esters - Google Patents
Elastomeric surgical sutures-comprising segmented copolyether/estersInfo
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- CA1141915A CA1141915A CA000341398A CA341398A CA1141915A CA 1141915 A CA1141915 A CA 1141915A CA 000341398 A CA000341398 A CA 000341398A CA 341398 A CA341398 A CA 341398A CA 1141915 A CA1141915 A CA 1141915A
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-
- D—TEXTILES; PAPER
- D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
- D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
- D01F6/00—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof
- D01F6/78—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from copolycondensation products
- D01F6/86—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from copolycondensation products from polyetheresters
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61L—METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
- A61L17/00—Materials for surgical sutures or for ligaturing blood vessels ; Materials for prostheses or catheters
- A61L17/04—Non-resorbable materials
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G63/00—Macromolecular compounds obtained by reactions forming a carboxylic ester link in the main chain of the macromolecule
- C08G63/66—Polyesters containing oxygen in the form of ether groups
- C08G63/668—Polyesters containing oxygen in the form of ether groups derived from polycarboxylic acids and polyhydroxy compounds
- C08G63/672—Dicarboxylic acids and dihydroxy compounds
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- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Engineering & Computer Science (AREA)
- Organic Chemistry (AREA)
- Vascular Medicine (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- General Chemical & Material Sciences (AREA)
- Materials Engineering (AREA)
- Surgery (AREA)
- Textile Engineering (AREA)
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Abstract
ABSTRACT
ELASTOMERIC SURGICAL SUTURES COMPRISING
SEGMENTED COPOLYETHER/ESTERS
Elastomeric monofilament surgical sutures are character-ized by the following combination of mechanical proper-ties:
Yield elongation - from about 2 to 9 percent Visco-elastic elongation - from about 10 to 30 percent Young's modulus - from about 30,000 to 200,000 psi Tensile strength - at least about 40,000 psi Knot strength - at least about 30,000 psi The sutures are soft and flexible with superior knot tying and knot security properties. The sutures may be prepared from selected elastomeric copolyether/ester polymers which may be melt extruded and drawn to obtain the desired fiber properties.
ELASTOMERIC SURGICAL SUTURES COMPRISING
SEGMENTED COPOLYETHER/ESTERS
Elastomeric monofilament surgical sutures are character-ized by the following combination of mechanical proper-ties:
Yield elongation - from about 2 to 9 percent Visco-elastic elongation - from about 10 to 30 percent Young's modulus - from about 30,000 to 200,000 psi Tensile strength - at least about 40,000 psi Knot strength - at least about 30,000 psi The sutures are soft and flexible with superior knot tying and knot security properties. The sutures may be prepared from selected elastomeric copolyether/ester polymers which may be melt extruded and drawn to obtain the desired fiber properties.
Description
BACKGROUND OF THE INVENTION
The present invention relates to surgical sutures, and more particularly, to soft, elastomeric sutures having unique handling and ~not tying characteristics. The sutures may be prepared from segmented copolyether/.
esters or other elastomeric polymers.
- .
Many natural and synthetic materials are presently used as surgical sutures. These materials may be used as single filament strands, i.e, monofilament sutures, or as multifilament strands in a braided, twisted or other multifilament construction. ~atural materials such as silk, cotton, linen, and the like, of course do not lend themselves to the fabrication of monofilament su-tures and are accordingly generally used in one of the multifilament constructions.
Synthetic materials which are extruded in continuous lengths can be used in monofilament form. Common syn-thetic monofilament sutures include polyethylene terephthalate, polypropylene, polyethylene, and nylon.
Such monofilament sutures are preferred by surgeons for many surgical applications due to their inherent smooth-ness and noncapillarity to body fluids.
The presently available synthetic monofilament sutures all suffer to a greater or lesser degree from one par-ticular disadvantage, that is inherent stiffness. Be-sides making the material more difficult to handle and use, suture stiffness can adversely affect knot tying ability and knot security. It is because of the in-herent stiffness of available monofilament sutures that most larger su~ure sizes are braided or have other multi-filament constructions with better handling flexibility.
Monofilament sutures of the prior art are also charac-terized by a low degree of elasticity, the most elastic of the above-men~ioned synthetics being nylon which has a yield elongation of about 1.7 percen~ and a visco-elastic elongation of about 8.5 percent. The inelas-ticity of these sutures also makes knot tying more dif-ficult and reduces knot security. In addition, the in-elasticity prevents ~he suture from "giving" as a newly sutured wound swells, with the result that the suture may place the wound tissue under greater tension than is de-sirable, and may even cause some tearing, cutting or necrosis of the tissue.
The problems associated with the use of inelastic sutures in certain applications were recogni.zed in U.S. Patent No. 3,454,011, where it was proposed to fabricate a surgical suture composed of Spandex polyurethane. Such sutures, however, were highly elastic with "rubbery"
characteristics and did not find general acceptance in the medical profession.
It is accordingly an object of the present invention to provide a novel soft, limp, monofilament suture mate-rial. It is a further object of this invention to pro-vide a monofilament suture with a controlled degree ofelasticity to accommodate changing wound conditions. It is another object of this invention to provide a new, -nonabsorbable suture having a diameter of from about 0.01 to 1.0 mm and possessing unique and desirable ~a~
b ~ . ETH-467 physical properties. These and other objects will be made apparent from the ensuing description and claims.
SUMMARY
Monofilament sutures of the present invention are charac-terized by the following cornbination of physical proper-ties:
Yield elongation - from about 2 to 9 percent Visco-elastic elongation - frorn about 10 to 30 percent Young's modulus - from about 30,000 to 200,000 psi Tensile stxength - at least about 40,000 psi Knot strength - at leas~ about 30,000 psi Sutures possessing the above characteristics may be pre-pared by melt extruding certain elastomeric polymers such as copolyether/ester polymers to form a continuous filarnentary strand, and thereafter drawing the extruded filarnent to obtain the desixed suture properties. Cer-tain copolyether/ester polymers available cornrnercially from E. I. du Pont de Nemours & Co. under the tradename -~ "HYTREL" have been discovered to be suitable starting ma~erials for the preparation of sutures in accordance with the present inVentiOrl.
Monofilarnent sutures having physical properties in ac-cordance with the present invention are particularly useful in many surgical procedures where the suture is used to close a wound which may be subject to later swelling or change in position. The cornbination of low Young's modulus and significant yield elongation pro-vides the suture with an appreciable degree of controlled elasticity under low applied force. As a result, the suture is able to "give" to accornrnodate swelling in the wound area. The relatively high visco-elastic yield elongation and high tensile strength of the suture allows the suture to stretch during knot tie-down so that the knot "snugs down" for improved tying ability and knot security with a rnore predlctable and consistent knot .
~TH-467 geometry regardless of variations in suture tying technique or tension.
BRIEF DESCRIPTION OF DRAWINGS
Figure 1 is a representative stress-strain curve charac-teristic of the surgical filaments o~ the present inven-tion.
.
Figure 2 is a representative stress-strain curve compar-ing filaments of the present invention with monofila-ment sutures of the prior art.
:' DESCRIPTION OF PREFERRE:D EMBODIMENTS
,. . .
The sutures of the present invention are characterized by a combination of physical properties which are unique for monofilament sutures, and which provide the sutures of the present invention with unique and desirable func-tional properties.
.
The characteristic properties of the inventive sutures are readily determined by conventional test procedures.
Figure 1 illustrates a typical stress-strain or load-elongation diagram for the sutures of this invention.
