Analysis of dopplerography of the arteries of the lower limb

In healthy individuals, the location of NPA, OBA, PKA was performed in all examined. When the vessels were damaged, blood flow signals were not received in the NSA in 1.7% of the examined patients, in the OBA in 2.6%, in the PKA in 3.7%, which in 96% of the examined patients was due to occlusion of the vessel in the study zone, angiography. Signals of one of the arteries: ZBBA or PBBA (ATC) - were not obtained in 1.8% of healthy individuals, and in patients the frequency of the location of the arteries of the lower leg decreased sharply, depending on the prevalence of the lesion.

Normally, the arterial signal is short and three-component. The initial sound is loud and high-frequency, and the next two have a lower volume and a lower key. The change in the acoustic characteristics of blood flow signals over the stenosis zone is associated with an increase in the rate of blood flow through the narrowed zone and with concomitant turbulence. As the stenosis increases, the characteristics of the Doppler signal change: the frequency decreases, the duration increases, and the three-component disappears. With occlusion, the changes are the same as with severe stenosis, but more pronounced, the signals have an even lower tonality and continue throughout the cardiac cycle.

Auscultatory analysis of Doppler blood flow signals is the initial stage of ultrasound and, with a certain experiment, provides a good opportunity to locate vessels and differentiate normal and pathological blood flow signals. The method acquires special significance when using ultrasonic stethoscopes that do not have recording devices.

Evaluation of Doppler curves of blood flow velocity along arteries of lower extremities

Registration of Doppler blood flow signals in the form of analog velocity curves (Dopplergram) makes it possible to conduct a qualitative and quantitative analysis of the blood flow velocity in the vessels under study.

[1], [2]

Qualitative analysis of Doppler blood flow velocity curves

The normal curve of the peripheral arterial blood flow, as well as the auscultatory signal, consists of three components:

1. the greatest deviation in systole, caused by direct blood flow;
2. reverse flow in early diastole, associated with arterial reflux due to high peripheral resistance;
3. deviation in late diastole, caused by the blood flow forward due to the elasticity of the walls of the arteries.

As the stenosing disease progresses, the shape of the pulse wave changes, transforming from the main type to the collateral type. The main criteria for disturbing the waveform are the disappearance of the component of the reverse blood flow, the blunting of the velocity peak and the elongation of the rise and fall time of the pulse wave velocity.

Normally, for all curves, steep ascent and descent, the sharp peak of the first component, and the expressed backflow wave are characteristic. When PAP is occluded, the deformation of the Doppler is detected from the PKA level, and in the case of OPA occlusion, the collateral type of the curve is recorded at all locations.

Quantitative and semi-quantitative analysis of Doppler blood flow velocity in the arteries of the lower limbs

Quantitative evaluation of dopplerograms can be performed on the basis of analysis of both the analog curves of blood flow velocity and the spectrograms of Doppler blood flow signals in real time. In the quantitative evaluation, the amplitude and time parameters of the Dopplergram are subjected to analysis, and for semiquantitative analysis its calculated indices. However, due to the presence of factors that change the shape of the Doppler velocity curve, there are problems associated with the interpretation and quantification of dopplerograms. Thus, the amplitude of the curve depends on the position of the sensor and its angle of inclination relative to the axis of blood flow, the depth of penetration of ultrasound in the tissue, the distance from the main site of constriction, amplification, background noise, superposition of venous noise, etc. If the ultrasound beam crosses the vessel partially not on the whole axis), and especially if it is directed to the axis of the vessel at an angle approaching 90 ^th, erroneous results are obtained. In connection with this series of researchers, a semiquantitative method for estimating the dopplerogram was proposed-a calculation of the relations characterizing the waveform and representing relative indices (for example, the ripple index, the dumping factor), for which the effect of the above-mentioned causes does not extend. However, this method is criticized by a number of authors, giving preference to a quantitative assessment of blood flow signals from spectral analysis data; other researchers, the reliability of non-invasive assessment of vascular lesion is associated only with duplex scanning, in which the detection and analysis of blood flow signals is performed in the visualized area of the vascular system.

