Surgical knot: use in various equipment. Clinical characteristics of knots used in surgery How to tie surgical knots

Since ancient times, knots have been used for various purposes, both in maritime affairs and in medicine. Even now, with the advent of new technologies, doctors tie threads when stitching skin and tissue. Nowadays, surgeons use catgut sutures when tying. This material slides when tied, so doctors tie knots using special clamps.

In this case, they most often use surgical knot. The line must be long enough to make a double turn. First, make two half-knots with two ends and tighten them in different directions; another half-knot is knitted on top, but made in the opposite direction. Its principle is that the edges of the threads do not diverge in different directions.

The surgical knot is also called a straight double knot and is used when there is a need to tie a load or gear, but when performing the first knot you have to hold it with your hand. To tie it, take a conical leader and a leash. Its name implies the presence of two revolutions. This knot is tied only with a leader, because with the usual method the length of the leader must pass through the simple knot twice. To fix it, you need to pull all its ends. Sometimes a triple surgical knot is used for strength.

The use of fishing line and various synthetic materials forced us to develop certain skills in weaving. Any novice angler, regardless of the method of fishing, will certainly encounter the problem of fishing line strength and knot tying. Therefore, the experience of sailors developed over thousands of years is used. There are only two situations when it is necessary to tie knots: connecting two ends of a fishing line and tying various hooks, fasteners, and leashes.

Fishermen sometimes have to deal with Then traditional knots are not used, since they do not hold well under load. They turn out to be not very reliable in operation. Therefore, their functions are performed by a surgical node. It is also recommended for use on most cables; it holds well on the ends of any slippery materials.

The fishing surgical knot is uncomplicated. They can reliably connect fishing lines of different diameters or monofilament fishing line. For example, this knot is used to connect a leash to a leader (conical leader). The breaking strength when using it is within 95%. This knot allows you to select a leash to match the size of the fly.

The choice of equipment and its components must be taken responsibly. Before tying a surgical knot, you need to remember that the knot that connects the hook to the fishing line is always a weak point. To prevent the fish from breaking loose and leaving with the elements of your equipment, it is important to take into account the strength of each component of the fishing rod. After all, there are no trifles when fishing. Knots play an important role here; they secure the fishing line. Before casting a fishing rod, fishermen must check its strength.

We tie the knots carefully, slightly moistening them before tightening. The line will become moisturized and retain its breaking force. The disadvantage of this knot is that it is not very small in size and, when tied, forms an angle on the fishing line.

Table of contents of the topic "Suture material. Operative technique.":
1. Suture material. Classification of suture material. Catgut. Okcelon, kacelon. Vicryl, Dexon, Polysorb. Silk. Nylon, nylon, lavsan, prolene.

3. Technique for dissecting the skin, subcutaneous tissue and superficial fascia. Cutting the skin, subcutaneous fat and fascia.
4. Technique for temporarily stopping bleeding from the vessels of subcutaneous fat. Temporary stop of bleeding from subcutaneous vessels.
5. Technique for finally stopping bleeding from the vessels of subcutaneous fat. Final stop of bleeding from subcutaneous vessels.
6. Technique for dissecting the native fascia and aponeurosis. Cutting the aponeurosis and its own fascia.
7. Technique for separating muscles along the muscle bundles. Cutting (cutting) muscles.
8. Technique for connecting soft tissues. Closing the surgical wound with hand sutures.
9. Technique for connecting the skin and subcutaneous fat (subcutaneous tissue). Suturing the skin and subcutaneous tissue.
10. Removal of stitches. Suture removal technique. Removal of interrupted skin sutures.

All nodes, used in surgical practice, double (sometimes triple). The first knot is the main one and should be tightened as much as possible. The second knot secures the first one, that is, it prevents it from untying or loosening. The third knot is applied when using catgut and synthetic ligatures for greater strength, since these threads are very elastic and their surface is slippery.

Rice. 2.16. Surgical nodes. 1 - simple; 2 - sea; 3 - surgical.

In surgery there are many types of nodes, but are considered basic simple, nautical And surgeons ical (Fig. 2.16).

We present classic way to tie a simple knot(Fig. 2.17).

