CH631897A5 - Surgical suturing material - Google Patents

Description

The present invention relates to a surgical suture that can be absorbable or non-absorbable.

Knot running properties are among the more important properties that determine the handling of surgical sutures. A commonly used technique is to tie a 5-fold knot at a more distant location, which is then pushed along the suture until it lies against the tissue with sufficient strength. The knot is tightened in such a way that it holds the tissue with the degree of flexibility selected by the surgeon and corresponding to the particular situation, whereupon further loops are untied on the first loops of the simple knot. In some cases, the first loop includes a double knot on which a single loop is tied to form a surgeon's knot, and further loops can be attached to attach additional simple knots.

In contrast to the simple attachability of the knot, there is the need for knot strength and knot security. Although it is desired that the knot 20 be easily tightened, it is essential that the knot remain firm for a reasonable amount of time without opening.

Some surgical sutures are so smooth that the knot can easily be moved, where it often loosens easily. Other sutures are made of materials where the knot tends to "tighten" and cannot be moved, making it difficult to push the loops onto the fabric. However, only a few loops are required and there are no problems with knot security. Knots in constantly moving tissue, such as those near the heart, tend to open much more than knots that are attached to a calm tissue, for example knots that hold a wound together within a cast.

U.S. Patent 2,734,502 (February 14, 1956, Nichols et al., Silk Sutures and Ligatures) describes poly (alkyl) methacrylate as a coating material for silk sutures and the use of a hot coating die system.

No. 3,297,033 (January 10, 1967, Schmitt and Polistina, Surgical Sutures) discloses synthetic surgical sutures made from polyglycolic acid, and it is stated that the surfaces of the fibers are treated with an Si-45 silicone, beeswax and the like. the like can coat in order to change the handling or the absorption rate of the material.

U.S. Patent Application 724,804 (September 20, 1976 to Perciaccante and Landi, Run-Down of Absorbable and Surgical Sutures) describes the prior art which is generally concerned with knot running properties, coating and lubrication of surgical sutures .

The coating, dyeing and treatment of surgical sutures with polymeric materials is very well known. Silicones, wax, poly-tetrafluoroethylene and other polymers were used for this. However, specific coating materials with unique properties are constantly being sought, which produce sutures with 60 improved properties.

According to the invention, a surgical suture material with improved knot running properties and reduced tissue resistance comprises a multifilament polymer strand which is provided with a thin, lubricating coating made of a lubricating, biologically absorbable copolymer. The lubricating copolymer has polyoxyethylene blocks and polyoxypropylene blocks, which increases the knot running properties and the manageability of the seam.

3rd

631 897

materiate be improved, and has such a molecular weight that it is pasty to solid at 25 ° C.

According to a preferred embodiment of the invention, the lubricating, bioabsorbable copolymer corresponds to the following general formula:

'ch2cho \ / ch2cho \

Rh

R,

(I)

where one of the symbols R.! and R2 means methyl and the other hydrogen, n and m have numerical values so large that the compound is pasty to solid at 25 ° C, R for the rest of a compound with reactive hydrogen atoms with a relatively low molecular weight, the two to six reactive hydrogen atoms and has no more than six carbon atoms, and c is the number of reactive hydrogen atoms on the compound forming the radical R.

According to a further embodiment of the invention, the polymer strand consists of a tissue-resorbable polymer which is broken down by hydrolytic degradation to non-toxic, tissue-compatible, resorbable constituents and which has glycolic acid ester bonds. According to a particularly preferred embodiment of the invention, the tissue-resorbable polymer consists of polyglycolic acid.

According to a further embodiment of the invention, the polymer strand consists of silk, cotton, nylon, a non-absorbable polyester, polypropylene and / or polyethylene.

The lubricating coating preferably makes up 0.1 to 25% by weight of the uncoated strand based on the weight of the uncoated strand forming the suture material, thereby reducing both plucking and friction to such an extent that a simple knot can be moved to define a wound edge on the suture.

To close a wound in living tissue, the edges of the wound can be sewn with the surgical suture material according to the invention, which is provided with the lubricating coating described above, the suture material can be linked to a simple knot, the simple knot at the desired location in the Push close to the tissue, tie more loops over the simple knot, and within less than 48 hours, reabsorb and remove the lubricating, absorbable copolymer from the suture, increasing knot security, and surgical suture,

if resorbable, remain in the living tissue until the suture strand has been resorbed from the living tissue during the healing process, the suture having sufficient strength to hold the tissue together for at least 15 days and substantially completely resorbed over 90 days or the suture material, if it is not absorbable, is left permanently in the living tissue, which reinforces it.

Resorbable polyglycolic acid sutures are described in the aforementioned U.S. Patent 3,297,033. Other synthetic resorbable sutures that are resorbed from the living tissue can also be used in the sutures according to the invention with improved results. At present, resorbable surgical sutures, in which tissue absorption is based on hydrolytic degradation of glycolic acid ester bonds, have become particularly popular. Materials of this type are currently available under the Dexon® and Vicryl® brands. The present invention can also be applied to other synthetic resorbable sutures, whether described in the art or under development. In the case of synthetic resorbable sutures, the problem of applying a coating to improve the knot running properties is more difficult since it is necessary that the coating must be non-toxic and absorbable.

