home Calculators Scientific review. Medical Sciences. Possibilities of ultrasound examination of deep vein thrombosis of the lower extremities Ultrasound diagnosis of thrombosis of the great veins

Scientific review. Medical Sciences. Possibilities of ultrasound examination of deep vein thrombosis of the lower extremities Ultrasound diagnosis of thrombosis of the great veins

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

ULTRASONIC DIAGNOSTICS 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 blood clots were detected on the vena cava filter after its implantation; in 17% of patients, floating blood clots were found below the site of vein plication, which confirms the need for urgent surgical prevention of pulmonary embolism and its high effectiveness.

Key words: sonography, Dopplerography, venous thrombosis, thrombus, vena 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 clots 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 in 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 clinical picture is erased, 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. The CDS of the lower extremities meets these criteria, although there are not many works devoted to the study of echosemiotics of floating thrombi. There is still no common point of view in defining 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 in 2011-2012 who were hospitalized in the department of vascular surgery of the state budgetary healthcare 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 of working age, and 19.5% were young. Basic information on the distribution of patients by gender and age is presented in Table 1.

Table 1

Distribution of patients by gender and age_

Up to 45 years old 45-60 years old 60 years old and older

Abs. quantity % Abs. quantity % Abs. quantity % Abs. quantity %

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 largest cohort of patients was the group aged 60 years and older (143 people); among men, persons aged 45 to 60 years predominated - 66 people (52.3%), among women aged 60 and older - 89 (62). .3%) people.

Acute venous thrombosis occurs more often in men under the age of 45 years, which is associated with the abuse of intravenous substances, and at the age of 60 years or more, the number of female patients begins to predominate over male patients. This can be explained by the fact that other risk factors begin to predominate in women: gynecological diseases, coronary artery disease, obesity, trauma, varicose veins, etc. The decrease in incidence in the general population in men aged 60 years or more is explained by a decrease in their share in the corresponding age groups , short life expectancy, high mortality from pulmonary embolism, development of chronic venous insufficiency and post-trophbophlebitis 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 groin area in transverse and longitudinal sections in relation to the vascular bundle. The blood flow of the adjacent artery was assessed. When obtaining an image of the veins, the following parameters were assessed: diameter, compressibility (compression by the sensor until the blood flow in the vein stops while blood flow in the artery is maintained), course features, the state of the internal lumen, the safety of the valve apparatus, changes in the walls, the condition 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 a straining test. At the same time, the condition of the veins of the thigh, popliteal vein, veins of the leg, as well as the great and small saphenous veins was assessed. When scanning the IVC, iliac vein, great saphenous vein, 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 the small saphenous vein was carried out with the patient lying on his stomach with a cushion placed under the ankle joints. To study the main veins and in case of difficulties in the study, convex sensors were used, otherwise linear sensors were used.

For the purpose of surgical prevention of pulmonary embolism in acute phlebothrombosis, 3 surgical methods were used: installation of a vena cava filter, plication of a vein segment, and crossectomy and/or phlebectomy. In the postoperative period, ultrasound diagnostics aimed to assess the state of venous hemodynamics, the degree of recanalization or intensification of the 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 vena cava filter, and the linear and volumetric blood flow rates were determined and collateral blood flow. 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 echo-positive 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 transmitting arterial pulsation disappeared, and the diameter increased

thrombosed vein 2-2.5 times compared to the contralateral vessel; when compressed by the sensor, it is not compressed. 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 3-4th day of the disease, condensation and thickening of the vein walls occurred due to phlebitis, and the perivasal structures became “blurred.”

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

The criteria for a floating thrombus were visualization of a thrombus in the lumen of the vein with the presence of free space, oscillatory movements of the head of the thrombus, absence of contact of the vein walls during compression with a sensor, the presence of free space when performing respiratory tests, a circumflex type of blood flow, and the presence of spontaneous blood flow during spectral Dopplerography. To finally determine the nature of the thrombus, the Valsalva maneuver was used, which poses a danger due to additional flotation of the thrombus.

Thus, according to ultrasound diagnostic data, floating thrombi were detected in 118 (35.3%) patients (Fig. 1).

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

Figure 1. 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 great veins.

ileofemoral segment

deep veins of the thigh

popliteal vein and veins of the leg

saphenous vein of thigh

saphenous vein of the thigh. There were no differences in the frequency of floating thrombi in the deep system between men and women.

