Catgut threads dissolve as quickly as possible. Absorbable surgical sutures. Surgical suture material. Classification of needles for stitching

Absorbable suture materials are surgical sutures with a high ability to self-degrade. Such materials come in both synthetic and natural origin. During the healing process of the wound, they completely dissolve and are removed from the body and do not require the traumatic procedure of removing sutures.

The properties of absorbable threads are determined by two main characteristics: biological strength and the period of complete resorption.

There are absolutely absorbable surgical threads of natural origin, such as threads made from catgut.

Catgut is highly purified collagen of animal origin. Two types of absorbable threads are produced from it - simple and chrome-plated, the periods of their complete disintegration are on average 80 days.

Synthetic absorbable threads

The group of synthetic absorbable sutures includes products made from polydioxanone, polyglycaprone and polyglycolic acid. There are varieties in the form of mono- or multi-filament. They have at different levels biostrength and periods of complete decay.

Such suture materials retain their original strength for a week and are completely destroyed in 40-45 days. The use of synthetic absorbable threads is common in general, pediatric, plastic surgery, urology and gynecology.

The group of surgical absorbable sutures with an average disintegration period includes multi- and monofilament sutures made of polyglycaprone. Polyglycarpone effectively holds the junction for 3-4 weeks, and after 2-4 months the material disintegrates and is completely eliminated from the body.

Polydioxanone threads have the longest resorption period. They retain biostrength for up to 40-50 days and are completely destroyed after 180-210 days. Such properties are indispensable in traumatology and oncology surgery, where tissue support is required for a long time.

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At the same time, they should not have hygroscopic, capillary properties, be toxic, allergenic, teratogenic, or carcinogenic to the body.

Let's look at some of the requirements given.

First of all, surgeons are interested in the mechanical strength of the thread. Moreover, it is necessary to take into account not so much the strength of the thread itself, but its strength in the knot (most threads lose from 10 to 50% of their strength).

Absorbable materials are characterized by an additional parameter - the rate of loss of strength. It should not exceed the rate of scar formation. In abdominal surgery when suturing wounds gastrointestinal tract a durable scar is formed within 1-2 weeks, when suturing tissues with low regenerative properties (aponeurosis) - 3-4 weeks. Accordingly, absorbable surgical sutures should remain sufficiently strong for 2-4 weeks after surgery. Otherwise, if, when suturing the aponeurosis, threads are used that lose strength up to 14 days, there is a possibility of eventeration.

An important property of surgical threads is also their biological compatibility with the patient’s tissues. All known threads have antigenic and reactogenic properties. Absolutely inert, areagen materials do not exist. The body's reaction to a foreign body (in the form of an inflammatory reaction and endogenous intoxication of the body) is always present to a greater or lesser extent. Ideally, the degree of its manifestation should be minimal.

Considering that the very fact of resorption involves the interaction of threads and the body, it is logical to conclude that modern non-absorbable threads are quite highly biocompatible.

The high hygroscopic and capillary properties of the threads contribute to the sorption of wound discharge on them. In conditions of a sufficient amount of nutrient material, even an insignificant infectious intervention will contribute to the rapid development of inflammation. An infecton is created - a local accumulation of infectious material that can damage biological barriers. To reduce the reactogenic properties of the threads, they are coated with a special coating.

The biodegradation properties of surgical threads are determined by their ability to be absorbed and excreted from the body. At the same time, biodegradation should occur no earlier than a certain time required for the formation of adhesions. After completing its main mission, the thread becomes a useless foreign body. Therefore, ideally, after performing its function, it should be removed. The only exceptions are the threads connecting the prosthesis to the tissues, since a scar never forms between them.

The quality of surgical threads is determined by their atraumatic nature. The smoother the surface structure of the thread, the less it damages the fabric. Considering the uneven surface of all twisted and braided threads, when they are pulled through the tissues of the body, a “saw effect” occurs (Fig. 5.5). Additional trauma certainly increases the inflammatory response. The “saw effect” is enhanced by the use of non-atraumatic needles, where the thread is fixed by the eye of the needle. This creates a duplication of the thread, which increases tissue damage when it is pulled through (Fig. 5.6).

Rice. 5.5 Tissue injury due to the “saw effect”

Rice. 5.6 Tissue injury when using a non-atraumatic needle

In order to reduce the roughness of the threads, as well as to acquire certain properties (unresponsiveness, thromboresistance, etc.), they are coated with silicone, wax, Teflon and other substances. However, we must remember that the smoother the surface of the thread, the less strong the knot. Therefore, when using smooth monofilament threads, it is necessary to tie many more knots. In turn, any extra node increases the amount of foreign material in the body. The fewer nodes, the less the inflammation reaction.

The manipulation properties of threads are determined by their elasticity and flexibility. Elasticity is one of the main physical parameters of a thread. It is more difficult for the surgeon to manipulate rigid threads, which leads to additional tissue damage. In addition, when a scar forms, inflammation and an increase in the volume of tissue connected by the thread initially occur. The elastic thread stretches as post-traumatic edema develops, while the inelastic thread cuts into it. At the same time, excessive elasticity of the thread is also undesirable, as it can lead to divergence of the edges of the wound. It is considered optimal to increase the length of the thread by 10-20% compared to the original.