Non-absorbable surgical sutures are sutures that are resistant to biodegradation in the tissue of living humans and mammals and remain as foreign bodies in the tissue if they are not surgically removed (skin sutures)

or be rejected by the body. Non-absorbable sutures maintain their strength in the tissue of the living organism for a long time, often during the life of the corresponding organism. Non-absorbable sutures, which are used to close skin wounds in which the knot lies above the surface of the skin, are known to be removed by the surgeon at an appropriate point in the healing process. In the case of those non-absorbable sutures in which the knot is present in the living tissue and is to be left there, the copolymer used according to the invention is absorbed in less than 48 hours and removed from the non-absorbable suture material, as a result of which the lubricating effect disappears and the knot security increases.

Non-absorbable surgical sutures are usually made of silk, cotton, nylon, non-absorbable polyester (Dacron®, polypropylene, polyethylene or linen). Even metals such as stainless steel, tantalum or platinum, in the form of monofilament threads or braided threads, are also used been.

The term “absorbable” or “biodegradable” 40, used in connection with the term coating, stands for a coating that is removed from the surface of the suture material by hydrolytic or enzymatic degradation or by its own properties, such as its molecular weight and its dissolving behavior removed and taken up either unchanged or in hydrolyzed or degraded form by the organism.

The lubricating coating or lubricant coating not only promotes knot running properties, but also improves the smoothness and pliability of the sutures so that they can be more easily pulled through the skin and other tissues while the surgical suture is being applied. This reduction in friction is known as reduced tissue resistance. The coating that causes reduced tissue resistance and lubricates the knot continues to make the knot glide better.

Another surprising and unforeseeable advantage of the lubricating coating can be seen in the fact that the lubricating copolymers are removed from the suture material within a few days by resorption, 60 so that the knot security increases with increasing wound healing.

To form the resorbable coating, one or more compounds can be used which have polyoxyethylene blocks and polyoxypropylene-65 blocks in their molecular structure. For simplicity and ease of description, it is believed that these links have only two or three such blocks in the chain. However, it is understood that not signifi

631 897

4th

edge portions of polyoxypropylene in the polyoxyethylene block and smaller amounts of polyoxyethylene in the polyoxypropylene block may be present. From the manufacture it can be seen that the chain can be and will likely be slightly mixed in this way. Commercially available materials of this type are suitable and have been found to have an acceptable level of toxicity.

The lubricating, organism-absorbable copolymers of formula I are often referred to as surface-active agents, since the polyoxyethylene blocks are predominantly hydrophilic and the polyoxypropylene blocks are predominantly hydrophobic. From Wyandotte Chemical Company, Michigan, USA, these materials are available if they have the following general formula:

h (ock-ch,) v / 0chcho \ (0chocho) "oh d d x Ij d \ d dz

CH3

in which x, y and z mean whole numbers, correspond to, under the name «PLURONICS»; if they have the general formula:

h / ochchA (och2ch2) / ochchAoh v ch-

ch-

where n, m and o represent integers, correspond to the name «REVERSE PLURONICS»; and if they have the general formula:

CH? N '1

yRi

10 CHpN ^ 1

Nrj in which Rt stands for groups of the formula 15 - (CH2CH0) q (CH2CH20) rH, in which q and r denote integers, correspond under the name «TE-TRONICS».

The synthetic, absorbable lubricants of the above formula that can be used according to the invention have such values of x, y, z, n, m, o, q and r that they are pasty to solid at 25 ° C.

The pastes are opaque, semi-solid materials whose melting point is above room temperature, preferably above about 40 ° C.

25 The materials known as “PLURONICS” are particularly suitable.

The approximate compositions of some commercial products of this type are summarized in Table I below. Since all products are mixtures, all values are approximate and to a certain extent rounded.

Table I

PLURONIC

Avg.

Mol. the

Values of

Polyoxyethylene

Mol. the

Values of melting point

Molecular weight

one. Polyoxy xundz content (%)

Polyoxy y

(° C)

ethylene blocks

propylene blocks

F-38

5000

2000

46

80

930

16

45

F-68

8350

3300

75

80

1750

30th

52

F-77

6600

2300

52

70

2050

35

48

P-85

4600

1200

27th

50

2250

39

40

F-87

7700

2700

62

70 '

2250

39

49

F-88

10800

4300

97

80

2250

39

54

F-98

13500

5400

122

80

2750

47

55

F-108

14400

5600

128

80

3150

54

57

F-127

12500

4300

98

70

3900

67

56

REVERSE

Mol. the

Mol. the

Values of

PLURONIC

Polyoxyethylene

Polyoxypropylene now and then

units

blocks

in the block m

10R8

3000

2000

45

65

562

9

46

17R8

4350

2600

59

60

870

15

53

25R8

9000

3250

74

57

1250

22

56

TETRONIC

Avg.