In 2011, the incidence of floating thrombosis was 29.1% of all those examined, which is 1.5 times less than in 2012 (Table 2). This is due to ultrasound diagnostics in all patients entering the clinic, as well as in cases of suspected acute pathology of the venous system. This fact is confirmed by the fact that in 2012, the proportion of patients in whom floating thrombi in the superficial system were identified only according to CDS data increased significantly. In this regard, the presence of superficial varicothrombophlebitis, despite a clear clinical picture, dictates the need to perform 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- I float- When- I float- When- I float-

Honoring blood clots Honoring blood clots Honoring 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%)

calf 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 occur in parallel. For clinical practice, it is very important to establish not only the flotation of the thrombus, but also the nature of the spread of the thrombus in the vein, the possibility of its fragmentation during the process of recanalization.

During CDS of the lower extremities, non-floating thrombi were identified in 216 patients (64.7%): occlusive thrombosis was detected in 183 patients (54.8%), non-occlusive mural thrombosis - in 33 (9.9%).

Parietal thrombi were most often fixed to the walls of the vein along their length and were characterized by maintaining a lumen between the thrombotic masses and the venous wall. However, they can fragment and migrate into the pulmonary circulation. When floating thrombi are fused 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

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

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

In patients with floating thrombi, ultrasound angioscanning of the veins of the lower extremities was mandatory before surgery, as well as 48 hours after implantation of a vena cava filter or vein plication (Fig. 2). Normally, during longitudinal scanning, the vena 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 the vena cava filter is at the level of or just distal to the orifices of the renal veins or at the level of the 1st or 2nd lumbar vertebrae. Usually there is an expansion of the lumen of the vein in the filter area.

Fig 2. Inferior vena cava with installed sensor. A colored blood flow is visible (blue flowing to the sensor, red flowing from the sensor). At the border between them there is a normally functioning vena cava filter.

According to color duplex scanning data, after installation of vena cava filters, 8 (32%) of 25 patients had massive thrombus fixation 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 area of plication was not possible at all visualize.

It should be noted that the rate of progression of the thrombotic process and recurrence of thrombosis is highest in patients who have undergone caval implantation.

filter, which can be explained by the presence of a foreign body in the lumen of the IVC, changing the nature of blood flow in the segment. The frequency of recurrent thrombosis in patients who underwent plication or were treated only conservatively is almost the same and is significantly lower in comparison with the same indicator after endovascular interventions.

Conclusions. The leading risk factors for thrombosis 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 allows you to determine the presence and level of a thrombotic process in a vein, flotation of blood clots, evaluate the effectiveness of drug therapy, and monitor the course of phlebothrombosis after surgical prevention of pulmonary embolism. After endovascular implantation, massive thrombi were detected on the vena cava filter in 32% of patients; after vein plication, floating thrombi were found in 17% of patients below the surgical site, which confirms the feasibility and high effectiveness 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.: LLC STROM, 2007. - 512 p.

4. Savelyev V. S., Gologorsky V. A., Kirienko A. I., etc. Phlebology. Guide for doctors / 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 “Territory of Safety” project) // Phlebology. - 2010. - No. 3. - P. 3-8.

6. Savelyev V. S., Kiriyenko A. I. Clinical surgery: national manual: 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 embologenicity of venous thrombosis // Angiol and vascular surgery. -2005. - No. 1. - P. 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.

10. Snow V., Qaseem A., Barry P. et al. Management of venous thromboembolism: a clinical practice guideline from the American College of Physicians and the American Academy of Family Physicians // Ann. Fam. Med. - 2007. - pp. 74-80.

Book "Ultrasound diagnosis of acute venous thrombosis"

ISBN: 978-5-900094-51-9

The guide reflects issues of variable anatomy of the superior and inferior vena cava systems, presents the basic principles and features of ultrasound examination in patients with suspected acute venous pathology, and highlights issues of differential diagnosis. Particular attention is paid to the role of ultrasound diagnostics in determining the potential embologenicity of phlebothrombosis as the basis for developing individual angiosurgical tactics. Separately, the issues of ultrasound diagnosis of venous thrombosis with an atypical source of formation are considered as the reason for the diagnosis of “PE from an unknown source”. The principles of dynamic ultrasound examination, including for surgical prevention of pulmonary embolism, are described in detail. The chapter devoted to special cases of venous thrombosis examines the issues of diagnosing this pathology of interventional origin. The manual comes with a CD with video clips of the research. The publication contains clinical examples, as well as illustrated and commentary protocols for ultrasound examinations for various types of venous thrombosis. A separate appendix is devoted to comments on video clips that complement the visual content of the publication. Intended for ultrasound diagnostic doctors, cadets of primary retraining cycles in the specialty “ultrasound diagnostics”, senior students of medical universities, phlebologists and doctors of other clinical disciplines, in whose practice acute venous pathology occurs.

