Scientific review. medical sciences

Acute venous thrombosis is a common and dangerous disease. According to statistics, its frequency in the general population is about 160 per 100,000 population. Thrombosis in the system of the inferior vena cava (IVC) is the most common and dangerous type of this pathological process and is the main source of pulmonary embolism (84.5%). The system of the superior vena cava gives 0.4-0.7% of pulmonary embolism (PE), the right heart - 10.4%. The share of thrombosis of the veins of the lower extremities accounts for up to 95% of cases of all thrombosis in the IVC system. The diagnosis of acute venous thrombosis is diagnosed in vivo in 19.2% of patients. In the long term, deep vein thrombosis (DVT) leads to the formation of post-thrombophlebitis disease, manifested by chronic venous insufficiency up to the development of trophic ulcers, which significantly reduces the ability to work and the quality of life of patients.

The main mechanisms of intravascular thrombus formation, known since the time of R.Virchow, are slowing down of blood flow (stasis), hypercoagulation, injury of the vessel wall (damage to the endothelium). Acute venous thrombosis quite often develops against the background of various oncological diseases (malignant tumors of the gastrointestinal tract, female genital area, etc.) due to the fact that cancer intoxication causes the development of hypercoagulable changes and inhibition of fibrinolysis, as well as due to mechanical compression of the veins by the tumor and germination it into the vascular wall. Obesity, pregnancy, oral hormonal contraceptives, hereditary thrombophilias (deficiency of antithrombin III, protein C and S, Leiden mutation, etc.), systemic connective tissue diseases, chronic purulent infections, allergic reactions are also considered predisposing factors for DVT. Patients of elderly and senile age and persons suffering from chronic venous insufficiency of the lower extremities, as well as patients with myocardial infarction, decompensated heart failure, stroke, bedsores, and gangrene of the lower extremities are at the greatest risk of developing DVT. Trauma patients are of particular concern, since fractures of the femur are mainly found in elderly and senile people who are most burdened with somatic diseases. Thrombosis in trauma patients can occur with any injury to the lower extremities, since in this case all the etiological factors of thrombosis (damage to the vessel, venous congestion and changes in blood coagulation properties) take place.

Reliable diagnosis of phlebothrombosis is one of the urgent clinical problems. Physical examination methods make it possible to make a correct diagnosis only in typical cases of the disease, while the frequency of diagnostic errors reaches 50%. For example, thrombosis of the veins of the gastrocnemius muscles with the remaining patency of the remaining veins often asymptomatic. Because of the risk of missing acute calf DVT, clinicians often make this diagnosis in every case of calf pain. Particular attention should be paid to "trauma" patients, in whom the presence of pain, swelling and discoloration of the limb may be a consequence of the injury itself, and not DVT. Sometimes the first and only manifestation of such thrombosis is massive pulmonary embolism.

The tasks of the instrumental examination include not only confirmation or refutation of the presence of a thrombus, but also the determination of its extent and degree of embologenicity. The allocation of embolic thrombi into a separate group and the study of their morphological structure are of great practical importance, since without this it is impossible to develop an effective prevention of pulmonary embolism and the choice of optimal treatment tactics. Thromboembolic complications are more often observed in the presence of a floating thrombus with a heterogeneous structure, an uneven hypo- or isoechogenic contour, in contrast to thrombi with a hyperechoic contour and a homogeneous structure. An important criterion for the embologenicity of a thrombus is the degree of its mobility in the vessel lumen. Embolic complications are more often observed with severe and moderate mobility of thrombus masses.

Venous thrombosis is a rather dynamic process. Over time, the processes of retraction, humoral and cell lysis contribute to a decrease in the size of the thrombus. At the same time, the processes of its organization and recanalization are going on. In most cases, the patency of the vessels is gradually restored, the valvular apparatus of the veins is destroyed, and the remains of blood clots in the form of parietal overlays deform the vascular wall. Difficulties in diagnosis may occur when repeated acute thrombosis occurs against the background of partially recanalized veins in patients with postthrombophlebitis disease. In this case, a fairly reliable criterion is the difference in veins in diameter: in patients with signs of thrombus recanalization, the vein decreases in diameter due to the subsidence of the acute process; with the development of retrombosis, a significant increase in the diameter of the vein again occurs with fuzzy ("blurred") contours of the walls and surrounding tissues. The same criteria are used in the differential diagnosis of acute parietal thrombosis with post-thrombotic changes in the veins.

Of all the non-invasive methods used to diagnose thrombosis, ultrasound scanning of the venous system has recently been increasingly used. The triplex angioscanning method proposed by Barber in 1974 includes the study of vessels in the B-mode, the analysis of the Doppler frequency shift in the form of a classical spectral analysis and flow (in high-speed and energy modes). The use of spectral allowed to accurately measure the blood flow inside the lumen of the veins. The use of the () method made it possible to quickly distinguish between occlusive and non-occlusive thrombosis, to identify the initial stages of thrombus recanalization, and to determine the location and size of venous collaterals. In studies in dynamics, the ultrasound method allows for a fairly accurate control over the effectiveness of thrombolytic therapy. In addition, with the help of ultrasound, it is possible to establish the causes of the appearance of clinical symptoms similar to those in the pathology of the veins, for example, to identify a Baker's cyst, an intermuscular hematoma, or a tumor. The introduction into practice of expert-class ultrasonic devices with sensors with a frequency of 2.5 to 14 MHz made it possible to achieve almost 99% diagnostic accuracy.

Material and methods

The examination included examination of patients with clinical signs of venous thrombosis and pulmonary embolism. Patients complained of swelling and pain in the lower (upper) limb, pain in the gastrocnemius muscle (usually bursting), "pulling" pain in the popliteal region, pain and induration along the saphenous veins. Examination revealed moderate cyanosis of the lower leg and foot, dense edema, pain on palpation of the lower leg muscles, most patients had positive symptoms of Homans and Moses.

All subjects underwent triplex scanning of the venous system using modern ultrasound machines with a linear transducer with a frequency of 7 MHz. At the same time, the state of the veins of the thigh, popliteal vein, veins of the lower leg, as well as the large and small saphenous veins were assessed. A 3.5 MHz convex transducer was used to visualize the iliac veins and IVC. When scanning the IVC, iliac, great saphenous veins, femoral veins and veins of the leg in the distal lower extremities, the patient was in the supine position. The study of the popliteal veins, veins of the upper third of the leg and small saphenous vein was carried out with the patient lying on his stomach with a roller placed under the area of ​​the ankle joints. Difficulties in diagnosis arose when visualizing the distal superficial femoral vein in obese patients, visualizing the veins of the lower leg with pronounced trophic and indural tissue changes. In these cases, a convex probe was also used. The scanning depth, echo signal amplification, and other study parameters were selected individually for each patient and remained unchanged during the entire examination, including follow-up observations.

Scanning was started in cross section to exclude the presence of a floating top of the thrombus, as evidenced by the complete contact of the venous walls during light compression by the transducer. After making sure that there was no free-floating top of the thrombus, a compression test was performed with a sensor from segment to segment, from proximal to distal. The proposed technique is the most accurate not only for detecting thrombosis, but also for determining its extent (excluding the iliac veins and IVC, where vein patency was determined in the CFM mode). veins confirmed the presence and characteristics of venous thrombosis. In addition, the longitudinal section was used to locate the anatomical confluence of the veins. During the examination, the condition of the walls, the lumen of the veins, the localization of the thrombus, its length, and the degree of fixation to the vascular wall were assessed.

Ultrasonic characterization of venous thrombi was carried out in relation to the lumen of the vessel: they were distinguished as parietal, occlusive and floating thrombi. Visualization of a thrombus with the presence of free blood flow in the lumen of the vein, the absence of complete collapse of the walls during compression of the vein with a transducer, the presence of a filling defect during color doppler imaging, and the presence of spontaneous blood flow during spectral Dopplerography (Fig. 1) were considered signs of parietal thrombosis.

Rice. one. Non-occlusive thrombosis of the popliteal vein. Longitudinal scan of the vein. Enveloping blood flow in the energy flow encoding mode.

The ultrasonic criteria for floating thrombi were: visualization of a thrombus as an echogenic structure located in the lumen of a vein with free space, oscillatory movements of the thrombus apex, absence of contact of the vein walls during compression by a transducer, presence of free space when performing respiratory tests, enveloping type of blood flow in CDI, the presence of spontaneous blood flow in spectral dopplerography. When a floating thrombus was detected, the degree of its mobility was assessed: pronounced - in the presence of spontaneous thrombus movements during quiet breathing and/or breath holding; moderate - upon detection of oscillatory movements of a blood clot during functional tests (cough test); insignificant - with minimal thrombus mobility in response to functional tests.

Research results

From 2003 to 2006, 236 patients aged 20 to 78 years were examined, 214 of them with acute thrombosis and 22 with PE.

