Collateral blood flow in the lower extremities treatment. Anterior jugular vein

– blood pressure gradient above and below the narrowed section of the vessel;

– accumulation in the ischemic zone of biologically active substances with a vasodilating effect (adenosine, acetylcholine, Pg, kinins, etc.);

– activation of local parasympathetic influences (promoting the expansion of collateral arterioles);

– high degree of development vascular network(collaterals) in the affected organ or tissue.

Organs and tissues, depending on the degree of development of arterial vessels and anastomoses between them, are divided into three groups:

– with absolutely sufficient collaterals: skeletal muscles, intestinal mesentery, lungs. In them, the total lumen of the collateral vessels is equal to or greater than the diameter of the main artery. In this regard, cessation of blood flow through it does not cause severe tissue ischemia in the region of blood supply to this artery;

– with absolutely insufficient collaterals: myocardium, kidneys, brain, spleen. In these organs, the total lumen of the collateral vessels is significantly less than the diameter of the main artery. In this regard, its occlusion leads to severe ischemia or tissue infarction.

– with relatively sufficient (or, which is the same thing: with relatively insufficient) collaterals: the walls of the intestines, stomach, bladder, skin, adrenal glands. In them, the total lumen of the collateral vessels is only slightly smaller than the diameter of the main artery. Occlusion of a large arterial trunk in these organs is accompanied by a greater or lesser degree of ischemia.

Stasis: a typical form of regional circulatory disorder, characterized by a significant slowdown or cessation of blood and/or lymph flow in the vessels of an organ or tissue.

What is collateral circulation

What is collateral circulation? Why do many doctors and professors focus on the important practical significance this type of blood flow? Blockage of the veins can lead to a complete blockage of blood movement through the vessels, so the body begins to actively look for the possibility of supplying liquid tissue through lateral routes. This process is called collateral circulation.

The physiological characteristics of the body make it possible to supply blood through vessels that are located parallel to the main ones. Such systems are called collaterals in medicine, which Greek language translated as "devious". This function allows you to pathological changes, injuries, surgical interventions, ensure uninterrupted blood supply to all organs and tissues.

Types of collateral circulation

In the human body, collateral circulation can have 3 types:

Absolute or sufficient. In this case, the sum of collaterals that will slowly open is equal to or close to the main vessels. Such lateral vessels perfectly replace pathologically altered ones. Absolute collateral circulation is well developed in the intestines, lungs and all muscle groups.
Relative, or insufficient. Such collaterals are located in the skin, stomach and intestines, and bladder. They open more slowly than the lumen of a pathologically altered vessel.
Insufficient. Such collaterals are unable to completely replace the main vessel and allow blood to fully function in the body. Insufficient collaterals are located in the brain and heart, spleen and kidneys.

As medical practice shows, the development of collateral circulation depends on several factors:

individual structural features vascular system;
the time during which the blockage of the main veins occurred;
age of the patient.

It is worth understanding that collateral circulation develops better and replaces the main veins at a young age.

How is the replacement of the main vessel with a collateral one assessed?

If the patient has been diagnosed with serious changes in the main arteries and veins of the limb, the doctor assesses the adequacy of the development of collateral circulation.

To give a correct and accurate assessment, the specialist considers:

metabolic processes and their intensity in the limbs;
treatment option (surgery, medications, and exercises);
the possibility of full development of new pathways for the full functioning of all organs and systems.

The location of the affected vessel is also important. It will be better to produce blood flow at an acute angle of departure of the branches of the circulatory system. If you choose an obtuse angle, the hemodynamics of the vessels will be difficult.

Numerous medical observations have shown that for the full opening of collaterals, it is necessary to block the reflex spasm in the nerve endings. Such a process may occur because when a ligature is applied to an artery, irritation of the semantic nerve fibers occurs. Spasms can block the full opening of the collateral, so such patients are given novocaine blockade of the sympathetic nodes.

SHEIA.RU

Collateral Circulation

The role and types of collateral circulation

The term collateral circulation implies the flow of blood through the lateral branches into the peripheral parts of the limbs after blocking the lumen of the main (main) trunk. Collateral blood flow- an important functional mechanism of the body, due to the flexibility of blood vessels and responsible for uninterrupted blood supply to tissues and organs, helping to survive myocardial infarction.

The role of collateral circulation

Essentially, collateral circulation is a roundabout lateral blood flow that occurs through the lateral vessels. Under physiological conditions, it occurs when normal blood flow is obstructed, or in pathological conditions - wounds, blockage, ligation of blood vessels during surgery.

The largest ones, taking on the role of a switched off artery immediately after blockage, are called anatomical or preceding collaterals.

Groups and types

Depending on the localization of intervascular anastomoses, previous collaterals are divided into the following groups:

In-system - shortcuts roundabout circulation, that is, collaterals that connect the vessels of the large arteries.
Intersystem - roundabout or long paths that connect the basins of different vessels with each other.

Collateral circulation is divided into types:

Intraorgan connections are intervascular connections within a separate organ, between muscle vessels and the walls of hollow organs.
Extraorgan connections are connections between the branches of the arteries that supply a particular organ or part of the body, as well as between large veins.

For strength collateral blood supply the following factors influence: the angle of departure from the main trunk; diameter of arterial branches; functional state of blood vessels; anatomical features lateral anterior branch; the number of lateral branches and the type of their branching. An important point for volumetric blood flow is the state in which the collaterals are: relaxed or spasmodic. The functional potential of collaterals is determined by regional peripheral resistance and general regional hemodynamics.

Anatomical development of collaterals

Collaterals can exist both under normal conditions and develop again during the formation of anastomoses. Thus, a disruption of the normal blood supply caused by some obstruction in the path of blood flow in a vessel involves already existing blood bypasses, and after that new collaterals begin to develop. This leads to the fact that the blood successfully bypasses the areas in which the patency of the vessels is impaired and the impaired blood circulation is restored.

Collaterals can be divided into the following groups:

sufficiently developed, characterized by wide development, the diameter of their vessels is the same as the diameter of the main artery. Even complete closure of the main artery has little effect on the blood circulation of such an area, since anastomoses fully replace the decrease in blood flow;
insufficiently developed ones are located in organs where intraorgan arteries interact little with each other. They are usually called ring ones. The diameter of their vessels is much smaller than the diameter of the main artery.
relatively developed ones partially compensate for impaired blood circulation in the ischemic area.

Diagnostics

To diagnose collateral circulation, you first need to take into account the speed metabolic processes in the limbs. Knowing this indicator and competently influencing it using physical, pharmacological and surgical methods, you can maintain the viability of an organ or limb and stimulate the development of newly formed blood flow pathways. To do this, it is necessary to reduce the tissue consumption of oxygen and nutrients supplied by the blood, or to activate collateral circulation.

What is collateral blood flow?

Clinical and topographic anatomy also studies such an important issue as collateral circulation. Collateral (roundabout) blood circulation exists under physiological conditions during temporary difficulties in blood flow through the main artery (for example, when vessels are compressed in areas of movement, most often in the joint area). Under physiological conditions, collateral circulation occurs through existing vessels running parallel to the main ones. These vessels are called collaterals (for example, a. collateralis ulnaris superior, etc.), hence the name of the blood flow - “collateral circulation”.

Collateral blood flow can also occur in pathological conditions - with blockage (occlusion), partial narrowing (stenosis), damage and ligation of blood vessels. When blood flow through the main vessels becomes difficult or stops, blood rushes through anastomoses into the nearest lateral branches, which expand, become tortuous, and gradually connect (anastomose) with existing collaterals.

Thus, collaterals exist under normal conditions and can develop again in the presence of anastomoses. Consequently, in case of a disorder of normal blood circulation caused by an obstacle to the blood flow in a given vessel, the existing bypass blood paths, collaterals, are first turned on, and then new ones develop. As a result, blood bypasses the area with impaired vessel patency and blood circulation distal to this area is restored.

To understand collateral circulation, it is necessary to know those anastomoses that connect the systems various vessels, through which collateral blood flow is established in case of injury and ligation or during development pathological process leading to blockage of the vessel (thrombosis and embolism).

Anastomoses between the branches of large arterial highways that supply the main parts of the body (aorta, carotid arteries, subclavian, iliac arteries, etc.) and representing, as it were, separate vascular systems are called intersystem. Anastomoses between the branches of one large arterial line, limited to the limits of its branching, are called intrasystemic.

No less important are anastomoses between systems of large veins, such as the inferior and superior vena cava, portal vein. Much attention is paid to the study of anastomoses connecting these veins (cavo-caval, portocaval anastomoses) in clinical and topographic anatomy.

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Ultrasound scanner, Doppler: Ultrasound Dopplerography of the lower extremities

Portable ultrasound scanner with color and power Doppler

Ultrasound Dopplerography of the lower extremities

(Selected chapter from the Educational and Methodological Manual "CLINICAL DOPPLEROGRAPHY OF OCCLUSING LESIONS OF THE ARTERIES OF THE BRAIN AND LIMB". E.B. Kuperberg (ed.) A.E. Gaidashev et al.)