At the same time, there are a number of situations where the only possible and diagnostic non-invasive method for evaluating vascular lesions is the analysis of the form and the quantitative evaluation of the Dopplergram: when the possibility of measuring the SSD is limited when it is not possible to apply the cuff proximally to the sensor when the cuff overlap coincides with the surgical wound , in assessing the condition of the iliac arteries, and also when in incompressible as a result of calcification or sclerosis of the arterial wall, zhno high MICs, despite the presence of arterial disease. According to the successful expression of J. Yao et al., Recording the pulse wave of peripheral arteries makes it possible to recognize limb ischemia, similar to how the ECG is used to diagnose myocardial ischemia.

Spectral analysis of Doppler blood flow signals

Spectral analysis of Doppler blood flow signals has become very widespread when working with continuous wave Doppler systems for evaluation of occlusive lesions of extracranial areas of the carotid basin, when the study zone is in close proximity to the location of the sensor and it is possible to examine the vessels throughout.

The availability of peripheral arteries to locate blood flow only at selected points where they are as close as possible to the surface of the body and the varying degree of removal of the main lesions from the study point reduce the value of spectral analysis for evaluating peripheral lesions. Thus, according to the data, the recording of the signals of the Doppler spectrum distal to the main part of the lesion by more than 1 cm is diagnostic insignificant and practically does not differ from the Doppler signals recorded proximally to the stenosis site. The spectra of Doppler signals of the blood flow of the common femoral arteries with 50% monofocus stenosis of the iliac arteries of different localization - there is no correlation of the spectral analysis data with the degree of stenosis: the spectral expansion (SB) - the main stenosis index characterizing the turbulent flow profile - varies widely 19 to 69%. The reason for such a wide spread of the SB values for the same degree of narrowing becomes understandable if we recall the scheme for the occurrence of flow turbulence. In the vessel, the blood flow is laminar. Reduction of the cross section during stenosis leads to an increase in the flow rate. When the vessel sharply expands after constriction, a "flow separation" is observed, motion at the walls is inhibited, backflows occur, turbulence is formed. Then the flow again acquires laminar character. Therefore, the spectrum obtained immediately after constriction of the vessel and having a spectral expansion of 69% is, in this case, the only diagnostically significant one.

The maximum Doppler shift in systole, which determines the rate of blood flow, increases with stenosis and decreases with occlusion. The index of vascular resistance decreased in the transition from stenosis to occlusion, and the spectral expansion increased at the same time. The greatest changes were observed for the index of pulsation during the transition from norm to occlusion.

Comparative evaluation of spectral analysis of Doppler blood flow signals and analog velocity curves showed that the most sensitive signs of occlusive disease development were: decrease or disappearance of the reverse blood flow wave, increase in A / D ratio (mainly due to lengthening of the deceleration phase), decrease in IP _GK and appearance of DF <1. Thus, reversible blood flow in the OBA was absent in all patients with occlusion of the iliac artery and stenosis> 75%. However, with PBA occlusion, we observed reversible blood flow in the arteries of the calf in 14% of patients and in the popliteal artery in 4.3% of patients. The same observations are described by M. Hirai, W. Schoop. The most indicative, and therefore the most widely spread index of occlusive disease is the Gösling-King pulsation index - IP _GK. Changes IP _GK in normal and odnosegmentarnom proximal lesion expressed in the growth value IP _VC in the distal direction; wherein the value of IP _ASRC normally was the highest, averaging 8.45 ± 3.71, and individual variations were within 5,6-17,2. IP _GK significantly decreased with occlusion and plummeted with stenosis. Reducing 1P _ASRC compared to the norm mentioned contact occlusion PBA, and more distally located defeat leg arteries had no effect on this indicator. The data obtained are consistent with the results of other authors who showed the dependence of IP _{GK on} both proximal and distal lesions:

With isolated lesions of the PBA or the arteries of the lower leg, the drop in IP _GK at the appropriate levels also proved highly reliable. With multilevel lesions, the dynamics of IP _GK was important for the diagnosis of primarily distal lesions.