In the first group, in 82 (38.3%) cases, the patency of deep and superficial veins was not impaired and clinical symptoms were due to other reasons (Table 1).

Table 1. Conditions that have symptoms similar to DVT.

The diagnosis of thrombosis was confirmed in 132 (61.7%) patients, while in most cases (94%) thrombosis was detected in the IVC system. DVT was detected in 47% of cases, superficial veins - in 39%, damage to both the deep and superficial venous system was observed in 14%, including 5 patients with involvement of perforating veins.

Probable causes (risk factors) for the development of venous thrombosis are presented in Table. 2.

table 2. Risk factors for the development of thrombosis.

In our observations, the most common form of thrombosis was detected, as well as vein damage at the level of the popliteal and femoral-popliteal segments (Table 3).

Table 3. Localization of DVT.

More often (63%) there were thromboses that completely occluded the lumen of the vessel, in second place in frequency (30.2%) were parietal thrombi. Floating thrombi were diagnosed in 6.8% of cases: in 1 patient - in the saphenofemoral fistula with ascending thrombosis of the trunk of the great saphenous vein, in 1 - ileofemoral thrombosis with a floating tip in the common iliac vein, in 5 - in the common femoral vein with thrombosis of the femoropopliteal segment and in 2 - in the popliteal vein with DVT of the leg.

The length of the non-fixed (floating) part of the thrombus, according to ultrasound data, varied from 2 to 8 cm. Moderate mobility of thrombotic masses was more often detected (5 patients), in 3 cases the mobility of the thrombus was minimal. In 1 patient, during quiet breathing, spontaneous movements of a thrombus in the lumen of the vessel were visualized (high degree of mobility). In our observations, floating thrombi with a heterogeneous echostructure were more often detected (7 people), while the hyperechoic component prevailed in the distal section, and the hypoechoic component prevailed in the area of ​​the thrombus head (Fig. 2).

Rice. 2. Floating thrombus in the common femoral vein. B-mode, longitudinal scanning of a vein. A thrombus of a heteroechoic structure with a clear hyperechoic contour.

In dynamics, 82 patients were examined to assess the course of the thrombotic process, of which 63 (76.8%) had partial recanalization of thrombotic masses. In this group, 28 (44.4%) patients had a central type of recanalization (during longitudinal and transverse scanning in the CFM mode, the recanalization channel was visualized in the center of the vessel); 23 (35%) patients were diagnosed with parietal recanalization of thrombotic masses (more often, the blood flow was determined along the wall of the vein directly adjacent to the artery of the same name); 13 (20.6%) patients had incomplete recanalization with fragmentary asymmetric staining in the CDI mode. Thrombotic occlusion of the lumen of the vein was observed in 5 (6.1%) patients, in 6 (7.3%) cases restoration of the lumen of the vein was noted. Signs of retrombosis persisted in 8 (9.8%) patients.

conclusions

Comprehensive ultrasound examination, including angioscanning using spectral, color and power Doppler modes and soft tissue echography, is a highly informative and safe method that allows you to most reliably and quickly resolve issues of differential diagnosis and therapeutic tactics in outpatient phlebological practice. This study should be carried out at the outpatient stage for earlier identification of patients who are not indicated (and sometimes contraindicated) for thrombolytic therapy, and refer them to specialized departments; when confirming the presence of venous thrombosis, it is necessary to identify individuals with a high risk of developing thromboembolic complications; monitor the dynamics of the course of the thrombotic process and thereby adjust the treatment tactics.

Literature

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M. I. Parkina, V. V. Makhrov, V. V. Shchapov, and O. S. Vedyashkina

ULTRASOUND DIAGNOSIS OF ACUTE VENOUS THROMBOSIS

LOWER LIMB Abstract. The article discusses the results of ultrasound diagnosis of acute venous thrombosis of the lower extremities in 334 patients. In 32% of patients, massive thrombi were found on the cava filter after its implantation; in 17% of patients, floating thrombi were found below the site of vein plication, which confirms the need for urgent surgical prevention of pulmonary embolism and its high efficiency.

Key words: sonography, dopplerography, vein thrombosis, thrombus, cava filter, veins of the lower extremities.

PARKIN M. I., MAKHROV V. V., SHCHAPOV V. V., VEDYASHKINA O. S.

ULTRASOUND DIAGNOSIS OF ACUTE VENOUS THROMBOSIS OF THE LOWER EXTREMITIES

abstract. The article considers the results of ultrasonic diagnosis of acute venous thrombosis of the lower extremities in 334 patients. 32% of patients showed massive blood clots on the cava filter after implantation. 17% of patients showed floating cloths below the vein plication. The ultrasound diagnosis confirms the need for an urgent surgical prophylaxis of pulmonary embolism, and its high efficiency.

Keywords: ultrasound, Doppler, blood clot, venous thrombosis, cava-filter, veins of the lower extremities.

Introduction. Acute venous thrombosis of the lower extremities is one of the most important problems of clinical phlebology in terms of practical and scientific significance. Phlebothrombosis is extremely common among the population, conservative treatment is not effective enough, and the level of temporary and permanent disability is high. Often the clinic is worn out, and the first symptom of venous thrombosis is pulmonary embolism (PE), which is one of the leading causes of postoperative mortality. In this regard, timely diagnosis of embologenic conditions using accessible and non-invasive methods is very important. These criteria are met by the CDS of the lower extremities, although there are not many works devoted to the study of the echosemiotics of floating thrombi. Until now, there is no single point of view in the definition of ultrasound criteria for embologenic thrombi. The insufficient level of information about the embologenic properties of floating thrombi explains the absence of these

The purpose of the study is to improve the diagnosis and treatment results of patients with acute venous thrombosis of the lower extremities.

Material and research methods. The results of clinical and ultrasound diagnostics of acute venous thrombosis of the lower extremities in 334 patients for 2011-2012, who were hospitalized in the department of vascular surgery of the state budgetary health care institution of the Republic of Mordovia "Republican Clinical Hospital No. 4", were analyzed.

The age of the patients ranged from 20 to 81 years; 52.4% were women, 47.6% were men; 57% of them were able-bodied, and 19.5% were young. Basic information about the distribution of patients by sex and age is presented in Table 1.

Table 1

Distribution of patients by sex and age_

Under 45 years old 45-60 years old 60 years and older

Abs. amount % Abs. amount % Abs. amount % Abs. amount %

Men 39 60.0 66 52.3 54 37.7 159 47.6

Women 26 40.0 60 47.6 89 62.3 175 52.4

Total 65 19.4 126 37.7 143 42.8 334 100

The most numerous cohort of patients was the group of 60 years and older (143 people), among men aged 45 to 60 years - 66 people (52.3%) prevailed, in women - at the age of 60 and older - respectively 89 (62 .3%) people.

Acute venous thrombosis occurs at the age of up to 45 years more often in men, which is associated with the abuse of intravenous psychoactive substances, and at the age of 60 years or more, the number of female patients begins to predominate over male ones. This can be explained by the fact that other risk factors begin to predominate in women: gynecological diseases, coronary artery disease, obesity, injuries, varicose veins, etc. The decrease in the incidence in the general population in men aged 60 years and over is explained by a decrease in their proportion in the corresponding age groups , short life expectancy, high mortality from pulmonary embolism, development of chronic venous insufficiency and posttrophbophlebitic syndrome.

Ultrasonographic diagnostics and dynamic echoscopy were performed on

ultrasonic devices SonoAce Pico (Korea), Vivid 7 (General Electric, USA), Toshiba

Xario SSA-660A (Toshiba, Japan) operating in real time using 7 and 3.5 MHz sensors. The study began with the inguinal region in transverse and longitudinal sections in relation to the vascular bundle. The blood flow was assessed next to the lying artery. When obtaining an image of the veins, the following parameters were evaluated: diameter, compressibility (compression by the sensor until the blood flow in the vein stops while maintaining blood flow in the artery), stroke features, the state of the internal lumen, the safety of the valvular apparatus, changes in the walls, the state of the surrounding tissues, and the blood flow of the adjacent artery was assessed. The state of venous hemodynamics was also assessed using functional tests: respiratory and cough tests or strain test. At the same time, the state of the veins of the thigh, popliteal vein, veins of the lower leg, as well as the large and small saphenous veins were assessed. When scanning the IVC, iliac, great saphenous veins, femoral veins and veins of the leg in the distal lower extremities, the patient was in the supine position. The study of the popliteal veins, veins of the upper third of the leg and small saphenous vein was carried out with the patient lying on his stomach with a roller placed under the area of ​​the ankle joints. To study the main veins and in case of difficulties in the study, convex probes were used, otherwise - linear probes.

Scanning was started in cross section to exclude the presence of a floating top of the thrombus, as evidenced by the complete contact of the venous walls during light compression by the transducer. During the examination, the nature of the venous thrombus was established: parietal, occlusive and floating thrombi.

