DE1642018B1 - Surgical sutures - Google Patents

Description

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The invention relates to surgical ligatures and to preventing spreading when the ends

Surgical suture material, in particular a cut through. The wax also gives that

bobbin lace or braided or twisted seam silk thread a certain structure, d. H. a certain

material made of silk that has undergone a treatment for rigidity combined with plasticity. this will

has been subjected to reduction of capillarity. 5 commonly referred to as the "handle". Lots of surgeons

Silk is used to a large extent in surgery as pulling silk threads with a "handle" to a slack one

proposed non-absorbable sutures for sewing silk thread, as the latter is more difficult to handle

Wounds or as a ligature to ligate it. Another method is to remove the capillary

bleeding blood vessels used. Here the fact of silk threads is eliminated by using water-

Silk mostly in the form of a braided or repellent connection, e.g. B. silicon compounds,

used bobbin thread, d. H. to be treated in the form of a.

central strand of a hose-like To achieve these properties must be up

Braiding or braiding is surrounded. The 20 to 30 percent by weight wax mass in the

central core is sometimes absent or fills the tube with silk thread incorporated. However, it is

more or less out. Depending on the used 15 knows that foreign substances, z. B. Waxes found in silk

Umklöppelungsverfahren is also the strength threads are incorporated to the capillarity

different from the winding. Another silk-eliminate, not well tolerated by the host tissue,

thread type, namely twisted silk, is used in the chir-

urgie used less often. To produce nulomas in these threads. A wax granuloma can

several silk fibers are twisted together. 20 at a slowly increasing speed

The invention relates to surgical suture material which form the suture material and in the case of a

Functional difficulties arise from braided, braided or twisted suturing of tendons

Silk threads. the tendon after 3 to 6 months.

Polished or braided multi-fiber silk - It has been found that a multi-fiber silk thread, threads are inherently slack. When they cut 25 its individual fibers with a coating material the ends tend to spread apart, d. h., which are provided, wherein the covering material made of silk carrier, from which the braiding or Umfibrion consists, a surgical suture material is allowed to braid consists, stands or spreads, represents which has the desired properties, especially in the case of pressure or friction, as is the case for ind. H. Elimination of capillarity, binding ability effect comes when an attempt is made to achieve the multifilament and improved grip without Pulling silk thread through the eye of a needle. The one thing that a foreign substance is added to the material threading can actually become impossible. Also has an adverse biological reaction with the host a multifilament silk thread that absorbs liquids, tissues.

Exposure to solutions or suspensions results in a capillary action or wicking effect. Through these 35 silk threads with a silk solution or capillary or wicking effect, z. B. an up-dispersion treated with a silk thread of suction of blood or serum taking place when the reduced capillarity and improved grip of the material is used for suturing a wound. will hold. If these tissue fluids of microorganism fibrous silk thread are infested with the silk men, these can be impregnated in the intermediate substance, which finds refuge in the spaces of the multifilament silk thread. Forms silk fibers, which envelops the silk fibers. It has been found that microorganisms that stick together and stick together,
Establish in such a silk structure, extremely natural silk, as it is in the cocoon of the usual resistant to destruction, so that this silk moth (Bombyx mori) is, silk threads pose a danger to the operated patient 45 two main components, the fibroin, which represent as a textile . Suturing material made from braided or encased silk fiber, and sericin, a bobbin silk thread that does not require any treatment for protein that is not fibrous. In the process of eliminating this wick effect, the sericin is subjected to various methods, is called "capillary silk" and is removed, and only the fibroin is not used for textile purposes by the Pharmacopeia of the United States. The present invention is concerned with absorbable surgical silk material type A, fibroin. To explain the term, it should be mentioned that denotes. Sewing material of type B or "not the term" silk "in the following description capillary" silk threads are treated in such a way that the and the claim is used to eliminate or reduce braided or twisted silk or strands or to reduce the wicking effect mentioned above. 55 made of silk thread. The expression »Fi