The ends of the thread are grabbed by hand(see Fig. 2.17; 1).

When forming the first (main) node first, the position of the ends of the threads in the hands is changed - the left end of the ligature is taken in the right hand, and the right end in the left, and a cross of threads is formed (the thread in the left hand is placed on top of the thread fixed right hand) (see Fig. 2.17; 2). This cross is fixed between the II and I fingers of the left hand (II finger on top, the cross of threads is pressed to the base of its nail phalanx on the palmar surface, see Fig. 2.17; 3).

I and II fingers of the right hand fix the end of the thread, pull it and bring it under the protruding end of the nail phalanx of the second finger of the left hand. The gap between the threads can be widened with the third finger of the right hand (see Fig. 2.17; 4). Next, by turning the left hand with a nodding movement of the second finger, the end of the thread is passed into the slot (see Fig. 2.17; 5).

The knot is tightened(see Fig. 2.17; 6).

Rice. 2.17. Stages of tying a knot. The explanation is in the text.

For forming a simple knot the second (fixing) knot is tied in the same way as the first, but the second stage - repositioning the ends of the ligatures - is not performed.

Simple knot not strong enough, it slips and can be stretched by pulling one end of the ligature from the loops of the other.

When forming a sea node at the second stage, repeat all the steps from the beginning: grabbing the ends of the thread, shifting the ends of the thread from hand to hand (cross), passing one of the ends of the thread into the slot, tightening.

Surgical The knot differs from a simple one in that when tying the first (main) knot, the right end of the ligature is wrapped twice around the left end. When tightened, such a first knot is more firmly fixed as a result of friction and does not relax before tying the second one. This is the most reliable knot, but more cumbersome compared to a marine or simple one.

To successfully tie a knot the ends of the threads must be constantly taut.

Choosing a node type depends on the stage of the operation and the suture material used.

In addition to what is described classic way of tying a knot, in surgical practice there are many other ways to knit knots. However, as a result of any manipulations, one of the three types of nodes described above should be obtained.

Training video of the technique of tying a simple knot in surgery

Knitting other types of knots in surgery is discussed in separate video lessons

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To fix the specified linear and volumetric characteristics of the seam, the ends of the thread are fastened with knots. Tying knots is an important element of any surgical procedure.

A surgical knot is the result of the sequential execution of two actions:
the formation of a loop due to the mutual entwining of the ends of the thread;
tightening the loop tightly until the edges of the wound are completely connected (the actual formation of a knot).

Correct execution of all the details of these actions ensures the achievement of high quality surgical units, which are subject to numerous requirements.

Requirements for units used in surgery

1. Ease of implementation.
2. Achieving maximum strength with a minimum number of loops.
3. Minimum unit volume.
4. Absence of the “sawing effect” of the thread, which contributes to its chafing and tissue damage when the knot is tightened.
5. Elimination of the tendency to weaken the previous node when performing each subsequent one.
6. Correspondence of the loop formation technique to the mechanical properties of the suture material.
7. Maintaining constant mechanical properties for the time necessary for wound healing.
8. Speed ​​of loop formation.
9. Prevention of self-tightening of the knot by changing the linear properties of the suture material (prevention of tissue cutting).
10. Possibility of completely tightening the knot in the plane of the loop (perpendicular to the length of the wound).

Methods for forming loops

Methods for forming loops (knots) used in surgery are divided into two groups:
manual;
apodactylous (using tools).

The main method of forming loops and knots is manual.

Apodactylic methods are used in the following cases:
for tightening a knot deep in a wound of complex shape;
in microsurgery;
in video endosurgery (VES).

In such cases, loops can form both extracorporeally and intracorporeally.

The instrumental method of forming and tightening knots can significantly reduce the consumption of suture material.

Loops used in surgery are divided into single-wrap (simple) and multi-wrap (complex) (Fig. 77).

Rice. 77. A simple loop formed by wrapping a thread once (the left side of the thread is dark, the right side is light).

Increasing the mechanical strength of the knot by increasing the contact surface of the thread is achieved by increasing the number of entanglements (Fig. 78).