For the purpose of surgical prevention of PE in acute phlebothrombosis, 3 methods of surgery were used: installation of a cava filter, plication of a vein segment, and crossectomy and/or phlebectomy. In the postoperative period, ultrasound diagnostics was aimed at assessing the state of venous hemodynamics, the degree of recanalization or increased thrombotic process in the venous system, the presence or absence of thrombus fragmentation, the presence of flotation, thrombosis of the veins of the contralateral limb, thrombosis of the plication zone or cava filter, and linear and volumetric blood flow velocities were determined. and collateral circulation. Statistical processing of the obtained digital data was carried out using the Microsoft Office 2007 software package.

Research results. The main signs of thrombosis included the presence of echopositive thrombotic masses in the lumen of the vessel, the echo density of which increased as the age of the thrombus increased. At the same time, the valve leaflets ceased to differentiate, the transmission arterial pulsation disappeared, the diameter increased

thrombosed vein 2-2.5 times compared to the contralateral vessel, when compressed by the sensor, it is not squeezed. In the first days of the disease, we consider compression ultrasonography especially important when the thrombus is visually indistinguishable from the normal lumen of the vein. On the 3rd-4th day of the disease, thickening and thickening of the vein walls occurred due to phlebitis, the perivasal structures became "blurred".

Signs of parietal thrombosis were considered to be the presence of a thrombus with free blood flow in the absence of complete collapse of the walls on compression ultrasonography, the presence of a filling defect on duplex scanning, and spontaneous blood flow on spectral Doppler sonography.

The criteria for a floating thrombus were the visualization of a thrombus in the lumen of the vein with the presence of free space, oscillatory movements of the head of the thrombus, the absence of contact between the walls of the vein during compression by the sensor, the presence of free space during breathing tests, the envelope type of blood flow, the presence of spontaneous blood flow in spectral Doppler sonography. For the final clarification of the nature of the thrombus, the Valsalva test was used, which is dangerous in view of the additional flotation of the thrombus.

Thus, according to ultrasound diagnostics, floating thrombi were found in 118 (35.3%) patients (Fig. 1).

60 -50 -40 -30 -20 -10 -0 -

Figure 1. The frequency of floating thrombi in the system of superficial and deep veins of the extremities

It has been established that the most frequently floating thrombi according to color duplex scanning are detected in the deep vein system (especially in the ileofemoral segment - 42.0%), less often in the deep vein system of the leg and large

ileofemoral segment

deep veins of the thigh

popliteal vein and leg veins

saphenous vein of the thigh

saphenous vein of the thigh. There was no difference in the frequency of floating thrombi in the deep system in men and women.

In 2011, the frequency of floating thrombosis was 29.1% of all examined, which is 1.5 times less than in 2012 (Table 2). This is due to the conduct of ultrasound diagnostics in all patients entering the clinic, as well as in the presence of suspicion of an acute pathology of the venous system. This fact is confirmed by the fact that in 2012 there was a significant increase in the proportion of patients in whom floating thrombi in the superficial system were detected only according to the CDS data. In this regard, the presence of superficial varicothrombophlebitis, despite a clear clinical picture, dictates the need for CDS to detect subclinical floating thrombosis of both superficial and deep veins.

Table 2

Distribution of floating thrombi in the deep vein system of the lower extremities

Localization 2011 2012 Total

When- Floating- When- Floating- When- Floating-

Quality blood clots Quality blood clots Quality blood clots

Ileofemoral 39 23 (59.0%) 35 27 (55.2%) 74 50 (67.6%)

Deep veins of the thigh 31 12 (38.7%) 33 15 (45.5%) 64 27 (42.2%)

Popliteal vein and 36 6 (16.7%) 31 10 (32.3%) 67 16 (23.9%)

leg veins

Saphenous veins of the thigh 69 10 (14.5%) 60 15 (25.0%) 129 25 (19.4%)

Total 175 51 (29.2%) 159 67 (42.2%) 334 118 (35.3%)

As is known, coagulation processes are accompanied by activation of the fibrinolytic system, these processes run in parallel. For clinical practice, it is very important to establish not only the flotation of a thrombus, but also the nature of the spread of a thrombus in a vein, the possibility of its fragmentation in the process of recanalization.

In CDS of the lower extremities, non-floating thrombi were found in 216 patients (64.7%): occlusive thrombosis was found in 183 patients (54.8%), non-occlusive parietal thrombosis - in 33 (9.9%).

Parietal thrombi were most often fixed to the walls of the vein throughout and were characterized by the preservation of the gap between the thrombotic masses and the venous wall. However, they can fragment and migrate into the pulmonary circulation. With floating thrombi, soldered to the vascular wall only in the distal part of the affected vein, a real high risk of pulmonary embolism is created.

Among the non-occlusive forms of thrombosis, a dome-shaped form can be distinguished.

thrombus, the morphological features of which are a wide base equal to

diameter of the vein, the absence of oscillatory movements in the blood flow and a length of up to 4 cm.

Control color duplex scanning was performed in all patients until the moment of fixation of the floating tail of the thrombus to the vein wall and subsequently within 4 to 7 days of treatment and before the patient was discharged.

Patients with floating thrombi underwent ultrasonic angioscanning of the veins of the lower extremities without fail before surgery, as well as 48 hours after cava filter implantation or vein plication (Fig. 2). Normally, during longitudinal scanning, the cava filter is visualized in the lumen of the inferior vena cava in the form of a hyperechoic structure, the shape of which depends on the modification of the filter. The most typical position of a cava filter in a vein is at or just distal to the orifices of the renal veins or at the level of 1-2 lumbar vertebrae. Usually there is an expansion of the lumen of the vein in the area of ​​the filter.

Figure 2. Inferior vena cava with transducer in place. A colored blood flow is visible (blue flowing to the sensor, red flowing from the sensor). On the border between them is a normally functioning cava filter.

According to the color duplex scanning after the installation of cava filters in 8 (32%) of 25 patients, massive thrombi were observed on the filter. The vein segment after plication was passable in 29 (82.9%) of 35 patients, in 4 (11.4%) ascending thrombosis was detected below the plication site, in 2 (5.7%) - blood flow in the plication area was not possible at all visualize.

It should be noted that the frequency of progression of the thrombotic process and recurrence of thrombosis is the highest in patients who underwent implantation of a cava

filter, which can be explained by the presence of a foreign body in the lumen of the IVC, which changes the nature of the blood flow in the segment. The frequency of thrombosis recurrence in patients who underwent plication, or who were treated only conservatively, is almost the same and, at the same time, is significantly lower compared to that after endovascular interventions.

Conclusions. The leading risk factors for thrombus formation in men include injuries and combined surgical interventions, severe cardiovascular diseases; in women - cardiovascular diseases and diseases of the female genital organs. Color duplex scanning makes it possible to establish the presence and level of a thrombotic process in a vein, thrombus flotation, evaluate the effectiveness of drug therapy, and monitor the course of phlebothrombosis after surgical prophylaxis of pulmonary embolism. After endovascular implantation, 32% of patients had massive thrombi on the cava filter, after vein plication, 17% of patients had floating thrombi below the operation site, which confirms the expediency and high efficiency of urgent surgical prevention of fatal pulmonary embolism.

LITERATURE

1. Zubarev A. R., Bogachev V. Yu., Mitkov V. V. Ultrasound diagnosis of diseases of the veins of the lower extremities. - M: Vidar, 1999. - 256 p.

2. Kulikov V.P. Ultrasound diagnosis of vascular diseases / Ed. V. P. Kulikova. - 1st ed. - M.: OOO STROM, 2007. - 512 p.

4. Savelyev V. S., Gologorsky V. A., Kirienko A. I. et al. Phlebology. A Guide for Physicians / Ed. V. S. Savelyeva. - M: Medicine, 2001. - 664 p.

5. Savelyev V. S., Kirieko A. I., Zolotukhin I. A., Andriyashkin A. I. Prevention of postoperative venous thromboembolic complications in Russian hospitals (preliminary results of the “Safety Territory” project) // Phlebology. - 2010. - No. 3. - S. 3-8.

6. Savelyev V. S., Kiriyenko A. I. Clinical surgery: national guidelines: in 3 volumes - T 3. - M: GEOTAR-Media. - 2010. - 1008 p.

7. Shulgina L. E., Karpenko A. A., Kulikov V. P., Subbotin Yu. G. Ultrasound criteria for venous thrombosis embologenicity // Angiol and vascular surgery. -2005. - No. 1. - S. 43-51.

8. Linkin L. A., Weitz J. L. New anticoagulants // Semin. Thromb. hemost. - 2003. - Vol. 6. - pp.619-623.

9. Michiels C. et al. Role of endothelium and blood stasis in the appearance of varicose veins // Int. Angiol. - 2006. - Vol. 21.-pp. l-8.