Segmental systolic blood pressure in the lower limbs

For the occurrence of blood flow between two points of the vascular system, there is a pressure difference (pressure gradient). At the same time, as the arterial pulse wave moves to the periphery of the lower extremities, the systolic pressure increases. This increase is the result of reflection of the wave from an area with a relatively high peripheral resistance and differences in the compliance of the walls at the central and peripheral arteries. Thus, the systolic pressure measured at the ankle is normally higher than on the shoulder. In this situation, to maintain blood flow in the distal direction, it is necessary that the diastolic and mean pressure gradually decrease. At the same time, studies by physiologists have shown that with occlusive diseases, a significant drop in diastolic pressure in the lower limbs occurs only in the presence of severe proximal stenosis, while maximum systolic pressure decreases with lower degrees of disease. Therefore, determining the maximum systolic blood pressure is a more sensitive non-invasive method for diagnosing arterial narrowing.

The first measurement of segmental systolic pressure in occlusive diseases of the lower limbs was proposed by T. Winsor in 1950, and the non-invasive measurement of segmental systolic pressure by the Doppler method was first described in 1967 by R. Ware and S. Laenger. The method involves the use of a pneumatic cuff that is tightly applied around the limb segment being examined and can be used where cuffing is possible. The pressure in the cuff, at which the blood flow is restored (which is recorded with dopplerography), in the distal part of the limb when decompressed, is the systolic blood pressure at the level of the cuff, or segmental systolic pressure. The necessary conditions for obtaining accurate results are sufficient cuff decompression speed, repeated (up to three times) measurements and the corresponding cuff length and width.

The size of the cuff to measure segmental systolic pressure foreign researchers pay special attention. After a lengthy and extensive discussion on this issue, the American Association of Cardiologists has developed recommendations that the width of the pneumatic cuff should be 40% of the circumference in the test segment or 20% larger than the diameter of the extremity to be examined, and the cuff length should be twice its width.

To carry out multilevel manometry it is necessary to have 10 cuffs: 6 brachial and 4 femoral. Shoulder cuffs are placed on both arms to determine pressure in the brachial arteries and on both shins below the knee and above the ankle, and the femoral cuffs are superimposed on the thigh in the upper and lower third. Measurement of the SSD on all four levels of the lower limb is performed on signals from the distal parts of the vascular system: ZBBA - at the ankle or ATC - in the first interdigital space. In the cuff located around the extremity, air is pumped up to a level exceeding 15-20 mm Hg. Art. Systolic blood pressure. The Doppler sensor is positioned above the artery distal to the cuff. Then they start releasing air slowly from the cuff until the Doppler signal is restored. The pressure at which the blood flow is restored at the point of registration distal to the cuff is the systolic pressure at its level. First, the pressure on the upper limbs at the level of the shoulder is determined by the signals from the brachial artery. Often in the norm - in the absence of lesions of the arteries supplying blood to the upper limbs - reveal a moderate asymmetry of blood pressure, equal to 10-15 mm Hg. Art. In connection with this systemic pressure is considered a greater BP. Then, segmental systolic pressure is measured at all four levels of the lower limb, beginning with the lower cuff by signals from the distal vascular system (as already mentioned, ZBA - at the ankle or ATC - in the first interdigital space). In the absence of signals from the ATS, which may be associated with anatomical variants of its development, for example, in a loose type, PBBA can be lobed over the ankle. In the presence of blood flow signals from both arteries, pressure measurement is performed on the one with a higher value of segmental systolic pressure at all four levels, and for the second artery, segmental systolic pressure is measured at two levels of the shin to avoid possible arterial involvement. It is advisable to follow the sequence of measurements from the distal cuff to the proximal cuff, since otherwise pressure measurement in the distal cuffs will take place under conditions of post-clusive reactive hyperemia.

In order to exclude individual differences in the segmental systolic pressure profile, the pressure index (ID) proposed in 1950 by T. Winsor for each level of the cuff is calculated from the system pressure value. The pressure index is the ratio of the pressure obtained at a particular level to the system pressure measured on the shoulder (in the domestic literature the pressure index is also called the ankle pressure index (LID), although, to be more precise, the latter reflects only the pressure ratio at the ankle (IV cuff ) to systemic pressure.The total segmental systolic pressure profile for each limb is usually formed on the basis of the absolute values of segmental systolic pressure and the pressure index at all levels of the endpoint aust.

Normally, the segmental systolic pressure measured in the upper third of the thigh may exceed the brachial one by 30-40 mm Hg. This is due to the need to apply excess pressure to the cuff to compress the muscle mass of the thigh.