Approximate

Approximate

Approximate

Approximate

Approx. average

Molecular weight

Mol. the

Polyoxyethylene

Mol. the

Polyoxypropy

Length of the chains per

single poly

salary individual lenght

block

blocks

(%)

Polyoxypropy

(%)

values

values

lenblock

vonr vonq

707

12,000

2312

74

673

26

52.5

11

908

26100

5588

85

923

15

127

15.9

1107

14500

2438

67

1173

33

55.4

20.2

1307

18600

3213

69

1423

31

73

24.5

1508

27000

5063

75

1673

25th

115

28.5

5

631897

In general, PLURONICS have a molecular weight in the range from about 4750 to 16 250 wax-like solids. The polyoxypropylene portion has a molecular weight from 950 to 4000, while the polyoxyethylene content is about 60 to 80%.

The pastes generally have a total molecular weight of 3500 to 5700 with a polyoxypropylene molecular weight in the range from 1750 to 6500 and a polyoxyethylene content of 30 to 50%. The transition from waxy to pasty to liquid is not sharp.

The low toxicity of the polyoxyethylene-polyoxypropylene compounds used according to the invention is shown in Table II below.

Table II Toxicity

PLURONIC No. total mol. Physical LDS0,

selected

consistency

Mouse (g / kg)

F-38

5000

wax

> 5

F-77

6600

wax

4.2

F-87

7700

wax

3.75

F-68

8350

wax

> 5

F-88

10800

wax

> 5

F-127

12500

wax

2.25

F-98

13500

wax

> 5

F-108

14400

wax

1.25

P-65

3400

paste

0.83

P-84

4200

paste

0.4

P-85

4600

paste

0.53

P-94

4600

paste

0.6

P-103

4950

paste

1.4

P-104

5850

paste

0.75

P-123

5750

paste

2.7

P-105

6500

paste

3rd

For a general description of the lubricant compounds and the methods of making them, reference is made to U.S. Patent Application 724,804 dated September 20, 1976 (Perciaccante and Landi, Run-Down of Absorbable Surgical Sutures), which is incorporated herein by reference.

The suture strand is used as the basis for the weight and amount of material that is applied to form the resorbable surgical suture on the synthetic resorbable polymer strand.

The amount of the lubricating, bioabsorbable copolymer preferably makes up 0.1 to 25% by weight of the uncoated strand, based on the weight of the uncoated strand forming the suture material. The coating is not required to be continuous, since a gap-coated coating on the surface also reduces friction and chatter. A larger amount of the material may be present when the lubricating, bioabsorbable copolymer penetrates the strand, the various threads being partially or completely covered.

The wide range of the coating weight enables the sutures according to the invention to be adapted to a large number of applications. The strand coated to form the suture material can have significant differences in surface roughness depending on its mechanical structure, i.e. whether it is braided, twisted or similar, whether it is made of threads with a denier less than 2

Denier per thread up to more than 6 denier per thread, the finer threads result in a smoother surface, or because the threads may be stretched after the suture has been made or after heat treatment. The smoother surfaces require a smaller amount of the lubricating, bioabsorbable copolymer in order to achieve a corresponding lubricity.

The various surgical techniques used influence the desired level of lubrication. For any given type of knot, a large amount of lubricant in a given knot technique will facilitate knot run, but will also cause the knot to run back or open, which affects what is known as "knot security". With some surgical methods, it is extremely desirable that the knot can be pulled together very easily, even if the knot moves more easily.

A surgeon tying the knot is faced with the interaction between the knot tying method and ease of sliding the knot. If a suture is comparatively well lubricated, the surgeon can tie a simple knot that can be easily pulled together, and further simple knots or loops can be tied to increase knot security. On the other hand, if the suture is less well lubricated, the surgeon can tie a double half stick or other knot that is easier to move to the desired location, after which the double half stick can be tightened to fasten the knot, or he can loop more loops tie the knot to achieve adequate knot security. Thus, the surgeon can either adapt his knot technique to a particular suture or can use sutures whose surface lubrication is best adapted to the technique that the surgeon intends to use. Generally the adjustment is done in both directions. The surgeon tries to use a suture that has the properties he prefers and then adapts his knot technique to the sutures that are available to him. Some surgeons have been very successful in knotting stainless steel wires using a knot technique that is adapted to those wires that have very poor knot running properties. Other surgeons prefer better-running, well-lubricated sutures.

Since the ease of knot running and knot security are opposed to each other, the surgeon is required to tie more loops or to use knots that provide the desired strength under the particular conditions of the surgical technique used. By changing the amount of the lubricating, bioabsorbable copolymer, the knot running properties can be modified to meet the needs of the surgeon using them.

The period of use of the nodes can vary widely.

Since the lubricating, bioabsorbable copolymer used in accordance with the invention is removed from the suture material in the living tissue, the knot security increases to the same extent, with the knot security increasing considerably after approximately 48 hours.

Surgeon requirements also vary significantly, with different coating weights allowing the surgical sutures to be adapted to different applications. When the surgeon desires a more lubricated suture, a larger amount of the lubricating, bioabsorbable copolymer is generally used when the surgeon

5

10th

15

20th

25th

30th

35

40

45

50

55

60

65

631 897

6

tolerates slightly poorer knot running properties and a higher fabric resistance, the amount of coating is reduced accordingly in order to achieve this particular compromise. In general, 2 to 8% of the lubricating, bioabsorbable copolymer provides a reasonable compromise between the ease of knot running and knot security.