1. Anatomy - physiological characteristics structure of the arterial system of the lower extremities

The internal iliac artery (IIA) supplies blood to the pelvic organs, perineum, genitals, and gluteal muscles.

The external iliac artery (EIA) supplies blood to the hip joint and the head of the femur. The direct continuation of the IFA is the femoral artery (FA), which arises from the IFA at the level of the middle third of the inguinal ligament.

The largest branch of the BA is the deep femoral artery (DFA). It plays a major role in the blood supply to the thigh muscles.

The continuation of the BA is the popliteal artery (PclA), which begins 3-4 cm above the medial epicondyle of the femur and ends at the level of the neck of the fibula. The length of PklA is approximately cm.

Fig.82. Scheme of the structure of the arterial system of the upper and lower extremities.

The anterior tibial artery, having separated from the popliteal, runs along the lower edge of the popliteal muscle to the gap formed by it with the neck of the fibula on the outside and the posterior tibial muscle on the bottom.

Distal to the PTA is in the middle third of the leg between the long extensor muscle thumb and tibialis anterior muscle. On the foot, the PTA continues into the dorsalis pedis artery (terminal branch of the PTA).

The posterior tibial artery is a direct continuation of the PclA. Behind the medial malleolus, midway between its posterior edge and the medial edge of the Achilles tendon, it passes to the base of the foot. The peroneal artery departs from the PTA in the middle third of the leg, supplying blood to the muscles of the leg.

Thus, the direct source of blood supply to the lower extremity is the IPA, which passes into the femoral ligament below the Pupart ligament, and three vessels provide blood supply to the lower leg, two of which (PTA and PTA) supply blood to the foot (Fig. 82).

Collateral circulation in lesions of the arteries of the lower extremities

Occlusive lesions of various segments of the arterial system of the lower extremities, like any other arterial systems, lead to the development of compensatory collateral circulation. The anatomical prerequisites for its development are inherent in the very structure of the arterial network of the lower limb. There are intrasystemic anastomoses, that is, anastomoses connecting the branches of one large artery, and intersystemic, that is, anastomoses between the branches of different vessels.

When the IPA is affected in any area up to the level of origin of its two branches - the inferior epigastric and deep, surrounding the ilium, collateral blood supply is carried out through intersystem anastomoses between the branches of these arteries and the IPA (iliopsoas, obturator, superficial and deep gluteal arteries) (Fig. 83).

Fig.83. Occlusion of the right IPA with filling of the BA through collaterals.

When the BA is affected, the branches of the GBA widely anastomose with the proximal branches of the PclA and constitute the most important roundabout path (Fig. 84).

When the PCL is damaged, the most important intersystem anastomoses are formed between its branches and the PTA (network of the knee joint). In addition, the branches of the PclA to the posterior group of muscles of the lower leg and its branches to the knee joint form a rich collateral network with the branches of the GBA. However, collateral flows in the PclA system do not compensate blood circulation as fully as in the BA system, since collateral compensation in any of the vascular systems with distal lesions is always less effective than with proximal ones (Fig. 85).

Fig.84. Occlusion of the right BA in the middle third with collateral flow through the branches of the GAB (a) and filling of the popliteal artery (b).

Fig.85. Distal damage to the arteries of the leg with poor collateral compensation.

The same rule corresponds to collateral compensation in case of damage to the tibial arteries. The terminal branches of the PTA and PTA are anastomosed on the foot widely through the planetary arch. The dorsum of the foot is supplied with blood terminal branches the anterior and plantar surfaces are branches of the posterior tibial arteries; between them there are numerous perforating arteries that provide the necessary compensation for blood circulation when one of the tibial arteries is damaged. However, distal involvement of the PCL branches often leads to severe ischemia that is difficult to treat.

The severity of ischemia of the lower limb is determined, on the one hand, by the level of occlusion (the higher the level of occlusion, the more complete collateral circulation) and, on the other hand, the degree of development of collateral circulation at the same level of damage.

2. Technique for examining the arteries of the lower extremities

Examination of patients using the Doppler ultrasound method is carried out using sensors with frequencies of 8 MHz (PTA and PTA branches) and 4 MHz (BA and PclA).

The technique for examining the arteries of the lower extremities can be divided into two stages. The first stage is the location of blood flow at standard points with obtaining information about its nature, the second stage is the measurement of regional blood pressure with the registration of pressure indices.

Location at standard points

Almost along the entire length, the arteries of the lower extremities are difficult to locate due to their great depth. There are several projections of vascular pulsation points, where the location of the blood flow is easily accessible (Fig. 86).

These include:

the first point in the projection of Scarp's triangle, one transverse finger medial to the middle of the Poupart ligament (point of the external iliac artery); the second point in the region of the popliteal fossa in the PclA projection; the third point is localized in the fossa formed anteriorly by the medial malleolus and posteriorly by the Achilles tendon (ATA);
the fourth point in the dorsum of the foot along the line between the first and second phalanges (terminal branch of the PTA).

Fig.86. Standard location points and Dopplerograms of the arteries of the lower extremities.

Locating blood flow at the last two points can sometimes present some difficulty due to the variability of the course of the arteries in the foot and ankle.

When locating the arteries of the lower extremities, Dopplerograms normally have a three-phase curve, characterizing the usual main blood flow (Fig. 87).

Fig.87. Dopplerogram of the main blood flow.

The first antegrade pointed high peak characterizes systole (systolic peak), the second retrograde small peak occurs in diastole due to retrograde blood flow towards the heart until the aortic valve closes, the third antegrade small peak occurs at the end of diastole and is explained by the occurrence of weak antegrade blood flow after blood is reflected from aortic valve leaflets.

In the presence of stenosis above or at the location, as a rule, an altered main blood flow is determined, which is characterized by a biphasic amplitude of the Doppler signal (Fig. 88).

Fig.88. Dopplerogram of altered main blood flow.

The systolic peak is flatter, its base is expanded, the retrograde peak may not be expressed, but is still most often present, there is no third antegrade peak.

Below the level of arterial occlusion, a collateral type of Dopplerogram is recorded, which is characterized by a significant change in the systolic peak and the absence of both retrograde and second antegrade peaks. This type of curve can be called monophasic (Fig. 89).

Fig.89. Dopplerogram of collateral blood flow.

Regional pressure measurement

The value of arterial systolic pressure, as integral indicator, is determined by the sum of potential and kinetic energy possessed by a mass of blood moving in a certain area of the vascular system. The measurement of arterial systolic pressure by ultrasound is, in essence, the registration of the first Korotkoff sound, when the pressure created by the pneumatic cuff becomes lower than the arterial pressure in a given section of the artery so that minimal blood flow appears.

To measure regional pressure in individual segments of the arteries of the lower limb, it is necessary to have pneumatic cuffs, essentially the same as for measuring blood pressure on the arm. Before starting the measurement, blood pressure is determined in the brachial artery, and then at four points in the arterial system of the lower limb (Fig. 90).

The standard cuff arrangement is as follows:

the first cuff is applied at the level of the upper third of the thigh; second - in lower third hips; the third - at the level of the upper third of the lower leg;
fourth - at the level of the lower third of the leg;

Fig.90. Standard arrangement of pneumatic cuffs.

The essence of measuring regional pressure is to register the first Korotkoff sound during sequential inflation of the cuffs:

the first cuff is designed to determine systolic pressure in the proximal BA; the second - in the distal part of the BA; the third - in PklA;
the fourth is in the arteries of the lower leg.

When recording blood pressure at all levels of the lower extremities, it is convenient to locate the blood flow at the third or fourth points. The appearance of blood flow, recorded by the sensor with a gradual decrease in air pressure in the cuff, is the moment of fixation of systolic blood pressure at the level of its application.

In the presence of hemodynamically significant stenosis or occlusion of the artery, blood pressure decreases depending on the degree of stenosis, and in the case of occlusion, the degree of its decrease is determined by the severity of the development of collateral circulation. Blood pressure in the legs is normally higher than in the upper extremities, approximately 1mmHg.

The topical value of measuring blood pressure in the legs is determined by sequentially measuring this indicator over each of the arterial segments. Comparison of blood pressure figures gives a sufficient idea of the state of hemodynamics in the limb.

Greater objectification of measurement is facilitated by the calculation of the so-called. indices, that is, relative indicators. The most commonly used is the ankle pressure index (API), calculated as the ratio of arterial systolic pressure in the PTA and/or PTA to this indicator in the brachial artery:

For example, blood pressure at the ankle is 140 mmHg, and at the brachial artery, mmHg, therefore, LID = 140/110 = 1.27.

With an acceptable blood pressure gradient in the brachial arteries (up to 20 mmHg), the ADP is taken at a higher value, and with hemodynamically significant damage to both subclavian arteries, the LID value drops. In this case, the absolute numbers of blood pressure and its gradients between individual vascular segments become more important.

Normal LID is between 1.0 and 1.5 at any level.

The maximum fluctuation of the LID from the upper to the lower cuff is no more than 0.2-0.25 in one direction or another. An LID below 1.0 indicates an arterial lesion proximal or at the measurement site.