A pressure index exceeding 1.2 indicates the absence of a hemodynamically significant lesion of APS. If ID ₁ is within the range of 0.8-1.2, then the presence of a stenosing process in the APS is very likely. With ID ₁ less than 0.8, AUC occlusion occurs).

The difference in segmental systolic pressure between the extremities in the upper third of the thigh is equal to or greater than 20 mm Hg. St., suggests the presence of an occlusive disease above the inguinal fold on the side with a lower pressure. At the same time, such a decrease in pressure in the upper third of the thigh may occur with combined injury of PBA and HBA. In these situations, the method of compression measurement of segmental systolic pressure in the OBA is useful, in addition to analyzing the Dopplerogram of the blood flow in the OBA, to detect the spread of the disease on the APS.

Normally, the gradient of segmental systolic pressure between two adjacent cuffs with a four-cuff method of measurement should not exceed 20-30 mm Hg. Art. A gradient exceeding 30 mm Hg. St., allows to assume the presence of a pronounced stenosing process, and with occlusion it is equal to or exceeds 40 mm Hg. Art.

The finger pressure of the lower extremities is usually determined if there is a suspicion of occlusion of the finger arteries or the plantar arch. Normally the systolic pressure in the fingers is about 80-90% of the shoulder pressure. The index of finger / shoulder pressure below 0.6 is considered pathological, and its value below 0.15 (or the absolute value of pressure less than 20 mm Hg) usually occurs in patients with pain at rest. The principle of measuring the finger pressure is the same as in the remaining levels of the lower limbs, and the special finger cuffs should be 2.5 x 10 cm or 1.2 times the diameter of the finger under examination.

Measurement of finger pressure in clinical practice using USDG is rarely used due to difficulties in locating the digital artery of the feet, in particular distal to the place of application of the finger cuff. The problem of finger artery location also exists in healthy individuals, and in patients with arterial blood circulation decompensation due to blood flow reduction, obliteration of distal vessels, hyperkeratosis phenomena and other causes, the location of distal vessels by the USDG method becomes difficult to achieve. Therefore, to measure the finger pressure, the photoplethysmography method is usually used.

Despite the success of non-invasive diagnosis in establishing the fact of arterial occlusive disease, difficulties remain in accurately determining the level of lesion.

The most difficult problem remains the exact localization and quantitative assessment of APS lesions, especially in combination with PBA lesions. As the studies of foreign clinics have shown, successful diagnosis of such combined lesions with the help of the Doppler method is achieved only in 71-78% of patients. B. Brener et al. Showed that in 55% of patients with angiographically proven aorto-iliac segment in the upper third of the thigh (I cuff) was normal, and 31% of patients with PAP occlusion without a lesion of the iliac artery SSD on I cuff was higher than the systemic one.

Compression measurement of blood pressure in the common femoral artery

In the practice of vascular surgery, when assessing the choice of the required level of reconstruction, an evaluation of the condition of the common femoral and iliac arteries is required, primarily on the basis of an important hemodynamic parameter, such as blood pressure. However, even the most proximally imposed hip cuff reflects pressure in the distal sections of the OBA and the proximal sections of its major branches. In connection with this, we used the method of measuring compression blood pressure (CAD) in OBA, which is presented in the diagram. A pneumatic chamber of a pediatric cuff measuring 5.0 x 9.0 cm is placed on the projection site of the femoral artery under the puarth ligament after pre-palpation of the OBA pulse or location of the blood flow signals in the BRA. A pressure of 10 mm Hg is created in the chamber. The graduates are overlapped so that they create a closed loop between the cuff and the measuring system. During the study, the blood flow signals are continuously located along the ZBBA or ATS. The femoral cuff is gradually pressed down with the palm of the researcher's hands until the blood flow signals disappear (when the palm compression did not produce any effect, a plate made of dense plastic was used, corresponding to the size of the cuff that was applied to the pneumatic chamber, which ensured its uniform compression). The pressure at which the blood flow signals (after decompression) appear is equal to the pressure in the BRA.