The use of approximately 5% by weight of Pluronic F-68 represents the preferred compromise between the knot running properties and the knot security of braided sutures made of polyglycolic acid with a titer of 2 to 6 denier per thread.

The following examples serve to further explain the invention and in particular the effect of different coatings and coating quantities under different conditions.

example 1

Examination of knot running properties and chattering or plucking. A series of 2/0 USP XIX (maximum diameter equal to 0.339 mm) braided surgical sutures made of polyglycolic acid, which are made from extrudxed threads with a titer of 2 denier, are coated with Pluronic F-68 in 7 different coating weights, uses a blank that has not been coated, and then subjects the sutures to an examination that determines the running properties and tightening behavior of a simple knot, s In this examination, the suture is tied by one using a simple knot 10.16 cm (4 inch) cylinder knotted. Then you pull the loop formed in this way from the cylinder and fasten the suture material in the jaws of the test device. Then you tighten the knot by pulling the originally free end with the tester that records the tensile force as the knot contracts on the suture. When the knot runs over the suture material, there is a certain rattling or plucking or a change in the tightening tension. This is recorded graphically. From a number of approaches with different coating weights, the proportion is given in which the maximum force for the knot tightening lies within the different ranges, which are given in Table III below. All knots of the coated sutures run the entire length of the suture without tearing. The knot tensile strength of the braided suture is in the range of 3.18 to 3.63 kg (7 to 8 pounds). In the case of the uncoated braided suture, the knot stuck, the suture tearing in 9 out of 10 examinations.

Table III

Knot running behavior of 2/0 polyglycolic acid sutures that have been treated with Pluronic F-68 as a lubricant

Coating quantity

Proportion of examinations in which the maximum resistance had the following values:

(%)

0-0.45 0.45-0.91

0.91-1.36

1.36-1.81

1.81-2.27

2.27-2.72

2.72-3.8 kg

(0-1 1-2

2-3

3-4

4-5

5-6

6-7 lbs.)

0.0

Eat in 9 out of 10 cases before the knot has fully expired

1.9

2/10

2/10

4/10

2/10

2.8

2/10

3/10

2/10

3/10

3.9

1/10

1/10

4/10

2/10

2/10

5.0

3/10

2/10

2/10

2/10

1/10

6.2

2/10

3/10

2/10

3/10

7.4

3/11 1/11

4/11

3/11

8.0

5/10 2/10

3/10

The maximum force of the running knot decreases continuously with increasing coating quantity. With a different approach to the braided suture material, lower coating quantities result in the following values:

0.51

1/10 2/10

2/10

3/10

2/10

1.09

5/10 1/10

3/10

1/10

1.53

5/10

1/10

1/10

1/10

1/10

1/10

To make these coatings, the braided suture was passed through a solution of the lubricant (Pluronic F-68) in chloroform, which had a concentration that was about twice the percentage of the coating on the suture.

With different suture material structures and other suture material sizes, the relative ease of knot displacement can be greater or less with the same amount of covering material, so that the amount of covering can be adjusted accordingly in order to achieve the desired knot running values.

The amount of lubricant (Pluronic) in the solvent can be varied and solvents other than chloroform can also be used. For example, other organic solvents such as methyl alcohol, ethyl alcohol, isopropyl alcohol, methylene chloride, warm xylene (at a temperature of about 60 ° C.), tetrahydrofuran can be used to form the coating.

Use hydrofuran, acetone, dimethylformamide, dimethyl sulfoxide and mixtures thereof and other similar solvents for the lubricant. Another suitable coating method is to let the solution flow onto the moving strand and to drain the excess material.

A small amount of water increases the solubility of the 6Q lubricants and favors the coating; however, the contact of the suture with the water should be kept as low as possible so that if the coating system contains moisture, the sutures should be dried and drained quickly.

65 In general, it is suitable to apply the coating from the solution for coating quantities below 10% and to use a heated mouthpiece for coating quantities of more than about 10%.

7

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Example 2

A series of investigations were carried out in which two commercially available lubricants, namely Pluronic F-68 and Pluronic F-127, were used on a braided, absorbable polyglycolic acid suture material of size 2/0 from threads with a titer of 6 denier per single thread. The coatings were applied from a solution of the lubricant in chloroform. The lubricant concentration in the solution used to apply the coating is approximately twice the percentage of the coating achieved on the suture. For example, a solution containing approximately 2.8% Pluronic F-68 in chloroform will coat 1.4% of this lubricant on the suture. All that is required to achieve any desired coating amount is to adjust the concentration accordingly. The coated suture strand is a size 2/0 suture that is braided from extruded polyglycolic acid thread with a titer of 6 denier per thread. For comparison purposes, an uncoated suture from the same lot was examined. A standard thread friction tester (ATLAB Yarn Friction Tester Model CS-151-026, Custom Scientific Instruments, Inc.,

Whippany, New Jersey 07981, USA), which is equipped with a two-channel amplifier recording device (Hewlett Packard Model 321). The jerk factor or chatter factor corresponds to the ratio of the maximum tensile force (T3) to the supply voltage (Tj) minus the ratio of the minimum tensile force (T2) to the supply chip T T

voltage (Tj), i.e. = r- —The friction values are those of T2

11 11 when gliding begins.

io The values of particular interest are the ratios and the percentage reduction. For other inspection devices, the numerical values can vary, while the relative ratios are analogous to the improvement index.

i5 This test uses an uncut strand coated in the manner specified. For use as suture material, this strand is cut to the appropriate length, provided with a needle, packaged and sterilized in the usual way. The friction and rattling or picking is easier to determine on endless threads.