Rice. 78. A complex loop formed by repeatedly wrapping a thread (the left side of the thread is dark, the right side is light).

The number of thread wraps is usually two, three or even four.

When tightening the loop with repeated wrapping of the thread, a double-turn loop of the surgical knot is formed (Fig. 79).

Rice. 79. Double-turn loop of surgical knot.

A significant increase in strength due to an increase in the contact surface of the thread can contribute to the manifestation of the “sawing” effect and its fraying.

Depending on the number of loops used to fasten the ends of the thread, knots are divided into three groups:
- single-loop;
- two-loop;
- multi-loop.

1. Single-loop nodes are usually used to change the orientation of the wound of the small intestine, colon, stomach, and bladder (Fig. 80). After completing the appropriate stage of the operation, they are removed.

Rice. 80. Use of single-loop stay sutures to orient the wound of a hollow organ in the transverse direction.

To increase strength, the stitch of the stay suture should be directed perpendicular to the length of the correctly oriented wound. The coincidence of the length of the wound and the direction of the stitch can lead to destruction of the organ wall when the holder is pulled.

2. Usually, successive formation and tightening is sufficient to connect tissues. two-loop node. In most cases, a double loop satisfies the requirements for knots to the maximum extent.

In surgical practice, loops of simple (female), marine and complex two-loop knots are used.

Loops of a simple (female) knot

A simple (female) knot has the following features (Fig. 81):
1. A knot is formed by tying two loops in succession with the ends of the thread wrapped once.
The thread is wound in each loop in the same way and in one direction (accordingly, only the right or only the left hand is leading).

Rice. 81. A simple (female) knot formed by two identical unidirectional single-wrap loops.

Advantages of a simple (female) knot
— Ease of learning;
- speed of execution.

Disadvantages of a simple (female) knot
- Tendency to self-detachment;
- rapid loss of fastening properties.

The surgeon should only know about the existence of a simple (female) node, but it should be used as rarely as possible, only when absolutely necessary.

Sea knot loops

The nautical knot is tied in such a way that two opposing single-winding interlocking loops are formed (Fig. 82). The principle of formation of a sea node is shown in Fig. 83.

Rice. 82. Sea knot.

Rice. 83. The principle of formation of a sea node:
1 - the left (dark) part of the thread crosses the right (light) part of the thread, first from the back and then from the front; a single wrap around the left side of the thread is done with the right hand;
2 - tighten the first loop;
3 - when forming the second loop, the left side of the thread first crosses the right side from behind, and then from the front (the thread is wrapped with the left hand).
4 - tighten the second loop.

Advantages of a maritime hub
— Relative reliability and durability;
- ability to quickly learn.

Disadvantages of a sea knot
— Difficulty of implementation;
Labor intensity can be reduced by using rational methods of forming loops and achieving a good technical level of knot tying over long periods of practice.
- tendency to self-unravel when using synthetic monofilament suture materials.
The sea knot is ideal for silk threads.

Combination loops

The combined unit can be used in several versions.

I. A combination of two successively formed multi-wrap and single-wrap loops (Fig. 84). In this case, it is possible to form a variant of both female and marine knots with their inherent positive qualities and disadvantages.

Rice. 84. A combination of two successively formed multi-twist and single-twist loops (the right part of the thread is light, the left is dark): 1 - with the formation of a female knot, 2 - with the formation of a sea knot.

Advantages of a combined unit
— Increased strength;
— high degree of reliability.

It is advisable to use such a combined knot for applying a piercing ligature to the end of a large-caliber artery or vein deep in a wound of complex shape. You need to be guided by the rule: “a large vessel - a thick thread.” For this type of knot, it is preferable to use threads with a high coefficient of surface friction.

Disadvantages of a combined unit
Possibility of thread rubbing when tightening the first loop;
- large volume of the node, slowing down its resorption;
— the complexity of loop formation;
- tendency to unraveling when using synthetic threads with pronounced sliding surface;
— insufficient fastening properties of the second loop;
Adding a third (“locking”) loop eliminates this drawback.
- a discrepancy in the strength characteristics of the first (multi-wrap) and second (single-wrap) loops, leading to deformation of both the knot and adjacent tissues.