Sutures made from multifilament silk threads can be used to mark a silk mass Treated in various ways in order not to be needed for use as a coating or to make capillary silk threads. Has been dissolved or dispersed in the known impregnating agents. or the methods described so far will contain some course to carry out the inventing material used that a foreign material for silk 60 dung solutions or dispersions used fibroin is and is worked into the silk threads in such a way that and are therefore with regard to their chemical composition adheres to the silk fibers and / or the intermediate composition is similar to the silk threads and strands, spaces in the multifilament silk thread. On the silk fibroin made from silk cocoons, raw silk Most often a process is used in which or waste silk is obtained in a solution die Silk threads dispersed or dissolved with wax or masses on a wax medium. Numerous solvents be treated on a basis. This method has the advantages for silk are known, but is an aqueous lithium part, that the silk threads are not capillary and thiocyanate is advantageous as a solvent, as this at the same time the fibers are glued together so that the fibroin does not break down significantly when the salt

pH of the aqueous solution is buffered to about 7. A solution of 50 percent by weight lithium thiocyanate in water is a very effective solvent, in which 20 to 25 percent by weight of fibroin is easy can be solved. However, such a solution cannot be used directly for the impregnation of silk fibers be used because it attacks these fibers very quickly. The lithium thiocyanate can be obtained from the silk solution can be removed by dialysis, for example. Exhaustive dialysis against water becomes a Obtained dispersion of fibroin in water. This fibroin dispersion can be used for impregnation and for Covering the silk to be used. However, a fibroin dispersion is labile in that it easily gels. Fibroin separates out of the dispersion after standing for a period of time or by agitation. This property is undesirable for processing purposes. It is therefore important to have such fibroin solutions to stabilize. One method of achieving this stabilization is by dialysis of the solution of fibroin in aqueous lithium thiocyanate against an aqueous solution of the hydrogen bond breaking Urea or guanidine. The proper removal of lithium thiocyanate from the fibroin solution can be detected by a negative reaction with iron (III) chloride.

Dialysis of the fibroin solution to remove lithium thiocyanate is not necessary if the concentration of the lithium thiocyanate is reduced to at most 20 percent by weight. The type of dilution however, is critically important. A dilution of the fibroin solution with water or with one molar aqueous urea solution leads to the formation of a flaky precipitate. The fibroin remains dispersed, when a! molar solution of calcium chloride is used as a diluent, but the fibrous one Solution takes on a milky, white appearance. As a diluent to reduce the concentration of lithium thiocyanate in the solution is suitable as well as an aqueous solution of dioxane 50 parts of acetamide in 50 parts of water. Dilution of the fibroin solution with aqueous acetamide is made preferably from the standpoint of optimal solution viscosity and minimal degradation of the fibroin made at a pH of 7.

In place of aqueous lithium thiocyanate, aqueous lithium bromide can be used as a solvent for fibroin be used. The lithium bromide solution thus obtained is also after dilution with aqueous acetamide stable.

Preferred embodiments of the invention are described in the following examples.

example 1

The impregnation and covering of the silk can be carried out using various methods be e.g. By dipping or preferably by dipping under vacuum to ensure good penetration to achieve. After being removed from the fibroin solution, the silk threads are allowed to drain or wipes off the excess fibroin, whereupon it air-dried with or without tension will. The fibroin can be subjected to further fixation by various methods, z. B. by heating or by fixing with precipitants, e.g. B. Salts. These salts as well as from dialysis Any urea that may still be present can be removed by placing the fixed threads in water or a water-alcohol mixture removed.

A fibroin solution containing 20% fibroin in 50 weight percent lithium thiocyanate is prepared. Aliquots of this solution are placed in cellophane bags against urea solutions for 24 hours Concentration dialyzed. The dialysis is against fresh urea solutions of the respective Concentration repeated. The complete removal of lithium thiocyanate is indicated by a negative Reaction of the fibroin solution in the cellophane bag with iron (III) chloride detected. The fibroin solutions, whose concentration has been reduced to 10% during dialysis are under

Filtered through glass frit under reduced pressure. Aliquots Portions of each solution are stored at room temperature (20-25 ° C) and 37 ° C.

Urea concentration,

against which the silk

dialyzed fibroin solution

will

0.1 molar
0.5 molar
1.0 molar
4.0 molar

Determined gel time

at
Room temperature

At 37 ° C

3 days
3 days

7 days

3 weeks

8 weeks

lday
3 days
3 days
7 days
6 weeks

The dialysis against l ° / _o sodium guanidine has a similar effect as the dialysis against urea.