The resistance of the surgical thread to infectious agents that are certainly present on the surgical field is very important. In the specialized literature, reports have appeared on the production of threads with antibacterial properties. In this case, the antibacterial effect of the suture material is determined by the introduction of antibiotics and nitrofuran drugs into its structure. Unfortunately, despite their pronounced antibacterial properties, they have not yet become widespread.

In addition to the above characteristics, the ability of the suture material to be sterilized and maintain sterility without changing its basic qualities is of particular importance. Almost all modern surgical threads are sterilized by manufacturers.

Let's look at the characteristics of some surgical threads. Traditionally, let's start with catgut - the most common and widely used suture material.

Catgut is an absorbable surgical suture made from the muscularis mucosa and submucosal layer. small intestines sheep It is used for applying submersible sutures, for suturing wounds of parenchymal organs, peritoneum, muscles, subcutaneous tissue and for dressing small blood vessels. In some cases, catgut is used when stitching the skin (under plaster cast, when forming a “cosmetic” seam).

The protein structure of catgut makes it difficult to sterilize, since boiling and dry steam destroy the thread. Therefore, it is sterilized by treatment with various antiseptics or irradiation with gamma rays.

There are 13 numbers of catgut (from 5/0 to 6) with a diameter of 0.1 to 0.8 mm. The higher the number, the stronger the thread. Thus, according to standards, the tensile strength of three-zero catgut is 1400 g, and that of the sixth number is 11,500 g.

Catgut threads must be tied into a knot with three loops. You need to cut off the free ends of the thread at a distance of at least 0.5-1 cm from the knot.

The period of resorption of catgut in tissues is quite variable. It ranges from 2 to 30 or more days. The resorption process depends on the thickness (number) of the thread, the method of its sterilization, and the condition of the tissue in the suture area. Inflammatory processes, suppuration of the wound, as well as locally applied medications (for example, proteolytic enzymes) and physiotherapeutic procedures, significantly accelerate the resorption of catgut. On the contrary, treatment during its production with formaldehyde, sulfate chloride, chromium, gold and other substances slows down the resorption time.

It was found that, being in tissues, catgut threads cause sensitization of the body. When using catgut repeatedly, the likelihood of immune aseptic inflammation occurring around the thread increases significantly. This, in turn, can cause the development of suture failure. Considering the above facts, the use of catgut can be considered an operation of transplantation of foreign tissue. This is the only thread that received a reaction anaphylactic shock.

Experimental studies have shown that if, when suturing a clean wound with catgut, 100 microbial bodies of staphylococci are introduced into it, then suppuration will occur. Moreover, catgut thread, even in the absence of microbes, can cause aseptic tissue necrosis. If we compare threads of the same diameter, the strength of catgut threads is less than that of synthetic absorbable ones. In addition, during the first five days they lose up to 90% of their strength.

Therefore, based on all of the above, the use of catgut is not recommended.

Silk is often used among absorbable threads of natural origin. Silk threads made from natural raw silk dissolve within 6-12 months. To increase strength, a small amount of cotton fiber is added to them. Both twisted and braided threads are produced in eleven numbers - from 7/0 to 8. Silk No. 3/0 has a thread diameter of 0.13 mm, its tensile strength is at least 370 g.

The diameter of the thickest thread (No. 8) is 0.77 mm, its tensile strength is 10500 g.

Threads of zero numbers are connected to atraumatic needles in sterile packaging. Threads of larger diameter are produced in non-sterile skeins or in sealed ampoules. In the latter case, they can be pre-sterilized with gamma rays.

Silk of zero numbers is used in vascular surgery, medium numbers (No. 2 - 4) are used for connecting soft tissues. Thick silk threads are used to sew up dense fabrics. They can also be useful in tightening tissue under pressure.

Silk is a fairly soft, flexible and durable material that allows you to tie a two-loop knot in the seam. The free ends of silk ligatures can be cut short, leaving small “tendrils”.

Silk has pronounced wicking properties and hygroscopicity. As a rule, it causes a long-term, moderately expressed aseptic inflammatory reaction of a predominantly proliferative nature. As a result, a capsule often forms around the thread. During an infectious intervention, purulent inflammation may develop around the thread, which can subsequently lead to the development of ligature fistulas. The experiment showed that 10 microbial bodies of staphylococcus are enough to suppurate a wound sutured with silk thread (remember, under other conditions one hundred thousand are needed).

It was found that silk threads can cause sensitization of the body, and therefore their use in repeated operations, especially on the digestive system, should be limited.

IN recent years Attempts are being made to improve the properties of silk. To do this, it is impregnated with wax or silver salts. Wax coating sharply reduces the wick properties, but negatively affects the reliability of the knot.

Thanks to the impregnation of silk thread with silver salts with their inherent antiseptic effect, the risk of suppuration is generally reduced. However, taking into account all of the above, we recommend using silk threads as little as possible. In our opinion, it is better to use synthetic suture materials.