The method of compression measurement of SSD in BIA was first described by J. Colt; further development of the method received in the works. It was tested on a group of healthy persons: 15 people aged 26 to 54 years (mean age 38.6 years) without signs of cardiovascular pathology were examined. The magnitude of CAD in OBA is compared with systemic arterial (shoulder) pressure, while the index of CAD was 1.14 ± 0.18 (fluctuations 1.0-1.24).

[3], [4], [5], [6], [7]

Ultrasonic dopplerography in the assessment of the degree of ischemia of the lower extremities

The severity of ischemic syndrome of the lower limbs with occlusive diseases of the abdominal aorta and its branches is due to the insufficiency of the peripheral circulation and depends on the localization of occlusion or stenosis, the presence of multi-storey lesions, the distal vascular bedding and the degree of development of the collateral circulation.

The clinical description of the severity of vascular disease of the limbs was first proposed by R. Fontaine, who distinguished 3 stages: intermittent claudication (I), rest pain (II) and gangrene or ulcer of limbs (III). Later, this graduation was expanded by the division of patients with intermittent claudication, depending on the distance of walking. On this principle, a classification developed by A.V. Pokrovsky in 1979, which is used at the present time. According to this classification, the first stage of the disease - pain in the lower limbs - occurs after the passage of more than 1000 m; IIА - distance of 200-1000 m; IIB - a distance of 25-200 m; III - a distance of less than 25 m or pain at rest; IV - the presence of gangrene or ulcers of the extremities.

The degree of ischemic manifestations in the lower limbs is determined by the summation of the hemodynamic effect of the severity and etiology of the lesion of the lower extremity vascular system at the peripheral level, and therefore changes in regional hemodynamics in the distal departments may be criteria in assessing the degree of ischemia of the lower limbs.

Carried out separately for patients with single- and multi-storey occlusions at the same degree of ischemia, the study of regional hemodynamics showed that there is no reliable difference in the parameters of regional hemodynamics between these groups of patients. Undoubtedly, the architectonics of thromboembolizing lesions affect the course and timing of chronic arterial insufficiency. However, the stage of the disease determines the functional state of the regional circulation.

In clinical practice, the most accepted is the assessment of the degree of ischemia of the lower extremities in terms of the magnitude of the main parameters of the USDG (SDS and ID at the ankle level, LCS) in comparison with the Dopplergram form. At the same time, it is useful to compare the parameters of arterial and venous pressure on the basis of the determination of post-clusional venous pressure at the ankle level (FOVD) and the calculated arteriovenous index (AVI), calculated by the formula: AVI = FLEG / SSD x 100%.

The procedure for determining the MAP is the same as for the SSS: when the compression pressure in the fourth cuff on the ankle is lowered, the first pulse hits correspond to the SSS, and with a further decrease in pressure, low-frequency venous noise is recorded, the moment of which reflects the magnitude of the FRA.

Comparison of the data of ultrasound methods with the study of the microcirculation of the skin of the legs according to the results of laser dopplerometry and percutaneous monitoring of the partial pressure of O ₂ and CO ₂ showed that in some patients referred to stage IV the regional hemodynamic parameters correspond to stage II, and the trophic ulcers occurred as a result of traumatic injury Integrity of the skin in conditions violated by blood circulation were not true ischemic ulcers. Thus, assessment of the degree of ischemia of the lower extremities in the presence of ulcerative necrotic changes is the most difficult task, requiring a comprehensive approach based on the study of the state of macro- and microhemodynamics.

The increase in MI and AVI on the background of a decrease in segmental systolic pressure is reliably noted in the II stage of ischemia, which is caused by the result of arterial blood discharge from the arterioles directly into the venules, bypassing the capillary bed. The expediency of arterio-venous shunting blood flow is that it promotes an increase in the blood flow velocity along the main arteries below the level of occlusion and, thereby, prevents their blockage.

The arterial inflow decreases with increasing ischemia and leads to a decrease in the level of the Internal Disorder Department. However, the magnitude of the AVI, reflecting the state of the shunting blood flow, practically does not change, and the increasing tissue hypoxia is the result of a decrease in the circulation of the soft tissues of the foot against the backdrop of the growing depletion of the second compensation mechanism-dilatation of the microcirculation system with oppression of vasoconstrictor reactions.