In Figure 1, yield elongation (Ey) is the point at which permanent deformation of the suture begins to take place.
So long as the filament is not elongated beyond Ey, elastic recovery is essentially complete. The sutures of the present invention have an Ey with the range of 2 to 9 percent.
Young's modulus is a measure of the slope of the stress-strain curve over the initial portion of the curve ex-tending from the origin. In Figure 1, line a is a drawn tangent to the curve at the origin, and Young's modulus is equal to tan ~. The slope of the curve, and Young ' 5 modulus, are seen to be a measure of the resistance to elongation in the initial elastic portion of the curve.
The sutures of the present invention are designed to have a significant, but relatively low modulus of 30,000 to I.ïr~-46 i r , 200,000 psi, and preferably within the range of 50,000 to 150,000 psi. A modulus within the claimed xange pro-vides the correct amount of increasing tension on the su-tuxe as the suture is extended toward its yield point (Ey). At lowex yalues of Young's modulus, the sutuxe readily elongates under very low tension to its yield point and the advantages of having a significant yield elongation are lost. At highex values of Young's modulus, filament stiffness becomes the controlling consideration, and the softness and good handling properties of the su-ture diminish.
The portion of the stress-strain curve extending between Ey and Ev on Figure 1 is the visco-elastic region during which there is consi~erable elongation and permanent deformation of the suture with only slightly increasing tension. The visco-elastic elongation (Ev) of the su-tures of the present invention is controlled to be with~
in the range of from about 10 to 30 percent. This property of the suture allows the suture to draw down during knotting to assure good knot security.
As the suture ls elongated beyond Ev, the load increases rapidly as indicated in Figure 1. This rapid increase in load imparts a positive feel to the suture which, in the hands of a skilled surgeon, signals when Ev and maximum knot security are achieved. Preferably, the value of Ev is at least 2.5 times the value of Ey in order to provide the surgeon with a broad visco-elastic region in which to work during suture tie-down.
As seen in Figure 1, the load from 0 to Ev elongation is relatively low compared to the breaking load (Sb).
Preferably, the breaking load or straight tensile strength is at least 40,000 psi, and the load Sv corresponding to visco-elastic elongation is less than one-third of the breaking load, with the result that the suture may be easily knotted under relatively low forces and without risk of unintentionally breaking the suture. Knot strength of the suture is preferably at least 30,000 psi.
The breaking elongatlon (Eb) of the sutures of the pres-ent invention are generally within the range of 30 to 100 percent. Although this property is not critlcal to `' the performance of the suture since suture elongation in use does not generally exceed Ev, it is preferable that Eb be at least 1.5 x Ev in order to' reduce the pos-sibility oî inadvertently over elongating and breaking the suture during tie-down.
The unique mechanical properties of the sutures of the present invention will be more readily appreciated from Figure 2 where such sutures are compared to nylon and polyprop,,vlene sutures of the prior art. Representative physical properties of these three suture materials are given in Table I. Each of these prior art sutures has a considerably higher Young's modulus which results in the characteristic stiffness of these materials. In addition, neither suture has a noticeable Ey or an extended visco-elastic region which characterize the sutures of the in-vention and impart the desirable properties discussed above.
The mechanical properties of the sutures of the pre~ent invention reflected in the relative values of Ev and Ey ~ in combination with the low Young's modulus and high '~ tensile strength are unique in the field of surgical su-tures and distinguish the monofilament sutures of the present invention from all prior art materials.
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Sutures having mechanical properties in accordance with the present invention may be prepared from the segmented copol-ether/ester compositions disclosed in U.S. Patent No. 3,023, - 5 192, which states in part at Column 2, line 20 et seq,:
"The copolyetheresters of this invention - are prepared by reacting one or more boxylic acids or their ester-forming deriva-tives, one or more difunctional polyethers with the formula: , HO(RO) H
(in which R is one or more divalent organic radicals and ~ is an integer of a value to provide a glycol with a molecular weight of between about 350 and about 6,000), and one or more dihydroxy-compounds selected from the class consistiny of bis-phenols and lower ali-phatic glycols with the formula:
HOtC~2)qOH
(in which q is 2-lo~with the proviso that the reactants be selected so that substantially all of the repeating units of the polyester contain :
'! at least one aromatic ring. The resulting ~ ester is then polymerized."
., ' The preparation of other related segmented thermoplastic copolymers are described in the following additional : references: U~S. Patents Nos. 3,651,014, 3,763,109; 3,766,146, ;
and 3,784,520, ,; .
' 35 According to the above re~erences, the disclosed segmented thermoplastic copolymers may be cast as films, injection ~; molded to form objects, or melt extruded to form filaments.
, me products obtained in accordance with these references, however, are characterized by physical properties which are not desirable for surgical sutures.
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E-rH-467 3~i In particular, the filaments of the references are rub-bery with a very high degree of elasticity as indlcated by break elongations in excess of 500 percent. Tensile strengths, on the other hand, are very low, generally less than 8,000 psi. The filaments prepared from co-polyether/esters in accordance with the teachings of these references therefore do not possess the mechanical properties of the sutures of the invention, and, in fact, are obviously not at all suitable for use as surgical sutures.
The disadvantages of the prior art references are over-come by means of the present invention wherein filaments extruded from certain copolyether/esters are quenched and drawn with the result that the mechanical properties of the filaments are controlled to be within the specific limits discovered to be particularly desirable for surgi-cal sutures.
The segmented copolyether/esters useful in the present invention comprise a multiplicity of recurring long chain ether/ester units and short chain ester units joined head to tail through ester linkages according to the following general formula:
O O O O
[(O ~ D - O - C - R ~ C)a~O ~ G - O - C - R - C ~ )b]n The long chain ether/ester units of the polymer are rep-resented by the general formula:
O o Il 11 - - O - G - O - C - R - C - (IIj wherein G is a divalent radical remaining after the re-moval of terminal hydroxyl groups from a poly(C2 10 alkylene oxide)glycol having a molecular weight within the range of about 350 to 6,000, and R is a divalent ..
radical remaining after the removal of carboxyl groups from an aromatic dicarboxylic acid having a molecular weight of less than about 300.
r . L ;~ b 7 , _ The short chain ester units are represented by the general formula: .
:.
O O -Il 11 , O - D - O - C - R - C - (III) wherein D is a divalent radical remaining after removal of hydroxyl groups from an alkyldiol having a molecular weight of less than about 250, and R is as defined above.
; In the above Formula I, a is an integer such that the short chain copolymer segments represented by a comprise from 50 to 90 percent by weight of the total copolymer composition; b is an integer such that the long chain copolymer segments represented by _ comprise from 10 to 50 percent of the total copolymer composition; and n is the degree of polymerization resulting in a fiber-forming copolymer.
The copolyether/esters represented by Formula I may bemelt extruded, quenched and drawn to obtain filaments having physical properties desirable for surgical su-tures as above defined. Polymer to be extruded is driedat about 200-220F in a circulating hot air oven and/or under vacuum in order to remove all traces of moisture and other volatile materials. The polymer is then melt extruded and water quenched in accordance with the con-ventional melt spinning techni~ues for synthetic fibers.
The fiber is finally drawn at least about 5X, and - :
usually from about 7X to 9X to achieve molecular orien~
tation.