Scheme of examination of the arteries of the lower extremities

The patient is in the supine position (with the exception of the examination of PCL, which is located when the patient is positioned on his stomach).

The first step is to measure blood pressure in both upper extremities.

The second stage consists of sequential location of standard points with obtaining and recording Dopplerograms of the NPA, BA, PTA and PTA.

It should be noted that it is necessary to use a contact gel, especially when locating the dorsal artery of the foot, where the subcutaneous fat layer is quite thin, and location without creating a kind of “cushion” of gel can be difficult.

The frequency of the ultrasound sensor depends on the artery being located: when locating the external iliac and femoral arteries, it is advisable to use a sensor with a frequency of 4-5 MHz, when locating smaller PTA and PTA - with a frequency of 8-10 MHz. The sensor must be installed so that arterial blood flow is directed towards it.

To carry out the third stage of the study, pneumatic cuffs are applied to standard areas of the lower limb (see previous section). To measure blood pressure (with subsequent conversion to LID) in the IPA and BA, registration can be carried out at 3 or 4 points on the foot, when measuring blood pressure in the arteries of the leg - sequentially at both 3 and 4 points. Blood pressure measurements at each level are carried out three times, followed by selecting the maximum value.

3. Diagnostic criteria for occlusive lesions of the arteries of the lower extremities

When diagnosing occlusive lesions of the arteries of the lower extremities using Doppler ultrasound, the nature of blood flow in direct location of the arteries and regional blood pressure play an equal role. Only a combined assessment of both criteria allows an accurate diagnosis to be made. However, the nature of the blood flow (mainline or collateral) is still a more informative criterion, since with a well-developed level of collateral circulation, LID values can be quite high and mislead regarding damage to the arterial segment.

Isolated lesion of individual segments of the arterial network of the lower limb

With moderately severe stenosis that does not reach hemodynamic significance (from 50 to 75%), the blood flow in this arterial segment has an altered main character, proximal and distal (for example, for BA, the proximal segment is the IPA, the distal segment is the PCL), the nature of the blood flow is main, LID values do not change throughout the entire arterial system of the lower limb.

Occlusion of the terminal aorta

When the terminal aorta is occluded, collateral blood flow is recorded at all standard location points on both limbs. On the first cuff, LID is reduced by more than 0.2-0.3; on the remaining cuffs, LID fluctuations are no more than 0.2 (Fig. 91).

It is possible to differentiate the level of aortic damage only angiographically and according to duplex scanning data.

Fig.91. Occlusion abdominal aorta at the level of the origin of the renal arteries.

Isolated occlusion of the external iliac artery

When the IPA is occluded, collateral blood flow is recorded at standard location points. On the first cuff, LID is reduced by more than 0.2-0.3; on the remaining cuffs, LID fluctuations are no more than 0.2 (Fig. 92).

Isolated femoral artery occlusion

in combination with GAB damage

When the BA is occluded in combination with a lesion of the GAB, the main blood flow is recorded at the first point, and collateral at the other points. On the first cuff, LID is reduced more significantly due to the exclusion of GAB from collateral compensation (LID can decrease by more than 0.4-0.5); on the remaining cuffs, LID fluctuations are no more than 0.2 (Fig. 93).

Isolated occlusion of the femoral artery below the origin of the GAB

When the BA is occluded below the level of origin of the GAB (proximal or middle third), the main blood flow is recorded at the first point, collateral in the rest, as well as with occlusion of the BA and GAB, but the decrease in LID may not be as significant as in the previous case, and the differential diagnosis with an isolated lesion of the IPA is carried out based on the nature of the blood flow at the first point (Fig. 94).

Fig.94. Isolated occlusion of the BA in the middle or distal third

With occlusion of the middle or distal third of the BA at the first point there is a main blood flow, at the rest there is a collateral type, while the LID on the first cuff is not changed, at the second it is reduced by more than 0.2-0.3, at the rest - LID fluctuations are not more than 0.2 (Fig. 95).

Fig.95. Isolated occlusion of PCL

With PclA occlusion, the main blood flow is recorded at the first point, collateral at the rest, while the LID on the first and second cuff is not changed, on the third it is reduced by more than 0.3-0.5, on the fourth cuff the LID is approximately the same as on the third (Fig. 96).

Isolated occlusion of the arteries of the leg

When the arteries of the leg are damaged, the blood flow is not changed at the first and second standard points, at the third and fourth points there is collateral blood flow. The ankle pressure index does not change on the first, second and third cuffs and sharply decreases on the fourth by 0.5 -0.7, down to an index value of 0.1 -0.2 (Fig. 97).

Combined damage to segments of the arterial network of the lower limb

Interpretation of data in cases of combined lesions of the arterial network of the lower extremity is more difficult.

First of all, an abrupt decrease in LID (more than 0.2-0.3) below the level of each of the lesions is determined.

Secondly, a kind of “summation” of stenoses is possible with a tandem (double) hemodynamically significant lesion (for example, IAD and BA), while collateral blood flow can be recorded in a more distal segment, indicating occlusion. Therefore, it is necessary to carefully analyze the data obtained taking into account both criteria.

Occlusion of the IPA in combination with damage to the BA and peripheral bed

In case of occlusion of the IPA in combination with damage to the BA and peripheral blood flow, collateral blood flow is recorded at standard location points. On the first cuff, LID is reduced by more than 0.2-0.3; on the second cuff, LID is also reduced by more than 0.2-0.3 compared to the first cuff. On the third cuff, the difference in LID in comparison with the second is no more than 0.2; on the fourth cuff, a difference in LID of more than 0.2 -0.3 is again recorded (Fig. 98).

Occlusion of the BA in the middle third in combination with damage to the peripheral bed

With occlusion of the BA in the middle third in combination with damage to the peripheral bloodstream, the main blood flow is determined at the first point, at all other levels - collateral blood flow with a significant gradient between the first and second cuffs, on the third cuff the decrease in LID compared to the second is insignificant, and on the fourth cuff again is happening significant decrease LID up to 0.1-0.2 (Fig. 99).

PCL occlusion in combination with peripheral lesions

With PclA occlusion in combination with peripheral lesions, the nature of the blood flow is not changed at the first standard point; at the second, third and fourth points, the blood flow is collateral. The ankle pressure index does not change on the first and second cuffs and sharply decreases on the third and fourth by 0.5 -0.7 down to an index value of 0.1 -0.2.

Infrequently, but simultaneously with PclA, not both, but one of its branches are affected. In this case additional defeat this branch (ZTA or PTA) can be determined by separate measurement of the LID on each of the branches at points 3 and 4 (Fig. 100).

Thus, with combined lesions of the arteries of the lower extremity, various options are possible, but careful adherence to the research protocol will avoid possible errors in making a diagnosis.

Also, the task of more accurate diagnosis is met by the automated expert diagnostic system for determining the pathology of the arteries of the lower extremities “EDISSON”, which allows, based on objective indicators of the pressure gradient, to determine the level of damage to these arteries.

4. Indications for surgical treatment

Indications for reconstruction of the aortoiliac, aortofemoral, iliofemoral and femoropopliteal segments of the arteries of the lower extremities

Indications for reconstructive operations on the arteries of the lower extremities with damage to the aorto-femoral-popliteal zones are quite widely covered in domestic and foreign literature, and their detailed presentation is impractical. But it is probably worth recalling their main points.

Based on clinical, hemodynamic and arteriographic criteria, the following indications for reconstruction have been developed:

Graduation I: severe intermittent claudication in an active individual, negatively affecting work ability, inability to change lifestyle with an adequate assessment by the patient of the risk of surgery (chronic ischemia of the lower limbs, grade 2B-3, reducing the patient’s quality of life);

In general, indications for surgical treatment are determined individually, depending on age, concomitant diseases and the patient's lifestyle. Thus, a clinical picture of intermittent claudication even after meters without pain at rest and without trophic disorders is not yet an indication for surgery, if this situation does not reduce the patient’s “quality of life” (for example, moving mainly by car, mental work). There is also the exact opposite situation, when intermittent claudication over meters, but taking into account the patient’s specialty (for example, employment in the field of heavy physical labor) makes him incapacitated and gives indications for surgical reconstruction. However, in any case, surgical reconstruction should be preceded by medical treatment, including, along with vasoactive and antiplatelet drugs, smoking cessation and an anti-cholesterol low-calorie diet.

Graduation II: pain at rest, not responding to non-surgical treatment conservative treatment(chronic ischemia of the lower limbs stage 3, psychoasthenia);

Graduation III: A non-healing ulcer or gangrene usually limited to the toes or heel or both. Ischemic pain at rest and/or tissue necrosis, including ischemic ulcers or fresh gangrene, are indications for surgery if appropriate anatomical conditions exist. Age rarely acts as a reason for contraindications to reconstruction. Even elderly patients can undergo TLBAP along with drug treatment if surgical reconstruction is not possible due to somatic condition patient.

Indications for grade I are for functional improvement, grades II and III are for salvage of the lower limb.

The frequency of atherosclerotic lesions of the arteries of the lower extremities is different (Fig. 101). Most common cause chronic ischemia is damage to the femoral-popliteal (50%) and aorto-iliac zones (24%).