The reduction in static friction, rattling or plucking and the coefficient of friction for typical coating quantities and sutures are summarized in Table 25 below.

Table IV Braided size 2/0 polyglycolic acid suture

Batch- Pluronic Quantity Static Pluck Number Plating (%) Friction Factor reduction

Percentage reduction in friction coefficient x 10 "2

Percentage decrease

1

Blank test

0

3.11

0.50

6.109

2nd

Blank test

0

3.29

0.60

6,284

3rd

F-68

1.39

2.78

13.1

0.30

45.5

5,766

7.0

4th

F-68

1.93

2.55

20.3

0.19

65.5

5,468

11.8

5

F-68

4.44

2.54

20.6

0.31

43.6

4,900

20.9

6

F-68

7.29

2.70

15.6

0.33

40.0

5,084

17.9

7

F-68

8.09

2.59

19.1

0.25

54.6

5,424

12.5

8th

F-127

1.38

2.55

20.3

0.33

40.0

4,938

20.3

9

F-127

1.57

2.63

17.8

0.24

56.4

5,539

10.6

10th

F-127

2.56

2.97

7.2

0.27

50.9

6.104

1.50

11

F-127

5.37

2.76

13.8

0.32

41.8

5,689

8.2

12th

F-127

5.62

2.82

11.9

0.40

27.3

5,617

9.4

13

F-127

5.62

2.87

10.3

0.29

47.3

6.007

3.1

14

F-127

8.14

2.81

12.2

0.29

47.3

5,891

4.9

15

F-127

9.83

2.74

14.4

0.29

47.3

5,621

9.3

The studies of knot security depend on the knotting technique used.

Results of a representative and typical investigation of the strength of a 2/0 size polyglycolic acid suture made from threads with a denier of 2 denier per

Monofilament is constructed using 4.79% Pluronic® F-68 as a lubricant with respect to various knots in Table V below, namely 5 times the force in kg required to move the knots or without moving the knots Leads to a break.

Table V

approach

Easier

Simple knot

Simple knot

Surgeons

Surgeon

Surgeon

number

node

+1 noose

+2 loop knots

+1 noose

+ 2 loops

1

1.70

2.95

breaks breaks

7.50

breaks

2nd

2.05

3.90

breaks

6.15

5.15

breaks

3rd

4.20

4.05

breaks

3.70

breaks breaks

4th

0.70

3.40

breaks breaks

3.35

breaks

5

3.95

breaks breaks

1.40

breaks breaks

medium

2.54

-

-

-

-

-

631 897

Example 3

Using the procedure of Example 2, a series of tests are carried out in which, in addition to a blank sample, solutions of a bioabsorbable, lubricating copolymer (Pluronic® R) in

Chloroform can be used to form lubricating coatings. Table VI below summarizes the improvements in plucking and friction for a variety of polymers and coating concentrations.

Table VI Braided polyglycolic acid suture (size 2-0-6 denier per thread with a Pluronic® coating

Suture material approach-covering

Coating Static Percentage Jerking Amount (%) Friction Factor Reduction

Percentage friction coefficient reduction x 10 ~ 2

Percentage reduction without coating

16

3.92

0.31

8,189

without cover

17th

3.45

0.21

7.503

without cover

18th

2.87

0.27

6,803

without cover

19th

2.87

0.18

6,300

10297B

20th

10R8

2.05

2.51

23.4

0.28

5,077

28

10297B

21st

10R8

3.00

2.33

28.9

0.16

34.1

4,932

31

10297B

22

10R8

3.96

2.31

29.5

0.21

13.6

4,753

33

10297B

23

10R8

5.31

2.41

26.5

0.23

5.4

4,962

30th

10297B

24th

10R8

7.49

2.39

27.1

0.25

4,843

32

10297B

25th

25R8

2.55

2.34

28.6

0.16

34.1

4,962

30th

10297B

26

25R8

3.85

2.40

26.8

0.15

38.3

5,162

27th

10297B

27th

25R8

6.29

2.23

32.0

0.15

38.3

4,662

34

10297B

28

25R8

7.15

2.31

29.5

0.13

46.5

4,990

34

10297B

29

25R8

8.74

2.37

27.7

0.11

54.7

5,175

27th

10297B

30th

31R4

2.18

2.53

22.8

0.15

38.3

5,520

22

10297B

31

31R4

3.42

2.53

22.8

0.17

30.0

5,466

23

10297B

32

31R4

4.51

2.57

21.6

0.14

42.4

5,652

23

I0297B

33

31R4

5.53

2.61

20.4

0.17

30.0

5.705

20th

10297B

34

31R4

7.26

2.51

23.4

0.11

54.7

5,782

19th

10297B

35

17R8

2.12

2.45

25.3

0.19

21.8

5,218

27th

10297B

36

17R8

3.13

2.45

25.3

0.25

5,019

30th

10297B

37

17R8

5.02

2.33

28.9

0.20

17.7.