The preparation of fibers useful as surgical sutures from copolyether/esters in accordance with the present in-vention is demonstrated by the following examples which are presented by way of illustration and are not limit-ing of the present invention. The polymers utilized in these examples are copolyether/esters prepared from 1,4-butanediol, dimethyl phthalate, and polytetra methylene ether glycol (M.W. of about 1,000), and are . . .
ll commercially a~ail~ le ~from E. I. du Pont de Nemours &
Co. under the t~ ~ "HYTREL". The polymer contains intrapolymerized butylenephthalate hard segments ~ (short chain ester units) and polytetramethvlene ether terephthalate soft segments ~long chain ester units) and has the following general structure as reported in the . Journal of Elastomers and Plastics 9, 416-38 (Oct., 1977):
ICUZ~ - C - ~3 - cla~o~c8;~ 2cH~cd~o) - -~ - C~
(hard segment) (soft segment) '~
.~ wherein a and b are às defined above and x is an integer reflecting the molecular weight of the ether glycol re-actant (x = 14 for M.W. of about 1,000).
In the following examples, physical properties of in-dividual monofilaments were determined on an Instron~
tensile tester under the following conditions:
Crosshead speed (XH): S in/min Chart speed (CS) : 10 in/min Sample length (GL) : 5 in Scale load (SL) : 2 lbs/in With reference to Figure 1, Young's modulus is calculated ; from the slope a of the stress-strain curve in the initial linear, elastic region as follows:
Young's modulu5 (psi~ = tan e X GL x CS x SL
wherein e = the angle indicated in Figure 1 XS = the cross-sectional area of the fiber, in L
SL, XH, CS, and GL are as identified above.
Yield stress (Sy) is the load at the point of inter-section of lines a and b drawn tangent to the initial elastic region and the visco-elastic region, respectivelv, of the curve as illustrated in Figure 1. Yield elonga- ~_ tion (Ey) is the elongation corresponding to Sy and is ir read directly off the stress-strain curve.
~ ~a~ k Visco-elastic stress (Sv) is the load at the point of intersection of line b with line c drawn tangent to the curve as illustrated in Eiyure 1. Visco-elastic elonga-tion (Ev) is the elongation corresponding to Sv and is read directly off the curve.
Brea~ elongation (Eb) and breaking tensile strength (Sb) are read directly off the stress-strain curve as illus-trated in Figure 1.
EXAMæLE I
A sample of copolyether/ester of Formula IV having ap-proximately 40 wt percent soft segments and comprising approximately 51 percent terephthaloyl units, 15 percent units derived from polytetramethylene ether glycol, and 33 percent units derived from 1,4-butanediol was dried four hours at 200F in a circulating hot air oven and then further dried under vacuum at 100 microns (no heat) for 16 hours. The dry polymer was placed in a one-inch horizontal extruder and extruded through a J/50/1 die at an extrusion temperature of 380F.
The extrudate was quenched in water at ambient temperature and drawn to a size 2-0 monofilament suture using a 8.8X
draw ratio at a temperature of 530F and with a take-up speed of 485 ft/min. Physical properties of the result-ing filaments are given in Table II.
, .
EXAMPLE II
A sample of copolyether/ester of Formula IV having ap-proximately 23 wt percent soft segments and comprising approximately 45 percent terephthaloyl units, 4 percent orthophthaloyl units, 20 percent units derived from poly-tetramethylene ethex glycol and 31 percent units derived , 35 from 1,4-butanediol was dried and extruded at 400F as de-scribed in Example I. The extrudate was quenched and drawn into a size 2-0 monofilament using a 7.5X draw ratio at a temperature of 450F and Wit}l a take-up speed of .~
~ 4 412 ft/min. Physical properties of the resulting fila-ments are given in Table II.
EXAMPLE III
S A sample of copolyether/ester of Formula IV haviny ap-proximately 18 wt percent soft segments and comprising approximately 41 percent terephthaloyl units, 35 per-cent units derived from polytetramethylene ether glycol and 24 percent units derived from 1,4-butanediol was dried and extruded at 405F as descrlbed in Example I.
The extrudate was quenched and drawn into a size 2-0 monofilament suture using a 6.5 draw ratio at a tempera-ture of 560~. The take-up speed was 75 ft/min. Physi-cal properties of the resulting filaments are given in Table II. It is noted that the Young's modulus of these filaments exceeded the maximum desirable llmit for su-tures of the present invention.
EXAMPLE IV
Three parts of a copolyether/ester of Exam~le I and two parts of a copolyether/ester of Example III were dry blended to provide a polymer having a total of 30.2 per-cent soft segments. The blended material was dried in a vacuum oven for two hours at 1-2 mm Hg (no heat), and then heated at 50C for three hours at 1-2 mm Hg.
The dried mixture was melt blended in a 3~4-inch Brabender extruder with a 25-inch barrel with a 20/1 screw and ex-truded at 430F through a 5/32-inch die in a vertical monofilament assembly. The extrudate was water quenched at ambient temperature, pelletized, and again dried as described above for the dry-blended material before ex-truding into monofilament sutures. A size 2-0 monofila-ment suture of this material was extruded at 400F using a 7.9X draw ratio at a temperature of 460F and a take-up speed of 435 ft/min. Physical properties of the resulting filaments are given in Table II.
ETH-~167 LS
EXAMPLE V
- 3.5 Parts of a copolyether~ester of Example I and 1.5 parts of a copolyether/ester of Example III were dry-blended for a total of 33.4 percent soft segments and extruded following the general procedure of Example IV, and using a flnal draw xatio of 7.5X with a draw tempera-ture of 485F and a take-up speed of 412 ft/min to ob-tain a size 2-0 monofilament suture. The physical properties of the resulting filamen-ts are given in Table II.
EXAMPLE VI
The procedure of Example IV was repeated using various blends of copolyether/ester polymers of Examples I, II
and III having the compositions and blended in ratios as shown in Table II. The physical properties of the re-sulting filaments are also given in Table III.
EXAMPLE VII
~0 A copolyether/ester of Example I with 40 wt percent soft segments was dried and extruded in accordance with the general procedure of Example I using a 20 mil spinnerette to obtain a size 5-0 suture, and a S0 mil spinnerette to obtain a size 0 suture. Drawing conditions and physical ~: 25 properties of the resulting suture are compared in ; Table IV with a size 2-0 suture of the same composition prepared according to Example I.
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P~ 3 ~ o~ o o o o o o o o o . ~iH-467 TABLE IV
Suture size _ _ _ Draw ratio 7-5 8.8 7.3*
Draw temperature, F 340 530 370 Take-up, ft/min 205 485 110 Diameter, mils 7.08 11.10 14.03 ~not strength, psi 48,60037,200 34,200 (Xg/cm2) .(3,400)(2,600)(2,400) T~nsile strength, psi 67,50064,100 68,600 (Xg/cm2) (4,700)(4,400)(4,800) Brea~ elongation, % 43.5 31.8 36.7 Visco-elastic elongation, ~ 10.8 18.6 17.6 Yield elongation, ~ 3.0 3.2 6.3 Young's modulus, psi 49,00050,~00 51,000 (Kg/cm2) (3,400)(3,5003(3,600) _ ~Two stage draw EXAMPLE VIII
Monofilament sutures prepared from a copolyether/ester of Example II with 23 wt percent soft segments were sterilized by cobalt-60 irradiation and with ethylene oxide in accordance wi~h conventional procedures for sterilizing surgical sutures. The physical properties of the sutures were affected only slightly by ethylene oxide sterilization, and even less by cobalt-60, as shown by the data in Table V.
TABLE V
. _ SutureNonsterile _ Sterilized ; control Co E.O.
