RU2257853C2 - Method for evaluating ischemic stage in lower limbs - Google Patents

Abstract

FIELD: medicine, cardiology.

SUBSTANCE: one should perform colored duplex sonography by measuring the resistance index in tibial arteries to evaluate the degree of functional insufficiency in lower limbs, that is at R1 being above 1.0 - the first stage, at R1 being 1.0-0.4 - the second stage, at R1 being below 0.4 and up to 0.2 - the third stage and at R1 being below 0.2 - the fourth stage should be detected. The method enables to objectively and quantitatively evaluate ischemic stages in case of occluding arterial diseases of lower limbs.

EFFECT: higher efficiency of evaluation.

12 dwg, 2 ex, 1 tbl

Description

The invention relates to medicine, namely to radiation diagnostics.

To date, a clinical description of the severity of occlusive diseases of the lower limb arteries (OZANK) has been used in medicine, proposed by Fontaine and expanded by A.V. Pokrovsky. A.V. Pokrovsky divided patients with intermittent claudication depending on the walking distance and grouped in the stage of chronic arterial insufficiency (KHAN). According to this classification, in stage I of the disease, pain in the lower extremities occurs after passing more than 1000 m; at stage IIA - after passing a distance of 200-1000 m; in stage IIB, respectively - 25-200 m, in stage III - pain at rest or when passing less than 25 m and, finally, stage IV is characterized by gangrene or ulcers of the extremities [1, 2].

To date, the opinion of most experts is that segmental systolic pressure (SJS) in the arteries of the lower extremities, measured using ultrasound dopplerography (Doppler ultrasound), is a quantitative objective and sensitive indicator of the occlusal process and may reflect the degree of functional failure in the studied limb segment.

Today, methods of studying microcirculation, such as laser Doppler flowmetry (LDF) and measurement of the transcutaneous voltage of O ₂ and CO ₂ , are acquiring diagnostic significance. In particular, when instrumental in assessing the effect of arterialization of the venous blood flow of the foot on changes in regional hemodynamics, today they are guided by indicators of LID and transcutaneous oxygen tension (TcpO ₂ ) on the foot in the supine and sitting position. Changes in TcpO ₂ on the foot reliably reflect changes in the microcirculation of the affected limb (p <0.01) [3].

It is known that the first measurement of SSD at OZANK was proposed by T. Winsor in 1950. It was he who proposed measuring the pressure index for each level of the cuff, which is also called the ankle pressure index (LID) or the ankle-brachial index. LID is the ratio of systolic blood pressure on the ankle to systolic blood pressure on the arm. This method is highly sensitive and specific for diseases of the peripheral arteries in patients without diabetes [4].

In 1967, R. Ware and C. Laenger first described the non-invasive measurement of SSD using the Doppler method. Normally, the average LID is 1.0 (0.9-1.2). The value of LID depends on the stage of lower limb ischemia. So, in stage I, the LID value varies from 0.9 or more, in stage II - 0.8-0.6, in stage III - 0.5-0.4, and in stage IV - 0.3 or less. In stages III and IV of ischemia, the etiology of the disease must be considered [5].

Today, according to the same principle, to assess the degree of development of the collateral system of the deep femoral artery, the deep femoral-popliteal collateral index (GPCI) is used, which is determined using ultrasound Dopplerometry and calculated by the formula: GPCI = ND - PD / ND, where ND is the patellar systolic pressure, PD - popliteal systolic pressure. With an HPLC <0.38, the degree of development of collaterals is assessed as good, and with an HPLC> 0.38 - poor. The value of GPKI is considered the most optimal indicator for predicting the results of limb revascularization operations through the deep femoral artery [6].

The disadvantages are, firstly, that LID and SSD measurement are inaccurate in patients with calcification of the walls, since the ankle pressure in this case has falsely elevated rates. It is also known that with diabetes mellitus, obliterating endarteritis, thromboangiitis, hemodynamic parameters can significantly differ from those for atherosclerosis. In the initial period of diabetes mellitus, this is due to the predominant lesion of the arteries of the foot with continued patency of the arteries of the leg to the level of the ankle for a long period [7]. Secondly, only this method does not provide complete information without combining it with another method that provides information about morphological changes in OZANK.

The goal is an objective assessment of the stage of lower limb ischemia during CDS by measuring RI in the tibial arteries.

The method is as follows. CDS is carried out along the anatomical course of arteries in axial and sagittal sections. Arteries are visualized throughout using the “gray scale” B-mode, Doppler D-mode, color C-mode and energy P-mode as required. Two types of sensors are used: with abdominal access - a convex sensor (2.5 MHz, 3.5 MHz), while examining peripheral arteries - a linear sensor with a frequency of 5 MHz and 7 MHz. The Doppler angle used is 60 ° or 40 °. A longitudinal scan of the lower leg arteries is carried out from trifurcation of the popliteal artery to the distal segments of the tibial arteries throughout. The RI value is calculated in the distal segments of the tibial arteries.

An inverse dependence of the RI value in the distal segments of the tibial arteries on the stage of lower limb ischemia was revealed - the higher the stage of CAS, the lower the resistance index value. In the absence of complaints or pain that occurs when passing more than 1000 m, the RI value is equal to or greater than 1.0; for pain that occurs when walking at a distance of 1000 to 25 m, the RI value is accordingly distributed in the range 1.0 - 0.4; in case of pain at rest or when traveling less than 25 m, the RI value is accordingly distributed within 0.4 - 0.2, and in trophic ulcers of the limbs or gangrene, the RI value is equal to or lower than 0.2. These results are shown in the table and the histogram.