Types of operations used for surgical treatment chronic ischemia of the lower extremities is extremely diverse. The bulk of them are so-called. bypass operations, the main purpose of which is to create a bypass shunt between unchanged sections of the vascular bed above and below the area of arterial damage.

Fig. 101. Frequency of atherosclerotic lesions of the arteries of the lower extremities.

1- aorto-iliac, 2- femoral-popliteal, 3- tibial,

4 - iliofemoral, 5 - popliteal zones.

In accordance with the frequency of damage to the arteries of the lower extremities, the most frequently performed operations are femoral-popliteal bypass (Fig. 102) and aorto-femoral bifurcation (Fig. 103a) or unilateral (Fig. 103b) bypass. Other operations of direct and indirect revascularization of the arteries of the lower extremities are performed much less frequently.

Fig. 102. Scheme of the femoropopliteal bypass operation.

B Fig.103. Aorto-femoral bifurcation (a) and unilateral (b)

Transluminal balloon angioplasty of the arteries of the lower extremities

Like all treatments vascular diseases, indications for the use of TLBAP are based on clinical and morphological criteria. Of course, TLBAP is indicated only for “symptomatic” patients, that is, for those in whom damage to the arterial bed of the lower extremities is accompanied by the development of ischemic symptoms of varying severity - from intermittent claudication to the development of gangrene of the limb. At the same time, if for surgical reconstruction (see the previous section) the indications are strictly defined only for severe ischemia, and for intermittent claudication the issue is resolved individually, then for TLBAP clinical indications may be represented much more widely due to the lower risk of complications and mortality.

Serious complications during surgical treatment also occur very rarely, but nevertheless, the risk of complications with TLBAP, if all conditions of the procedure are met and the indications are correctly established, is even lower. Therefore, clinical indications for TLBAP should not only include patients with critical ischemia of the lower extremities (rest pain or arterial ischemic ulcers, incipient gangrene), but also patients with intermittent claudication, which reduces the quality of life.

Anatomical indications for TLBAP: ideal:

short stenosis of the abdominal aorta (Fig. 104); short stenosis involving the aortic bifurcation including the mouths of the common iliac arteries; short stenosis of the iliac artery and short occlusion of the iliac artery (Fig. 105); short single or multiple stenosis of the superficial femoral artery (Fig. 106a) or its occlusion of less than 15 cm (Fig. 106b);
short stenosis of the popliteal artery (Fig. 107).

Fig. 104. Angiogram of arterial stenosis.

Fig. 105. Angiogram of iliac abdominal aortic stenosis (arrow).

B Fig.106a. Angiograms of stenosis (a) and occlusion (b) of BA before and after TLBAP.

Fig. 107. Angiogram of popliteal artery stenosis.

Some types of lesions can also undergo TLBAP, but with lower efficiency than in the group of “ideal” patients:

prolonged stenosis of the common iliac artery;
short stenoses of the branches of the popliteal artery below the knee joint.

However, prolonged stenoses in the IAS and noncircular prolonged stenoses of the abdominal aorta may be indicated for TLBAP if there are serious contraindications for surgical reconstruction, although it should be emphasized again that the short-term and long-term effectiveness may be reduced.

Contraindications are based on anatomical considerations, but must always be weighed in light of the risk of TLBAP in relation to alternative procedures (surgical or medical treatment).

The following situations may be accompanied by low effectiveness and, most importantly, a high risk of complications with TLBAP:

prolonged occlusion of the iliac artery due to its tortuosity; iliac artery occlusion, but which clinically and/or angiographically can be suspected as thrombosis;
the presence of aneurysms, especially the iliac and renal arteries.

In some cases (relatively recent occlusion), targeted thrombolytic therapy can be effective, the use of which is advisable before TLBAP.

In the presence of calcium deposits at the site of stenosis, TLBAP may be risky due to possible dissection or rupture of the artery. However, the use of transluminal atherotomy has expanded the capabilities of the method and made it feasible in these situations.

An important aspect of the use of TLBAP is the possibility of combining this method with surgical treatment, including:

TLBAP of iliac artery stenosis before femoropopliteal bypass or other distal procedures; TLBAP restenosis;
TLBAP of existing shunts, but with a narrow thread-like lumen of the latter.

Thus, TLBAP can be used either as an alternative to surgical treatment, or as an aid to this type of treatment, or can be used before or after surgical treatment in a selectively selected group of patients.

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It is known that along its path the main artery gives off numerous lateral branches to supply blood to surrounding tissues, and the lateral branches of neighboring regions are usually interconnected by anastomoses.

In the case of ligation of the main artery, blood through the lateral branches of the proximal section, where high pressure is created, will be transferred, thanks to anastomoses, to the lateral branches of the distal artery, flowing through them retrogradely to the main trunk and then in the usual direction.

This is how bypass collateral arches are formed, in which they distinguish: adductor knee, connecting branch and abductor knee.

Adducting knee are the lateral branches of the proximal artery;

abductor knee– lateral branches of the distal artery;

connecting branch constitute anastomoses between these branches.

For brevity, collateral arches are often simply called collaterals.

There are collaterals pre-existing And newly formed.

Preexisting collaterals are large branches that often have anatomical designations. They are included in the collateral circulation immediately after ligation of the main trunk.

Newly formed collaterals are smaller branches, usually innominate, that provide local blood flow. They are included in the collateral circulation after 30-60 days, because it takes a lot of time to open them.

The development of collateral (roundabout) blood circulation is significantly influenced by a number of anatomical and functional factors.

TO anatomical factors include: the structure of the collateral arches, the presence of muscle tissue, the level of ligation of the main artery.

Let's look at these factors in more detail.

· Structure of collateral arches

It is customary to distinguish several types of collateral arches, depending on the angle at which they extend from main trunk lateral branches forming the adductor and abducens knees.

The most favorable conditions are created when the adductor knee moves away at an acute angle, and the abductor knee at an obtuse angle. Collateral arches in the area have this structure elbow joint. When the brachial artery is ligated at this level, gangrene almost never occurs.

All other options for the structure of collateral arches are less advantageous. Especially wives are not benefited by the type of structure of the collateral arches in the area of the knee joint, where the adducting branches depart from the popliteal artery at an obtuse angle, and the abducent branches at an acute angle.

That is why, when ligating the popliteal artery, the percentage of gangrene is impressive - 30-40 (sometimes even 70).

· Presence of muscle mass

This anatomical factor is important for two reasons:

1. Pre-existing collaterals located here are functionally advantageous, because accustomed to the so-called “game of blood vessels” (rather than vessels in connective tissue formations);

2. Muscles are a powerful source of newly formed collaterals.

The importance of this anatomical factor will become even more obvious if we consider the comparative figures for gangrene of the lower extremities. Thus, when the femoral artery is injured immediately under the Poupart ligament, ligation usually results in 25% gangrene. If the injury to this artery is accompanied by significant muscle damage, the risk of developing gangrene of the limb increases sharply, reaching 80% or higher.

Levels of artery ligation

They can be favorable for the development of circuitous circulation and unfavorable. In order to correctly navigate this issue, the surgeon must, in addition to a clear knowledge of the places where large branches originate from the main artery, have a clear understanding of the ways of development of the circuitous blood flow, i.e. know the topography and severity of collateral arches at any level of the main artery.

Consider, for example, the upper limb: slide 2 - 1.4% gangrene, slide 3 - 5% gangrene. Thus, ligation should be done within the most pronounced collateral arches

TO functional factors that influence the development of collaterals include: blood pressure indicators; spasm of collaterals.

Low blood pressure with large blood loss does not promote sufficient collateral circulation.

· Spasm of collaterals is, unfortunately, a companion to vascular injuries, associated with irritation of sympathetic nerve fibers located in the adventitia of blood vessels.

The surgeon’s tasks when ligating blood vessels:

I. Consider anatomical factors

Anatomical factors can be improved, i.e. influence the angles of origin of the lateral branches of the artery in order to create a favorable type of structure of the collateral arches. For this purpose, if the artery is incompletely damaged, it must be completely crossed; It is imperative to cross the artery when ligating it along its length.

It is economical to excise muscle tissue during PSO of a wound, because muscle mass is the main source of both pre-existing and newly formed collaterals.

Consider dressing levels. What does this mean?

If the surgeon has the opportunity to choose the site of ligation of the artery, then he must do this consciously, taking into account the topography and severity of the collateral arches.

If the level of ligation of the main artery is unfavorable for the development of collateral circulation, you should refuse ligature method stopping bleeding in favor of other methods.

II. Influence functional factors

In order to increase blood pressure, a blood transfusion should be performed.

In order to improve the blood supply to the tissues of the limb, it was proposed to introduce 200 ml of blood into the peripheral stump of the damaged artery (Leifer, Ognev).

Introduction of a 2% solution of novocaine into the paravasal tissue, which helps relieve spasm of collaterals.

Mandatory intersection of the artery (or excision of a section of it) also helps relieve spasm of collaterals.

Sometimes, in order to relieve spasm of the collaterals and expand their lumen, anesthesia (blockade) or removal of the sympathetic ganglia is performed.