Methodology of ultrasound examination in the diagnosis of acute venous thrombosis

Research methodology

Ultrasound techniques for determining the presence of acute venous thrombosis

Ultrasound characteristics of acute venous thrombosis

Combined thrombosis of deep and superficial veins

Ultrasound criteria and algorithm for determining the potential embologenicity of floating phlebothrombosis

Ultrasound criteria for assessing the embologenicity of floating phlebothrombosis

Location and hemodynamics in the area of the floating thrombus head

Source of thrombosis

Neck width and flotation length, their ratio

Flotation with quiet breathing

Spring effect during Valsalva maneuver

Structure of a floating thrombus head

Dynamics of increase in the level and/or length of thrombus flotation

Algorithm for determining the degree of potential embologenicity of floating phlebothrombosis

Features of ultrasound examination before performing surgical prevention of pulmonary embolism

Differential diagnosis of acute venous thrombosis

Special cases of acute venous thrombosis

Phlebothrombosis in cancer patients

Phlebothrombosis in pregnant women

Interventional phlebothrombosis

Dynamic ultrasound examination in the treatment of acute venous thrombosis

With conservative treatment

With conservative treatment when signs of recanalization appear

For surgical prophylaxis of pulmonary embolism

After vena cava filter implantation

In extreme cases of negative dynamics of acute venous thrombosis

Ultrasound diagnosis of atypical venous thrombosis as

one of the methods for differential diagnosis of pulmonary embolism from an unknown source

Features of ultrasound examination

acute venous thrombosis of the superior vena cava system

Examples of ultrasound protocols

List of abbreviations

Annex 1

Test questions

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 inferior vena cava (IVC) system is the most common and dangerous type of this pathological process and is the main source of pulmonary embolism (84.5%). The superior vena cava system accounts for 0.4-0.7% of pulmonary embolisms (PE), the right side of the heart - 10.4%. 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 intravitally in 19.2% of patients. In the long term, deep vein thrombosis (DVT) leads to the formation of postthrombophlebitic 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 of blood flow (stasis), hypercoagulation, injury to the vessel wall (endothelial damage). 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. Predisposing factors for DVT are also considered obesity, pregnancy, taking 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. Elderly and senile patients 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 femoral fractures are mainly found in elderly and senile people, most burdened by somatic diseases. Thrombosis in trauma patients can occur with any injury to the lower extremities, since all etiological factors of thrombosis (vascular damage, venous stagnation and changes in blood coagulation properties) occur.

Reliable diagnosis of phlebothrombosis is one of the current clinical problems. Physical examination methods make it possible to make a correct diagnosis only in typical cases of the disease, and the frequency of diagnostic errors reaches 50%. For example, thrombosis of the veins of the calf muscles with preserved patency of the remaining veins is often asymptomatic. Because of the danger of missing acute DVT of the legs, clinicians often make this diagnosis in every case of pain in the calf muscles. 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 of DVT. Sometimes the first and only manifestation of such thrombosis is massive pulmonary embolism.

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

Venous thrombosis is a fairly dynamic process. Over time, the processes of retraction, humoral and cellular lysis help reduce the size of the thrombus. At the same time, processes of its organization and recanalization are underway. In most cases, vascular patency is gradually restored, the valve apparatus of the veins is destroyed, and the remains of blood clots in the form of wall overlays deform the vascular wall. Difficulties in diagnosis may arise when repeated acute thrombosis occurs against the background of partially recanalized veins in patients with postthrombophlebitic disease. In this case, a fairly reliable criterion is the difference in vein diameter: in patients with signs of recanalization of thrombus masses, the vein diameter decreases due to the subsidence of the acute process; with the development of rethrombosis, there is again a significant increase in the diameter of the vein with unclear (“blurred”) contours of the walls and surrounding tissues. The same criteria are used in the differential diagnosis of acute parietal thrombosis with postthrombotic 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 blood vessels in B-mode, analysis of the Doppler frequency shift in the form of classical spectral analysis and flow (in speed and energy modes). The use of spectral technology made it possible to accurately measure blood flow inside the lumen of the veins. The use of method () made it possible to quickly distinguish occlusive from non-occlusive thrombosis, identify the initial stages of recanalization of thrombi, and also determine the location and size of venous collaterals. In dynamic studies, the ultrasound method allows for fairly accurate monitoring of the effectiveness of thrombolytic therapy. In addition, with the help of ultrasound, it is possible to determine the causes of clinical symptoms similar to those in venous pathology, for example, to identify a Baker's cyst, intermuscular hematoma or tumor. The introduction into practice of expert-class ultrasonic devices with sensors with frequencies from 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 calf muscle (usually of a bursting nature), “pulling” pain in the popliteal region, pain and compaction along the saphenous veins. Upon examination, moderate cyanosis of the leg and foot, dense swelling, pain on palpation of the leg muscles were revealed; in most patients, positive Homans and Moses symptoms.