4,782

33

10297B

38

17R8

6.32

2.36

28.0

0.25

4,723

34

10297B

39

17R8

8.60

2.33

28.9

0.15

38.3

4,962

30th

Example 4

A braided polyglycolic acid strand of the titer, which is suitable for forming a suture material of size 2/0 USP, is immersed in a 10% solution of Pluronic F-68 in chloroform and the material is dried. The coating absorption is about 5% by weight, based on the weight of the strand.

The dried, coated strand is cut into 137.16 cm (54 inch) long sections, provided with needles, packaged, sterilized, and dried using conventional procedures.

The sutures made in this way are used for surgical purposes. When used to pull the tissue of a wound together, the suture is inserted at an appropriate location and tied with a simple knot. The simple knot pulls on easily and pulls the wound edges together to the strength desired by the surgeon. The suture material shows a low fabric resistance and excellent knot running properties. When the knot has reached the desired end position, three more simple loops are tied to fix the knot. The lubricating, bioabsorbable copolymer is removed from the knots present in the tissue within 48 hours, thereby increasing knot security. The suture retains the strength that holds the fabric together for at least 15 days and is essentially absorbed in 90 days. 45 Although in the examples the investigations were carried out with simple knots, the improvement of the knot running properties and the reduction of the tissue resistance are suitable for most methods of applying the suture material and the knot fixation. The amount of coating and the relative values for knot running properties and reduced tissue resistance can be varied to adapt material to a particular surgical situation.

The coated sutures are provided with needles in the usual way, packaged and sterilized.

Example 5 Friction and picking tests A series of braided silk 60 seam materials of size 2/0 USP XIX (maximum diameter 0.339 mm) is coated with Pluronic F-68 in 5 different coating quantities and with Pluronic F-127 in 12 different coating quantities.

For comparison purposes, 4 blank samples are used, 65 which are the braided sutures from the same batch that are not covered, with the average of these four blank samples being used to determine the comparative values.

9

631 897

In addition, 5 approaches are carried out in which a commercially available, silicone-coated silk seam material according to US Pat. No. 3,187,752 is used as a comparison material.

To form the coatings according to the invention, the braided suture is passed through a solution of the lubricant in chloroform, which contains the lubricant in a concentration which is approximately twice the percentage of the coating aimed at on the suture, after which the suture is air-dried .

A standard yarn friction tester (ATLAB Yarn Friction Tester Model CS-151-026, Custom Scientific Instruments, Inc., Whippany, New Jersey, USA) is used to record the tension of the strand inserted into and out of the tester. which is equipped with a dual channel amplifier recording device (Hewlett Packard Model 321). The pick factor or chatter factor corresponds to the ratio of maximum traction (T3) to supply voltage (Tt) minus the minimum traction

T

(T2) to the supply voltage (Tt), i.e. the value -

T t 1

The friction values correspond to the ratio when gliding begins.

The values of particular interest are the ratios and the percentage reduction in the values in question. In other inspection devices, the numerical values can change while the relative ratios and the improvement index are analog.

In this test, an uncut strand is coated and used in the manner indicated. When used as a suture material, this strand is cut to the desired length, seen with a needle, packaged and sterilized, using conventional methods. Friction and picking are easier to determine on endless threads.

The reduction in static friction, picking and the coefficient of friction are summarized in Table 20 VII below.

Table VII size 2/0 silk seam material

approach

lubricant

amount

Static

Percentages

Plucking

Percentages

Friction

Processor number

coating

(%)