Conventionally, all synthetic absorbable suture materials are usually divided into two groups:
First group. Polyfilament materials: polysorb (Auto Suture), dexon (Davis&Geck), vicryl (Ethicon), dar-win (Ergon Sutramed), PGA (Resorba), sofil (B.Braun), Helm-Syntha.

Their distinctive features are: low reactogenicity, hydrophobicity, high mechanical properties (synthetic threads are two to three times stronger than silk threads of the same diameter). Of the above threads, polysorb is considered the most durable. It is approximately 1.5 times stronger than vicryl and 3 times stronger than catgut.

Synthetic absorbable polyfilament suture materials have good handling properties, strictly defined, optimal periods of loss of strength and resorption. Vicryl, Dexon and Darwin lose up to 80% of their strength within two weeks, Polysorb - three weeks. Synthetic polyfilament materials dissolve approximately 2-3 months after surgery.

Literary data indicate that vicryl is the most difficult to handle among the listed threads. In addition, it has a more pronounced “saw effect”. Coating vicryl with calcium stearate significantly improves its quality. At the same time, the traumatic “sawing effect” is undoubtedly reduced, but at the same time, the strength of the knot also decreases. Based on this, when using regular “uncoated” vicryl, it is recommended to tie the thread into a knot with three loops. To securely tie coated vicryl, at least four loops must be knitted.

The polymer coating is used to reduce sawing properties in other threads of this group.

Second group. Monofilament threads: maxon (Davis&Geckn), polydioxanone (PDS) (Ethicon), biosin (Auto Suture), monocryl (Ethicon).

Unlike multifilament threads, monofilament threads are less reactogenic and practically lack sawing properties when pulled. At the same time, like all monofilament threads, Maxon and PDS, due to their low friction coefficient, require a knot of complex configuration. To securely tie two or even three loops, as a rule, is not enough. A PDS knot, for example, is recommended to be formed from no less than six loops.

The resorption period of monofilament threads is 3-6 months. Given the long resorption time, these threads can serve as a source of ligature fistulas or choledocholithiasis (urolithiasis).

Monofilament threads are superior or comparable in strength to multifilament threads. In terms of the period of loss of strength and resorption, they are similar to the threads of the first group. Thus, monocryl loses 80% of its strength within two weeks, biosin - four weeks.

Synthetic non-absorbable threads made of nylon, nylon, lavsan, letilan-lavsan, dacron, fluorolone, etc. are widely used as suture material. When developing non-absorbable suture materials, researchers strive to ensure good handling qualities of the thread and minimize their reactogenicity. Despite the fact that threads made from these materials are not capable of being absorbed and excreted from the body, they are indispensable for prosthetics or the need for long-term immobilization of connected tissues. In addition, they are widely used in surgery due to their low cost, ease of use and high strength.
Kapron (polyamides) has pronounced reactogenic properties.

Initially, nylon (polyamide) was twisted, then braided and monofilament threads appeared. However, changing the structure of the thread did not significantly change the rectogenicity of the material. Sutures with nylon thread are often used for removable sutures of the skin, bronchi, tendons and aponeurosis. Although they initiate a long-term inflammatory reaction in the connected tissues.

Mylar (polyester) threads are more inert than polyamides and cause less tissue reaction. They are mainly produced wicker. Their exceptional strength is used in endosurgery for intracorporeal knot tying methods. The fact is that monofilament threads can lose strength or even break due to manipulation with tools.

Polypropylene was the first of a group of modern non-absorbable sutures that are inert to body tissue. Threads made from this material are only monofilament.

There is virtually no tissue reaction to polyolefins, so they can be used in infected tissues or, at least, not removed if the wound has become suppurated. In addition, we use polyolefins in cases where even minimal inflammation is undesirable. Polypropylene remains the most used suture in cardiovascular surgery, organ transplantation, hernia surgery, pancreatic surgery and for skin removable sutures.

Of all monofilament threads (with the exception of biosin), polypropylene retains the reliability of the knot for a long time (you can knit a knot of four loops). The only reason limiting the widespread use of polypropylene is its “non-absorbability”.

Recently, there have been reports of the development of suture materials that are more inert to body tissues than polypropylene. First of all, these are fluoropolymers. Threads made of highly purified polytetrafluoroethylene (Go-lex) are completely inert to body tissues and have high thromboresistance. They are mainly used in vascular surgery for graft suturing, because the diameter of these threads is larger than the diameter of the needle. When pulled through the tissue, the thread, due to its elasticity, stretches and then contracts, completely filling the wound channel.

For better contrast with tissues, surgical threads are painted in different colors—black, blue, dark brown, etc. This facilitates visual control when forming surgical sutures using thin threads. This is especially true in microsurgery.

Most companies use a specific color for certain groups of threads. This allows you to determine the structure of the thread by its color. Although color coding is not mandatory, as a rule, silk threads are produced white. Polyamide is painted black; green - polyesters, maxon, sofil; blue - polypropylenes; purple - polysorb, vicryl, resorb; green-white - dexon. Catgut threads are traditionally brown or light brown in color.