Warming the limb (with heating pads) above the dressing level and cooling it (with ice packs) below.

This is the current understanding of collateral circulation and methods of influencing its improvement during artery ligation.

However, in order to complete our consideration of the issue of collateral circulation, we should introduce you to another method of influencing the bypass blood flow, which stands somewhat apart from the methods outlined earlier. This method is associated with the theory of reduced blood circulation, developed and experimentally substantiated by Oppel (1906 - 14).

Its essence is as follows (detailed commentary on the diagram of reduced blood circulation on an overhead projector).

By ligating the vein of the same name, the volume of the arterial bed is brought into correspondence with the venous one, some stagnation of blood is created in the limb and, thus, the degree of oxygen utilization by tissues increases, i.e. tissue respiration improves.

So, reduced blood circulation is blood circulation reduced in volume, but restored in the ratio (between arterial and venous).

Contraindications to the use of the method:

Vein diseases

Tendency to thrombophlebitis.

Currently, vein ligation according to Oppel is resorted to in cases where ligation of the main artery leads to a sharp pallor and coldness of the limb, which indicates a sharp predominance of blood outflow over inflow, i.e. insufficiency of collateral circulation. In cases where these signs are not present, it is not necessary to ligate the vein.

The term collateral circulation implies the flow of blood through the lateral branches into the peripheral parts of the limbs after blocking the lumen of the main (main) trunk. Collateral blood flow is an important functional mechanism of the body, due to the flexibility of blood vessels and is responsible for uninterrupted blood supply to tissues and organs, helping to survive myocardial infarction.

The role of collateral circulation

The largest ones, taking on the role of a switched off artery immediately after blockage, are called anatomical or preceding collaterals.

Groups and types

Depending on the localization of intervascular anastomoses, previous collaterals are divided into the following groups:

Intrasystemic - short paths of roundabout circulation, that is, collaterals that connect the vessels of the large arteries.
Intersystem - roundabout or long paths that connect the basins of different vessels with each other.

Collateral circulation is divided into types:

Intraorgan connections are intervascular connections within a separate organ, between muscle vessels and the walls of hollow organs.
Extraorgan connections are connections between the branches of the arteries that supply a particular organ or part of the body, as well as between large veins.

The strength of collateral blood supply is influenced by the following factors: the angle of departure from the main trunk; diameter of arterial branches; functional state of blood vessels; anatomical features of the lateral anterior branch; the number of lateral branches and the type of their branching. An important point for volumetric blood flow is the state in which the collaterals are: relaxed or spasmodic. The functional potential of collaterals is determined by regional peripheral resistance and general regional hemodynamics.

Anatomical development of collaterals

Collaterals can be divided into the following groups:

sufficiently developed, characterized by wide development, the diameter of their vessels is the same as the diameter of the main artery. Even complete closure of the main artery has little effect on the blood circulation of such an area, since anastomoses fully replace the decrease in blood flow;
insufficiently developed ones are located in organs where intraorgan arteries interact little with each other. They are usually called ring ones. The diameter of their vessels is much smaller than the diameter of the main artery.
relatively developed ones partially compensate for impaired blood circulation in the ischemic area.

Diagnostics

To diagnose collateral circulation, you first need to take into account the rate of metabolic processes in the extremities. Knowing this indicator and competently influencing it using physical, pharmacological and surgical methods, you can maintain the viability of an organ or limb and stimulate the development of newly formed blood flow pathways. To do this, it is necessary to reduce the tissue consumption of oxygen and nutrients supplied by the blood, or to activate collateral circulation.

GOU VPO SIBERIAN STATE MEDICAL UNIVERSITY

Department of Operative Surgery and Topographic Anatomy

A.A. Sotnikov, O.L. Minaeva.

COLLATERAL CIRCULATION

(methodological manual for students of medical universities)

Doctor of Medical Sciences, Professor of the Department of Operative Surgery and Topographical

Anatomy A.A. Sotnikov,

Resident O.L. Minaeva.

^ Collateral circulation, Tomsk, 2007. – 86 p., ill.

IN methodological manual The history of the emergence of collateral circulation, indications and basic rules for ligation of vessels throughout, the development of a roundabout outflow path when ligating the main arteries is presented.

Chapter 1. GENERAL PART…………………………………... 5

The concept of collateral circulation ………. 5

Life and work of V.N. Tonkov………………... 7

Development of the arterial system……………………. 17

Indications and rules for vascular ligation …………… 20

Chapter 2. COLLATERAL CIRCULATION

VESSELS OF INTERNAL ORGANS ………… 22

Collateral circulation of the brain…….. 23

Atherosclerosis coronary arteries …………………….. 26

Classification of atherosclerotic lesions

Coronary arteries……………………………………… 30

Coarctation of the aorta…………………………………………. 32

Collateral circulation of the lung vessels……. 38

Abdominal tonsillitis syndrome………………………………… 41

Collateral circulation of the kidney…………………. 49

Collateral circulation of the spleen……………… 51

Chapter 3. COLLATERAL CIRCULATION

VESSELS OF THE NECK AND UPPER LIMB……. 55

Collateral circulation of neck vessels………….. 56

1. Development of collateral circulation

after dressing a. carotidis communis…………... 56

after dressing a. carotidis externa………………… 57

Collateral circulation of the vessels of the upper

Limbs…………………………………………………………… 59
^

after dressing a. subclavia………………………59

2. Development of collateral circulation

after dressing a. axillaries………………………61
^

after ligation of a.brachialis……………………… 63

after dressing a. ulnaris et radialis…………….. 66

5.Collateral circulation of the hand………….. 67

Access to vessels upper limb ………………… 69

Ligations of the arteries of the upper limb……………….. 70

Chapter 4. COLLATERAL CIRCULATION

VESSELS OF THE LOWER LIMB ………………… 71

1. Development of collateral circulation

after dressing a. iliaca externa ………………….. 72
^

2. Development of collateral circulation

after dressing a.femoralis……………………….. 73

3. Development of collateral circulation

after ligation of the popliteal artery…………… 77
^

4. Development of collateral circulation

after ligation of the tibial artery……… 78

5. Collateral circulation of the foot………… 80

Access to the vessels of the upper limb…………………. 83

Scheme of development of collateral circulation during

Ligations of the arteries of the lower limb……………….. 85

Literature………………………………………………………. 86

^ CHAPTER I. GENERAL PART.

CONCEPT OF COLLATERAL CIRCULATION.

(Collateral circulation)

Collateral circulation is an important functional adaptation of the body, associated with the great plasticity of blood vessels, ensuring uninterrupted blood supply to organs and tissues.

It has long been noticed that when the vascular line is turned off, blood rushes along roundabout paths - collaterals, and nutrition to the disconnected part of the body is restored. The main source of development of collaterals is vascular anastomoses. The degree of development of anastomoses and the possibility of their transformation into collaterals determine the plastic properties (potential capabilities) of the vascular bed of a specific area of the body or organ. In cases where pre-existing anastomoses are not enough for the development of collateral circulation, new vessel formation is possible. Thus, there are two types of collaterals: some exist normally,

They have the structure of a normal vessel, others develop from anastomoses due to a disorder of normal blood circulation and acquire a different structure. However, the role of newly formed vessels in the process of compensating for impaired blood flow is very insignificant.

Collateral circulation is understood as a lateral, parallel flow of blood, which occurs as a result of obstruction of blood flow, which is observed during blockage, damage, wounds of a vessel, as well as ligation of vessels during surgery. Subsequently, the blood rushes through the anastomoses into the nearest lateral vessels, which are called collaterals. They, in turn, expand, their vascular wall is rebuilt due to changes in the muscular layer and elastic frame.

The difference between anastomoses and collaterals must be clearly defined.

^ Anastomosis – anastomosis, the connection between two different vessels or the connection of two vessels with a third, is a purely anatomical concept.

Collateral (collateralis) – the lateral, parallel path of the vessel along which the roundabout flow of blood occurs is an anatomical and physiological concept.

The circulatory system has enormous reserve capabilities and high adaptability to changed functional conditions. So, when applying ligatures to dogs on both carotid and vertebral arteries There was no noticeable disruption of brain activity. In other experiments on dogs, up to 15 ligatures were applied to large arteries, including the abdominal aorta, but the animals did not die. Of course, only ligation of the abdominal aorta above the beginning of the renal arteries was fatal, coronary arteries heart, mesenteric arteries and pulmonary trunk.

Vascular collaterals can be extraorgan and intraorgan. ^ Extraorgan collaterals are large, anatomically defined anastomoses between the branches of arteries supplying a particular part of the body or organ, or between large veins. There are intersystem anastomoses, which connect the branches of one vessel and the branches of another vessel, and intrasystemic anastomoses, formed between the branches of one vessel. Intraorgan collaterals are formed between the vessels of muscles, the walls of hollow organs, and in parenchymal organs. Vessels are also sources of development of collaterals subcutaneous tissue, perivascular and peri-nervous bed.