; Diameter, mils 12.5 12.6 13.2 Knot strength; psi 35,300 33,400 29,900 (Kg/cm2) (2,500) (2,300) (2,100) Tensile strength, psi70,300 70,000 67,700 (Kg/cm2) (4,900) (4,900) (4,800) Break elongation, % 28.2 31.6 45.2 Visco-elastic elongation, ~i 13.2 15.0 23.5 Yield elongation, % 2.9 2.3 2.2 ` Young's modulus, psi185,000 165,000 138,000 (Kg/cm2) (13,000) (11,600) (9,600) The important physical properties of the sutures pre-pared from copolyether/esters are responsive to changes ln polymer composit.ion and processing conditions. For example, visco-elastic elongation and yield elongation increase as the proportion of sof-t segments in polymer are increased, and conversely, Young's modulus decreases with an increasing proportion of soft segments. The break elongation may be decreased and tensile strength increased by employing higher draw ratios during the manufacture of the suture. By regulation of the com-position and processing variables therefor, it is pos-sible to obtain specific mechanical properties for in-dividual sutures with a great degree of latitude.
While the preceding examples have been directed to thepreparation of monofilament sutures of copolyether/esters, this was for the sake of convenience in describing one polymer system and the effect of various polymer composi-tions and spinning conditions on fiber properties. The copolyether/ester polymers may also be used in the manufacture of braided or other multifilament suture con-vl structions, and single filaments and braids may be used in the preparation of surgical fabrics and knitted or woven prosthetic devices such as vein and arterial grafts.
In addition, elastomeric filaments having a combinationof physical properties in accordance with the present in-vention may be prepared from other polymer systems such as polyurethane or sillcone elastomers or polyether co-polymers of urethane or silicone elastomers. Furthermore, elastomeric filaments of the present invention may be blended with each other, with other elastomeric or non-elastomeric filaments, and with either absorbable or non-absorbable filaments in order tc provide yarns and fabrics with special properties, all of which is deemed to be in-cluded within the scope of the present invention.
The present invention relates to surgical sutures, and more particularly, to soft, elastomeric sutures having unique handling and ~not tying characteristics. The sutures may be prepared from segmented copolyether/.
esters or other elastomeric polymers.
- .
Many natural and synthetic materials are presently used as surgical sutures. These materials may be used as single filament strands, i.e, monofilament sutures, or as multifilament strands in a braided, twisted or other multifilament construction. ~atural materials such as silk, cotton, linen, and the like, of course do not lend themselves to the fabrication of monofilament su-tures and are accordingly generally used in one of the multifilament constructions.
Synthetic materials which are extruded in continuous lengths can be used in monofilament form. Common syn-thetic monofilament sutures include polyethylene terephthalate, polypropylene, polyethylene, and nylon.
Such monofilament sutures are preferred by surgeons for many surgical applications due to their inherent smooth-ness and noncapillarity to body fluids.
The presently available synthetic monofilament sutures all suffer to a greater or lesser degree from one par-ticular disadvantage, that is inherent stiffness. Be-sides making the material more difficult to handle and use, suture stiffness can adversely affect knot tying ability and knot security. It is because of the in-herent stiffness of available monofilament sutures that most larger su~ure sizes are braided or have other multi-filament constructions with better handling flexibility.
Monofilament sutures of the prior art are also charac-terized by a low degree of elasticity, the most elastic of the above-men~ioned synthetics being nylon which has a yield elongation of about 1.7 percen~ and a visco-elastic elongation of about 8.5 percent. The inelas-ticity of these sutures also makes knot tying more dif-ficult and reduces knot security. In addition, the in-elasticity prevents ~he suture from "giving" as a newly sutured wound swells, with the result that the suture may place the wound tissue under greater tension than is de-sirable, and may even cause some tearing, cutting or necrosis of the tissue.
The problems associated with the use of inelastic sutures in certain applications were recogni.zed in U.S. Patent No. 3,454,011, where it was proposed to fabricate a surgical suture composed of Spandex polyurethane. Such sutures, however, were highly elastic with "rubbery"
characteristics and did not find general acceptance in the medical profession.
It is accordingly an object of the present invention to provide a novel soft, limp, monofilament suture mate-rial. It is a further object of this invention to pro-vide a monofilament suture with a controlled degree ofelasticity to accommodate changing wound conditions. It is another object of this invention to provide a new, -nonabsorbable suture having a diameter of from about 0.01 to 1.0 mm and possessing unique and desirable ~a~
b ~ . ETH-467 physical properties. These and other objects will be made apparent from the ensuing description and claims.
SUMMARY
Monofilament sutures of the present invention are charac-terized by the following cornbination of physical proper-ties:
Yield elongation - from about 2 to 9 percent Visco-elastic elongation - frorn about 10 to 30 percent Young's modulus - from about 30,000 to 200,000 psi Tensile stxength - at least about 40,000 psi Knot strength - at leas~ about 30,000 psi Sutures possessing the above characteristics may be pre-pared by melt extruding certain elastomeric polymers such as copolyether/ester polymers to form a continuous filarnentary strand, and thereafter drawing the extruded filarnent to obtain the desixed suture properties. Cer-tain copolyether/ester polymers available cornrnercially from E. I. du Pont de Nemours & Co. under the tradename -~ "HYTREL" have been discovered to be suitable starting ma~erials for the preparation of sutures in accordance with the present inVentiOrl.
Monofilarnent sutures having physical properties in ac-cordance with the present invention are particularly useful in many surgical procedures where the suture is used to close a wound which may be subject to later swelling or change in position. The cornbination of low Young's modulus and significant yield elongation pro-vides the suture with an appreciable degree of controlled elasticity under low applied force. As a result, the suture is able to "give" to accornrnodate swelling in the wound area. The relatively high visco-elastic yield elongation and high tensile strength of the suture allows the suture to stretch during knot tie-down so that the knot "snugs down" for improved tying ability and knot security with a rnore predlctable and consistent knot .
~TH-467 geometry regardless of variations in suture tying technique or tension.
BRIEF DESCRIPTION OF DRAWINGS
Figure 1 is a representative stress-strain curve charac-teristic of the surgical filaments o~ the present inven-tion.
.
Figure 2 is a representative stress-strain curve compar-ing filaments of the present invention with monofila-ment sutures of the prior art.
:' DESCRIPTION OF PREFERRE:D EMBODIMENTS
,. . .
The sutures of the present invention are characterized by a combination of physical properties which are unique for monofilament sutures, and which provide the sutures of the present invention with unique and desirable func-tional properties.
.
The characteristic properties of the inventive sutures are readily determined by conventional test procedures.
Figure 1 illustrates a typical stress-strain or load-elongation diagram for the sutures of this invention.
In Figure 1, yield elongation (Ey) is the point at which permanent deformation of the suture begins to take place.
So long as the filament is not elongated beyond Ey, elastic recovery is essentially complete. The sutures of the present invention have an Ey with the range of 2 to 9 percent.
Young's modulus is a measure of the slope of the stress-strain curve over the initial portion of the curve ex-tending from the origin. In Figure 1, line a is a drawn tangent to the curve at the origin, and Young's modulus is equal to tan ~. The slope of the curve, and Young ' 5 modulus, are seen to be a measure of the resistance to elongation in the initial elastic portion of the curve.