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E.A. MARUSHCHAK, Ph.D., A.R. ZUBAREV, Doctor of Medical Sciences, Professor, A.K. DEMIDOVA

Russian Research Medical University. N.I. Pirogova, Moscow

Methodology of ultrasound examination of venous thrombosis

The article presents a four-year experience in performing ultrasound examinations of venous blood flow (12,394 outpatients and inpatients with acute venous pathology of the Central Clinical Hospital of the Russian Academy of Sciences). Based on extensive clinical material, the methodology for performing primary and dynamic ultrasound examinations in patients with conservative treatment of venous thrombosis and with various methods of surgical prevention of pulmonary embolism is outlined. Particular attention is paid to the interpretation of the results of ultrasound studies in terms of the likelihood of pulmonary embolism. The results of the application of the proposed ultrasound examination methodology in the practice of a multidisciplinary emergency hospital and a treatment and diagnostic center are analyzed.

Keywords: ultrasound angioscanning, vein, acute venous thrombosis, deep vein thrombosis, pulmonary embolism, surgical prevention of PE

About Introduction

The epidemiology of acute venous thrombosis (AVT) is characterized by disappointing data: the incidence of this pathology in the world reaches 160 people per 100 thousand people annually, and in the Russian Federation - at least 250 thousand people. According to M.T. Severinsen (2010) and L.M. Lapie1 (2012), the incidence of phlebothrombosis (FT) in Europe is 1:1000 annually and reaches 5:1000 in patients with skeletal trauma. Conducted in the United States in 2012, a large-scale analysis of the incidence of deep vein thrombosis (DVT) showed that 300-600 thousand Americans are diagnosed with this pathology annually, and 60-100 thousand of them die from pulmonary embolism (PE) . These indicators are due to the fact that OBEs occur in patients with a wide variety of pathologies and are often secondary, complicating any diseases or surgical interventions.

For example, the frequency of venous thromboembolic complications (VTEC) in inpatient (including surgical) patients reaches 10-40%. V.E. Barinov et al. cite data on the frequency of PE in air travelers, equal to 0.5-4.8 cases per 1 million passengers, with fatal PE being the cause of 18% of deaths in aircraft and airports. PE is the cause of death in 5-10% of hospital patients, and this figure is steadily increasing. Massive and, as a result, lethal PE in some patients is the only, first and last manifestation of OBE. In the study of L.A. Laberko et al., devoted to the study of PE in surgical patients, provides data on mortality from VTEC in Europe: their number exceeds the total mortality from breast cancer, acquired immunodeficiency syndrome and car accidents and is more than 25 times higher than the mortality from infections caused by Staphylococcus aureus .

An interesting fact is that 27 to 68% of all deaths from PE are potentially preventable. The high value of the ultrasound method in the diagnosis of OVT is due to non-invasiveness and approaching 100% sensitivity and specificity. Physical methods of examination of patients with suspected OBE allow making a correct diagnosis only in typical cases of the disease, while the frequency of diagnostic errors reaches 50%. Thus, the ultrasound doctor has a 50/50 chance of verifying or excluding OBE.

Instrumental diagnostics of OBE is one of the urgent tasks in terms of visual assessment of the disease substrate, since the data obtained determine the angiosurgical tactics, and, if necessary, surgical prevention of pulmonary embolism, the choice of its method. Execution of dynamic

Ultrasound is necessary both during conservative treatment of OBT in order to assess the emerging changes in the affected venous bed, and in the postoperative period.

Ultrasound physicians are at the forefront of visual assessment of OBT. It is ultrasound that is the method of choice in this category of patients, which dictates the need not only for the detection of OBE, but also for the correct description and interpretation of all possible characteristics of this pathological condition. The purpose of this work was to standardize the methodology for performing ultrasound examinations in OBT, aimed at minimizing possible diagnostic errors and maximizing adaptation to the needs of clinicians who determine treatment tactics.

About Materials

In the period from October 2011 to October 2015, 12,068 primary ultrasounds of the blood flow of the inferior vena cava system and 326 of the superior vena cava system were performed at the Central Clinical Hospital of the Russian Academy of Sciences (Central Clinical Hospital of the Russian Academy of Sciences, Moscow) (a total of 12,394 ultrasounds). It is important to emphasize that the Central Clinical Hospital of the Russian Academy of Sciences purposefully does not accept acute venous pathology through the ambulance channel. Out of 12,394 studies, 3,181 were performed on an outpatient basis for patients of the treatment and diagnostic center, 9,213 - for patients in a hospital with suspected acute venous pathology or for prophylactic purposes in patients at risk for venous thromboembolic complications, as well as according to indications as preoperative preparation. OVT was diagnosed in 652 inpatients (7%) and 86 outpatients (2.7%)

(total 738 people, or 6%). Of these, the localization of OVT in the bed of the inferior vena cava was detected in 706 (95%), in the bed of the superior vena cava - in 32 patients (5%). Vascular ultrasound was performed on the following devices: Voluson E8 Expert (GE HC, USA) using multifrequency convex (2.0-5.5 MHz) and linear (5-13 MHz) transducers in the following modes: B-mode, color Doppler mapping, power Doppler mapping, pulsed wave mode and Doppler blood flow imaging mode (B-flow); Logiq E9 Expert (GE HC, USA) with a similar set of sensors and programs plus high-quality ultrasonic elastography mode.

About Methodology

The first task during ultrasound is to detect the substrate of the disease - the actual venous thrombosis. OBT are characterized by individual and often mosaic anatomical localization in the bed of the vena cava. That is why it is necessary to investigate in detail and polypositional not only the superficial and deep bed of both lower (or upper) limbs, but also the iliocaval segment, including with the renal veins. Before performing an ultrasound scan, it is necessary to familiarize yourself with the available data on the patient's medical history, which in some cases will help to refine the search and suggest atypical sources of OBT formation. One should always be aware of the existing possibility of a bilateral and/or multifocal thrombotic process throughout the venous bed. The informativeness and value of ultrasound for angiosurgeons is associated not so much with the very fact of OBT verification, but with the interpretation of the results obtained and their de-

talization. So, on the basis of the ultrasound report, presented as “non-occlusive thrombosis of the common femoral vein”, the angiosurgeon, in addition to confirming the fact of OVT, does not receive any other information and, accordingly, cannot determine further tactics in detail. Therefore, in the ultrasound protocol, the identified OBT must necessarily be accompanied by all its characteristics (boundary, nature, source, extent, flotation length, relation to anatomical landmarks, etc.). In the conclusion of the ultrasound, there should be an interpretation of the results, aimed at further determining the tactics by the clinician. The terms "iliocaval", "iliofemoral" are also clinical and not ultrasonic.

About Primary Ultrasound

The main technique for verifying OBE during ultrasound is the compression of the area of ​​interest (a fragment of the visualized vessel) by the sensor. It should be noted that the force of compression should be sufficient, especially when examining a deep channel, in order to avoid obtaining false positive information about the presence of thrombotic masses where they are not. A clean vessel that does not have pathological intravenous inclusions, containing only liquid blood, undergoes complete compression when squeezed, its lumen “disappears”. If there are thrombotic masses in the lumen (the latter can be of different structure and density), it will not be possible to completely compress the lumen, which can be confirmed by compression of the unchanged contralateral vein at a similar level. The thrombosed vessel has a larger diameter compared to the free contralateral one, and its staining in the color mode

Doppler mapping (CDM) will be at least uneven or completely absent.

The study of the iliocaval segment is carried out with a convex probe with a low frequency, however, in some cases, in patients with a small body weight, it is possible to use high-frequency linear probes. In obese patients with severe flatulence, as well as in the presence of adhesive disease after surgical interventions, visualization of the iliocaval segment will be sharply difficult. The use of drugs that suppress and reduce the manifestations of gas formation, as well as cleansing enemas, improves imaging conditions slightly, and in addition, it requires additional time or may be completely contraindicated in patients with suspected non-occlusive OBE. The use of auxiliary modes, such as color flow, does not reduce the risk of diagnostic errors in these cases. For example, with non-occlusive local thrombosis of the external iliac vein in an obese patient, the lumen of the vessel in the CDI mode can be completely stained, and it is not possible to compress the vein. To study the veins of the pelvis and some fragments of the iliac veins in case of their poor visualization from the transabdominal access, it is possible to use intracavitary sensors (transvaginal or transrectal ultrasound). When examining the deep venous bed of the lower extremities in obese patients, as well as in the presence of lymphostasis, when the penetration depth of the ultrasonic beam from the linear high-frequency transducer is insufficient, it is necessary to use a low-frequency convex one. In this case, one can define

border of thrombosis, but the quality of visualization of the actual top of the thrombus in the B-mode will be unimportant. With poor visualization of the upper border and the nature of thrombosis or the venous segment as such, it is not necessary to give these characteristics in the conclusion, remembering the main rule of the ultrasound doctor: do not describe what you have not seen or seen poorly. In this case, it is worth making a note that obtaining this information by ultrasound at the time of the examination is not possible for technical reasons. It should be understood that ultrasound as a technique has its limitations and the lack of a clear visualization of the upper limit and the nature of thrombosis is a reason to use other research methods.