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

The scan was started in cross-section to exclude the presence of a floating tip of the thrombus, as evidenced by complete contact of the venous walls during light compression with the sensor. After making sure that there was no freely floating tip of the thrombus, a compression test with a sensor was carried out from segment to segment, from proximal to distal sections. The proposed method is the most accurate not only for detecting thrombosis, but also for determining its extent (excluding the iliac veins and IVC, where the patency of the veins was determined in the CD mode). veins confirmed the presence and characteristics of venous thrombosis. In addition, longitudinal sectioning was used to locate the anatomical venous confluence. During the examination, the condition of the walls, the lumen of the veins, the localization of the thrombus, its extent, 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. Signs of parietal thrombosis were considered to be 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 when the vein is compressed by a sensor, the presence of a filling defect during color circulation, and the presence of spontaneous blood flow during spectral Dopplerography (Fig. 1).

Rice. 1. Non-occlusive thrombosis of the popliteal vein. Longitudinal scanning of the vein. Envelope blood flow in energy flow coding mode.

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

Research results

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

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

Table 1. Conditions with 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 systems was observed in 14%, including 5 patients with involvement of perforating veins.

The probable causes (risk factors) of the development of venous thrombosis are presented in table. 2.

table 2. Risk factors for thrombosis.

Risk factor	Number of patients
Risk factor	abs.	%
Trauma (including long-term plaster immobilization)	41	31,0
Varicose veins	26	19,7
Malignant neoplasms	23	17,4
Operations	16	12,1
Taking hormonal medications	9	6,8
Thrombophilia	6	4,5
Chronic limb ischemia	6	4,5
Iatrogenic causes	5	4,0

In our observations, the most common form of thrombosis was detected, as well as damage to the veins at the level of the popliteal-tibial 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 mural thrombi. Floating thrombi were diagnosed in 6.8% of cases: in 1 patient - in the saphenofemoral anastomosis with ascending thrombosis of the trunk of the great saphenous vein, in 1 - ileofemoral thrombosis with a floating apex in the common iliac vein, in 5 - in the common femoral vein with thrombosis of the femoral-popliteal vein 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 the 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), with the hyperechoic component predominant in the distal section, and the hypoechoic component in the area of the thrombus head (Fig. 2).

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

Over time, 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 (with longitudinal and transverse scanning in the color flow mode, the recanalization channel was visualized in the center of the vessel); in 23 (35%) patients, parietal recanalization of thrombotic masses was diagnosed (most often, blood flow was determined along the wall of the vein directly adjacent to the artery of the same name); In 13 (20.6%) patients, incomplete recanalization was detected with fragmentary asymmetric staining in the Color Doppler mode. Thrombotic occlusion of the vein lumen was observed in 5 (6.1%) patients; in 6 (7.3%) cases, restoration of the vein lumen was noted. Signs of rethrombosis persisted in 8 (9.8%) patients.

conclusions

A comprehensive ultrasound examination, including angioscanning using spectral, color and power Doppler modes and echography of soft tissues, is a highly informative and safe method that allows the most reliable and quick solution to issues of differential diagnosis and treatment tactics in outpatient phlebological practice. It is advisable to conduct this study on an outpatient basis for earlier identification of patients for whom thrombolytic therapy is not indicated (and sometimes contraindicated), and to refer them to specialized departments; when confirming the presence of venous thrombosis, it is necessary to identify individuals at high risk of developing thromboembolic complications; monitor the dynamics of the thrombotic process and thereby adjust treatment tactics.