Table. Patient Complaints No complaints or pain in the legs when passing> 1000 m
(ROW 4) Leg pain during the passage of 1000-25 m
(Row 3) Pain at rest or when passing <25 m
(ROW 2) Gangrene or ulcers of the limbs
(ROW 1) KHAN stages on Pokrovsky-Fontaine 0-I II III IV KHAN stages by RI value ≥1.0 1.0 - 0.4 0.4 - 0.2 ≤0.2

Example 1

Anamnesis. Patient M., 49 years old, with complaints of acute pain in the right lower limb, cooling and chilliness in the right foot, turned to conduct a planned CSA. A history of chronic renal failure, surgery: kidney transplantation on the right.

Physical examination. Auscultatory over the main arteries at typical points of noise was not detected. On the left, pulsation on the femoral, popliteal, and anterior and posterior tibial arteries is preserved. On the right, pulsation is only on the femoral artery. A clinical diagnosis was made: femoral thrombosis; condition after kidney transplantation.

Color duplex sonography. A transplanted kidney was found in the right iliac region. The femoral artery is occluded from the level of discharge of the deep femoral artery, the deep femoral artery is passable. The lumen of the femoral artery to the lower third of the thigh is filled with thrombotic masses. Collateral blood flow is mapped in color in the lower third of the femoral artery, in the popliteal and tibial arteries.

CSA right transfemoral access. On the right - the femoral artery is occluded from the level of discharge of the deep femoral artery with collateral contrast in the middle third. The popliteal and tibial arteries are contrasted. Left CSA was not performed (figures 1 to 4).

Example 2

Anamnesis. Patient Z., 73 years old, was admitted with complaints of constant pain in the right lower limb, brittle nails, peeling of the skin, cyanosis of the fingers of the right foot, as well as an increase in systolic blood pressure to 260 mm Hg No interventions on the arteries were noted.

Physical examination. Systolic murmur was heard over the abdominal aorta, iliac and femoral arteries. Both the right and left pulsations were determined on the femoral arteries, and the pulsation could not be determined on the popliteal and tibial arteries. The feet are cyanotic, cold to the touch (more to the right). Toes of the right foot with initial trophic disorders. Clinical diagnosis: atherosclerosis, occlusion of the femoral arteries of both lower limbs, KHAN stage III-IV; arterial (vasorenal?) hypertension.

CSA transfemoral access. Angiographically revealed stenosis of the renal arteries, critical stenosis of the femoral arteries of both lower limbs, proximal occlusion of the tibial arteries of the right lower limb.

The relationship of arterial hypertension with renal artery stenosis was called into question, since antihypertensive conervative therapy was effective and a 24-hour monitoring of blood pressure revealed a decrease to 140 mmHg. The patient was consulted by an angiosurgeon and, taking into account the age and occlusion of the tibial arteries, she was offered a minimally invasive HFA of critical stenosis of the right femoral artery. An FFA and control CSA of the right superficial femoral artery with a 6.0 mm - 60.0 mm balloon from Cordis were performed.

Color duplex sonography. Before and after FFA, CDS was performed with RI measurement in the right posterior tibial artery. The resistance index before PFA corresponded according to the Pokrovsky-Fontaine classification to 0.43, and after PFA, RI was already 0.55, despite proximal occlusion of the posterior tibial artery. The dilatation efficiency was also confirmed by a decrease in V _max at the site of critical stenosis of the superficial femoral artery from 180 cm / s to 90 cm / s. The patient was discharged with a subjective improvement in the condition of the limb: pain and coldness stopped (Figs. 5-12).

Sources of information

1. Fontaine R. Les obliterations femoro-poplitees d′origine arteriosclereuse // J.Chiz. - 1972. - V.104. - No. 6. - R.505-524.

2. Pokrovsky A.V. Clinical angiology // M .: Medicine. - 1979. - 368 p.

3. Pokrovsky A.V., Dan V.N., Chupin A.V. Arterialization of the venous blood flow of the foot to save the limb from amputation in patients with thromboangiitis obliterans with occlusion of the leg and foot arteries in critical ischemia // Angiology and Vascular Surgery. - 2000. - T.6. - No. 1. - S.86 - 99.

4. Winsor T. Influence of arterial disease on the systolic blood pressure gradients of the extremity // Am. J. Med. Sci. -1950. - V.220. - R.117 - 120.

5. Ware R.W., Laenger C.J. Inderect blood pressure measurement by Doppler ultrasonic kinetoarteriography // Med. Biol. -1967. - V.27. - R.3 - 7.

6. Karimov 3.3. Surgery of the occlusion of the femoral-popliteal-tibial segment in critical ischemia // Angiology and Vascular Surgery. - 2001. - T.7. - No. 2. - S.88-92.

7. Gordon I. Peripheral Arterial Disease. Current Clinical Strategies, Surgery, 2002 Edition. The University of California, Irvine, Manual of Surgery. - 2001 .-- P.100 - 103.

Claims (1)

A method for assessing the stage of ischemia in occlusive diseases of the arteries of the lower extremities, characterized in that they perform color duplex sonography with a measurement of the resistance index in the tibial arteries, the value of which assesses the degree of functional insufficiency of the lower extremities, namely, with a value of R1> 1.0 - the first stage, with a value of R1 - 1.0-0.4 the second stage, with R1 less than 0.4 and up to 0.2 - the third stage, and with R1 less than 0.2 - the fourth stage.

Images