In some cases, the visualization of the upper border and the nature of thrombosis is helped by the Val-salvi test (straining the patient in order to create retrograde blood flow in the vessel under study, in which the diameter of the vein will increase and, possibly, thrombus flotation will be visible) and the test of distal compression (clamping of the lumen of the vein above the level of thrombosis, at which the diameter of the vessel will also increase, which will improve the visual assessment). Figure 1 shows the moment of occurrence of retrograde blood flow in the OBV during the Valsalvi test, as a result of which the floating thrombus, being washed from all sides by the blood flow, took a central position with respect to the axis of the vessel. The Valsalvi test, as well as the test with distal compression, must be used with caution, because in embolic thrombosis they can provoke PE. In relation to OBT, it is the B-mode that has the greatest diagnostic value. With good visualization, one se-

ro-scale mode for a detailed description of all the characteristics of the OBE. Other modes (CFM, energy mapping (EC), V-A^, elastography) are auxiliary. In addition, additional modes are somewhat inherent artifacts that can mislead the doctor. Such artifacts include the phenomenon of “filling” the lumen in the CDI mode in case of non-occlusive thrombosis or, conversely, the complete absence of staining of the lumen of a known patency vessel. There is little chance of diagnosing thrombosis not recognized in B-mode using only ancillary. Also, when drawing up an ultrasound report, you should not completely rely on data obtained only by additional modes.

It was mentioned above that for the competent construction of an ultrasound conclusion, one fact of detecting thrombotic masses in the lumen of a vein is not enough. The conclusion should contain information about the nature of thrombosis, its source, the boundary in relation to ultrasound and anatomical landmarks, and - in the case of floating thrombosis - an individual characteristic of its potential embologenicity. A detailed assessment of these parameters allows you to determine the indications for conservative treatment or surgical prevention of PE, including the choice of its type.

Occlusive OBEs and non-occlusive OBEs of the parietal nature, being completely fixed to the walls of the vessel or on one side, respectively, have a low degree of embologenicity and, as a rule, are treated conservatively. A floating thrombus is a thrombus that has a single fixation point and is surrounded by blood flow from all sides. it

FIGURE 1. Application of the Valsalvi test to improve the visualization of the floating head of a thrombus in B-mode (common femoral vein in the projection of the saphenofemoral anastomosis)

1 - retrograde blood flow in the common femoral vein during straining with the effect of "spontaneous contrast"; 2 - lumen of the common femoral vein; 3 - floating thrombus; 4 - sapheno-femoral fistula

FIGURE 2. Floating thrombi with varying degrees of embologenicity (above, a low-threat PE thrombus; below, a high-threat PE thrombus)

classic definition of FT. However, in different patients with floating thromboses, even with the same length of flotation, the degree of embologenicity will be different, and therefore must be determined individually in real time. So, in a floating thrombus with a small body length and localization in the superficial femoral vein, the embologenicity will be quite low. In a long floating thrombus, which looks like a "worm" and is located in the lumen of the common femoral vein and above, embolism is more dangerous (Fig. 2). Below we will consider in more detail the characteristics of the floating head of a thrombus from the standpoint of determining its embolism.

The need to measure the flotation length, as a rule, is not in doubt, as is the fact that the larger the value obtained, the worse the prognosis in terms of possible thrombus fragmentation. The thickness of the neck of the thrombus and its ratio to the length of the floating head, as well as the amplitude and type of oscillatory (actually floating) movements of the head in the lumen of the vein, characterize the elastic forces of deformation acting on the thrombus, leading to separation. Echo-

The genicity and structure of the thrombus also provide information on the probability of fragmentation: the lower the echogenicity and the less homogeneous the structure of the thrombus, the higher the probability of its fragmentation. In addition to the characteristics of the tip of the floating thrombus, the upper border of the thrombus (the zone where the vessel begins to be completely compressed and no longer contains thrombotic masses) and its source are important to determine the degree of potential embologenicity. The higher the thrombosis limit, the greater the blood flow velocity there. The more fistulas a venous segment has, the more “washing away” turbulent flows there are. The closer the localization of the head of the thrombus to the places of natural folds of the limb (groin, knee), the higher the likelihood of permanent compression of the lumen containing the thrombus. When characterizing the source of thrombosis, it should be remembered that a typical OVT “originates” in small muscle branches that give rise to the medial group of sural veins and progresses from bottom to top, spreading to the popliteal (PV), then to the superficial femoral (SFS), common femoral vein (CFV). ) and higher. Typical

thrombophlebitis is formed in the dilated great saphenous (GSV) and small saphenous (MSV) veins.

The definition and description of a typical OBE on ultrasound is not difficult. A thrombus with an atypical source in some cases remains completely undiagnosed, namely, atypical thromboses are the most embolically dangerous. Sources of atypical OVT may include: deep femoral veins (TFV), pelvic veins, injection sites of narcotic drugs (so-called vascular fistula), site of venous catheter placement and the catheter itself, renal veins, tumor invasion, gonadal veins, hepatic veins , as well as the transition of thrombosis to deep veins through fistulas and communicants of the affected saphenous veins (Fig. 3). Most often, atypical thromboses are floating in nature with weak fixation in the neck and are located in the femoral and iliocaval segments. Interventional OBT (post-injection and post-catheter) are formed at the point of damage (alteration) of the vessel, which is also the only point of fixation of the thrombus. Interventional thromboses are often local

nymi, or segmental, i.e., are determined only in one venous segment (usually, OBV), while the deep veins above and below the thrombus are passable. Another group of atypical OVT is combined deep and superficial vein thrombosis. Among them, according to the ultrasound picture, 3 options can be distinguished: 1. Ascending thrombophlebitis in the GSV basin and thrombosis of the medial group (most often) of the sural veins (occurs through the passage of a blood clot from the superficial veins through the thrombosed perforant veins).

2 Ascending thrombophlebitis in the basin of the GSV and / or SSV with the transition to the deep vein system at the site of the anastomosis of the trunks (sapheno-femoral, sapheno-popliteal phlebothrombosis).

3 Various combinations of the above options, up to CVR thrombosis with multiple float heads. For example, ascending thrombophlebitis in the GSV basin with a transition to OBV at the site of the saphenofemoral fistula (SFJ) plus OBV thrombosis with progression of thrombosis from the deep veins of the leg through the passage of a thrombus from the superficial veins through thrombosed perforators (Fig. 4). The likelihood of developing combined

The study of thrombosis of the superficial and deep vein systems and bilateral PT once again confirms the need to perform a complete ultrasound of the venous blood flow of the system of the inferior vena cava throughout both the primary and dynamic studies.

Atypical thrombosis also includes OVT, which complicates the course of oncological diseases (thrombosis of the renal veins with the transition to the inferior vena cava is not uncommon). Another atypical source is the deep femoral veins, which are most often affected during operations on the hip joint, as well as the pelvic veins, in which thrombosis occurs in a number of diseases of the organs of this region. The most insidious variant of atypical thrombosis is in situ thrombosis. This is a variant of local segmental thrombosis with no apparent source. As a rule, the site of thrombus formation in these cases is the valvular sinuses with a low blood flow velocity in this area. Thrombi in situ often occur in the iliac veins or OBV and in most cases are diagnosed after PE has already taken place, using second-order imaging techniques (computer tomography).

phlebography, angiography) or are not diagnosed at all, thus being the source of "PE without a source", completely breaking away from the vessel wall, leaving no substrate in the lumen of the vein.

The description of mosaic or bilateral OBE should contain detailed information for both lower extremities and for all segments of the lesion separately. The assessment of the potential embolism of a floating thrombus is carried out by a cumulative analysis of its characteristics. To facilitate this process, each of the criteria for the floating head of a thrombus is assigned 1 or 0 conditional points according to the scheme described below (Table 1). The resulting total score gives a more accurate idea of ​​potential PE. Work according to this scheme allows you to avoid missing one or a number of criteria in the assessment and, thus, not only standardize the ultrasound technique, but also improve its effectiveness. When diagnosing an OBE patient with a high risk of PE, it is necessary to understand that he will probably be shown to perform one or another type of surgical prevention of this complication. The main operation in OBT for

FIGURE 3. Various sources of atypical thrombosis (projection of the saphenofemoral anastomosis of the common femoral vein)

1 - source - femoral catheter; 2 - source - cutaneous-vascular fistula (patients with drug addiction); 3 - source - great saphenous vein; 4 - source - deep femoral vein; 5 - source - superficial femoral vein

TABLE 1. Determination of the potential degree of embologenicity of floating phlebothrombosis