friction

Reduction factor

Reduction coefficient x 10-2

Ver-mindei

1

Blank test

-

3.15

-

0.46

-

6,300

-

2nd

Blank test

-

3.40

-

0.47

-

6,822

-

3rd

Blank test

-

3.32

-

0.46

-

6,690

-

4th

Blank test

-

3.78

-

0.93

-

6,666

-

5

silicone

-

3.75

-

0.66

7.203

-

6

silicone

-

3.60

-

0.63

-

6,930

-

7

silicone

-

3.63

-

0.74

-

6,756

-

8th

silicone

3.63

0.63

-

7,015

-

9

Sili

3.56

0.89

-

6,156

-

10th

F-68

2.46

2.85

16.4

0.13

-

6,370

3.77

11

F-68

3.09

2.46

27.9

0.09

-

5,520

16.6

12th

F-68

3.51

2.34

31.4

0.07

-

5,190

21.6

13

F-68

3.51

2.44

28.5

0.08

5,466

17.4

14

F-68

4.43

2.49

27.0

0.10

5,546

16.2

15

F-127

1.68

2.51

26.4

0.08

77.6

5,652

14.6

16

F-127

1.68

2.41

29.3

0.05

91.4

5,466

17.4

17th

F-127

2.57

2.51

26.4

0.06

89.7

5,652

14.6

18th

F-127

2.57

2.40

29.6

0.09

84.4

5,329

19.5

19th

F-127

4.16

2.53

25.8

0.07

87.9

5,782

12.7

20th

F-127

4.16

2.39

29.9

0.05

91.4

5,412

18.2

21st

F-127

5.16

2.48

27.3

0.06

89.7

5,626

15.0

22

F-127

5.16

2.38

30.2

0.05

91.4

5,357

19.1

23

F-127

5.95

2.45

28.2

0.10

82.8

5,412

18.2

24th

F-127

5.95

2.52

26.1

0.07

87.9

5.705

13.8

25th

F-127

5.95

2.43

28.7

0.04

93.1

5,520

16.6

26

F-127

7.72

2.43

28.7

0.08

86.2

5,439

17.8

In the case of other suture material structures and other sizes, the relative lightness of the knot run can be greater or less with the same amount of cover, so that the amount of cover can be adjusted accordingly to achieve the desired knot run properties.

The amount of lubricant in the solvent can be varied and solvents other than chloroform can be used. For example, other organic solvents such as methyl alcohol, ethyl alcohol, isopropyl alcohol,

Use methylene chloride, warm xylene (at a temperature of about 60 ° C), tetrahydrofuran, acetone, dimethylformide, di-60 methyl sulfoxide, mixtures thereof, and other similar solvents for the lubricant. Another useful coating method is to let the solution flow onto a moving strand and drain the excess material.

65 A small amount of water increases the solubility of the lubricant and supports the deposition of the coating.

In general, it is suitable for coating quantities of

631 897

10th

less than 10% use the solvent coating and use a heated mouthpiece if the coating is greater than about 10%.

Example 6

Braided nylon sutures of size 2/0 Using the procedure of Example 1, tests are carried out on braided nylon material which has sufficient thread size to form a suture of size 2/0. The reduction in friction and plucking factor achieved are summarized in Table VIII below.

It can be seen that the plucking reduction is particularly strong.

Table VIII Size 2/0 braided nylon suture

Batch lubricant quantity number (%)

Static chattering friction factor reduction

Percentage friction Percentage coefficient reduction x 10 "2 reduction

1

Blank test

-

3.02

-

0.33

-

6,300

-

2nd

Blank test

-

2.89

-

0.53

6.205

-

3rd

Blank test

-

3.06

0.51

5,933

-

4th

silicone

-

2.69

20.0

0.34

26.1

5,466

11.1

5

silicone

-

2.89

3.34

0.42

8.69

5,762

6.25

6

silicone

3.43

0.55

-

6,734

-

7

F-68

2.53

2.24

25.1

0.18

60.9

4,632

24.6

8th

F-68

2.53

2.47

17.4

0.23

50.0

5,162

16.0

9

F-68

2.53

2.43

18.7

0.16

65.2

5,218

15.1

10th

F-68

4.91

2.41

19.4

0.23

50.0

4,942

19.6

11

F-68

5.60

2.29

23.4

0.18

60.9

4,726

23.1

12

F-68

5.60

2.42

19.1

0.20

56.5

5,077

17.4

13

F-68

5.60

2.46

17.1

0.17

63.0

5,274

14.2

14

F-68

6.09

2.54

15.1

0.22

52.2

5,347

13.0

15

F-127

2.83

2.49

16.7

0.19

58.7

5,302

13.7

16

F-127

3.08

2.32

22.4

0.22

52.2

4,783

22.2

17th

F-127

3.36

2.36

21.1

0.17

63.0

4,989

18.8

18th

F-127

5.60

2.37

20.7

0.17

63.0

4,989

18.8

19th

F-127

5.60

2.36

21.1

0.12

73.9

5,133

16.5

20th

F-127

5.60

2.38

20.4

0.13

71.7

5,162

16.0

21st

F-127

6.21

2.37

20.7

0.15

67.4

5,077

17.4

22

F-127

6.79

2.45

18.1

0.14

69.6

5,329

13.3

23

F-127

7.57

2.65

11.4

0.28

39.1

5,520

10.2

Example 7

Braided polyester suture materials of size 2/0 Using the measures of Example 1, tests are carried out on a braided polyester material (Dacron®) which has such a thread strength that a suture material of size 2/0 is obtained.

The reduction in friction and the pick factor are summarized in Table IX below.

For comparison purposes, both an uncoated braided suture from the same lot and a 45 braided silicone suture are used. To clarify the improvement, the mean value obtained with the uncoated braided sutures is used as the basis.

Table IX

Braided polyester suture of size 2/0

Batch lubricant quantity number (%)

Static chattering friction factor reduction

Percentage Friction Percentage Coefficient Reduction x IG-2 Reduction

1

Blank test

-

2.89

-

0.31

-

6,027

-

2nd

Blank test

-

2.65

-

0.34

-

5,310

-

3rd

Blank test

-

2.54

-

0.28

-

5,189

-.