II. A combination of two multi-wrap loops makes it possible to form a so-called “academic” knot (Fig. 85). This knot can be in women's and marine versions.

Rice. 85. Scheme of the “academic” knot: 1 - variant of the female knot, 2 - variant of the marine one

Advantages of an “academic” node
Maximum reliability;
significant strength;
lack of tendency to self-detachment;
stability of the listed positive properties when used various types suture material.

Disadvantages of the “academic” node
The relative complexity of loop formation;
large unit volume;
impossibility of use to stop bleeding from small vessels due to the large lumen of the internal loop.

Increasing the strength and reliability of the knot can be achieved by doubling the thread, however, excessively increasing the volume of the knot limits the use of this option. A compromise solution is the Barkov knot.

III. A combination of two successively formed single-strand mutually reinforcing loops, the inner of which consists of a double thread, and the outer of which consists of a single thread (Barkov knot) (Fig. 86).

Rice. 86. Barkov knot.

Advantages of the Barkov knot
Increased reliability;
possibility of very close comparison of tissues;
lack of tendency to self-unbinding.

Disadvantages of the Barkov knot
Significant labor intensity;
using a fragment of thread of considerable length to form a knot;
discrepancy between the elastic-elastic properties of the internal and external loops.

It is preferable to use this type of node:
with a suture on the bone;
when ligating large vessels deep in a narrow wound;
to prevent weakening of the first loop during the formation of the second;
for comparison of low-elastic tissues of significant thickness (for example, when applying sutures to soft tissues in the fronto-parietal-occipital region).

Loops of a multi-loop knot

A multi-loop knot can be formed by several unidirectional single-wrap loops (Fig. 87).

Rice. 87. Scheme of a multi-loop knot with single-wrap unidirectional loops.

Advantages of a multi-loop knot
Ease of learning;
speed of execution.

Disadvantages of a multi-loop knot
— Poor fastening properties;
- maintaining a tendency to loosen the loops, just like a regular simple (female) knot.

This type of knot is a multiplied version of a simple (female) knot without any improvement in properties and maintaining the previously mentioned disadvantages.

Multi-tiered sea knot

A multi-loop knot, represented by a complex of single-winding mutually reinforcing loops (Fig. 88), is a multi-tiered maritime knot.

Rice. 88. Scheme of a multi-loop knot with single-wrap mutually reinforcing loops.

Advantages of a multi-tiered node
Reliability;
ease of execution;
thread fixation strength;
versatility for various types of suture material.

Disadvantages of a multi-tiered node
Relative labor intensity;
the possibility of loosening loops when using mono-filament synthetic threads;
significant node volume.

Various options for combined multi-loop knots are presented in Fig. 89, 90 and 91.

Rice. 89. Three-loop knots, which are a combination of female and sea knots: 1 - female knot, 2 - sea knot.

Rice. 90. Three-loop knot, which is a combination of academic and naval knots: 1 - female, 2 - naval.

Rice. 91. Three-loop knot, which is a combination of marine (1) and feminine (2) knots.

Advantages of these node options
— Increased reliability;
- strength;
preventing the first loop from weakening when subsequent ones are formed.

Disadvantages of these node options
— Labor intensity;
— significant volume of the unit;
- a disproportionate increase in the volume of the unit with a weakly expressed improvement in strength characteristics.

Multi-tiered surgical unit

Multi-loop nodes also include a multi-tiered surgical node (Fig. 92).

Rice. 92. Double “academic” knot.

Advantages of a surgical multi-tier unit
Exceptional strength;
highest degree of reliability;
universality of use for all types of suture material.

Disadvantages of a surgical multi-tiered unit
Labor intensity;
large volume of thread complex in the knot;
significant consumption of suture material;
high probability of formation of ligature fistulas due to the possibility of developing a pronounced tissue reaction.

Based on the level of loop formation relative to the wound surface, two options can be distinguished.
1. Directly approaching the level of loop formation to the seam line (Fig. 93).

Rice. 93. Forming loops near the seam line.

In these cases, the usual looping technique is used. In microsurgery and video endosurgery, a “croquet” loop can be used (Fig. 94).