Ultrasound criteria Interpretation of ultrasonic criteria Points

Phlebohemodynamics in the zone of localization of the floating head Active 1

Thrombus exit zone Atypical thrombosis 1

Typical thrombosis 0

Neck width to float length ratio (in mm, ratio) Less than 1.0 1

Greater than or equal to 1.0 0

Floatation during quiet breathing Yes 1

Spring effect during Valsalva maneuver Yes 1

Flotation length More than 30 mm 1

Less than 30 mm 0

The structure of the floating head Heterogeneous, low echogenicity, with contour defects or torn top 1

Homogeneous, increased echogenicity 0

Dynamics of thrombosis increase Negative 1

None or minimal 0

Note. Evaluation of the received data. 0-1 point - low degree of potential embologenicity. 2 points - the average degree of potential embologenicity. 3-4 points - a high degree of potential embologenicity. More than 4 points - an extremely high degree of potential embologenicity.

the level of the lower extremities proper is the PMB ligation. A necessary condition for the implementation of this intervention is a statement of the fact of the patency of the GBV, as well as the upper limit of thrombosis. Thus, if the float head moves from the PBV to the PBV, then a thrombectomy from the PBV will be necessary. In this case, information about the length of the flotation and the anatomical landmark of the location of the thrombus apex (for example, relative to the inguinal fold, SPS, fistula of the PMB with distal GBV) will be very important. In case of transition of thrombosis significantly above the level of the inguinal fold, ligation of the external iliac vein (NarIV) is likely to be performed, for which it is also necessary to obtain information about the anatomical landmark of the upper border

thrombosis (for example, its relationship to the anastomosis with the internal iliac vein (SVC) or its distance from the inguinal fold) and patency of the SVC. All this information should be contained in the descriptive part of the ultrasound protocol.

When an embolism-prone OVT is located in the iliocaval segment, implantation of a cava filter or plication of the inferior vena cava (IVC) is most often performed. The cava filter or plication zone should be below the renal orifices.

FIGURE 5. Upper limit of ascending thrombophlebitis of the great saphenous vein

1 - lumen of the common femoral

2 - thrombus in the lumen of the great saphenous vein; arrow - distance to the sapheno-femoral anastomosis

veins to exclude violations of the venous outflow through the renal veins in case of closure of the lumen of the IVC distal to this area. In addition, it is necessary to assess the patency of the renal veins proper, as well as the deep bed of the contralateral side and the veins of the superior vena cava system, since these veins, if patency, will provide access for intervention. It is also necessary to indicate the distance from the top of the thrombus to the renal vein closest to it, since cava filters are of different types and differ from one another at least in their size. For the same purposes, it is necessary to indicate the diameter of the IVC during inhalation and exhalation. When the floating head of the thrombus is located above the mouth of the renal veins, it should be indicated exactly where, in relation to the mouths of the renal veins, thrombosis changes its character from occlusive or parietal to actually floating, and measure the length of flotation. If flotation starts below the renal vein orifices, it is possible to perform endovascular thrombectomy from the IVC. With ascending thrombophlebitis, it is necessary to indicate the upper limit of thrombosis in relation to anatomical landmarks (for example, the distance to the SPS, Fig. 5), as well as the presence and diameter of the upper tributaries of the GSV (in some cases, with severe varicose transformation of the upper tributaries, their diameter is greater than the diameter of the trunk GSV, which can lead to ligation of the wrong vessel). It is also important to state the fact that the lumen of the vessels of the deep channel is intact (OBV, GBV, PBV), excluding the variant of combined thrombosis. As a rule, indications for surgical intervention are set when thrombosis passes to the thigh. It should be remembered that with ascending thrombophlebitis, the true border of thrombosis is practically

tically always above the clinical zone of hyperemia! In case of thrombophlebitis of the GSV with the transition of a thrombus into the lumen of the OBV (combined sapheno-femoral phlebothrombosis), one should remember the need for venotomy and thrombectomy from the OBV, which will require information on the length of the floating head of the thrombus in the lumen of the OBV and the anatomical landmark of localization of its apex in a deep channel . In some cases, in the presence of concomitant thrombosis, it will be necessary to perform simultaneous ligation of the PMB and ligation of the GSV, possibly in combination with thrombectomy. In these cases, information should be given in detail on the deep and superficial channels separately: on thrombophlebitis (thrombosis of superficial veins with or without transition to the deep channel and in relation to anatomical landmarks) and on phlebothrombosis (deep vein thrombosis, also in relation to anatomical landmarks) according to the algorithms described above.

About Repeated Ultrasounds

Ultrasound dynamics of OBT during conservative treatment is interpreted as positive with a decrease in the length of flotation and/or the level of thrombosis, as well as with the appearance of signs of recanalization. Also a positive point is the increase in echogenicity and homogeneity of thrombotic masses, the absence of floating movements. Negative dynamics is the registration of reverse processes. Ultrasound dynamics of OBT in the postoperative period is interpreted as positive if there are no thrombotic masses above the level of deep vein ligation and if there are signs of recanalization of thrombotic masses below the ligation site; with preserved blood

current through the veins above the level of ligation. Ultrasound dynamics is interpreted as negative in the presence of thrombotic masses above the site of deep vein ligation, with lesions of the GBV or the appearance of bilateral phlebo-thrombosis.

According to dynamic ultrasound data, including the degree of recanalization of thrombotic masses in the postoperative period (as well as during conservative treatment), the effectiveness of anticoagulant therapy is assessed, and doses of drugs are adjusted. When performing ultrasound after surgery, one should be aware of the possibility of progression of thrombosis. The greatest risk of this complication arises in a situation where, in addition to ligation of the PBV, thrombectomy from the OBV was performed. With the progression of thrombosis, "fresh" thrombotic masses are located above the site of ligation of the vein. In this case, the HBV, the ligation site itself, or the site of thrombectomy can be the source. The cause of thrombosis progression may be inadequate anticoagulant therapy and / or technical errors of surgical intervention (for example, when ligating a vein above the anastomosis with HVD - this situation is interpreted not as PBV ligation, but as OBV ligation).

With ascending thrombophlebitis of the GSV, ligation of the GSV at the anastomosis with OBV or ostial resection of the GSV can be performed. A possible finding with technical errors in the operation may be a residual GSV stump, often with upper tributaries opening into it or the presence of stump thrombosis. In the presence of a residual stump, the so-called. "Mickey Mouse's second ear", i.e. with a transverse scan in the projection of the groin, 3 gaps are determined

TABLE 2. Decreased mortality from PE

2009 2010 2011 2012 2013 2014 2015

Treated 13,153 1,4229 14,728 15,932 14,949 14,749 10,626

Died 119 132 110 128 143 105 61

Died of PE b 12 11 0 4 3 3

vessel: common femoral artery, OBV and GSV stump opening into it. The GSV stump, especially if the upper tributaries flowing into it, can serve as a source of progression of thrombosis with the transition to OBV. Another finding may be a statement of the actual failure of the operation. This is possible in case of ligation or resection not of the GSV trunk itself, but of one of its large varicose-transformed tributaries. This ultrasound picture should be differentiated from the upper tributary separately flowing into the CWT or from doubling the trunk of the GSW. Simultaneous performance of ostial resection of the GSV and ligation of the GSV (with or without thrombectomy from the GSV) due to concomitant thrombosis during postoperative ultrasound, the blood flow along the GSV, originating only from the GSV, is located. The presence of additional flows in this case may indicate the technical errors of the operation.

The cava filter is located in the form of clear hyperechoic signals, different in shape, depending on the type of filter: like an umbrella or a spiral. The presence of a clear blood flow in the projection of the cava filter, which occupies the entire lumen of the vein during CDI, indicates its complete patency. In the B-mode, the complete patency of the filter is characterized by the absence of thrombotic masses in it, which look like echo-positive fragments.

There are 3 types of thrombotic damage to the cava filter. 1. Filter embolism due to detachment of the floating head of the thrombus (depending on the size of the head occluding it, it can be complete or incomplete, with complete occlusion of the lumen or with the presence of parietal blood flow).

2. Germination of the filter due to the progression of iliofemoral thrombosis. It is also necessary to assess the safety or absence of blood flow in the inferior vena cava.

3. Thrombosis of the filter as a new source of thrombus formation (the cava filter is a foreign body and by itself can serve as an intravenous matrix for thrombus formation).

Extremely rare, single observations are cases of migration of the cava filter above the established position and the progression of thrombosis above the level of the renal veins through the filter (the latter is prevented by blood flow from the renal veins). In the latter case, it is necessary to establish the anatomical landmarks of the upper limit of thrombosis already above the level of the filter, to establish its nature, the presence or absence of flotation, and to measure its length, i.e., to describe all those characteristics that are described in the initial study.

In patients with an implanted cava filter or IVC plication, attention should be paid to the presence or absence of retroperitoneal hematoma, as well as free fluid in the abdominal cavity.