4th

silicone

-

2.14

-

0.19

-

4,263

-

5

silicone

-

2.20

-

0.17

-

4,478

-

6

silicone

2.40

0.27

4,800

-

7

F-127

2.39

2.60

3.45

0.33

5,216

5.30

8th

F-127

5.37

2.47

8.28

0.21

32.2

4,996

9.30

9

F-127

5.12

2.36

12.4

0.21

32.3

4,871

11.6

10th

F-68

4.03

2.20

18.3

0.19

38.7

4,269

22.5

11

F-68

4.03

2.28

15.3

0.21

32.3

4,628

16.0

11

Table IX (continued)

631 897

Approach- Lubricant Quantity Static Percentage Pluck- Percentage Friction Percentage Number (%) Friction Factor Coefficient Reduction Reduction x 10 "2 reduction

12 F-68 5.04 2.45 9.02 0.19 38.7 5.084 7.70

13 F-68 6.26 2.24 16.8 0.18 41.9 4.580 16.8

14 F-68 6.98 2.52 6.42 0.24 22.6 5.247 4.74

15 F-68 8.59 2.26 16.1 0.14 54.8 4.785 13.1

From the figures in the table above, it can easily be seen that a reduction in friction and plucking is achieved with all sizes of suture material. With different materials and differently constructed materials, however, the results can be different.

The amount of coating and the ease of thread travel can be varied so that the values desired by the surgeons are achieved.

For either resorbable or non-resorbable sutures where capillarity is a problem, a coating of a phosphatide, preferably purified lecithin, may be applied to reduce capillarity and friction, as disclosed in U.S. Patent No. 2,576,576, wherein the coating according to the invention is used as a further means of reducing the reduction. Lecithin causes some tissue irritation under certain conditions, especially when the material is not pure.

Example 8

Dip a strand of braided silk suture of one size to form a suture of size 2/0 USP in a 10% solution of Pluronic F-68 in chloroform and dry the material. The coating absorption is about 5% by weight, based on the weight of the strand.

The dried, coated strand is cut to a length of 137.16 cm (54 inches) using needles, provided with needles, packaged, sterilized and dried.

The silk sutures produced in this way are used for surgical purposes. If you use them to pull tissue from a wound, attach the suture to the appropriate location i5 and tie it with a simple knot. The simple knot can easily be tightened to contract the wound edges with the strength desired by the surgeon. The suture material shows low tissue resistance and excellent knot-20 running properties. When the knot is in the desired position, three more simple loops are tied to secure the knot. The lubricating, bioabsorbable copolymer is removed in the course of 48 hours from the surface of the suture material of the knots embedded in the tissue 25, which further increases the knot security.

If the simple knot is removed from the examined animals after 48 hours, it shows greater security or knot strength without additional loops than immediately after the knot has been tied.

In human tissue, it can be seen that knot security increases as the bioabsorbable lubricating coating is absorbed by the tissue.

35 Although the studies were performed using simple knots, facilitating knot running and reducing tissue resistance can be used for most suture attachment methods and fixations. The amount of the coating and the values achieved thereby regarding the knot running properties and the reduced tissue resistance can be varied in order to adapt the material to a specific surgical purpose.

The coated sutures are then provided with needles, packed and sterilized in the usual way.

s

Claims (8)

631 897 PATENT CLAIMS 1. Surgical suture material with improved knot running properties and reduced tissue resistance, characterized by a multifilament polymer strand which is provided with a thin, lubricating coating made of a lubricating, bioabsorbable copolymer which has polyoxyethylene blocks and polyoxypropylene blocks and a to improve the knot running properties and the manageability has such a molecular weight that it is pasty to solid at a temperature of 25 ° C. 2. Suture material according to claim 1, characterized in that the lubricating, bioabsorbable polymer of the formula: F. 'CH2CHO \ / CH2CHO \ R-, R, u | _C (I) in which one of the symbols Rj and R2 is methyl and the other is hydrogen, n and m have numerical values so large that the compound is pasty to solid at 25 ° C, R represents the rest of a compound with reactive hydrogen atoms, which is a relative has a low molecular weight, has 2 to 6 reactive hydrogen atoms and contains no more than 6 carbon atoms, and c represents the number of reactive hydrogen atoms in the compound forming the radical R. 3. Suture material according to claim 1 or 2, characterized in that the polymer strand consists of a tissue-resorbable polymer which is broken down by hydrolytic degradation into non-toxic, tissue-compatible, resorbable constituents and has glycolic acid ester bonds. 4. Suture material according to claim 3 or 4, characterized in that the polymer resorbable polymer is polyglycolic acid. 5. Suture material according to claim 1 or 2, characterized in that the polymer strand consists of silk, cotton, nylon, a non-absorbable polyester, polypropylene and / or polyethylene. 6. Suture material according to claim 1 or 2, characterized in that the lubricating coating 0.1 to 25 wt .-% of the uncoated strand, based on the weight of the uncoated strand forming the suture, is. 7. Suture material according to claim 4, characterized in that the lubricating coating is 0.1 to 25 wt .-% of the non-coated strand, based on the weight of the non-coated strand forming the suture material. 8. Suture material according to claim 5, characterized in that the lubricating coating is 0.1 to 25 wt .-% of the non-coated strand, based on the weight of the non-coated strand forming the suture material.