RU2284755C1 - Non-invasive method for producing portal hypertension diagnosis - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: method involves measuring hemodynamic properties in the portal vein. Cardiovascular system indices are also measured by applying ultrasonic Doppler flowmetry method. To characterize portal hypertension intensity, portal vein coefficient (PVC) is used found from relation PVC=(84*HBR*SV)/(π*V_l*D²*CP), where HBR is the heart beat rate stokes/min; SV is the stroke volume of the heart in ml; V_l is the mean linear speed of blood circulation in the portal vein in m/s; D is the portal vein diameter in mm; CP is the systolic arterial blood pressure in mm of mercury column. PVC value being found equal to 25.000±2.28, satisfactory portal vein hypertension state is to be diagnosed after splenorenal bypass operation. PVC value being found equal to 133.1675±28.8, its worsening is to be diagnosed.

EFFECT: high accuracy of the diagnosis.

2 dwg, 4 tbl

Description

The invention relates to medicine and can be used for non-invasive determination of the degree of pressure increase in the portal system, as well as for monitoring postoperative treatment of patients after splenorenal bypass surgery.

In recent years, in our country there has been an increase in diseases of viral hepatitis B and C, as well as liver diseases of alcoholic etiology, which, in a chronic course, cause the development of liver cirrhosis (CP) in 30% of cases, which is the main cause of the development of portal hypertension syndrome (GH). Bleeding from varicose veins of the esophagus (HRVP), progressive liver failure (as a manifestation of the development of porto-systemic collaterals) are one of the main causes of mortality in this disease. As a result, early non-invasive diagnosis of this syndrome is extremely relevant. On the other hand, a number of surgical interventions have now been developed aimed at creating artificial port-system shunts to reduce pressure in the portal vein system. Assessment of the condition of patients in the postoperative period using non-invasive techniques is also very important.

GHG syndrome refers to a number of clinical manifestations arising from an increase in pressure in the portal vein system of more than 10-12 mm Hg. (normal pressure is about 7 mmHg). Two factors are of primary importance in the formation of GHGs: vascular resistance and blood flow, which determine the pressure gradient. In most cases with PG, both of these factors change.

Known methods for non-invasive diagnosis of GHG based on the calculation of indices reflecting GHG (See Kamalov Yu.R. Abdominal ultrasound examination for portal hypertension syndrome. M: Sechenov Moscow Medical Academy, 2003, p.13 )

The following indices can be used to evaluate GHGs:

- the robbery index, determined by the ratio of the difference in the volumetric blood flow velocity of the main portal vein and the sum of the volumetric velocities of the superior mesenteric and splenic arteries to the patient’s body weight. Normally, this index is 0.8 ± 2.1 ml / min / kg, and in patients with cirrhosis of the liver (CP) with GH syndrome - 2.2 ± 4.3 ml / min / kg;

- stagnation index, determined by the ratio of the cross-sectional area of the main portal vein to the average linear velocity of blood flow in it. Normally, this index is equal, according to different authors, from 0.03 ± 0.01 to 0.07 ± 0.029 cm / sec;

- Splenno-portal index, determined by the ratio of the volumetric blood flow velocity of the splenic vein to the volumetric blood flow velocity of the main portal vein, expressed in%. With CP with the presence of varicose veins of the esophagus, this index is 43.1 ± 23.7%;

- index of effective portal blood flow, determined by the difference in volumetric blood flow velocities of the main portal vein and the umbilical vein. In patients with CP without expansion of the umbilical vein, this index is significantly higher than in patients with CP with passable umbilical vein;

- portal hypertension index, determined by the ratio of the product of the resistance indices of its own hepatic and splenic arteries to the average linear blood flow velocity of the main portal vein. If this index exceeds 12 cm / s ^-1 , the accuracy of the diagnosis of GHG syndrome is 75%;

- hepatic-venous pressure gradient, determined by the product of the splenic artery resistance index and the volumetric blood flow velocity of the main portal vein.

A disadvantage of the known methods is the low accuracy and reliability of the determination of GHGs. The numerical values of the indices of different authors vary widely and are not always confirmed in practice. The calculation of indices is laborious and requires complex mathematical calculations. Indexes are not informative enough. Most indices contain the parameter "volumetric blood flow velocity", which must be calculated before proceeding to the calculation of the indices themselves. In addition, and this is very important, it is not possible to determine the resistance index and pulsation indices of the splenic artery, the robbery index, portal hypertension index, hepatic-venous pressure gradient, which does not allow monitoring of postoperative treatment of patients, by known methods in patients after splenectomy.