Metal wire is widely used to connect bones. Wire threads are single-core and multi-core, of various diameters - from 0.1 to 1 mm. Metal braces are used in gastrointestinal surgery. The mechanical suture greatly facilitates and standardizes the surgical technique.

Plastic surgery is an art form in which the doctor, wielding a scalpel, like a sculptor, carves out new appearance features for his patient. The work of a plastic surgeon is a very delicate matter, in which every detail, even the most insignificant at first glance, affects the final result. In plastic surgery, as in any other branch of surgery, wounds are sutured using surgical threads. The doctor must approach the issue of choosing suture material with all seriousness, since correctly selected surgical threads are the final touch in the entire process. surgical intervention.

How the quality of suture material affects the outcome of the operation

Suture material in plastic surgery is selected in accordance with each type of surgical intervention. The quality of suture materials is one of the main factors influencing the healing process postoperative wound. All patients look forward to the day of suture removal. postoperative period, because only then can we examine and evaluate the result of the operation in more detail. Suture material in surgery is used not only to close skin wounds, but also to stitch other tissues of the body, so when choosing surgical threads, you should take into account what will subsequently happen to the tissues that are stitched.

Suture material:

requirements for suture materials;
basic properties of absorbable suture materials;
when it is advisable to use non-absorbable suture material.

Requirements for suture materials

Today, plastic surgery places high demands on the quality of suture materials. The basic requirements for surgical threads are as follows:

suture materials must be biocompatible - that is, the threads must not produce a toxic, teratogenic or allergic effect on the patient’s body;
biodegradation - the suture material must have the ability to disintegrate and be removed from the patient’s body, and the rate of this process should not exceed the rate of scar formation;
the threads must be atraumatic - this means that the surgical threads must have sufficient flexibility and elasticity, connect well to the needle and not produce a “dissolving” effect;
suture materials must be strong - the strength of the thread must guarantee the preservation of the seam until the postoperative scar is completely formed.

Basic properties of absorbable suture materials

Absorbable threads are the main suture material in modern plastic surgery, since they do not require removal and dissolve in the wound on their own. The main absorbable suture materials include:

catgut is an absorbable suture material that completely dissolves within 60-90 days after surgery. Most relevant when applying sutures to the posterior surface auricle after otoplasty, or when closing wounds of the scalp;
Vicryl and Dexon are coated multifilament surgical sutures. Such threads are stronger and less reactogenic than catgut. Vicryl is completely absorbed 70 days after surgery, and Dexon is completely absorbed after 90 days;
Polysorb is an absorbent coated suture material. Its density is even higher than the density of vicryl and dexon, while complete resorption of the thread occurs 70 days after surgery;
monocryl is an elastic absorbable suture material that practically does not cause an inflammatory reaction and completely dissolves no earlier than 90-120 days after surgery.

When is it appropriate to use non-absorbable suture material?

Non-absorbable suture materials differ from absorbable ones in much higher strength, better handling properties, less reactogenicity, and such materials are not able to disintegrate and be removed from the patient’s body. Such suture materials are most often used for fixing implants and cartilage structures, as well as for suspending soft tissues of the body. These include:

polyamides - have high strength and flexibility, but cause a fairly pronounced reaction from tissues;
pyloethers are more inert, but less elastic than polyamides;
polyolefins - have high inertness, elasticity and strength, guarantee the reliability of the surgical unit;
metal clips - often used in plastic surgery to close wounds on the scalp. Their main advantage is the ease of application and removal, as well as the formation of a reliable and quick connection of damaged tissues.

Requirements for suture materials first began to be formulated in the 19th century. So, N.I. Pirogov in “The Beginnings of Military Field Surgery” wrote: “...the best material for a suture is one that: a) causes the least irritation in the puncture channel, b) has a smooth surface, c) does not absorb liquid from the wound, does not swell, does not go into fermentation, does not become a source of infection, d) with sufficient density and ductility, it is thin, not bulky and does not stick to the walls of the puncture. This is the ideal seam.” It should be admitted that Nikolai Ivanovich, in comparison with modern surgeons, was surprisingly modest in his demands. More modern requirements were formulated by Szczypinski A. in 1965.

Easy to sterilize

· Inertia

· The strength of the thread must exceed the strength of the wound at all stages of its

healing

· Node reliability

Resistance to infection

Absorbability

Comfortable in the hand (more precisely, good handling qualities)

· Suitable for any operation

· Lack of electronic activity

· Lack of carcinogenic activity

· No allergenic properties

· Tensile strength in the knot is not lower than the strength of the thread itself

· Low price

According to the thread structure:

1. Monofilament, or single-filament (monofilament) is a thread consisting of a single solid fiber. It has a smooth, even surface.

2. Polyfilament, or multifilament (multifilament), which can be:

a) twisted

b) wicker

These threads can be coated or uncoated. Uncoated multi-filament threads have a sawing effect. This leads to more tissue damage and more bleeding at the puncture site. To avoid this effect, many polyfilaments are coated with a special coating that gives the thread a smooth surface. Such threads are called combined.