Measurement of MI and AVI allows to understand the processes of development of chronic ischemia of the lower limbs and the formation of mechanisms for compensating blood circulation, which include arteriovenous shunting blood flow and vasodilation in the microcirculation system.

When assessing the extent of ischemia from the data of non-invasive diagnostics, it is necessary to take into account the etiology of the disease. Thus, in diabetes mellitus (as well as with obliterating endarteritis, thromboangiitis), hemodynamic parameters may differ significantly from those of atherosclerosis, especially in the initial period of diabetes mellitus, which is associated with a predominant lesion of the arteries of the foot with the remaining patency of the arteries of the shin to the level of the ankle for a long time time. In diabetes mellitus, the IDs of the ankle will correspond to or exceed the norm, and changes in the dopplerograms at the ankle and at the rear of the foot will be insignificant and do not correspond to the severity of ischemic lesions in the toes. Under these conditions, the diagnostic significance is acquired by methods of studying microcirculation, such as laser doppler flowmetry and percutaneous monitoring of the partial pressure of O ₂ and CO ₂.

Algorithm for the study of patients with lesions of the arteries of the lower extremities

Screening in the prehospital stage makes it possible to differentiate the obstructive lesion of peripheral arteries from neuroorthopedic disorders. The established fact of arterial disease determines the necessity of conducting a full complex of non-invasive examination of peripheral arteries, which allows to reveal the localization and extent of the lesion, the degree of hemodynamic disorders, the type of lesion. If necessary, surgical treatment shows aorto-arteriographic study to determine the feasibility and necessary volume of surgical reconstruction.

[8], [9], [10], [11], [12]

Errors and disadvantages of ultrasound non-invasive diagnostics of lower limb arteries

Ultrasound Doppler study of peripheral arteries, like any other instrumental diagnostic method, contains potential opportunities for diagnostic errors, both objective and subjective. The latter include the qualifications and experience of the researcher, the accuracy of calculations, pedantry, while observing all the conditions of the methodology. The objective reasons are quite diverse and require special consideration.

• The impossibility of examining vessels throughout - this is possible only at fixed points, which excludes precise topical diagnosis of the lesion. Duplex scanning solves the problem only partially, since individual parts of the lower limb vascular system, such as the middle third of the PBA, the popliteal artery trifurcation area, and the proximal parts of the lower leg arteries, remain inaccessible for imaging in most subjects due to deep vascular deposition and powerful muscle mass in these zones.
• Errors in the measurement of blood pressure in the lower limbs.
  • In obese patients, due to excessive subcutaneous fat and muscle mass of the thigh, the measured segmental systolic pressure proves to be false because of the need to pump the femoral cuff for full compression of the arteries under high pressure; while differences in shoulder and femoral pressure can reach 50-60%, whereas direct puncture pressure measurement at the same levels does not reveal significant differences. Therefore, in this category of patients it is recommended to measure the pressure on the shin.
  • In patients with diabetes or chronic renal insufficiency, the vascular wall can be impregnated with calcium salts so that it becomes incompressible, and therefore measuring segmental systolic pressure in this category of patients becomes meaningless.
  • Often there may be an overestimated pressure in the upper third of the shin, which significantly prevails over the pressure in the lower third of the thigh and is associated with the peculiarities of the development of bone formations in this zone and the need to create an increased pressure in the compression cuff.
• There are difficulties in measuring the finger pressure on the feet by ultrasound Doppler ultrasound, since the location of the digital arteries distal to the superimposed finger cuff is rarely feasible. Usually, the photoplethysmography method is used for this purpose.
• Recently nonlinear dependence of ankle segmental systolic pressure from shoulder (systemic) has been shown: at system pressure below 100 and above 200 mm Hg. Art. Ankle segmental systolic pressure was below the norm (up to 25%), and in the range of 100-200 mm Hg. Art. It was equal to or higher than the shoulder. Thus, with hypo- and hypertension, the pressure index can be less than one.