The sutures of the present invention are designed to have a significant, but relatively low modulus of 30,000 to I.ïr~-46 i r , 200,000 psi, and preferably within the range of 50,000 to 150,000 psi. A modulus within the claimed xange pro-vides the correct amount of increasing tension on the su-tuxe as the suture is extended toward its yield point (Ey). At lowex yalues of Young's modulus, the sutuxe readily elongates under very low tension to its yield point and the advantages of having a significant yield elongation are lost. At highex values of Young's modulus, filament stiffness becomes the controlling consideration, and the softness and good handling properties of the su-ture diminish.
The portion of the stress-strain curve extending between Ey and Ev on Figure 1 is the visco-elastic region during which there is consi~erable elongation and permanent deformation of the suture with only slightly increasing tension. The visco-elastic elongation (Ev) of the su-tures of the present invention is controlled to be with~
in the range of from about 10 to 30 percent. This property of the suture allows the suture to draw down during knotting to assure good knot security.
As the suture ls elongated beyond Ev, the load increases rapidly as indicated in Figure 1. This rapid increase in load imparts a positive feel to the suture which, in the hands of a skilled surgeon, signals when Ev and maximum knot security are achieved. Preferably, the value of Ev is at least 2.5 times the value of Ey in order to provide the surgeon with a broad visco-elastic region in which to work during suture tie-down.
As seen in Figure 1, the load from 0 to Ev elongation is relatively low compared to the breaking load (Sb).
Preferably, the breaking load or straight tensile strength is at least 40,000 psi, and the load Sv corresponding to visco-elastic elongation is less than one-third of the breaking load, with the result that the suture may be easily knotted under relatively low forces and without risk of unintentionally breaking the suture. Knot strength of the suture is preferably at least 30,000 psi.
The breaking elongatlon (Eb) of the sutures of the pres-ent invention are generally within the range of 30 to 100 percent. Although this property is not critlcal to `' the performance of the suture since suture elongation in use does not generally exceed Ev, it is preferable that Eb be at least 1.5 x Ev in order to' reduce the pos-sibility oî inadvertently over elongating and breaking the suture during tie-down.
The unique mechanical properties of the sutures of the present invention will be more readily appreciated from Figure 2 where such sutures are compared to nylon and polyprop,,vlene sutures of the prior art. Representative physical properties of these three suture materials are given in Table I. Each of these prior art sutures has a considerably higher Young's modulus which results in the characteristic stiffness of these materials. In addition, neither suture has a noticeable Ey or an extended visco-elastic region which characterize the sutures of the in-vention and impart the desirable properties discussed above.
The mechanical properties of the sutures of the pre~ent invention reflected in the relative values of Ev and Ey ~ in combination with the low Young's modulus and high '~ tensile strength are unique in the field of surgical su-tures and distinguish the monofilament sutures of the present invention from all prior art materials.
:
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Sutures having mechanical properties in accordance with the present invention may be prepared from the segmented copol-ether/ester compositions disclosed in U.S. Patent No. 3,023, - 5 192, which states in part at Column 2, line 20 et seq,:
"The copolyetheresters of this invention - are prepared by reacting one or more boxylic acids or their ester-forming deriva-tives, one or more difunctional polyethers with the formula: , HO(RO) H
(in which R is one or more divalent organic radicals and ~ is an integer of a value to provide a glycol with a molecular weight of between about 350 and about 6,000), and one or more dihydroxy-compounds selected from the class consistiny of bis-phenols and lower ali-phatic glycols with the formula:
HOtC~2)qOH
(in which q is 2-lo~with the proviso that the reactants be selected so that substantially all of the repeating units of the polyester contain :
'! at least one aromatic ring. The resulting ~ ester is then polymerized."
., ' The preparation of other related segmented thermoplastic copolymers are described in the following additional : references: U~S. Patents Nos. 3,651,014, 3,763,109; 3,766,146, ;
and 3,784,520, ,; .
' 35 According to the above re~erences, the disclosed segmented thermoplastic copolymers may be cast as films, injection ~; molded to form objects, or melt extruded to form filaments.
, me products obtained in accordance with these references, however, are characterized by physical properties which are not desirable for surgical sutures.
, ~' ,.. ~
' :
E-rH-467 3~i In particular, the filaments of the references are rub-bery with a very high degree of elasticity as indlcated by break elongations in excess of 500 percent. Tensile strengths, on the other hand, are very low, generally less than 8,000 psi. The filaments prepared from co-polyether/esters in accordance with the teachings of these references therefore do not possess the mechanical properties of the sutures of the invention, and, in fact, are obviously not at all suitable for use as surgical sutures.
The disadvantages of the prior art references are over-come by means of the present invention wherein filaments extruded from certain copolyether/esters are quenched and drawn with the result that the mechanical properties of the filaments are controlled to be within the specific limits discovered to be particularly desirable for surgi-cal sutures.
The segmented copolyether/esters useful in the present invention comprise a multiplicity of recurring long chain ether/ester units and short chain ester units joined head to tail through ester linkages according to the following general formula:
O O O O
[(O ~ D - O - C - R ~ C)a~O ~ G - O - C - R - C ~ )b]n The long chain ether/ester units of the polymer are rep-resented by the general formula:
O o Il 11 - - O - G - O - C - R - C - (IIj wherein G is a divalent radical remaining after the re-moval of terminal hydroxyl groups from a poly(C2 10 alkylene oxide)glycol having a molecular weight within the range of about 350 to 6,000, and R is a divalent ..
radical remaining after the removal of carboxyl groups from an aromatic dicarboxylic acid having a molecular weight of less than about 300.
r . L ;~ b 7 , _ The short chain ester units are represented by the general formula: .
:.
O O -Il 11 , O - D - O - C - R - C - (III) wherein D is a divalent radical remaining after removal of hydroxyl groups from an alkyldiol having a molecular weight of less than about 250, and R is as defined above.
; In the above Formula I, a is an integer such that the short chain copolymer segments represented by a comprise from 50 to 90 percent by weight of the total copolymer composition; b is an integer such that the long chain copolymer segments represented by _ comprise from 10 to 50 percent of the total copolymer composition; and n is the degree of polymerization resulting in a fiber-forming copolymer.
The copolyether/esters represented by Formula I may bemelt extruded, quenched and drawn to obtain filaments having physical properties desirable for surgical su-tures as above defined. Polymer to be extruded is driedat about 200-220F in a circulating hot air oven and/or under vacuum in order to remove all traces of moisture and other volatile materials. The polymer is then melt extruded and water quenched in accordance with the con-ventional melt spinning techni~ues for synthetic fibers.
The fiber is finally drawn at least about 5X, and - :
usually from about 7X to 9X to achieve molecular orien~
tation.
The preparation of fibers useful as surgical sutures from copolyether/esters in accordance with the present in-vention is demonstrated by the following examples which are presented by way of illustration and are not limit-ing of the present invention. The polymers utilized in these examples are copolyether/esters prepared from 1,4-butanediol, dimethyl phthalate, and polytetra methylene ether glycol (M.W. of about 1,000), and are . . .
ll commercially a~ail~ le ~from E. I. du Pont de Nemours &
Co. under the t~ ~ "HYTREL". The polymer contains intrapolymerized butylenephthalate hard segments ~ (short chain ester units) and polytetramethvlene ether terephthalate soft segments ~long chain ester units) and has the following general structure as reported in the . Journal of Elastomers and Plastics 9, 416-38 (Oct., 1977):
ICUZ~ - C - ~3 - cla~o~c8;~ 2cH~cd~o) - -~ - C~
(hard segment) (soft segment) '~
.~ wherein a and b are às defined above and x is an integer reflecting the molecular weight of the ether glycol re-actant (x = 14 for M.W. of about 1,000).