Thread properties:

1. Durability- the stronger the thread, the smaller its diameter you can sew fabric. And the smaller the diameter of the thread, the less mass of foreign suture material we leave in the tissues, and, accordingly, the less pronounced the tissue reaction. Studies have shown that the use of a thread with a nominal diameter of 4/0 instead of 2/0 leads to a twofold decrease in tissue reaction. So thread strength is one of the important parameters. Moreover, it is not so much the strength of the thread itself that should be taken into account, but its strength in the knot, since for most threads the loss of strength in the knot ranges from 10 to 50% of the original. For absorbable suture materials, one more parameter must be taken into account - the rate of loss of strength. As we have already said, the rate of loss of thread strength should not be higher than the rate of scar formation. In surgery of the gastrointestinal tract, a scar is formed in 1-2 weeks, with aponeurosis suture - in 3-4 weeks. Accordingly, it is desirable that the suture material retains sufficient strength until 2-4 weeks after surgery (in this case, depending on the type of absorbable material, it will be necessary to use threads of different diameters). Braided threads are more tensile; they also retain greater strength in the knot. Monofilament becomes less strong in the knot area. At endoscopic operations use multi-filament threads.

2. Manipulative properties- the manipulation properties of threads include: elasticity and flexibility. Elasticity is one of the main physical parameters of a thread. Rigid sutures are more difficult for the surgeon to manipulate, resulting in more tissue damage. In addition, when a scar forms, the tissue initially becomes inflamed and the volume of tissue connected by the thread increases. An elastic thread stretches as the fabric increases, while an inelastic thread cuts through the fabric. At the same time, excessive elasticity of the thread is also undesirable, as it can lead to divergence of the edges of the wound. It is considered optimal to increase the length of the thread by 10-20% compared to the original. The flexibility of the thread is associated not only with ease of manipulation for the surgeon, but also with less tissue trauma. It is still believed that silk has the best manipulation properties (it is also called the “gold standard” in surgery).
Multifilament thread is much softer, more flexible, and has less memory. Braided thread is knitted with fewer knots. When pulled through fabric, monofilament passes through more easily; when removing it from a wound, say, an intradermal suture, it does not adhere to the tissues and is easily removed. It takes 5-6 days for a woven thread to adhere to the fabric, so it is very difficult to remove it.

3. Knot strength. As a rule, the smoother the surface of the thread, the less strong the knot on it. Therefore, more knots are knitted on monofilament threads.

4. Biocompatibility or inertness- this is the ability of a thread to cause tissue irritation. Monofilaments have a less irritating effect. All things being equal, multifilament thread will cause a greater tissue inflammatory response than monofilament thread.

5. Wick effect- this is the ability of the thread to absorb the contents of the wound. As we already know, multifilament threads have this effect, but monofilament threads do not. Therefore, being in an infected wound, monofilaments do not support the suppurative process.

Properties of suture material:

Biodegradation (absorbability). This is the ability of a material to be absorbed and excreted from the body. The purpose of the thread is either to stop bleeding from a vessel or to connect tissues until a scar forms. In any case, after completing its main mission, the thread becomes simply a foreign body. And of course, it is ideal if, after performing its function, the thread dissolves and is removed from the body. In this case, the rate of loss of thread strength (the main parameter for all absorbable threads) should not exceed the rate of scar formation. For example, if a strong scar is formed during the suture of the aponeurosis no earlier than on the 21st day, and the thread loses its strength on the 14th day - as you understand, there is a possibility of eventration. Only the threads that connect the prosthesis with the tissues of the body should not dissolve, since a scar never forms between the prosthesis and the tissues.

According to ability biodegradation(resorption in the body) suture material is divided into:

1. absorbable;

2. conditionally absorbable;

3. non-absorbable.

Absorbable materials include:

§ catgut;

§ synthetic absorbable threads.

Catgut plain and chrome-plated catgut is a material of natural origin from the serous tissue of cattle or small livestock. The biological strength of simple catgut is 7-10 days; chromed 15-20 days.

Synthetic absorbable threads short resorption period. These are braided threads made from polyglycolic acid or polyglycolide. The biological strength of these threads, like that of simple catgut, is 7-10 days, the period of complete resorption is 40-45 days.

The group of conditionally absorbable threads includes:

§ polyamides or nylon;

§ polyurethanes.

Silk due to its physical properties it is considered the gold standard in surgery. It is soft, flexible, durable, and allows you to knit two knots. However, due to the fact that it is a material of natural origin, it causes aseptic inflammation, up to the formation of necrosis. While in human body, silk dissolves within 6-12 months, which makes it impossible to use for prosthetics.

Group of polyamides (nylons) dissolves in the body within 2-5 years. Polyamides are historically the first synthetic suture materials that are chemically unsuitable for surgical sutures. These threads are the most reactogenic among all artificial synthetic threads, and the tissue reaction is in the nature of sluggish inflammation and lasts the entire time that the thread is in the tissues.

The last polymer from the group of conditionally absorbable materials is polyurethane ester. Of all monofilaments, it has the best handling properties. It is very plastic and has virtually no thread memory; it is convenient to work with in a wound. This is the only monofilament that can be knitted with three knots.