If a patient has been implanted with a removable cava filter, then a combination of two factors determined by ultrasound will be a necessary condition for its removal: the absence of fragments of thrombotic masses in the filter and the absence of embolism-dangerous thrombi in the channel of the inferior vena cava. May have me-

one hundred variants of the flow of floating FT, when there is no embolism in the filter: the head does not come off, but continues to stay at its level for several days, maintaining the threat of separation; at the same time, over time, under the action of anticoagulant therapy, its lysis occurs “in place”. This is the case when the cava filter is removed without fulfilling its intended purpose.

0 Ultrasound in OBT of the superior vena cava system

In most cases, OBT of the upper extremities are occlusive in nature and are not embolism-prone. The authors did not meet the floating nature of the PT of the bed of the superior vena cava in any patient. The bed of the superior vena cava is well accessible for ultrasound, difficulties may arise only when visualizing some fragments of the subclavian veins. Here, as in the study of the iliocaval segment, it is possible to use a convex low-frequency sensor, as well as the use of auxiliary modes. The main information that is required from an ultrasound doctor is to verify the OBT of a superficial or deep channel, or their combined lesion, as well as to describe the occlusive or parietal nature of thrombosis, since thrombosis of the superficial and deep channels has different conservative treatment. Ultrasound becomes especially important

in case of suspected OVT of the bed of the superior vena cava in patients with intravenous catheters (cubital, subclavian). With occlusive thrombosis of the venous segment carrying the catheter, its removal is indicated, and with atypical non-occlusive catheter thrombosis, when thrombotic masses, localized on the catheter, float in the lumen, venotomy with thrombectomy and removal of the catheter is likely. The very fact of diagnosing catheter thrombosis as a probable source of angiosepsis can provide additional information regarding

carrying the severity of the patient's condition and further tactics of its management.

About Conclusion

Ultrasound of venous blood flow is a mandatory study both for the purpose of primary diagnosis of OBE and throughout the entire hospital stage of patient treatment. A wider implementation of ultrasound with a preventive purpose, taking into account the risks of venous thromboembolic complications in the relevant categories of patients, minimizes the onset of both

my TELA, and, accordingly, a lethal outcome from it. The methodology for performing ultrasound of venous blood flow presented in the article, combined with the high frequency of prescribing the study itself, as well as with the active introduction of endovascular methods of surgical prevention of pulmonary embolism (used at the Central Clinical Hospital of the Russian Academy of Sciences since 2012), led to a significant decrease in mortality from pulmonary embolism, which is reflected in Table 2 (2015 - data at the time of submission of the article to the editor as of the beginning of October).

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1 GBUZ of the Republic of Mordovia "Republican Clinical Hospital No. 4"

2 Saratov State Medical University named after I.I. IN AND. Razumovsky Ministry of Health of Russia"

The article discusses the results of sonographic diagnosis of phlebothrombosis of the lower extremities in 334 patients. The main factors in the development of thrombosis in men were polytrauma, combined surgical interventions and cardiovascular diseases; in women - cardiovascular diseases and tumors of the uterus and ovaries. Color duplex scanning of veins allows to detect the presence and level of phlebothrombosis, flotation of thrombotic masses, to evaluate the effectiveness of anticoagulant therapy and surgical prevention of pulmonary embolism. Tactical issues in floating thrombosis of the inferior vena cava system should be addressed individually, taking into account both the location and extent of the proximal part of the thrombus, and the age of the patient and the presence of phlebothrombosis factors. In the presence of embolic thrombosis against the background of severe concomitant pathology and contraindications to open surgery, the installation of a cava filter is a measure for the prevention of pulmonary embolism. In young patients, open or endovascular placement of temporary cava filters is reasonable. Massive thrombosis was detected in 32.0?% of patients on the cava filter after its implantation, and flotation of thrombi below the plication level was found in 17.0?%, which confirms the importance and effectiveness of urgent surgical prevention of pulmonary embolism.

sonography

dopplerography

vein thrombosis

cava filter

veins of the lower extremities

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DIAGNOSIS AND TREATMENT OF FLOATING THROMBOSIS IN THE SYSTEM OF THE VENA CAVA INFERIOR

1 State budgetary institution of health of the Republic of Mordovia "Republican clinical hospital No. 4"

2 Saratov State Medical University. V. I. Razumovsky

Abstract:

The article contains the results of ultrasonic diagnosis of acute venous thrombosis of lower extremities in 334 patients. The main risk factors venous thrombosis in men include injury, combined surgery and severe cardiovascular diseases; in women - cardiovascular diseases and tumors of female genitals. Color duplex scanning of the veins allows to establish the presence and level of the thrombotic process, flotation of a blood clot, to evaluate the effectiveness of treatment and surgical prevention of pulmonary embolism. Tactical issues with floating thrombus in the inferior Vena cava should be decided individually, taking into account both the localization of the proximal part of the thrombus and its extent and age of the patient and factors of the phlebothrombosis. In the presence of this conclusion was thrombosis on the background of severe comorbidity, and contraindications for open surgery to install a Vena cava filter is a measure for the prevention of pulmonary embolism. In patients of young age appropriate to install a removable Vena cava filters, or perform open surgery with a temporary Vena cava filter. From 32.0?% of patients showed thrombosis of the Vena cava filter after implantation, 17.0?% of patients found to have a floating thrombus below the level of plication, which confirms the importance and effectiveness of urgent surgical prevention of pulmonary embolism.

keywords:

venous thrombosis

veins of the lower extremities

Phlebothrombosis of the lower extremities is one of the leading problems of practical phlebology in terms of clinical and scientific significance. They are widespread among the adult population, and drug treatment is not effective enough. At the same time, a high level of incapacity for work and disability remains. Phlebothrombosis is distinguished by the blurring of the clinical picture in the first hours and days of the disease, and the first symptom is pulmonary thromboembolism (PE), which is the leading cause of both general and surgical mortality. In this regard, timely and accurate diagnosis of embolic venous thrombosis using informative, accessible and non-invasive methods is extremely important. Ultrasound Doppler scanning (USDS) has become the main method for diagnosing these phlebothrombosis, which is a potential source of pulmonary thromboembolism.

There are few publications in the literature that cover in detail the ultrasonic characteristics of the embologenicity of a venous thrombus. The leading criteria for the embologenicity of a thrombus are the degree of its mobility and the length and echogenicity of the floating part, the characteristics of the external contour of the thrombus (smooth, uneven, indistinct), the presence of a circular blood flow around the thrombus in the color duplex mapping mode, both in longitudinal and transverse scanning.

Prevention of PE is an essential component of the treatment of patients with acute venous thrombosis. Unfortunately, the use of indirect anticoagulants does not contribute to the prevention of detachment and migration of formed thrombi into the pulmonary arteries. Therefore, when an extended floating and embolic thrombosis is detected, surgical intervention is indicated to prevent the migration of thromboembolus (thrombectomy, plication, or endovascular implantation of a cava filter).

The issue of surgical tactics in case of floating deep vein thrombosis of the extremities should be decided individually, taking into account the localization of the proximal part of the thrombus, its length, flotation, the presence of comorbid and intercurrent pathology.

In the presence of severe intercurrent pathology and contraindications to open surgery in patients with embolic thrombosis of the main veins, the installation of a cava filter is indicated according to absolute indications (contraindications to anticoagulant therapy, embolic thrombosis when surgical thrombectomy is impossible, recurrent PE). At the same time, it is important to take into account the fact of fixation of floating thrombi (the length of a thrombus is not more than 2 cm) and the possibility of conservative treatment tactics.

The unpredictability of the course of venous thrombosis in the system of the inferior vena cava is proved by the diagnosis of floating thrombosis in patients without any clinical signs of venous pathology, the detection of embolic thrombosis in patients with chronic venous diseases, the facts of pulmonary embolism in occlusive forms of deep vein thrombosis.

Purpose of the study: improvement of sonographic diagnostics and results of urgent interventions in patients with acute phlebothrombosis.

Materials and methods of research

We analyzed the results of physical and sonographic diagnosis of phlebothrombosis of the lower extremities in 334 patients who were hospitalized in the state budgetary health care institution of the Republic of Mordovia "Republican Clinical Hospital No. 4". The age of the patients was 20-81 years; 52.4% were women, 47.6% - men; 57.0% of them were able-bodied, and 19.4% were young (Table 1).

Table 1

Gender and age of the examined patients

table 2

Distribution of floating thrombi in the deep vein system of the lower extremities

The largest group of patients was aged 61 years and older (143 people), among men, persons aged 46 to 60 years - 66 (52.3%) people prevailed, among women - aged 61 years and older - respectively 89 (62 .3%) people.

Phlebothrombosis in men under the age of 45 was more common in people who abuse intravenous psychoactive substances. At the age of 60 years or more, the number of female patients begins to predominate over males, which is explained by the predominance of other risk factors in women: gynecological diseases (large uterine fibroids, ovarian tumors), coronary artery disease, obesity, injuries, varicose veins and others. The decrease in the incidence in the general population in men aged 60 years and over is explained by a decrease in their proportion in the corresponding age groups, high mortality from PE, the development of chronic venous insufficiency and post-thrombophlebitic syndrome.