In the following examples, physical properties of in-dividual monofilaments were determined on an Instron~
tensile tester under the following conditions:
Crosshead speed (XH): S in/min Chart speed (CS) : 10 in/min Sample length (GL) : 5 in Scale load (SL) : 2 lbs/in With reference to Figure 1, Young's modulus is calculated ; from the slope a of the stress-strain curve in the initial linear, elastic region as follows:
Young's modulu5 (psi~ = tan e X GL x CS x SL
wherein e = the angle indicated in Figure 1 XS = the cross-sectional area of the fiber, in L
SL, XH, CS, and GL are as identified above.
Yield stress (Sy) is the load at the point of inter-section of lines a and b drawn tangent to the initial elastic region and the visco-elastic region, respectivelv, of the curve as illustrated in Figure 1. Yield elonga- ~_ tion (Ey) is the elongation corresponding to Sy and is ir read directly off the stress-strain curve.
~ ~a~ k Visco-elastic stress (Sv) is the load at the point of intersection of line b with line c drawn tangent to the curve as illustrated in Eiyure 1. Visco-elastic elonga-tion (Ev) is the elongation corresponding to Sv and is read directly off the curve.
Brea~ elongation (Eb) and breaking tensile strength (Sb) are read directly off the stress-strain curve as illus-trated in Figure 1.
EXAMæLE I
A sample of copolyether/ester of Formula IV having ap-proximately 40 wt percent soft segments and comprising approximately 51 percent terephthaloyl units, 15 percent units derived from polytetramethylene ether glycol, and 33 percent units derived from 1,4-butanediol was dried four hours at 200F in a circulating hot air oven and then further dried under vacuum at 100 microns (no heat) for 16 hours. The dry polymer was placed in a one-inch horizontal extruder and extruded through a J/50/1 die at an extrusion temperature of 380F.
The extrudate was quenched in water at ambient temperature and drawn to a size 2-0 monofilament suture using a 8.8X
draw ratio at a temperature of 530F and with a take-up speed of 485 ft/min. Physical properties of the result-ing filaments are given in Table II.
, .
EXAMPLE II
A sample of copolyether/ester of Formula IV having ap-proximately 23 wt percent soft segments and comprising approximately 45 percent terephthaloyl units, 4 percent orthophthaloyl units, 20 percent units derived from poly-tetramethylene ethex glycol and 31 percent units derived , 35 from 1,4-butanediol was dried and extruded at 400F as de-scribed in Example I. The extrudate was quenched and drawn into a size 2-0 monofilament using a 7.5X draw ratio at a temperature of 450F and Wit}l a take-up speed of .~
~ 4 412 ft/min. Physical properties of the resulting fila-ments are given in Table II.
EXAMPLE III
S A sample of copolyether/ester of Formula IV haviny ap-proximately 18 wt percent soft segments and comprising approximately 41 percent terephthaloyl units, 35 per-cent units derived from polytetramethylene ether glycol and 24 percent units derived from 1,4-butanediol was dried and extruded at 405F as descrlbed in Example I.
The extrudate was quenched and drawn into a size 2-0 monofilament suture using a 6.5 draw ratio at a tempera-ture of 560~. The take-up speed was 75 ft/min. Physi-cal properties of the resulting filaments are given in Table II. It is noted that the Young's modulus of these filaments exceeded the maximum desirable llmit for su-tures of the present invention.
EXAMPLE IV
Three parts of a copolyether/ester of Exam~le I and two parts of a copolyether/ester of Example III were dry blended to provide a polymer having a total of 30.2 per-cent soft segments. The blended material was dried in a vacuum oven for two hours at 1-2 mm Hg (no heat), and then heated at 50C for three hours at 1-2 mm Hg.
The dried mixture was melt blended in a 3~4-inch Brabender extruder with a 25-inch barrel with a 20/1 screw and ex-truded at 430F through a 5/32-inch die in a vertical monofilament assembly. The extrudate was water quenched at ambient temperature, pelletized, and again dried as described above for the dry-blended material before ex-truding into monofilament sutures. A size 2-0 monofila-ment suture of this material was extruded at 400F using a 7.9X draw ratio at a temperature of 460F and a take-up speed of 435 ft/min. Physical properties of the resulting filaments are given in Table II.
ETH-~167 LS
EXAMPLE V
- 3.5 Parts of a copolyether~ester of Example I and 1.5 parts of a copolyether/ester of Example III were dry-blended for a total of 33.4 percent soft segments and extruded following the general procedure of Example IV, and using a flnal draw xatio of 7.5X with a draw tempera-ture of 485F and a take-up speed of 412 ft/min to ob-tain a size 2-0 monofilament suture. The physical properties of the resulting filamen-ts are given in Table II.
EXAMPLE VI
The procedure of Example IV was repeated using various blends of copolyether/ester polymers of Examples I, II
and III having the compositions and blended in ratios as shown in Table II. The physical properties of the re-sulting filaments are also given in Table III.
EXAMPLE VII
~0 A copolyether/ester of Example I with 40 wt percent soft segments was dried and extruded in accordance with the general procedure of Example I using a 20 mil spinnerette to obtain a size 5-0 suture, and a S0 mil spinnerette to obtain a size 0 suture. Drawing conditions and physical ~: 25 properties of the resulting suture are compared in ; Table IV with a size 2-0 suture of the same composition prepared according to Example I.
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D~ -- oo 00 00 00 00 00 00 ~0 00 .rl ~ O In o ~ o ~ o o~ o ~ o ~ o ~ o co o ~D
~ ~ o c~ o ~ o ~ o ~ o ~ o ~ o cr o o o o H ~1 ~ Q' C ~ ~ Irl 1~ t` O ~ O 0~ O ~
H O ~O ~; C~ o o ~ r~ 1 0 --1 .` E'l , ~ U~ O O O O O O O O
" f~ o Ll~ In ~r ~ ~ ~( ~D ~1 c ~ ~r ~ ~ ~ ~ ,~ c ~D
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P~ 3 ~ o~ o o o o o o o o o . ~iH-467 TABLE IV
Suture size _ _ _ Draw ratio 7-5 8.8 7.3*
Draw temperature, F 340 530 370 Take-up, ft/min 205 485 110 Diameter, mils 7.08 11.10 14.03 ~not strength, psi 48,60037,200 34,200 (Xg/cm2) .(3,400)(2,600)(2,400) T~nsile strength, psi 67,50064,100 68,600 (Xg/cm2) (4,700)(4,400)(4,800) Brea~ elongation, % 43.5 31.8 36.7 Visco-elastic elongation, ~ 10.8 18.6 17.6 Yield elongation, ~ 3.0 3.2 6.3 Young's modulus, psi 49,00050,~00 51,000 (Kg/cm2) (3,400)(3,5003(3,600) _ ~Two stage draw EXAMPLE VIII
Monofilament sutures prepared from a copolyether/ester of Example II with 23 wt percent soft segments were sterilized by cobalt-60 irradiation and with ethylene oxide in accordance wi~h conventional procedures for sterilizing surgical sutures. The physical properties of the sutures were affected only slightly by ethylene oxide sterilization, and even less by cobalt-60, as shown by the data in Table V.
TABLE V
. _ SutureNonsterile _ Sterilized ; control Co E.O.