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

2 Federal State Budgetary Educational Institution of Higher Education “Saratov State Medical University named after. 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 for 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 makes it possible to identify the presence and level of phlebothrombosis, flotation of thrombotic masses, and assess the effectiveness of anticoagulant therapy and surgical prevention of pulmonary embolism. Tactical issues in case of floating thrombosis of the inferior vena cava system should be resolved individually, taking into account both the localization and extent of the proximal part of the thrombus, as well as 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, installation of a vena cava filter is a measure to prevent pulmonary embolism. In young patients, open or endovascular installation of temporary vena cava filters is advisable. In 32.0?% of patients with a vena cava filter after its implantation, massive thrombosis was detected, and in 17.0?%, flotation of thrombi was detected below the level of plication, which confirms the importance and effectiveness of urgent surgical prevention of PE.

sonography

dopplerography

vein thrombosis

vena 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

Ipatenko T.V. 1 Davydkin V.I. 2 Shchapov V.V. 1 Savrasov T.V. 1, 2 Makhrov V.V. 1 Shirokov I.I. 2

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 of 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 it is appropriate to install a removable Vena cava filters, or perform open surgery with a temporary Vena cava filter. From 32.0?% 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 in 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 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. Doppler ultrasound scanning (USD) has become the main method for diagnosing these phlebothrombosis, which is a potential source of the development of pulmonary thromboembolism.

There are few publications in the literature that detail the ultrasound characteristics of embologenicity of 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, fuzzy), the presence of a circular blood flow around the thrombus in color duplex mapping mode both in longitudinal and transverse scanning.

Prevention of pulmonary embolism is an integral component of the treatment of patients with acute venous thrombosis. Unfortunately, the use of indirect anticoagulants does not help prevent the separation and migration of formed blood clots into the pulmonary arteries. Therefore, when extensive floating and embolic thrombosis is detected, surgical intervention aimed at preventing thromboembolic migration (thrombectomy, plication or endovascular implantation of a vena cava filter) is indicated.

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

In the presence of severe intercurrent pathology and contraindications to open surgery in patients with embolic-dangerous thrombosis of the main veins, installation of a vena cava filter is indicated according to absolute indications (contraindications to anticoagulant therapy, embolic-dangerous thrombosis when it is impossible to perform surgical thrombectomy, recurrent pulmonary embolism). In this case, it is important to take into account the fact of fixation of floating blood clots (the length of the blood clot is no more than 2 cm) and the possibility of conservative treatment tactics.

The unpredictability of the course of venous thrombosis in the inferior vena cava system is proven 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 diagnosis and results of urgent interventions in patients with acute phlebothrombosis.

Materials and research methods

We analyzed the results of physical and sonographic diagnostics of phlebothrombosis of the lower extremities in 334 patients who were hospitalized in the state budgetary healthcare 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% were men; 57.0% of them were of working age, and 19.4% were young (Table 1).

Table 1

Gender and age of examined patients

table 2

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

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

Phlebothrombosis in men under 45 years of age was more common in individuals who abuse intravenous substances. At the age of 60 years or more, the number of female patients begins to predominate over male patients, which is explained by the predominance of other risk factors in women: gynecological diseases (large uterine fibroids, ovarian tumors), coronary artery disease, obesity, trauma, varicose veins and others. The decrease in incidence in the general population in men aged 60 years or more is explained by a decrease in their proportion in the corresponding age groups, high mortality from pulmonary embolism, the development of chronic venous insufficiency and postthrombophlebitis 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 sensors 2-5, 4-6 MHz and linear sensors with a frequency of 5 -12 MHz. The study began with a projection of the femoral artery (in the groin area) with an assessment of blood flow in the transverse and longitudinal sections in relation to the longitudinal axis of the vein. At the same time, the blood flow of the femoral artery was assessed. During 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 valve apparatus, the presence of changes in the walls, and the condition of the paravasal tissues were assessed. The hemodynamic state of the veins was assessed using functional tests: respiratory and cough tests or straining tests. At the same time, the condition of the veins of the thigh, popliteal vein, veins of the leg, as well as the great and small saphenous veins was assessed. The hemodynamics of the inferior vena cava, as well as the iliac, great saphenous, femoral and distal calf veins were assessed 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 cushion placed under the ankle joints. To study the main veins and in case of difficulties in the study, convex sensors were used, otherwise linear sensors were used.

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

The list of laboratory diagnostic methods included determination of D-dimer level, coagulogram, and study of thrombophilia markers. If a history of pulmonary embolism is suspected, the examination also included computed tomography in angiopulmonography mode and examination of the abdominal cavity and pelvis.