The well-known and most common method for diagnosing portal hypertension is ultrasound dopplerography (Doppler ultrasound) of the vessels of the abdominal organs, in which the conclusion about the presence of GH syndrome is made on the basis of an increase in the diameter of the portal vein (BB) of more than 13 mm, an increase in the diameter of the splenic vein (CB) of more than 10 mm and a decrease in the linear velocity of blood flow in the BB less than 16 cm / s.

So known is the ultrasonic dopplerographic method for diagnosing portal blood flow disorders in chronic diffuse liver diseases, in particular with liver cirrhosis, which is the closest to the invention and selected by the authors as a prototype. The assessment of portal blood flow disorders is based on the study of hemodynamic parameters in the portal vein (vessel cross-sectional area, linear and volumetric blood flow velocities). Depending on the severity of the pathological process in the liver parenchyma, these parameters are characterized by an increase in volumetric blood flow in the portal vein with an initially constant linear velocity in it, then their normalization in combination with a decrease in linear velocity and a further gradual decrease in both indicators with the development and pronounced morphological changes (Lelyuk V.G., Lelyuk S.E. Ultrasound Diagnostics, Dopplerography (Moscow: VIDAR, 1993).

The disadvantage of this method is the low accuracy of GHG determination, due to the fact that the use of this method in diagnostics is characterized by conflicting data due to the fact that these changes are sufficiently polymorphic, and the mechanism of their formation is not fully understood. In addition, a number of authors consider the change in the volumetric and linear blood flow velocities in the portal vein to be an insufficiently reliable criterion for the diagnosis of GHG. In addition, the diagnosis takes into account only venous blood flow in the portal system, excluding arterial inflow.

The task to which the invention is directed, is to increase the accuracy and reliability of non-invasive diagnostics, as well as to enable monitoring of postoperative treatment of patients.

To solve the problem and achieve the specified result, a method for non-invasive diagnosis of portal hypertension by measuring hemodynamic parameters in the portal vein by ultrasound dopplerography was developed, in which according to the invention the parameters of the cardiovascular system are additionally measured, and the coefficient is used as a criterion characterizing the severity of portal hypertension portal vein, determined from the expression:

где

Where

Heart rate - heart rate, beats / min,

UO - stroke volume of the heart, ml,

Vl - average linear blood flow velocity in the portal vein, m / s,

D is the diameter of the portal vein, mm,

DM - systolic blood pressure, mmHg

The essence of the proposed invention lies in the fact that non-invasive diagnosis of portal hypertension is carried out using the portal vein coefficient (CVI) introduced by the authors to assess portal pressure, which reflects the increase in hydrodynamic resistance in the portal vein, calculated from a number of hemodynamic parameters in the portal vein and indicators of the cardiovascular system .

It is known (Physiology of the Cardiovascular System. Part I, "Dr. James Rogers, Frenchay Hospital, Bristol, UK, 2003) that mean arterial pressure (SBP) is defined as:

SV - cardiac output, ml, determined by the product of heart rate (HR), beats / min, and stroke volume (UO) of the heart, ml SV = heart rate · UO,

OPSS - total peripheral resistance of the vascular system, mm Hg · min / ml.

On the other hand

DD - diastolic blood pressure,

PD - pulse blood pressure equal to the difference in systolic (DM) and diastolic pressures.

Equating (1) and (3) we get

Heart rate · UO · OPSS = SD / 3

Where from

It is also known that the volumetric velocity of blood flow Vob is defined as the volume of blood flowing through the cross section S of a vessel of radius r per unit time (Ultrasound diagnostics (practical guide). Edited by VV Mitkov. Head of the Basis of Hemodynamics. M., 1999) .

Vl - average linear blood flow velocity, mm / min,

S = π · r ² = π · D ^2/4, m ^2, where D - diameter of the blood vessel mm.

On the other hand, Vob can be defined as

Vob = P / R, where

P is the pressure in the vessel, mmHg,

R is the hydrodynamic resistance of the vessel, mm Hg · min / ml.

Hence, R = P / Vob, or taking into account (5)

Assuming conditionally that the pressure in the portal vein is normal P = 7 mm Hg, we obtain the hydrodynamic resistance of the portal vein

Vl is the average linear blood flow velocity of the portal vein, mm / min;

D is the diameter of the portal vein, mm.

Considering that in the presence of portal hypertension syndrome, there is an increase in hydrodynamic resistance in the portal vein compared with the general peripheral resistance of the vascular system, the authors experimentally derived the CVI indicator, called the portal vein coefficient, which reflects the increase in the hydrodynamic resistance of the portal vein:

Rvv = OPSS · KVV

From here

Substituting (4) and (6) in (7), we obtain the expression for the KBB:

From (8), it is obvious that to determine the CVE, it is necessary to measure the diameter of the portal vein (mm), the average linear blood flow velocity (mm / min), stroke volume of the heart (ml), systolic blood pressure (mmHg), heart rate (bpm), quite simply determined using the ultrasonic research method. To simplify the calculations, the average linear blood flow velocity is conveniently represented in m / s.