Rice. 94. Formation of the Aberdeen croquet loop.

2. Formation of loops (extracorporeal or intracorporeal) at some distance from the level of the wound, followed by reduction to the suture line. This technique can be performed using either conventional technology, and through the education of the so-called
sliding loop (Fig. 95).

Rice. 95. Sliding loops formed on the basis of standard knots: 1 - female, 2 - marine, 3 - surgical.

To connect the tightly elastic edges of the wound, you can use an original multi-turn loop (Fig. 96).

Rice. 96. Multi-turn sliding loop: 1 - loop formed at a distance from the edge of the wound, 2 - tightening the loop at the edge of the wound.

In surgery, there is a wary attitude towards sliding loops, which are the basis of the technique of remote node formation. This is due to the high probability of their weakening.

However, in a number of cases the use of sliding loops is advisable and necessary:
to bring the knot down to the bottom of a deep wound;
when using microsurgical equipment;
in performing operations using video endosurgical methods.

Methods for bringing down sliding loops

1. To the bottom of a deep wound with the distal phalanx of the finger (Fig. 97) or Vinogradov’s stick.

Rice. 97. Reduction of the sliding loop by the distal phalanx of the finger.

2. In video endosurgery, sliding loops can be formed both intracorporeally and extracorporeally. The methods for bringing them down depend on the type of loop.

In Fig. 98 presented various options bringing down sliding loops:

Rice. 98. Methods of bringing down sliding loops (explanations in the text).

Rice. 98 (continued).

Using a Vinogradov wand when using “open” access (1);
using Clark's fork: an extracorporeal method of forming a loop with
subsequent reduction, used in video endosurgery (2);
using a standard pusher: bringing down the extracorporeal loops of Roeder (3) and Melz (4) - in video endosurgery;
using remote manipulators: delivery of extracorporeally formed Dandy loops (5) and “anchor” loops (6) into the abdominal or thoracic cavity in video endosurgery.

Methods for tightening loops to form a knot

1. Directly tighten the loops after applying each suture to a linear wound with elastic edges (Fig. 99).

Rice. 99. Securing the ends of the thread with knots immediately after applying each seam.

The use of this method requires the following conditions:
constancy of the elastic-elastic properties of the wound throughout;
wound length no more than 8-12 cm;
linear shape of the wound.

2. Sequential tying of knots of all previously applied sutures when strengthening the hernial orifice of the anterolateral abdominal wall or applying pleuromuscular sutures (Fig. 100).

Rice. 100. Sequential tying of previously applied sutures to connect the edges of the chest wall wound.

3. Step-by-step tying of support sutures to connect the edges of a complex-shaped wound (Fig. 101).

Rice. 101. Use of support sutures to better adapt the edges of a wound of complex shape, followed by suturing the spaces between them.

G.M. Semenov, V.L. Petrishin, M.V. Kovshova

A surgical feeder knot will help the angler while fishing. It is quite simple, universal, and although often not the best choice, you can master and apply it quickly enough. Used for tying two fishing lines, tying a shock leader and tying loops.

This knot, as the name suggests, was first used in medicine by surgeons. It is used to tie two suture threads together during surgery, as well as to secure the thread at the beginning of the suture. This knot must be simple and very reliable, since if the seam comes apart, the consequences can be very tragic. It is used at the beginning and end of a seam, as well as for tying two threads. Many medical schools recommend that surgeons, especially beginners, use this unit exclusively.

How to tie two threads with a simple surgical knot

The easiest way to master this knot is with two ropes. When you begin to understand what and how to do, it’s easier to switch to fishing line, braided cord or other materials. The knot used for two threads can be easily transferred to loops. The knitting sequence is as follows:

• Take two ends of the ropes, one in left hand, the other - to the right
• Two ropes are twisted together to form something like a spiral. For a high-quality assembly you need to make at least four turns.
• Then the ends of the ropes are placed on top of each other to form a loop between the spiral and the ends.
• One of the ends is passed into this loop. It is better to do this twice, but the knot on the ropes will hold even after one pass.
• By pulling the ends, the knot is tightened.

The result should be a fairly strong and simple connection.