To understand the mechanism of collateral circulation, you need to know those anastomoses that connect systems of different vessels - for example, intersystem anastomoses are located between the branches of large arterial highways, intra-system - between the branches of one large arterial highway, limited by the limits of its branching, arteriovenous anastomoses - between the thinnest intraorgan arteries and veins. Blood flows through them, bypassing the microcirculatory bed when it is overfilled and, thus, forms collateral pathway, directly connecting arteries and veins, bypassing capillaries.

In addition, numerous components take part in collateral circulation. thin arteries and veins accompanying the main vessels in the neurovascular bundles and constituting the so-called perivascular and perivascular arterial and venous beds.

A major role in the development of collateral circulation belongs to the nervous system. Disruption of the afferent innervation of blood vessels (deafferentation) causes persistent dilatation of the arteries. On the other hand, preservation of afferent and sympathetic innervation makes it possible to normalize recovery reactions, and collateral circulation turns out to be more effective.

Thus, the pledge successful work The surgeon, when performing manipulations on blood vessels, is an accurate knowledge of the circuitous pathways of the blood circulation.

^ LIFE AND ACTIVITY OF VLADIMIR NIKOLAEVICH TONKOV.

The deep study of collateral circulation is associated with the name of the prominent Soviet anatomist Vladimir Nikolaevich Tonkov. His life and creative path cemented traditions together scientific activity N.I. Pirogova, P.F. Lesgafta, P.A. Zagorsky, along with whom V.N. Tonkov is deservedly considered one of the founders of Soviet functional anatomy.

V.N. Tonkov was born on January 15, 1872 in the small village of Kose, Cherdyn district, Perm province. In 1895 he graduated from the Military Medical Academy in St. Petersburg, receiving a doctor's diploma with honors. Tonkov became interested in a deep study of the structure of the human body in the 1st year, starting from the 3rd year, he especially diligently studied normal anatomy, was engaged in the manufacture of drugs, and from the 5th year he taught practical lessons in anatomy along with prosectors, participated in the reading of so-called “demonstrative lectures” on the anatomy of the perineum and the central nervous system.

Fig.1. Vladimir Nikolaevich Tonkov (1872 – 1954).

After graduating from the academy, he was assigned to a clinical military hospital, which gave Vladimir Nikolaevich a huge opportunity to improve himself at the department of normal anatomy.

In 1898 V.N. Tonkov successfully defended his dissertation for the degree of Doctor of Medicine on the topic “Arteries feeding the intervertebral nodes and spinal nerves of humans,” thanks to which he was sent to Germany for improvement.

Staying abroad and working in the laboratories of leading anatomists enriched V.N.’s knowledge. Tonkova in the field of histology, embryology, comparative anatomy. The two-year trip was marked by the publication of a number of works, the main place among which is the famous study on the development of the spleen in Amniota. Since the autumn of 1905, Vladimir Nikolaevich headed the department of anatomy at Kazan University, which served as the basis for his scientific direction (school) - a deep study of the circulatory system.

Vladimir Nikolaevich himself describes the beginning of his famous research on collateral circulation as follows:

“In the winter of 1894, in the dissection department of normal anatomy of the Military Medical Academy, regular classes on the vascular and nervous systems were held with 2nd year students. At that time, it was customary to inject arteries with a hot wax mass.

When the prosector Batuev began to dissect one of the limbs, it turned out that the mass had not penetrated into the femoral artery. It later turned out that the external iliac artery (and femoral) did not accept the mass because it was apparently ligated several years before the person’s death. The vessels of the other limb were completely normal. Professor Tarenetsky instructed Tonkov, a senior student working at the department, to examine this rare find, who made a report at the Surgical Society on the developed anastomoses and then published it.”

This study is interesting as the starting point from which the now widely known works of V.N. Tonkov and his schools on collateral circulation, representing a whole new doctrine about the vessel from the point of view of its dynamics. An ordinary person, having described the developed roundabout pathways, would limit himself to this, but Tonkov looked at this case from the field of pathology as an experiment set up by nature itself, and realized that without experiments on animals it is impossible to reveal the patterns of development of roundabout pathways leading to the restoration of blood flow in an anemic areas.

Under his leadership, collaterals developing in the limbs, walls of the body, internal organs, in the head and neck region, the amazing ability of the arteries to deep structural and functional changes, which occurs after a disruption of blood flow in the basins of all major highways of the animal’s body.

A detailed study of collaterals developing in animals, normally and when one or another arterial trunk is turned off,

Tonkov's school studied the most carefully. During operations on paired vessels, the arteries of the opposite side served as control; on an unpaired area or organ, a healthy object was used as a control. Through certain time the animal was killed, a thin injection of the vessels was made with a contrast mass, radiography and detailed preparation were used.

It was found that the transformation of an insignificant artery into a powerful trunk of significant diameter with a thick wall occurs during the phenomena of cell reproduction and growth of tissues that make up the vessel wall.

First, destruction processes occur: under the influence of increased blood pressure and faster blood flow, the expanding artery cannot withstand it, and both the intima and elastic membranes are disrupted, which are torn to pieces. As a result, the vessel wall is relaxed and the artery expands. Subsequently, tissue regeneration occurs, and the active role here belongs to the subendothelium. Intima is restored; in it and in the adventitia there is rapid hyperplasia of collagen fibers and new formation of elastic fibers. A very complex restructuring of the vascular wall is taking place. From a small muscular artery a large vessel with a thickened wall of a unique structure is formed.

The roundabout tracts develop both from previous vessels and from newly formed collaterals, in which initially there are no distinct outer membranes, and then a thick subepithelial layer is found, a relatively thin muscular layer and the outer one reaches significant thickness.

Of primary importance in the matter of the main sources collaterals develop in muscle arteries, to a lesser extent in skin arteries, then in nerve arteries and vasa vasorum.

The attention of Tonkov's students was attracted by the study of the phenomenon vascular tortuosity , which normally was quite rare, but with the development of collaterals it always happened, especially long after the operation. Normally, the arteries go to the organs in the shortest, often direct way, they do not twist (the exceptions are a. ovarica, a. testicularis in the caudal section, aa. umbilicales of the fetus, branches of the a. uterine during pregnancy - this is undoubtedly a physiological phenomenon) . This is a general law.

Tortuosity is a constant phenomenon for arterial anastomoses developing in muscles, skin, along nerves, in the wall of large vessels (from vasa vasorum). Lengthening of arteries and the formation of bends negatively affects the nutrition of the corresponding organ.

The development of tortuosity of collaterals can be imagined in the following way: when the line is turned off, the effect of blood flow (change in pressure and speed) on the collaterals of a given area changes dramatically, their wall is radically rebuilt. Moreover, at the beginning of the restructuring, the phenomena of destruction are expressed, the strength of the wall and its resistance to blood flow weakens, and the arteries spread out in width, lengthen and become tortuous (Fig. 2).

Lengthening of the arteries and the formation of tortuosity are phenomena that impede the supply of blood to the corresponding organs and impair their nutrition; this is a negative side. As positive points An increase in the diameter of the roundabout tracts and a thickening of their walls were noted. Ultimately, the formation of tortuosity leads to the fact that the amount of blood brought by collaterals to the area where the line is turned off gradually increases and after a certain period of time reaches the norm.

^ Fig.2. Development of tortuosity of the collateral vessel.

(A– collateral vessel in calm state, B– blockage of the main trunk of the artery is indicated and working condition collateral vessel).

Thus, the collateral, as a formed vessel, is characterized by uniform expansion of the lumen throughout the entire anastomosis, coarsely wavy tortuosity and transformation of the vascular wall (thickening due to elastic components).

In other words, the tortuosity of collaterals is a very

unfavorable and it occurs as a result of relaxation of the vessel wall and stretching it in the transverse and longitudinal direction.

Highlight persistent tortuosity, which develops over a long period of time (months, years) due to complex changes in the structure of the arterial wall and persists after death. AND transient tortuosity, in which changes in the structure of the arterial wall have barely begun, the vessel is somewhat stretched, this is a process of a functional nature rather than a morphological one: when the artery is under the influence of increased blood pressure, tortuosity is pronounced; As pressure decreases, tortuosity decreases.

It is impossible not to take into account a number of points that influence the process of development of collaterals:

1 – number of anastomoses in this area;

2 – the degree of their normal development, length, diameter, thickness and wall structure;

3 – age-related and pathological changes;

4 – state of vasomotors and vasa vasorum;

5 – blood pressure and blood flow speed in the collateral system;

6 – wall resistance;

7 – nature of the intervention – excision, ligation of the line, complete or incomplete cessation of blood flow in it;

8 – period of development of collaterals.

The study of anastomoses is undoubtedly of great interest: it is important for the surgeon to know in what ways and to what extent blood circulation is restored after the operation he performed, and from a theoretical point of view it is necessary to find out to what extent certain arteries can replace each other and what anastomoses are the most profitable.

It is interesting to note Tonkov's study of the development of anastomoses after ligation of a. iliaca externa.

Winter 1985 The Academy Museum received a limb from the preparation room for detailed examination (due to the fact that A. iliaca externa did not accept the injection mass).

After an additional injection of cold Teichmann mass (chalk, ether, linseed oil) through the anterior tibial artery, it turned out that only some small anastomoses on the knee were filled.