Ultrasonographic diagnostics and echoscopic monitoring were carried out on ultrasonic devices Vivid 7 (General Electric, USA), Toshiba Aplio, Toshiba Xario (Japan), operating in real time using convex probes 2-5, 4-6 MHz and linear probes with a frequency of 5 -12 MHz. The study began with a projection of the femoral artery (in the inguinal region) with an assessment of blood flow in transverse and longitudinal sections relative to the longitudinal axis of the vein. At the same time, the blood flow of the femoral artery was assessed. When scanning, the diameter of the vein, its compressibility (by compressing the vein with a sensor until the blood flow stops while maintaining blood flow in the artery), the state of the lumen, the safety of the valvular apparatus, the presence of changes in the walls, the state of the paravasal tissues were evaluated. The state of hemodynamics of the veins was assessed using functional tests: respiratory and cough tests or tests with straining. At the same time, the state of the veins of the thigh, popliteal vein, veins of the lower leg, as well as the large and small saphenous veins were assessed. The assessment of the hemodynamics of the inferior vena cava, as well as the iliac, great saphenous, femoral and veins of the leg in the distal section was performed with the patient lying on his back. The study of the popliteal veins, veins of the upper third of the leg and the small saphenous vein was carried out with the patient lying on his stomach with a roller placed under the area of ​​the ankle joints. To study the main veins and in case of difficulties in the study, a convex probe was used, otherwise linear probes were used.

Cross-sectional scanning was performed to detect the mobility of the thrombus head, as evidenced by the complete contact of the venous walls with slight compression by the transducer. During the examination, the nature of phlebothrombosis was established: parietal, occlusive or floating.

The list of laboratory diagnostic methods included the determination of the level of D-dimer, coagulogram, and the study of thrombophilia markers. If PE was suspected, the examination complex also included computed tomography in the angiopulmonography mode and examination of the abdominal cavity and small pelvis.

For the purpose of surgical prevention of PE in acute phlebothrombosis, 3 methods of surgery were used: implantation of a cava filter, plication of a vein segment, and crossectomy and/or phlebectomy. In the postoperative period, ultrasound diagnostics was aimed at assessing the state of venous hemodynamics, the degree of recanalization or increased thrombotic process in the venous system, the presence or absence of thrombus fragmentation, the presence of flotation, thrombosis of the veins of the contralateral limb, thrombosis of the plication zone or cava filter, and linear and volumetric blood flow velocities were determined. and collateral circulation.

Statistical analysis was performed using the Statistica program. Evaluation of differences in results between groups was carried out according to Pearson's criteria (carried out according to Pearson's criteria) and Student's (t). Differences were considered statistically significant, the significance level of which was more than 95% (p< 0,05).

Research results and discussion

The leading sign of phlebothrombosis was the presence of echopositive thrombotic masses in the lumen of the vessel, the density of which increased as the age of the thrombus increased. At the same time, the valve leaflets ceased to differentiate, the transmission pulsation from the artery was not detected, the diameter of the thrombosed vein increased by 2–2.5 times compared to the contralateral vessel, and it is not compressed by the transducer. At the onset of the disease, when thrombi are visually indistinguishable from the normal lumen of the vein, we consider it especially important to perform compression ultrasonography. On the 3rd-4th day of the disease, thickening and thickening of the venous wall due to phlebitis was noted, perivasal tissues became "blurred".

Parietal thrombosis was diagnosed in the presence of a thrombus, free blood flow in the absence of complete contact of the walls during a compression test, the presence of a filling defect in duplex scanning and spontaneous blood flow in spectral Doppler sonography.

The criteria for floating thrombosis were the visualization of a thrombus in the lumen of the vein with the presence of free space and blood flow around the head, the movement of the head of the thrombus in time with cardiac activity, during the test by straining or compression with a vein sensor, the absence of contact of the venous walls during the compression test, the envelope type of blood flow, the presence of spontaneous blood flow with spectral dopplerography. For the final clarification of the nature of the thrombus, the Valsalva test was used, which, however, is dangerous due to the additional flotation of the thrombus.

Thus, according to color duplex scanning, floating thrombi were found in 118 (35.3%) cases. Most often they were detected in the system of deep veins of the pelvis and thigh (in 45.3% - in the deep veins of the thigh, in 66.2% - in the iliac veins), less often in the system of deep veins of the leg and the great saphenous vein of the thigh. There was no difference in the frequency of thrombus flotation in men and women.

The frequency of floating phlebothrombosis has increased in recent years, which is associated with color duplex scanning in all patients before surgery, in long-term immobilization, as well as without fail in patients with limb injuries and after operations on the osteoarticular system. We believe that, despite the obvious clinical picture of the presence of superficial varicothrombophlebitis, there is always a need for CDS to exclude subclinical floating thrombosis in both superficial and deep veins.

As is known, coagulation processes are accompanied by activation of the fibrinolytic system, and these processes run in parallel. For clinical practice, the fact of establishing both the flotation of a thrombus, the nature of the spread of a thrombus in a vein, and the probability of its fragmentation during recanalization is very important.

In CDS of the lower extremities, it is important: non-floating thrombi were found in 216 (64.7%) patients, of which occlusive thrombosis was found in 181 (83.8%) patients, non-occlusive parietal thrombosis - in 35 (16.2%).

Parietal thrombi were detected as masses fixed to the walls of the veins over a considerable extent. At the same time, the lumen of the vein between the thrombotic masses and the wall itself was preserved. In the course of anticoagulant therapy, parietal thrombi can fragment, cause an embolism-threatening state and recurrent embolism of small branches of the pulmonary artery. With mobile and floating thrombi, soldered to the venous wall only in its distal part, a real and high risk of thrombus separation and pulmonary embolism is created.

Among the non-occlusive forms of thrombosis, a dome-shaped thrombus can be distinguished, the sonographic features of which are a wide base equal to the diameter of the vein, the absence of oscillatory movements in the blood flow, and the length of the thrombus up to 4 cm. The risk of pulmonary embolism in this variant of thrombosis is low.

Repeated color duplex scans were performed in all patients until the moment of fixation of the floating tail of the thrombus to the vein wall, then in the period from 4 to 7 days of treatment and always before the patient was discharged.

Patients with floating thrombi underwent ultrasound angioscanning of the veins of the lower extremities on the day of surgery, as well as 48 hours after cava filter implantation or venous plication (figure). Normally, during longitudinal scanning of the inferior vena cava, the cava filter is visualized as a hyperechoic structure, the shape of which depends on the model of the filter. The position of the cava filter in the vein at the level or slightly distal to the orifices of the renal veins or at the level of 1-2 lumbar vertebrae was considered typical. With CDS, an expansion of the lumen of the vein is usually noted at the site of the filter.

According to the data of color duplex scanning after implantation of cava filters in 8 (32.0 %) of 25 patients, fixation of massive thrombi was detected on the filter. The segment of the vein in the area of ​​plication was passable in 29 (82.9%) of 35 patients, 4 (11.4%) had continued thrombosis below the site of plication, and 2 (5.7%) had no blood flow in the area of ​​plication at all. to determine, and the blood flow was carried out only along the collateral pathways.

Inferior vena cava with transducer installed. A colored blood flow is visible (blue - flowing to the sensor, red - flowing from the sensor). On the border between them, a normally functioning cava filter

It has been established that the implantation of a cava filter contributes to the progression of the thrombotic process and increases the frequency of recurrence of thrombosis, which can be explained, among other things, not only by the progression of the process, but also by the presence of a foreign body in the lumen of the vein and slowing down of the main blood flow in this segment. The frequency of cases of thrombosis progression in patients who underwent plication and were treated only with medication is almost the same, but it is significantly lower compared to that after endovascular interventions.

conclusions

1. The main risk factors for phlebothrombosis in men include combined trauma, combined surgical interventions, and the presence of severe cardiovascular diseases; in women - severe diseases of the cardiovascular system and genitals.

2. The advantages of color duplex scanning include the possibility of objective monitoring of the presence and level of a thrombotic process, thrombus flotation, evaluating the effectiveness of drug therapy, monitoring the course of phlebothrombosis after surgical prevention of pulmonary embolism. Ultrasonography allows solving tactical issues in floating thrombi individually, taking into account both the localization of the proximal part of the thrombus, its length, the nature of the thrombotic process and phlebothrombosis factors.

3. In the presence of embolic thrombosis against the background of severe concomitant pathology and contraindications for open surgery, the installation of a cava filter is a measure for the prevention of pulmonary embolism. In young patients, it is advisable to install removable cava filters or perform open operations with the installation of a temporary cava filter.

4. In 32.0% of patients, massive thrombi were found on the cava filter after its endovascular implantation; in 17.0% of cases, floating thrombi were found below the site of vein plication. These data indicate the effectiveness of PE prevention by surgical treatment of floating embologenic thrombosis in the inferior vena cava system.

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