How to fix the thread at the base of a surgical suture

Of course, this has an indirect relation to fishing. However, in order to tie a swivel at the end of a fishing line, and for other purposes, it is quite suitable. A description will be given of how to make a fixation using your hands. Experienced surgeons do everything using available tools - clamps, tweezers. This is one of the main advantages of such a knot - the ability to make it using a tool, but more on that later. The use of the instrument saves the surgeon’s fingers from being pricked, which saves the doctor from infections when performing operations on patients, for example, HIV or tuberculosis, and also by minimizing contact with large-area surfaces such as gloves to reduce the likelihood of introducing microbes from outside into the treated wound.

• At the beginning of the suture, the surgeon threads the needle through the edges of the wound.
• He then makes a loop, which he crosses on his finger, placing one end of the thread over the other.
• After this, one end of the thread is passed through the loop several times.
• A loop is formed, and it tightens, tightening the edges of the wound.
• Then make another loop on top, passing one end of the thread into it and tightening it. It secures the knot from unraveling quite reliably.

Expert opinion

Chashchin Pavel

Federation of Fishing Sports of the Moscow Region

Ask a question to an expert

This type of knot is used by all surgeons, without exception, at least once in their practice.

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The main parameters of the clinical characteristics of knots used in surgery are reliability, strength, knot volume (amount of suture material) and complexity of formation.

The ability of a node to perform its functions (maintain tissue contact) for the entire time required to form a durable scar is called the reliability of the node in surgery. In addition, one of the most significant parameters for the characteristics of a knot is its strength - the maximum possible limit of the influence of the force acting on the knot from the connected tissues, without leading to its destruction. In turn, the breaking of the thread in the knot occurs under the influence of a force greater than the force required to break the thread without a knot.

The volume of a node is a characteristic that determines the possibility of complications occurring in the postoperative period due to the presence of foreign material in the wound. The smaller the volume of the node, the lower the risk of tissue reaction to the presence of suture material.

The difficulty of forming a node depends on the manual skills of the surgeon. Long training sessions will help to neglect this obstacle to the use of this unit.
Here are brief clinical characteristics of the nodes most commonly used in surgery.

Two loop knots

Simple (female) knot. Knot characteristics: a simple crossed knot of two loops (Fig. 8.1).

Rice. 8.1 Structure of the female knot

The knot consists of two identical crossed loops. It is formed by tying loops made in the same way with one hand. This is the simplest of all surgical knots. The advantage of the female knot is the ability to tighten the knot after the formation of the second loop is completed. However, the reliability of the female knot is very low - it slides along the thread even when matching fabrics with little tension. Therefore, the name “killer node” was assigned to it. The surgeon must remember this and not use it in practice.
Knot. Knot characteristics: a simple parallel knot of two loops (Fig. 8.2).

Rice. 8.2 Structure of the maritime hub

A sea knot is formed from two multidirectional (counter) intertightening loops - right and left.

This is an ideal knot for silk threads. The use of synthetic monofilament suture materials with a reduced coefficient of friction revealed the disadvantages of this knot - slipping along the thread, a tendency to unravel. This is especially evident when using threads soaked in blood or when the tissue being stitched is under significant tension. Therefore, surgeons began to treat the maritime knot more carefully. Although the sea knot is more reliable than the female knot, it is better to refrain from using it during operations, since there is no sufficient guarantee of the reliability of its existence.

Surgical node. Characteristics of the knot: a complex parallel knot consisting of two loops with double interlacing of the threads of the first loop (Fig. 8.3). During its formation, two outcomes are possible: the formation of both female and maritime nodes, with their inherent advantages and disadvantages.

Rice. 8.3 Structure of the surgical unit

The surgical knot is one of the most common knots.

The undoubted advantage of the surgical unit is its high degree of reliability. It is very convenient when tying, since the first loop, thanks to the double interlacing of the threads, does not allow the adjacent tissues to separate during manipulation. At the same time, the use of the first complex loop, in addition to its advantages, also determines the disadvantages of the surgical knot. When tightening the first loop, the possibility of fraying the thread is not excluded. In addition, the use of synthetic monofilament sutures with a smooth surface increases the risk of untying the surgical knot. Especially if it is formed with a rather thick, rigid thread.