A. iliaca externa was a cluster of very dense connective tissue (Fig. 3A, 12) 3.5 cm in diameter, and its continuation was a. femoralis also represented connective tissue and in diameter was equal to 7 mm. In his studies, Tankov measured the diameter of the arteries after injection with a compass, showing an increase of 2 or more times. Thus, the diameter of a.hypogastrica with a norm of 6 mm reached 12 mm, and its branch - a.glutea superior 3 mm reached 9 mm. The main trunk of a.glutea superior goes upward and is divided into two branches: the larger one (Fig. 3. B, 2) penetrates into the thickness of m. glutea minimus, runs along the bone and appears on the outside of the beginning of m.rectus femoris, then passing into the ascending branch of a. circumflexa femoris lateralis, thus connecting the a.hypogastrica and a.profunda femoris systems.

Another branch (Fig. 3.B,1) through its smaller branches flows into the one described above large branch a.glutea superior.

The branches of a.glutea inferior also anastomose with the a.profunda femoris system: the first (Fig. 3 B. 4), giving off branches along the way to the adjacent muscles, passes into a. circumflexa femoris medialis. Second branch

(Fig. 3, B 17) is divided into two branches, one of which, twisting strongly, turns into a. communis n. ischiadicus (Fig. 3. B 14), and the other goes into a. perforantes, a. The profunda femoris strongly twists along its path, gives off branches to the adjacent muscles, and at the level of the upper edge of the femoral condyles flows into a. poplitea.

The figure shows that instead of the usual pathways (a.iliaca communis, a. iliaca externa, a. femoralis, a. poplitea), blood flows mainly through a.iliaca communis, a.hypogastrica, a.glutea superior, a. circumflexa femoris lateralis, a. profunda femoris, a. poplitea.

^ Rice. 3.Development of collateral circulation after ligation a. iliaca externa.

A – view of anastomoses on the anterior surface of the thigh and pelvis.

1 – a. iliaca communis, 2 – a. iliaca interna, 3 – a. glutea inferior 4 – a. pudenda interna, 5 – connective tissue mass under the ligament of the pupart, 6 – a. сir-cumflexa femoris medialis, 7 – a. profunda femoris, 8 – a. femoralis, 9 –r. descen-dens a. circumflexa femoris lateralis, 10 –r. ascendens a. circumflexa femoris lateralis, 11 – a. obturatoria, 12 – a. iliaca externa, 13 – a. iliolumbalis.

B - view of anastomoses on the back of the thigh and pelvis.

1, 2 – branches a. glutea superior 3 - a. glutea superior 4 –r. a. glutea inferior 5, 6 –r. a.perforantis, 7 - a.perforantis secunda, 8 – anastomoses between a.perforantis secunda and a. profunda femoris, 9 – n. peroneus, 10 – n. tibialis, 11 – a. poplitea, 12 – a. com-munis n.tibialis, 13 – a. femoralis, 14 – a. communis n. ischiadicus, 15 - a. circumflexa femoris medialis, 16 – n. ischiadicus, 17 –r. a. glutea inferior 18 - a. glutea inferior.

Tonkov's school managed to establish a connection between the nervous system and the development of collateral circulation. I.D. The lion cut the dogs' dorsal roots and injured the spinal ganglia within segments from IV lumbar to II sacral.

Through different terms After the operation, the arterial system of the hind limbs was studied (fine injection, radiography, careful preparation).

At the same time, not only the muscles as a whole were studied, but also each muscle separately. The development of exceptionally powerful anastomoses was discovered in the thickness of the muscles. Simultaneously with the operation on the vessels, deafferentation was performed on one side - always in the area of the same segments.

It has been shown that in half of the cases there is a sharp reaction of the arterial system: in the deafferented limb, the development of roundabout pathways occurs more intensively than in the limb with intact innervation: collaterals in the muscles, skin and partly in large nerves are more numerous, characterized by a particularly large caliber and more pronounced tortuosity .

This fact is explained by the following: as a result of injury to the spinal ganglion, degenerative processes occur in the nerve, which lead to the formation of histamine-like substances on the periphery, which contributes to an increase in the caliber of blood vessels and the occurrence of trophic changes in their wall (loss of elasticity), in addition, cutting of the posterior roots, reducing

the tone of the sympathetic vasoconstrictor innervation facilitates the use of collateral tissue reserve.

It has been established that the development of macroscopically visible collaterals after occlusion of the main arteries occurs only after 20-30 days, after occlusion of the main veins - after 10-20 days. However, restoration of organ function during collateral circulation occurs much earlier than the appearance of macroscopically visible collaterals. It was shown that in early dates after occlusion of the main trunks important role in the development of collateral circulation belongs to the hemomicrocirculatory bed.

With arterial collateral circulation based on arteriolo-arteriolar anastomoses, microvascular arteriolar collaterals are formed, with venous collateral circulation based on venulo-venular anastomoses, microvascular venular collaterals are formed.

They ensure the preservation of organ viability in the early stages after occlusion of the main trunks. Subsequently, due to the release of the main arterial or venous collaterals, the role of microvascular collaterals gradually decreases.

As a result of numerous scientific studies of the Tankov school, the stages of development of the roundabout pathways of blood flow were studied and described:

Involvement in the bypass circulation maximum quantity anastomoses existing in the zone of occlusion of the main vessel (early periods - up to 5 days).
Transformation of arteriolo-arteriolar or venulo-venular anastomoses into microvascular collaterals, transformation of arterio-arterial or veno-venous anastomoses into collaterals (from 5 days to 2 months).
Differentiation of the main bypass pathways of blood flow and reduction of microvascular collaterals, stabilization of collateral circulation in new hemodynamic conditions (from 2 to 8 months).

The duration of the second and third stages with arterial collateral circulation compared to venous circulation is 10-30 days longer, which indicates a higher plasticity of the venous bed.

Thus, the life and work of V.N. Tonkov and his school have become the property of the history of science, and his works, which have passed the strictest test of time, continue in the school he created through the efforts of many generations of students and their followers.

^ DEVELOPMENT OF THE ARTERIAL SYSTEM.

The circulatory system is formed in the human embryo very early - on the 12th day of intrauterine life. The beginning of the development of the vascular system is indicated by the appearance of so-called blood islands in the extraembryonic mesenchyme surrounding the yolk sac.

Later they are laid in the stem of the body and in the body of the embryo itself, surrounding its epithelial endodermal digestive tube. Blood islands are clusters of angioblast cells that arise during the differentiation of mesenchyme cells.

At the next stage of development, in these islets, on the one hand, marginal cells differentiate, forming a single-layer endothelial wall blood vessel, on the other - the central cells, which give rise to the red and white formed elements of blood.

First, a primary capillary network appears in the body of the embryo, consisting of small, branching and anastomosing tubes lined with endothelium. Larger vessels are formed by expanding individual capillaries and merging them with neighboring ones. At the same time, the capillaries into which the blood flow stops undergo atrophy.

Developing vessels provide blood supply to the developing and growing organs of the embryo. The largest vessels are formed in centers of increased metabolic activity, in rapidly developing organs, such as the liver, brain, and digestive tube.

The circulatory system of the embryo is characterized by a symmetrical arrangement of the main vessels (phasis bilateralis), but soon their symmetry is broken, and unpaired vascular trunks (phasis inequalis) are formed through complex rearrangements.

The most significant features of the fetal circulatory system are the absence of pulmonary circulation and the presence of umbilical vessels connecting the fetal body with the placenta, where metabolism with the mother’s body occurs. The placenta performs the same functions that the intestines, lungs and kidneys perform after birth.

The development of blood vessels plays a primary role in the embryogenesis of all organs and systems. Local circulatory disorders lead to atrophy of organs or their abnormal development, and turning off one of the large vessels can lead to the death of the embryo or fetus.

Arterial system The human embryo largely repeats the structural features of the vascular system of lower vertebrates. At the 3rd week of embryo development, paired ventral and dorsal aortas are formed. They are connected by 6 pairs of aortic arches, each of which passes in the corresponding branchial arch. The aortas and aortic arches give rise to the main arterial vessels head, neck and chest cavity.

The first two aortic arches quickly atrophy, leaving behind plexuses small vessels. The third arch, together with the continuation of the dorsal aorta, gives rise to the internal carotid artery. The continuation of the ventral aorta in the cranial direction gives rise to the external carotid artery.

In the embryo, this vessel supplies the tissues of the first and second gill arches, from which the jaws and face are subsequently formed.

The section of the ventral aorta, located between the III and IV aortic arches, forms a common carotid artery. The IV aortic arch on the left transforms into the aortic arch; on the right, the brachiocephalic trunk and the initial part of the right subclavian artery develop from it. The V aortic arch is unstable and quickly disappears.

The VI arch on the right connects with the arterial trunk leaving the heart and forms the pulmonary trunk; on the left, this arch retains its connection with the dorsal aorta, forming ductus arteriosus, which remains until birth as a canal between the pulmonary trunk and the aorta. Restructuring of the aortic arches occurs within 5-7 weeks embryonic development.