Fibroin dispersions that remain viscous (approx. 3.0 cP), homogeneous and clear after dialysis and filtration and show no fiber agglomerations are preferred for the purposes of the invention.

Since the pH of lithium thiocyanate solutions due to fluctuations in the purity of the Commercially sourced lithium thiocyanate can fluctuate widely if the pH of the fibroin solution is before the Adjust dialysis to about 7. Dialysis of acidic or basic fibroin solutions can cause precipitation (Aus. cause flocculation) of the fibroin from the solution-

Example 2

2 parts fibroin fibers obtained from the purified silk cocoons are dissolved in 10 parts of 50 ° / _D LiSCN. The fibroin solution is filled into a bag made of regenerated cellulose and dialyzed against 1000 parts of a 4 molar urea solution for 24 hours. The solution is then dialyzed again for 5 hours against 100 parts of 4 molar urea. The SCN ion in the fibroin solution now reacts negatively with FeCl ₃ . The fibroin solution is filtered through a glass filter under reduced pressure and stored at 25 ° C.

A roll of U.S.P. No. 1 braided silk is dipped in the fibroin solution, in air dried and then heated to 110 ° C for 1.5 hours. The silk thread obtained in this way is not capillary.

Example 3

2.5 parts of silk fibroin from silk cocoons are dissolved in 10 parts of 50% LiSCN. The fibroin solution is dialyzed against 1000 parts of molar urea for 24 hours. Then another 24 hours dialyzed with a further 1000 parts of molar urea. The fibroin solution is based on that in Example 1 way described filtered. In 5 ml of the fibroin solution

1.52 m of bobbin lace (USP size 1 H ₂ O) are made soluble at pH 7.0. The fibroin concentration is immersed and the whole thing is kept under vacuum for 2 hours against 4000 parts of imolar urea. The impregnated silk roll is dialyzed at room temperature for 24 hours. After the drained dialysis for about 20 hours in the air, the fibroin solution is dried with iron (III) chloride and then heated to 105 ° C. for 2.5 hours. The 5 is checked for complete salt removal and then through the dried sample, a coarse glass frit is held for 3 hours at room temperature under reduced pressure in 50% aqueous isopropanol to filter.

remove the urea from the silk. The sample of black lace-up silk of size 3-0 becomes loose

is not capillary and tied in such a way that it is wound around a spool that is perforated around the Cut through does not fray, and has a handle to allow io penetration. The coil will be in that of the untreated comparison sample clearly placed a container in which there was enough urea solution is different. is poured to completely cover the coil.

The container with the coil and the fibroin solution is kept in Example 4 overnight in a vacuum chamber in the

15 a vacuum of 762 mm is maintained.

20 parts of waste silk fibers are divided into 100 parts. The silk strand is then mechanically removed from the

50 ° / _o sodium dissolved LiSCN. The fibroin solution is drawn against a fibroin bath through an opening through which the 2000 parts of imolar urea are dialyzed. The dialysis strength of the surface coating is regulated. That is repeated. The dialyzed fibroin solution speed is 7.3 m / minute. The train holds 10.5 ° / ₀ fibroin. A bobbin of bobbin-lined zo runs one after the other through a container with 70% silk is kept under vacuum for 2.5 hours in an aliquot of the aqueous ammonium sulfate to dissolve the fibroin into the er-fibroin. The silk is to bring rigid, taken out through a water-filled sawn A, and the excess liquid container to remove the salts and urea ™ is wiped with a towel. The silk threads and through hot air chambers, which are kept at 50 ^° C. under two different conditions, are used to dry the strand. The suture dries: is again in the silk solution under a vacuum

. ".", - ", _". ,, "of 762 mm impregnated for 2 hours and then again

A. A thread of 9.14 m long is _{treated without tension in the} manner described above, dried. _The physical tests of the double-impervious