; Diameter, mils 12.5 12.6 13.2 Knot strength; psi 35,300 33,400 29,900 (Kg/cm2) (2,500) (2,300) (2,100) Tensile strength, psi70,300 70,000 67,700 (Kg/cm2) (4,900) (4,900) (4,800) Break elongation, % 28.2 31.6 45.2 Visco-elastic elongation, ~i 13.2 15.0 23.5 Yield elongation, % 2.9 2.3 2.2 ` Young's modulus, psi185,000 165,000 138,000 (Kg/cm2) (13,000) (11,600) (9,600) The important physical properties of the sutures pre-pared from copolyether/esters are responsive to changes ln polymer composit.ion and processing conditions. For example, visco-elastic elongation and yield elongation increase as the proportion of sof-t segments in polymer are increased, and conversely, Young's modulus decreases with an increasing proportion of soft segments. The break elongation may be decreased and tensile strength increased by employing higher draw ratios during the manufacture of the suture. By regulation of the com-position and processing variables therefor, it is pos-sible to obtain specific mechanical properties for in-dividual sutures with a great degree of latitude.
While the preceding examples have been directed to thepreparation of monofilament sutures of copolyether/esters, this was for the sake of convenience in describing one polymer system and the effect of various polymer composi-tions and spinning conditions on fiber properties. The copolyether/ester polymers may also be used in the manufacture of braided or other multifilament suture con-vl structions, and single filaments and braids may be used in the preparation of surgical fabrics and knitted or woven prosthetic devices such as vein and arterial grafts.
In addition, elastomeric filaments having a combinationof physical properties in accordance with the present in-vention may be prepared from other polymer systems such as polyurethane or sillcone elastomers or polyether co-polymers of urethane or silicone elastomers. Furthermore, elastomeric filaments of the present invention may be blended with each other, with other elastomeric or non-elastomeric filaments, and with either absorbable or non-absorbable filaments in order tc provide yarns and fabrics with special properties, all of which is deemed to be in-cluded within the scope of the present invention.
Claims (25)
1. An elastomeric surgical suture comprising a mono-filament having the following combination of mechanical properties:
Yield elongation - from about 2 to 9 percent Visco-elastic elongation - from about 10 to 30 percent Young's modulus - from about 30,000 to 200,000 psi Tensile strength - at least about 40,000 psi Knot strength - at least about 30,000 psi
Yield elongation - from about 2 to 9 percent Visco-elastic elongation - from about 10 to 30 percent Young's modulus - from about 30,000 to 200,000 psi Tensile strength - at least about 40,000 psi Knot strength - at least about 30,000 psi
2. A suture of Claim 1 having a diameter of from about 0.01 to 1.0 mm.
3. A suture of Claim 1 wherein the Young's modulus is 50,000 to 150,000.
4. A suture of Claim 1 wherein the tensile stress at the visco-elastic elongation yield point is less than about one-third the suture tensile strength.
5. A suture of Claim 1 having an elongation to break of about 30 to 100 percent.
6. A suture of Claim 5 wherein the elongation to break is at least 1.5 times the visco-elastic elongation.
7. A suture of Claim 1 wherein the visco-elastic elongation is at least about 2.5 times the yield elonga-tion.
8. A suture of Claim 1 in a sterile condition.
9. A suture of Claim 8 with a needle attached to at least one end thereof.
10. A suture of Claim 1 comprising a drawn and oriented monofilament of a segmented copolyethertester polymer.
11. A drawn and oriented elastomeric surgical filament comprising a segmented copolyether/ester polymer consisting es-sentially of a multiplicity of recurring long chain ether/ester units and long chain ester units joined head to tail through ester linkages and having the following general formula:
wherein G is a divalent radical remaining after the removal of terminal hydroxyl groups from a poly(C2-10 alkylene oxide) glycol having a molecular weight of about 350 to 6,000: R is a divalent radical remaining after removal of carboxyl groups from an aromatic dicarboxylic acid having a molecular weight less than about 300, and D is a divalent radical remaining after removal of hydroxyl groups from an alkyldiol having a molecular weight less than about 250, a and b are integers such that the long chain units represented by a comprise from 50 to 90 percent by weight of the composition, and n is the degree of polymeriza-tion resulting in a fiber-forming polymer, said drawn filaments being characterized by the following physical properties:
Tensile strength - at least about 40,000 psi Knot strength - at least about 30,000 psi Yield elongation - from about 2 to 9 percent Visco-elastic elongation - from about 10 to 30 percent Young's modulus - from about 30,000 to 200,000 psi.
wherein G is a divalent radical remaining after the removal of terminal hydroxyl groups from a poly(C2-10 alkylene oxide) glycol having a molecular weight of about 350 to 6,000: R is a divalent radical remaining after removal of carboxyl groups from an aromatic dicarboxylic acid having a molecular weight less than about 300, and D is a divalent radical remaining after removal of hydroxyl groups from an alkyldiol having a molecular weight less than about 250, a and b are integers such that the long chain units represented by a comprise from 50 to 90 percent by weight of the composition, and n is the degree of polymeriza-tion resulting in a fiber-forming polymer, said drawn filaments being characterized by the following physical properties:
Tensile strength - at least about 40,000 psi Knot strength - at least about 30,000 psi Yield elongation - from about 2 to 9 percent Visco-elastic elongation - from about 10 to 30 percent Young's modulus - from about 30,000 to 200,000 psi.
12. A filament of Claim 11 having a surgical needle attach-ed to at least one end and useful as a surgical suture.
13. A filament of Claim 12 in a sterile condition.
14. A filament of Claim 11 wherein G is derived from poly(tetramethyleneoxide)glycol, D is derived from 1,4-butane-diol, and R is derived from a phthalic acid.
15. A filament of Claim 14 wherein R is selected from the group consisting of terephthaloyl, isophthaloyl, orthophthaloyl, and mixtures thereof.
16. A filament of Claim 14 wherein said poly(tetramethylene-oxide)glycol has a molecular weight of about 1,000.
17. A filament of Claim 14 wherein the long chain units represented by b comprise about 40 wt percent of the copoly-ether/ester.
18. A filament of Claim 17 comprising approximately 51 percent terephthaloyl units, 16 percent units derived from poly-tetramethylene ether glycol, and 33 percent units derived from 1,4-butanediol.
19. A filament of Claim 18 characterized by a visco-elastic elongation of about 19 percent and a Young's modulus of about 50,000 psi.
20. A filament of Claim 14 wherein the long chain units represented by b comprise about 23 wt percent of the copoly-ether/ester.
21. A filament of Claim 20 comprising approximately 45 percent terephthaloyl units, 4 percent orthophthaloyl units, 20 percent units derived from polytetramethylene ether glycol and 31 percent units derived from 1,4-butanediol.
22. A filament of Claim 21 characterized by a visco-elastic elongation of about 13 percent and a Young's modulus of about 170,000 psi.
23. A filament of Claim 16 comprising a mixture of indiv-idual segmented copolyether/ester polymers, each of said poly-mers having from about 18 to 40 percent by weight long chain ester units, the mixture of said individual polymers containing an average of from about 26 to 35 percent long chain ester units.
24. A filament of Claim 23 wherein said polymer-mixture comprises from about 55 to 75 percent by weight of polymer having about 40 percent long chain ester units, and from about 25 to 45 percent by weight of polymer having about 18 percent long chain ester units.