At the 4th week, the dorsal aortas merge with each other into an azygos trunk. In the embryo, the dorsal aorta gives rise to 3 groups of arteries: dorsal intersegmental, lateral segmental and ventral segmental.

The first pairs of dorsal intersegmental arteries give rise to the vertebral and basilar arteries. The sixth pair expands, on the right it forms the distal portion of the subclavian artery, and on the left - the entire subclavian artery and continues on both sides into the axillary arteries.

The lateral segmental arteries develop in connection with the excretory and genital organs, from which the diaphragmatic, adrenal, and renal arteries and gonadal arteries. The ventral segmental arteries are initially represented by the vitelline arteries, which are partially reduced, and from the remaining vessels the celiac trunk and mesenteric arteries are formed. The ventral branches of the aorta include the allantois artery, from which the umbilical artery develops.

As a result of the connection of the umbilical artery with one of the dorsal intersegmental arteries, the common iliac artery is formed. Part of the trunk of the umbilical artery gives rise to the internal iliac artery. The outgrowth of the umbilical artery is the external iliac artery, which goes to the lower limb.

The arteries of the limbs are formed from the primary capillary network, formed in the kidneys of the limbs. In each limb of the embryo there is an axial artery that accompanies the main nerve trunks. The axial artery of the upper limb is a continuation axillary artery, it runs first as the brachial artery and continues into the interosseous artery.

The branches of the axial artery are the ulnar and radial arteries and the median artery, which accompanies the nerve of the same name and passes into choroid plexus brushes

The axial artery of the lower limb originates from the umbilical artery and runs along the course of the sciatic nerve. Subsequently, it is reduced, and its distal portion is preserved in the form of the peroneal artery. The main arterial line of the lower limb is a continuation of the external iliac artery; it consists of the femoral and posterior tibial arteries. The anterior tibial artery is formed as a result of the fusion of the branches of the axial artery.

^ INDICATIONS AND RULES FOR VESSEL LIGATION.

Indications for ligation of arterial trunks throughout the following:

1* stopping bleeding when a vessel is injured (some surgeons recommend, instead of simply ligating the artery during bleeding, excision of a section of the vessel between two ligatures, this technique turns off sympathetic innervation segment of the artery, which contributes to the expansion of anastomoses and better ensures the development of collateral circulation) and the impossibility of applying hemostatic forceps, followed by a ligature on its segments within the wound itself. For example, if the sections of the wounded artery are far from each other; as a result of the suppurative process, the vessel wall has loosened, and the applied ligature may slip off; badly crushed and infected wound when isolating the ends of the artery is contraindicated;

2* as a preliminary measure used before amputation of a limb (for example, when high amputation or disarticulation of the hip, when applying a tourniquet is difficult), resection of the jaw (preliminary ligation of a. carotidis externa), resection of the tongue for cancer (ligation of a. lingualis);

^ 3* with arteriotomy, arteriolisis (release of arteries from compressive scars).

Rules for ligation of arteries.

Before proceeding with ligation of the vessel, it is necessary to accurately determine its topographic-anatomical location and projection onto the skin. The length of the incision should correspond to the depth of the vessel.

After dissecting the skin, subcutaneous tissue, superficial and intrinsic fascia, it is necessary to use a grooved probe to bluntly push back the edge of the muscle behind which the artery being sought lies. Having pulled the muscle with a blunt hook, it is necessary to dissect the posterior wall of the muscle sheath, and behind it, find the neurovascular bundle in your own vagina.

The artery is isolated in a stupid way. IN right hand hold a grooved probe, and in the left - tweezers, with which they grasp the perivascular fascia (but not the artery!) on one side and, carefully stroking the tip of the probe along the vessel, isolate it for 1-1.5 cm (Fig. 4). Isolation over a longer period should not be done for fear of disrupting the blood supply to the vessel wall.

The ligature is placed under the artery using a Deschamps or Cooper needle. When ligating large arteries, the needle is placed on the side on which the vein accompanying the artery is located, otherwise the vein can be damaged by the end of the needle. The ligature is tightly tightened with a double surgical knot.

^ Fig.4. Isolation of the vessel.

With ischemia, complete or partial restoration of blood supply to the affected tissue often occurs (even if the obstruction in the arterial bed remains). The degree of compensation depends on the anatomical and physiological factors blood supply to the corresponding organ.

To anatomical factors include features of arterial branching and anastomoses. There are:

1. Organs and tissues with well-developed arterial anastomoses (when the sum of their lumen is close in size to that of the blocked artery) - this is the skin, mesentery. In these cases, blockage of the arteries is not accompanied by any disturbance of blood circulation in the periphery, since the amount of blood flowing through the collateral vessels is sufficient from the very beginning to maintain normal blood supply to the tissue.

2. Organs and tissues whose arteries have few (or no) anastomoses, and therefore collateral blood flow into them is possible only through a continuous capillary network. Such organs and tissues include the kidneys, heart, spleen, and brain tissue. If an obstruction occurs in the arteries of these organs, severe ischemia occurs in them, and as a result, a heart attack.

3. Organs and tissues with insufficient collaterals. They are very numerous - these are the lungs, liver, and intestinal wall. Clearance collateral arteries they are usually more or less insufficient to ensure collateral blood flow.

Physiological factor promoting collateral blood flow is the active dilatation of the arteries of the organ. As soon as a deficiency of blood supply occurs in the tissue due to blockage or narrowing of the lumen of the afferent arterial trunk, a physiological regulatory mechanism begins to operate, causing an increase in blood flow through the preserved arterial pathways. This mechanism causes vasodilation, since products of impaired metabolism accumulate in the tissue, which have a direct effect on the walls of the arteries, and also excite sensitive nerve endings, resulting in a reflex dilatation of the arteries. At the same time, all collateral pathways of blood flow into the area with circulatory deficiency expand, and the speed of blood flow in them increases, facilitating blood supply to the tissue experiencing ischemia.

This compensation mechanism functions differently in different people and even in the same organism under different conditions. In people weakened by a long-term illness, the mechanisms of compensation for ischemia may not function sufficiently. For effective collateral blood flow, the condition of the artery walls is also of great importance: collateral blood flow paths that are sclerotic and have lost elasticity are less capable of expansion, and this limits the possibility of a complete restoration of blood circulation.

If the blood flow in the collateral arterial pathways supplying blood to the ischemic area remains increased for a relatively long time, then the walls of these vessels are gradually rebuilt in such a way that they turn into arteries of a larger caliber. Such arteries can completely replace a previously blocked arterial trunk, normalizing blood supply to tissues.

There are three degrees of severity of collaterals:

Absolute sufficiency of collaterals - the sum of the lumen of the collaterals is either equal to the lumen of the closed artery or exceeds it.

Relative sufficiency (insufficiency) of collaterals - the sum of the lumen, collaterals less than the lumen of a closed artery;

Absolute insufficiency of collaterals - collaterals are poorly expressed and even with full disclosure they are not able to compensate for impaired blood circulation to any significant extent.

Shunting. Shunting is the creation of an additional path bypassing the affected area of a vessel using a system of shunts. An effective method for treating myocardial ischemia is coronary artery bypass grafting. The affected area of the artery is bypassed using shunts - an artery or vein taken from another part of the body, which is fixed to the aorta and below the affected area of the coronary artery, thus restoring blood supply to the ischemic area of the myocardium. In case of hydrocephalus, surgical cerebrospinal fluid shunting of the brain is performed - as a result, the physiological flow of cerebrospinal fluid is restored and the symptoms of increased cerebrospinal fluid pressure disappear (excess cerebrospinal fluid is removed from the ventricles of the brain into the body cavity through a system of valves and tubes).

Insufficiency of lymph circulation during blockade of the lymphatic bed can be compensated by a certain functional reserve, which allows to increase the volume and speed of drainage to a certain extent (lymphatic-lymphatic shunts, lymph-venous shunts).

Stasis

Stasis- this is a stop of blood and/or lymph flow in capillaries, small arteries and venules.

Types of stasis:

1. Primary (true) stasis. It begins with the activation of FEC and their release of proaggregants and procoagulants. FEC aggregate, agglutinate and attach to the wall of microvessels. Blood flow slows and stops.

2. Ischemic stasis develops as an outcome of severe ischemia, with a decrease in the influx of arterial blood, a slowdown in the speed of its flow, and its turbulent nature. Blood cell aggregation and adhesion occurs.

3. Congestive (venous-congestive) variantstasis is the result of a slowdown in the outflow of venous blood, its thickening, changes in physicochemical properties, and damage to blood cells. Subsequently, the blood cells agglutinate, adhere to each other and to the wall of microvessels, slowing down and stopping the outflow of venous blood.

Causes:

Ischemia and venous hyperemia. When blood flow slows down, the formation or activation of substances that cause the adhesion of FEC, the formation of aggregates and blood clots.

Proaggregants (thromboxane A2, Pg F, Pg E, adenosine diphosphate, catecholamines, antibodies to FEC) are factors that cause aggregation and agglutination of FEC with their lysis and release of biologically active substances.

Rice. 8 – The mechanism of development of stasis under the influence of proaggregants.