Non-absorbable threads:

§ polyesters (polyesters or lavsan);

§ polypropylene (polyolefins);

§ group of fluoropolymer materials;

§ steel, titanium.

Polyester(polyester or lavsan) threads are more inert than polyamides and cause less tissue reaction. At the same time, the use of these threads in surgery is increasingly limited; they are quietly disappearing from the arsenal of surgeons. This is due to the advent of synthetic absorbable threads.

The second group is polypropylenes(polyolefins). This material is produced only in the form of monofilaments from all of the above polymers; these threads are the most inert to human tissue, the reaction of tissues to polypropylene is practically absent, so they can be used in infected tissues.

The third group of non-absorbable threads includes fluoropolymers. These threads have the same properties and are used in the same operations as threads of the polypropylene group. The only difference is that these threads are softer, more flexible, and can be knitted with fewer knots.

The last material from the group of non-absorbable threads is steel and titanium.

History of origin

Suture materials have been used for several millennia. The first mention of suture material was found 2000 BC in a Chinese treatise on medicine. Intestinal and skin sutures using threads were mentioned plant origin. In ancient times, various materials were used for seams: horse hair, cotton, scraps of leather, tree fibers and animal tendons.

In 175 BC, Galen first described catgut. Interestingly, the literal translation of this word from English is “cat gut.” In the mid-19th century, Joseph Lister described methods for sterilizing catgut threads and since then they have come into widespread practice as the only material. Another modern suture material is silk. Its use in surgery was first described in 1050 AD. In 1924, in Germany, Hermann and Hochl first produced polyvinyl alcohol, which is considered the first synthetic suture material. In 1927, in America, Corotes repeated the discovery and named the resulting material nylon. In the 30s, two more synthetic suture materials were created in Western laboratories: nylon (polyamide) and lavsan (polyester). Already in the late 30s and 40s, these materials began to be widely used in surgery.
In 1956, a fundamentally new material: polypropylene.
In 1971, synthetic absorbable sutures were first used.

Modern surgical suture material

Surgical suture material is a foreign thread used to connect tissue to form a scar. In 1965, A. Shchupinsky formulated the requirements for modern surgical suture material:

Easy to sterilize
Inertia
The strength of the thread must exceed the strength of the wound at all stages of its healing
Node reliability
Resistance to infection
Absorbability
Comfortable in the hand, softness, plasticity, good handling properties, no thread memory
Applicable for any operation
Lack of electronic activity
No allergenic properties
The tensile strength in the knot is not lower than the strength of the thread itself
Low cost

Classification of suture materials

According to the thread structure

Monofilament, or single-filament- This is a thread consisting of a single solid fiber. It has a smooth, even surface. Monofilament
Polyline, or multi-filament(Multifilament), which can be:

twisted
wicker

These threads can be coated or uncoated. Uncoated multi-filament threads have a sawing effect. When such a thread is pulled through the fabric, due to its rough, uneven surface, it cuts through and injures the fabric. This leads to more tissue damage and more bleeding at the puncture site. Such threads are difficult to pull through the fabric. To avoid this effect, many polyfilaments are coated with a special coating that gives the thread a smooth surface. Such threads are called combined. Multifilament threads have a so-called wick effect. This is when microvoids remain between the fibers of a braided or twisted thread, which are filled with tissue fluid when such a thread is in the wound. If this wound is infected, then through these micropores microbes can move to a healthy, uninfected part of the tissue, causing an inflammatory or suppurative process there. Having considered all the above points, we can draw the following conclusion that mono- and polyfilaments have both positive and negative properties:

Strength - braided threads are more tensile; they also retain greater strength in the knot. Monofilament becomes less strong in the knot area. For endoscopic operations, multi-filament threads are used. This is due to the fact that endosurgery mainly uses intracorporeal methods of knot tying, which involves tying a thread using instruments. At the same time, monofilaments at the point of compression by the tool may lose strength and break.
Manipulation properties - the manipulation properties of threads include: elasticity and flexibility. Elasticity is one of the main parameters of the thread. Rigid threads are more difficult for the surgeon to manipulate, which leads to more tissue damage. Again, when working in a small surgical field, a rigid thread, having increased memory, gathers in a ball in the wound, creating additional difficulties for the surgeon. Multifilament thread is much softer, more flexible, and has less memory. Braided thread is knitted with fewer knots. When pulled through fabric, monofilament passes through more easily; when removing it from a wound, say, an intradermal suture, it does not adhere to the tissues and is easily removed. It takes 5-6 days for a woven thread to adhere to the fabric, so it is very difficult to remove it.
The strength of the knot is also related to the surface properties of the threads. As a rule, the smoother the surface of the thread, the less strong the knot on it. Therefore, more knots are knitted on monofilament threads. By the way, one of the points of modern requirements for suture material is the minimum number of knots required for its reliability. After all, any extra node is a foreign material. The fewer nodes, the less the tissue inflammation reaction.
Biocompatibility or inertness is the ability of a thread to cause tissue irritation. Monofilaments have a less irritating effect. All things being equal, multifilament thread will cause a greater tissue inflammatory response than monofilament thread.
The wick effect is the ability of the thread to absorb the contents of the wound. As we already know, multifilament threads have this effect, but monofilament threads do not. Therefore, being in an infected wound, monofilaments do not support the suppurative process.