In this case, the length of the double weave of the first loop is greater than the length of the single weave of the second loop, which determines its insufficient fastening properties. When the knot is tightened, the double weave is deformed, and the knot is subject to the elastic force of not only the fabrics, but also the elastic force of the thread in the weave of the first loop. The discrepancy between the strength characteristics of the first (complex) and second (simple) loops leads to destabilization of the knot.

Most often, the surgical knot is untied when using monofilament threads, as well as threads with a coating that increases their sliding properties. In this regard, to form this type of knot it is preferable to use threads with a high coefficient of friction.

You can prevent the knot from untying by adding a third simple safety (“stopping”) loop.

The surgical knot, like other complex knots to which it belongs, is best not used for applying ligatures to small vessels. When ligating a vessel using a surgical knot, the ratio of the length of the weave to the diameter of the vessel should be assessed. A thick thread ligature applied to a small vessel will almost certainly fail and slip off its stump in the postoperative period. You should be guided by the principle - the thicker the vessel, the thicker the thread it is necessary to ligate it.

Academic node. Characteristics of the knot: a complex parallel knot of two loops with two weaves in both loops (Fig. 8.4). This knot can also be in simple (female) and nautical versions.

Rice. 8.4 Structure of the academic node

The equal length of the weave of both loops in an academic knot removes the basis for the “internal conflict” described for uneven knots. The advantages of the knot, assessed by surgeons, are strength, maximum reliability, and ease of tying. In this case, during the formation of the second loop, the first loop does not unravel, and therefore the knot can usually be used without a third safety loop. In addition, it is characterized by the stability of the listed properties, regardless of the nature of the suture material. The strength of the academic knot turned out to be comparable to the strength of knots consisting of three loops, with undoubtedly less consumption of suture material for the formation of the academic knot.

Restrictions on the use of an academic knot are associated with the relative difficulty of tying it and the large volume of the knot. The knot should not be used to stop bleeding from small-diameter vessels due to the large lumen of the first loop.

The described advantages of the academic knot motivate the gradual replacement of the currently widely used surgical knot.

Barkov knot. Characteristics of the knot: a simple parallel double-ring knot consisting of two loops. The first (inner) of them consists of a double thread, and the outer one - of a single thread (Fig. 8.5).

Rice. 8.5 Structure of the Barkov knot

The main purpose of the knot is the ligation of deep-lying large vessels, as well as ligation of vessels en massae. It can be very useful for comparing low-elastic tissues of significant thickness, for example, when applying a suture to bones or soft tissues in the fronto-parietal-occipital region.

When matching fabrics under tension, the first two-ring loop is more secure than a regular single-ring loop. It creates the possibility of very close comparison of fabrics. In addition, when tying the second loop of the knot, the first loop remains stable. Such a knot practically cannot be untied on its own.

The disadvantages of the Barkov knot are the high consumption of suture material and the significant time required to form the knot.

A sliding knot of two loops. Characteristics of the knot: a simple sliding knot of two loops (Fig. 8.6). By tightening the ends of the threads of a two-loop knot in the wrong direction, you can get both loops asymmetrical, that is, a slip knot is formed. In such a knot, the loops are strung on the main thread. The two-loop slip knot is very unreliable and therefore very dangerous.

Rice. 8.6 Structure of a sliding knot made of two heifers

A turned knot of two loops. By tightening the first loop correctly and the second with a twist (asymmetrically), you can get a rotated knot (Fig. 8.7). Given its unreliability, it is necessary to completely exclude it from the surgeon’s arsenal. An offset knot of two loops. If the first loop in the knot is asymmetrical (tightened in the wrong direction), and the second is symmetrical, then a displaced knot is formed (Fig. 8).

Rice. 8.7 Structure of a turned knot of two loops

Rice. 8.8 Structure of an offset knot of two loops

Under the influence of tissue tension in the postoperative period, the displaced node rotates, which leads to deterioration of tissue fixation. A displaced knot can also transform into a sliding knot, which can subsequently lead to its rapid untying.