B. A suture 9.14 m long will have the following results under a 30 gnicked suture: Tension of 50 g dried. Diameter 249 μ

Tensile strength untied 2.09 kg

Both silk threads are knotted to a knot strength of 1 32 kg at 105 ° C. for 3 hours

hitztund3 hours in 50 ° / ₀ isopropanol at room wet knot strength ............... ΐ | θ4 kg

temperature kept. When drying under tension 35

if there is a shrinkage or shortening of 0.4 ° / ₀ , the suture material obtained in this way is not capillary,

while drying without tension does not fray, has an excellent grip and is shortened by 1.7%. Both samples are acceptably excellently bound,
bar. The physical properties such as tensile strength, knotability and knot holding capacity are 40
excellent. The samples are not capillary. Example 8

Black, braided, ungewachstes Nahtma- g

Example 5 material made of silk (size 3-0) is threefold to the im ™

45 Example 7 coated manner. After

The suture material has the threefold impregnation described in Example 3, silk strands

bene way treated with the difference that the following physical properties:

Fibroin solution for a 1 ° / _o solution of a quaternized μ average diameter 250

natural ammonium salt and not untied against an imolar mean tensile strength .... 2.17 kg

Urea solution is dialyzed. 50 Average knot strength 1.45 kg

the silk does not become capillary. Average knot strength, wet 1.04 kg

The finished strand is about 2% heavier, a

Example 6 Signs that the suture is about 2 percent by weight

55 cent of fibroin has absorbed. The suture is

Silk strands are treated in the manner described in Example 3, not capillary, do not spread when being cut, with the difference that they have an excellent grip and excellent dialy-binding properties for the fibroin solution against a 0.1 molar solution,
is sated. The treatment does not become capillary
Preserved silk. 60

Example 9 Example 7

In the manner described in Example 7 is

Black, braided, unwaxed suture material - black, braided, unwaxed suture material rial made of silk (size 3-0) is made from silk in sizes 2-0, 3-0, 4-0 and 6-0 according to the following 65 Impregnated method: 20 parts of degummed silk fibroin using the cocoons in Example 7 are impregnated overnight in 100 parts of a written fibroin solution. After easier 50% LiSCN solution (50 parts LiSCN and 50 parts impregnation of the sutures of the various

Sizes were obtained the following physical properties:

Diameter, μ.

tensile strenght

untied, kg

Wet strength

untied, kg

Knot strength, kg

Knot strength wet, kg

size 4-0 2-0 3-0 2.22 5.85 4.49 1.41 3.31 2.17 1.04 2.45 1.63 0.95 2.04 1.36 0.77 1.54 1.09

All sizes of sutures are non-capillary, excellent bonded, and excellent Handle.

Example 10

20 parts of degummed silk cocoons are grown overnight in 100 parts of a 50 ° / ₀ aqueous LiSCN solutions (LiSCN 50 parts and 50 parts H ₂ O) at pH 7.0 made soluble. After the dissolution of the Fibroinkonzentrat will ° / ₀ diluted aqueous Acetamidlösung with a 50, 2 parts of Acetamidlösung be used per part of fibroin LiSCN concentrate. The solution is nitrated through cotton gauze (6 layers).

Spools of loosely wound, unwaxed, black, braided silk suture material in the Sizes 0 and 3-0 are impregnated in the manner described in Example 7. All samples are not capillary, have an excellent grip and are excellently bound.

Example 11

Black, bobbin lace, unwaxed silk of size 3-0 is made with a fibroin solution using Impregnated by LiBr instead of LiSCN as a solubilizing agent. The degummed silk cocoons are made soluble in LiBr by adding 20 parts

ίο silk are given in 100 parts of lOmolar LiBr, which is adjusted to pH 7.0. After solubilization, the solution is washed with aqueous acetamide dissolved and used to impregnate silk sutures in the manner described in Example 10. The following physical properties of the impregnated sutures are determined:

Diameter 250 μ.

Tensile strength untied 2.04 kg

Knot strength 1.36 kg

Knot strength wet 1 kg

The suture is non-capillary and has excellent physical properties such as knot retention, No slippage, no fraying, good s5 grip.

Claims (1)

Claim: Multi-fiber silk thread, the individual fibers of which are provided with a covering material, as surgical suturing material, characterized in that that the coating material consists of silk fibroin. 109533/347