Properties of suture material

Based on its ability to biodegrade (absorb in the body), suture material is divided into:

absorbable;
conditionally absorbable;
non-absorbable.

TO absorbable materials include:

catgut;
synthetic absorbable threads.

Plain catgut and chromed catgut is a material of natural origin from the serous tissue of cattle or small livestock. Absorbable threads have two characteristics in terms of absorption time. This:

Biological strength or tissue support - the period during which the absorbable thread is in the human body retains another 10-20% of its original strength.
The period of complete resorption is the time it takes for the absorbable thread to completely dissolve in the body.

The biological strength of simple catgut is 7-10 days; chromed 15-20 days. The period of complete resorption for simple catgut is 50-70 days, and for chrome-plated catgut it is 90-100 days.

These terms are very arbitrary, since the resorption of catgut in the human body occurs through its breakdown by cellular proteolytic enzymes. Therefore, the rate of resorption of catgut will depend on the condition of the person, as well as on the health of the animal from which the catgut thread was made. There are often cases where catgut does not dissolve even after six months.

Absorbable materials of artificial origin include threads made from polyglycolic acid, polydiaxonone and polyglycaprone. They differ in structure: mono and polyline, in terms of tissue retention and complete resorption.

All companies that produce surgical suture material make it from the same polymers. Therefore, as a basis for the classification of synthetic absorbable threads, we will take their tissue retention time and complete resorption time:

Synthetic absorbable sutures with short absorption period. These are braided threads made from polyglycolic acid or polyglycolide.

The biological strength of these threads, like that of simple catgut, is 7-10 days, the period of complete resorption is 40-45 days. These threads are used in general surgery, pediatric surgery, plastic surgery, urology and in any other surgery where tissues need 7-10 days to form a scar. The advantage of these threads is their short resorption period of 40-45 days. This is a short enough period of time so that urinary or gallstones do not form on these threads, they are very good for absorbable intradermal cosmetic sutures, the patient does not need to return to the surgeon to remove the threads.

Synthetic absorbable sutures with medium absorption period: They can be braided or monofilament.

This group of threads is most often used in surgery, since their tissue support period is 21-28 days - this is the period during which a scar forms in most human tissues. Then there is no need for threads and they dissolve after 60-90 days, leaving no traces in the body. These threads are used in various areas of surgery. Monofilaments made of polyglycaprone also belong to the group of medium resorption period. The tissue retention period of these threads is 18-21 days, complete resorption occurs in 90-120 days. These threads can be used in any surgery. Their disadvantage is that they have worse handling properties than braided absorbable threads - they need to be tied with more knots.

The third group of absorbable synthetic threads are long-lasting threads from polydiaxanone.

Their tissue support period is about 40-50 days. Complete resorption after 180-210 days. These threads are used in general and thoracic surgery, in traumatology, in maxillofacial and oncology surgery, as well as in any other surgery where an absorbable thread is needed to support tissues with a long period of scar formation: these are cartilage tissue, aponeuroses, fascia, tendons. Recently, all over the world, catgut has been replaced by synthetic absorbable threads. Let's look at several reasons why this happens: catgut thread is the most reactogenic of all threads currently used - it is the only thread to which an anaphylactic shock reaction has been described. The use of catgut threads can be considered a foreign tissue transplantation operation, since it is made from foreign protein. Experimental studies have proven that when suturing a clean wound with catgut, it is enough to introduce 100 microbial bodies of staphylococcus into it to cause suppuration (usually one hundred thousand is required). Catgut thread, even in the absence of microbes, can cause aseptic tissue necrosis. Previously, it was said about the unpredictable periods of loss of the strength of the resorption of catgut; moreover, if we compare threads of the same diameter, the strength of catgut is less than that of synthetic threads. Catgut, being in the wound, causes irritation and inflammation, which leads to longer healing. Tissue sutured with synthetic absorbable thread heals faster. It has long been noted that as soon as the surgical department switches from catgut to synthetic thread, the percentage postoperative complications decreases. All of the above suggests that in modern surgery there are no indications for the use of catgut. At the same time, some surgeons continue to use it and consider catgut to be a satisfactory suture material. First of all, this is due to the habit of surgeons and lack of experience in using synthetic absorbable sutures. To the group conditionally absorbable threads we include:

polyamides or nylon;
polyurethanes.