For the purpose of surgical prevention of pulmonary embolism in acute phlebothrombosis, 3 surgical methods were used: implantation of a vena cava filter, plication of a vein segment, and crossectomy and/or phlebectomy. In the postoperative period, ultrasound diagnostics aimed to assess the state of venous hemodynamics, the degree of recanalization or intensification of the 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 vena cava filter, and the linear and volumetric blood flow rates were determined and collateral blood flow.

Statistical analysis was performed using the Statistica program. Differences in results between groups were assessed using Pearson's (Pearson's) and Student's tests (t). Differences with a significance level of more than 95% were considered statistically significant (p< 0,05).

Research results and discussion

The leading sign of phlebothrombosis was the presence of echo-positive thrombotic masses in the lumen of the vessel, the density of which increased as the age of the thrombus increased. In this case, the valve leaflets ceased to differentiate, the transmitting pulsation from the artery was not determined, the diameter of the thrombosed vein increased by 2-2.5 times compared to the contralateral vessel, and when compressed by the sensor, it is not compressed. At the beginning of the disease, when blood clots are visually indistinguishable from the normal lumen of the vein, we consider it especially important to perform compression ultrasonography. On the 3-4th day of the disease, compaction and thickening of the venous wall due to phlebitis was noted, and the 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 ultrasound.

The criteria for floating thrombosis were visualization of a thrombus in the lumen of the vein with the presence of free space and blood flow around the head, movement of the head of the thrombus in rhythm with cardiac activity, when testing by straining or compression with a vein sensor, absence of contact of the venous walls during a compression test, an enveloping type of blood flow, the presence of spontaneous blood flow with spectral Dopplerography. To finally determine the nature of the thrombus, the Valsalva maneuver was used, which, however, poses a danger due to additional flotation of the thrombus.

Thus, according to color duplex scanning data, floating thrombi were detected 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 were no differences in the incidence of thrombus flotation between 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 who are in long-term immobilization, as well as mandatory 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 to perform 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 occur in parallel. For clinical practice, the fact of establishing both the flotation of a blood clot, the nature of the spread of a blood clot in a vein, and the likelihood of its fragmentation during the process of recanalization is very important.

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

Parietal thrombi were detected as masses fixed to the walls of the veins over a significant extent. At the same time, the lumen of the vein between the thrombotic masses and the wall itself was maintained. During anticoagulant therapy, parietal thrombi can fragment, causing an embolic state and recurrent embolism of small branches of the pulmonary artery. With mobile and floating thrombi, fused to the venous wall only in its distal section, a real and high risk of thrombus rupture and pulmonary embolism is created.

Among the non-occlusive forms of thrombosis, one can distinguish a dome-shaped thrombus, the sonographic signs 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 with this type of thrombosis is low.

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

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

According to color duplex scanning data after implantation of vena cava filters, fixation of massive blood clots was detected on the filter in 8 (32.0%) of 25 patients. The vein segment in the area of plication was passable in 29 (82.9%) of 35 patients, in 4 (11.4%) continued thrombosis was detected below the plication site, in 2 (5.7%) blood flow in the area of plication was not possible at all determine, and blood flow was carried out only through collateral pathways.

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

It has been established that implantation of a vena cava filter promotes the progression of the thrombotic process and increases the frequency of recurrent 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 a slowdown in the main blood flow in this segment. The incidence 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 the same indicator after endovascular interventions.

conclusions

1. The main risk factors for phlebothrombosis in men include concomitant 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 ability to objectively monitor the presence and level of the thrombotic process, flotation of blood clots, evaluate the effectiveness of drug therapy, and monitor the course of phlebothrombosis after surgical prevention of pulmonary embolism. Ultrasonography allows you to solve tactical issues with floating thrombi individually, taking into account both the localization of the proximal part of the thrombus, its extent, 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 to open surgery, installation of a vena cava filter is a measure to prevent pulmonary embolism. In young patients, it is advisable to install removable vena cava filters or perform open operations with the installation of a temporary vena cava filter.

4. In 32.0% of patients, massive thrombi were detected on the vena 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 through surgical treatment of floating embologenic thrombosis in the inferior vena cava system.

Bibliographic link

Ipatenko V.T., Davydkin V.I., Shchapov V.V., Savrasova T.V., Makhrov V.V., Shirokov I.I. DIAGNOSTICS AND TREATMENT OF FLOATING THROMBOSIS IN THE INNER VENA CAV SYSTEM // Scientific review. Medical Sciences. – 2017. – No. 6. – P. 34-39;
URL: https://science-medicine.ru/ru/article/view?id=1045 (access date: 01/27/2020). We bring to your attention magazines published by the publishing house "Academy of Natural Sciences"