• 5. When interpreting the waveform of the Dopplergram, in order to avoid errors, it should be remembered that normally a component of reverse blood flow in the popliteal arteries can be absent in 10-11% of cases, in the posterior tibial - in 4% and in the artery of the rear of the foot - in 8%. The third component of the dopplerogram remains in the iliac and common femoral arteries in all healthy individuals, in the popliteal, posterior tibial and arteries of the rear of the foot, it may be absent in 22, 4 and 10%, respectively. Normally, in 2-3% of cases, it is also possible that there is no location of one of the lower leg arteries because of the anatomical features of their development (loose type of structure).
• 6. The development of compensatory collateral circulation, which corrects arterial insufficiency, can cause both false positive and false negative diagnostic errors.
  • A. Well-developed collateral vessels with high LSC in the ileum-femoral area with occlusion of the iliac artery can cause erroneous diagnosis.
  • An analysis of such errors showed that they are based on well-developed collateral circulation of the ileum-femoral zone. The use of synchronous ECG recording can be useful in complex cases of diagnosis of iliac arteries.
  • B. Well-developed collateral circulation in the basin of the lower leg arteries is a frequent cause of false-positive assessment of the condition of the lower leg arteries and erroneous indications for reconstructive surgery in the aorto-iliac and femoral-popliteal zones. This is important, since the effectiveness of surgical treatment depends on the state of the outflow tract, the function of which is performed by the calf arteries. Erroneous preoperative diagnosis of the distal vascular bed of the extremities limits the operation only to revision of the vessels with intraoperative angiography.
  • B. Decompensation of the collateral circulation, especially with multilevel lesions, makes it difficult to diagnose the lesion of the underlying segments of the arteries of the lower extremities. Difficulties in assessing the condition of the arteries of the legs with occlusion of the abdominal aorta and iliac arteries, accompanied by severe failure of the collateral circulation, were noted by different researchers in 15-17% of patients. The significance of this problem increases in patients who need repeated operations. The number of these patients in connection with the wide development of reconstructive vascular surgery increases every year, and repeated operations often lead to damage to the ways of compensating collateral circulation.
• 7. The lack of information on the volume flow, summarizing the main and collateral channel, when using USDG, makes it difficult to diagnose PBA lesions in APS occlusions. Quantitative analysis of dopplerograms using the index of pulsation and dumping factor appears to be sensitive in this situation only in 73% of patients. Inclusion in the complex of non-invasive diagnostics of plethysmographic techniques, such as volumetric segmental sphygmography (sometimes called "volumetric segmental plethysmography") included in the mandatory list of methods of angiology laboratories of leading foreign clinics, but undeservedly circumvented by specialists in our country, increases the sensitivity of the diagnosis of the lesion of the indicated localization up to 97%.
• 8. The possibilities of ultrasonic dopplerography in the determination of only hemodynamically significant (> 75%) lesions are already insufficient in modern conditions when, in connection with the appearance of sparing and vasoconstrictive angioplasty treatment of stenotic lesions, conditions for preventive treatment more effective at early stages of the disease development are created.

Therefore, there will be a significant increase in the need to introduce the duplex scanning method into the clinic, which allows to detect the disease at early stages, to determine the type and nature of vascular lesions, indications for choosing a particular treatment in most patients without prior angiography.

• The possibilities of ultrasonic dopplerography in determining the damage to HBA, even hemodynamically significant, are limited, and in most patients the diagnosis of HBD lesion is only presumed or is an accidental angiographic finding. Therefore, successful non-invasive diagnosis of GBA damage and the degree of its hemodynamic insufficiency is possible only with the help of duplex scanning.

In conclusion, it should be noted that the introduction of the ultrasound dopplerography method in the clinical diagnosis of ischemia of the lower extremities was invaluable and revolutionary in its essence of significance, although it should not be forgotten about the limitations and disadvantages of the method. Further increase in the diagnostic significance of ultrasonic diagnostics is associated both with the use of the entire arsenal of ultrasound methods and with their integration with other noninvasive methods of diagnosing vascular diseases, taking into account the clinic and etiology of the disease in each particular patient, the wide spread of a new generation of ultrasound equipment that implements the latest technologies of the three-dimensional scanning of blood vessels.

However, assessment of the possibilities of diagnosing lesions of the vessels of the lower extremities may not be complete enough, since arterial lesions are often combined with disease of the veins of the lower limbs. Therefore, ultrasound diagnosis of leg lesions can not be complete without evaluating the anatomical and functional state of their extensive venous system.

[13], [14], [15]