25. A filament of Claim 23 wherein said polymer mixture comprises approximately 40 percent by weight of a polymer having about 40 percent long chain ester units, from about 30 to 40 percent by weight of a polymer having about 23 percent long chain ester units, and from about 30 to 40 percent by weight of a polymer having about 18 percent long chain ester units.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US96765678A | 1978-12-08 | 1978-12-08 | |
| US967,656 | 1978-12-08 | ||
| US7705579A | 1979-09-26 | 1979-09-26 | |
| US77,055 | 1979-09-26 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1141915A true CA1141915A (en) | 1983-03-01 |
Family
ID=26758834
Family Applications (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000341398A Expired CA1141915A (en) | 1978-12-08 | 1979-12-06 | Elastomeric surgical sutures-comprising segmented copolyether/esters |
| CA000485231A Expired CA1203137B (en) | 1978-12-08 | 1985-06-25 | Elastomeric surgical sutures-comprising segmented copolyether/esters |
Family Applications After (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000485231A Expired CA1203137B (en) | 1978-12-08 | 1985-06-25 | Elastomeric surgical sutures-comprising segmented copolyether/esters |
Country Status (23)
| Country | Link |
|---|---|
| AR (1) | AR222361A1 (en) |
| AT (1) | AT370999B (en) |
| AU (1) | AU530057B2 (en) |
| BR (1) | BR7907998A (en) |
| CA (2) | CA1141915A (en) |
| CH (1) | CH643460A5 (en) |
| DE (1) | DE2949181A1 (en) |
| ES (1) | ES486698A0 (en) |
| FR (1) | FR2473316B1 (en) |
| GB (1) | GB2038704B (en) |
| HK (1) | HK30083A (en) |
| IL (1) | IL58897A (en) |
| IN (1) | IN151798B (en) |
| IT (1) | IT1164078B (en) |
| MX (1) | MX152227A (en) |
| MY (1) | MY8400142A (en) |
| NL (1) | NL7908845A (en) |
| NZ (1) | NZ192138A (en) |
| PH (1) | PH22728A (en) |
| PL (1) | PL141223B1 (en) |
| PT (1) | PT70564A (en) |
| SE (1) | SE7910106L (en) |
| SG (1) | SG10283G (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4388926A (en) * | 1980-12-22 | 1983-06-21 | Ethicon, Inc. | High compliance monofilament surgical sutures comprising poly[alkylene terephthalate-co-(2-alkenyl or alkyl)succinate] |
| US4689424A (en) * | 1981-08-06 | 1987-08-25 | Ethicon, Inc. | Radiation sterilizable absorbable polymeric materials and methods for manufacturing the same |
| NL8202893A (en) * | 1982-07-16 | 1984-02-16 | Rijksuniversiteit | ORGANIC Tolerant, ANTHITHROMBOGENIC MATERIAL, SUITABLE FOR RECOVERY SURGERY. |
| US4906729A (en) * | 1988-08-05 | 1990-03-06 | E. I. Du Pont De Nemours And Company | Thermoplastic copolyetherester elastomers |
| US5009955A (en) * | 1989-03-06 | 1991-04-23 | General Motors Corporation | Dual modulus oriented elastomeric filaments |
| AU694983B2 (en) * | 1994-06-06 | 1998-08-06 | Johnson & Johnson Consumer Companies, Inc. | Novel compositions for dental floss |
| AU2007201213A1 (en) * | 2006-04-06 | 2007-10-25 | Tyco Healthcare Group Lp | Yarns containing thermoplastic elastomer copolymer and polyolefin filaments |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3454011A (en) * | 1966-12-28 | 1969-07-08 | Marvin Wagner | Sutures and prosthetic patches |
| CA933319A (en) * | 1968-12-04 | 1973-09-11 | Sumoto Misao | Melt spinning elastic polyester polyether block copolymer |
| US4127127A (en) * | 1977-05-23 | 1978-11-28 | Alza Corporation | Therapeutic systems made from certain segmented copolyesters |
| US4224946A (en) * | 1978-08-14 | 1980-09-30 | American Cyanamid Company | Surgical sutures derived from segmented polyether-ester block copolymers |
-
1979
- 1979-10-30 IN IN1132/CAL/79A patent/IN151798B/en unknown
- 1979-11-15 NZ NZ192138A patent/NZ192138A/en unknown
- 1979-11-27 AU AU53197/79A patent/AU530057B2/en not_active Ceased
- 1979-12-05 IT IT50997/79A patent/IT1164078B/en active
- 1979-12-06 CA CA000341398A patent/CA1141915A/en not_active Expired
- 1979-12-06 DE DE19792949181 patent/DE2949181A1/en active Granted
- 1979-12-06 PL PL1979220182A patent/PL141223B1/en unknown
- 1979-12-06 FR FR7929946A patent/FR2473316B1/en not_active Expired
- 1979-12-07 ES ES486698A patent/ES486698A0/en active Granted
- 1979-12-07 NL NL7908845A patent/NL7908845A/en not_active Application Discontinuation
- 1979-12-07 CH CH1089979A patent/CH643460A5/en not_active IP Right Cessation
- 1979-12-07 GB GB7942325A patent/GB2038704B/en not_active Expired
- 1979-12-07 AT AT0776179A patent/AT370999B/en not_active IP Right Cessation
- 1979-12-07 MX MX180381A patent/MX152227A/en unknown
- 1979-12-07 BR BR7907998A patent/BR7907998A/en unknown
- 1979-12-07 AR AR279206A patent/AR222361A1/en active
- 1979-12-07 SE SE7910106A patent/SE7910106L/en unknown
- 1979-12-07 IL IL58897A patent/IL58897A/en unknown
- 1979-12-07 PT PT70564A patent/PT70564A/en unknown
- 1979-12-07 PH PH23379A patent/PH22728A/en unknown
-
1983
- 1983-03-11 SG SG102/83A patent/SG10283G/en unknown
- 1983-08-18 HK HK300/83A patent/HK30083A/en unknown
-
1984
- 1984-12-30 MY MY142/84A patent/MY8400142A/en unknown
-
1985
- 1985-06-25 CA CA000485231A patent/CA1203137B/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| NL7908845A (en) | 1980-06-10 |
| FR2473316A1 (en) | 1981-07-17 |
| NZ192138A (en) | 1984-05-31 |
| CH643460A5 (en) | 1984-06-15 |
| ATA776179A (en) | 1982-10-15 |
| PL141223B1 (en) | 1987-07-31 |
| IT7950997A0 (en) | 1979-12-05 |
| PH22728A (en) | 1988-11-28 |
| IN151798B (en) | 1983-07-30 |
| MY8400142A (en) | 1984-12-31 |
| SE7910106L (en) | 1980-06-09 |
| AT370999B (en) | 1983-05-25 |
| IT1164078B (en) | 1987-04-08 |
| ES8101387A1 (en) | 1980-12-16 |
| GB2038704A (en) | 1980-07-30 |
| BR7907998A (en) | 1980-07-22 |
| ES486698A0 (en) | 1980-12-16 |
| AU530057B2 (en) | 1983-06-30 |
| CA1203137B (en) | 1986-04-15 |
| DE2949181A1 (en) | 1980-06-26 |
| AU5319779A (en) | 1980-06-19 |
| PL220182A1 (en) | 1980-12-01 |
| SG10283G (en) | 1983-12-16 |
| MX152227A (en) | 1985-06-12 |
| HK30083A (en) | 1983-08-26 |
| GB2038704B (en) | 1983-01-12 |
| PT70564A (en) | 1980-01-01 |
| DE2949181C2 (en) | 1990-01-18 |
| AR222361A1 (en) | 1981-05-15 |
| FR2473316B1 (en) | 1986-05-23 |
| IL58897A0 (en) | 1980-03-31 |
| IL58897A (en) | 1982-09-30 |
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