Due to its physical properties, silk is considered the gold standard in surgery. It is soft, flexible, durable, and allows you to knit two knots. However, due to the fact that it belongs to materials of natural origin, it is chemical properties comparable only to catgut and the inflammatory reaction to silk is only slightly less pronounced than to catgut. Silk also causes aseptic inflammation, up to the formation of necrosis. When using silk thread in an experiment, 10 microbial bodies of staphylococcus were enough to cause suppuration of the wound. Silk has pronounced sorption and wicking properties, so it can serve as a conductor and reservoir of microbes in the wound. While in the human body, silk is absorbed within 6-12 months, which makes it impossible to use it in prosthetics, and therefore it is recommended to replace silk threads with another material. The group of polyamides (nylon) is absorbed in the body within 2-5 years. Polyamides are historically the first synthetic suture materials that are chemically unsuitable for surgical sutures. These threads are the most reactogenic among all artificial synthetic threads, and the tissue reaction is in the nature of sluggish inflammation and lasts the entire time that the thread is in the tissues. Initially, polyamide, or nylon, was produced twisted, then braided and monofilament threads appeared. According to the degree of inflammatory reaction of tissues to these threads, they are arranged as follows: the least reaction to monofilament threads, more to braided ones, even more to twisted ones. Of the polyamides used in surgical practice, monofilament threads are the most common; It should also be noted that the cost of these threads is the lowest. These threads are most often used for intradermal, removable, non-absorbable sutures, for sutures of blood vessels, bronchi, tendons, aponeurosis, and are used in operative ophthalmology. The last polymer from the group of conditionally absorbable materials is polyurethane ether. Of all monofilaments, it has the best handling properties. It is very plastic and has virtually no thread memory; it is convenient to work with in a wound. This is the only monofilament that can be knitted with three knots. Unlike polyamides, it does not support inflammation in the wound. When swelling occurs in the wound, it does not allow it to cut through the inflamed tissue, and when the swelling disappears, this thread acquires its original length, which does not allow the edges of the wound to separate. It also happens with devices (beads) that allow you not to tie knots. This thread is used in general, plastic, vascular surgery, in traumatology, gynecology.

the third group is non-absorbable threads:
- polyesters (polyesters or lavsan).
- polypropylene (polyolefins)
- group of fluoropolymer materials.

Polyester (polyester or lavsan) threads are more inert than polyamides and cause less tissue reaction. The threads are mainly braided and are exceptionally durable, but at the same time, the use of these threads in surgery is increasingly limited, they are quietly disappearing from the arsenal of surgeons. This is due both to the advent of synthetic absorbable threads and to the fact that initially in all areas except strength, polyesters are inferior to polypropylenes. Currently, polyesters (polyesters) are used in 2 cases:

when it is necessary to sew tissues that have been under tension for a long time after surgery and at the same time you need the most durable and reliable thread;
in cases where a non-absorbable thread is needed in endosurgery.

These threads are used in cardiac surgery, traumatology, orthopedics, general surgery and in any other surgery where a strong non-absorbable thread is needed. The second group is polypropylenes (polyolefins). This material is produced only in the form of monofilaments from all of the above polymers; these threads are the most inert to human tissue, the tissue reaction to polypropylene is practically absent, so they can be used in infected tissues or not removed if the wound has become suppurated; in addition, they are used in cases where even a minimal inflammatory reaction is undesirable, also in patients with a tendency to form a colloidal scar. The use of these threads never leads to the formation of ligature fistulas. Threads of this group have only two disadvantages: - they do not dissolve - they have worse handling properties than braided threads; they are knitted a large number nodes The area of application of these threads is cardiovascular surgery, general surgery, thoracic surgery, oncology, traumatology and orthopedics, operative ophthalmology and any other surgery where a durable, non-inflammatory, non-absorbable monofilament is needed. The third group of non-absorbable threads includes fluoropolymers. These are the latest scientific developments of all companies in the field of polymers from which surgical suture material is made. Scientists have noticed that if a fluorine-containing component is added to the polymer, the material acquires greater strength and becomes more flexible and ductile. These threads have the same properties and are used in the same operations as threads of the polypropylene group. The only difference is that these threads are softer, more flexible, and can be knitted with fewer knots. The last material from the group of non-absorbable threads is STEEL and TITANIUM. Steel can be either monofilament or braided. Steel monofilament is used in general surgery, traumatology and orthopedics, braided in cardiac surgery to make an electrode for temporary cardiac pacing. There are several ways to connect thread to needle. The most common is when a needle is drilled with a laser beam, a thread is inserted into the hole and crimped. This method is more reliable, since the strength of the needle and the strength of the needle-thread connection are preserved as much as possible. Some manufacturers continue to connect the thread with the needle the old fashioned way: the needle is drilled in the base area, cut lengthwise, unrolled, the thread is inserted inside and wrapped around the thread, while at the point of the “needle-thread” connection there is a weak point in which the needle can bend and break, and also at the junction of the two edges of the needle, sometimes a burr forms, which will injure the tissue when pierced with a needle. The strength of the needle-thread connection suffers with this technology. This causes the thread to come off the needle more frequently as it is pulled through the fabric. Currently, there are still reusable traumatic needles, where the thread is threaded into the eye of the needle. When such a thread passes through the tissue, a rough wound channel is created, which significantly exceeds the diameter of the thread. This channel bleeds much more, and tissue inflammation develops more often through it. Such wounds take longer to heal. How important the atraumatic properties of suture material are can be understood from the data of V.V. Yurlov, who, when applying colonic anastomoses, switched from a non-atraumatic needle and twisted nylon to atraumatic monofilament suture material, reduced the incidence of anastomotic leakage from 16.6% to 1.1 %, and mortality from 26% to 3%.