The portal vein coefficient introduced by the authors, which reflects an increase in hydrodynamic resistance in GH syndrome, has proven itself in practice and has made it possible to increase the accuracy and reliability of determining portal hypertension.

The studies were carried out on an analog-digital apparatus "Megas". Used convex electronic scanning sensors with a frequency of 3.5-5 MHz. To optimize ultrasound images, a vascular imaging program was pre-selected. Examinations were carried out in shades of gray scale (B - scanning, gray-scale scanning), color Doppler mapping (CDC) of blood flow velocities and energy, pulse-wave (spectral) study. In case of difficulties during imaging, the tissue harmonic mode was used. Since ultrasound research is largely subjective, all studies were performed by one operator and on the same diagnostic equipment.

The proposed method is illustrated using illustrations, in which Fig. 1 shows the measurement of the diameter of the portal vein, and Fig. 2 shows the measurement of the velocity of blood flow in the portal vein.

The inventive method is as follows.

The method of two-dimensional ECHO-Doppler cardiography using a standard method using an electronic sensor 2.5-3.5 MHz determine the magnitude of the stroke volume of the heart (UO). Next, systolic blood pressure (DM), heart rate (HR) are determined.

Using ultrasound dopplerography, a visualization of veins in the portal system is preliminarily performed, qualitative indicators of blood flow — the direction and form of blood flow — are evaluated, and quantitative indicators are determined — the average linear velocity of the blood flow in the portal vein and the diameter of the portal vein (see Figure 1 and Figure 2). According to the obtained data, the portal vein coefficient is calculated and the severity of portal hypertension is diagnosed.

To confirm the effectiveness of the proposed diagnostic method, the quantitative values of the CVE (diagnostic criteria) were determined for different groups of patients. The proposed method was examined in 3 groups of patients. The first included 30 people of healthy individuals - 5 women aged 18 to 40 years and 25 men aged 18 to 35 years. The research results are shown in table 1. The second and third groups of patients included 14 people - 4 men aged 15 to 40 years and 10 women aged 20 to 40 years with GH syndrome who underwent various types of portosystemic shunting (splenorenal anastomosis) .

The second group - with a satisfactory clinical picture of the disease (according to clinical and laboratory methods for examining patients). The group included 7 people (3 women and 4 men). The survey results are shown in table 2;

The third group - with a worsening clinic of the disease, the progression of liver failure. The subgroup also included 7 people (7 women). The research results are shown in table 3.

According to the data in Tables 1, 2, 3, the mean values of the EHC for each of the patient groups were calculated. The results are shown in table 4. The calculated coefficients were used further for the diagnosis of portal hypertension.

Specific examples of the application of the proposed method.

Example 1. Patient M., aged 18, was measured by the proposed method, the diameter of the portal vein D = 8.0 mm, the average linear blood flow velocity of the portal vein Vl = 0.49 m / s, stroke volume of the heart UO = 36 ml, heart rate heart rate reduction = 73 beats / min, systolic blood pressure DM = 118 mm Hg The portal vein coefficient calculated by the formula (8), KBV = 18,998407. The patient’s diagnosis is almost healthy, which is consistent with clinical and laboratory studies.

Example 2. Patient Nagovitsina SV, 41 years old, was treated in a hospital with a diagnosis of small-codular cirrhosis, portal hypertension in the stage of subcompensation, varicose veins of the esophagus. Hospitalized for surgical treatment. Operation - distal termino-lateral splenorenal anastomosis. Discharged home in satisfactory condition. During the control examination by the proposed method of non-invasive diagnosis of GHG, the following data were obtained: D = 9.9 mm, Vl = 0.23 m / s, VO = 56 ml, heart rate = 68 beats / min, DM = 140 mm Hg The portal vein coefficient, calculated according to the formula (8), - KBV = 32.279327, is close in magnitude to the second group of patients (table 4) - with a satisfactory clinic of the disease, but exceeds the value of the CVB of practically healthy individuals.

Example 3. Patient Diganova TI, 45 years old, was treated inpatiently with a diagnosis of cirrhosis, portal hypertension, splenomegaly with hypersplenism phenomena. Hospitalized for surgical treatment. Operation - termino-lateral splenorenal anastomosis of the type "end to side". Histological examination of a liver biopsy specimen: a picture of portal cirrhosis of the liver. The patient has a progression of the disease. During the control examination of the proposed method for non-invasive diagnosis of GHG, the following data were obtained: D = 12.8 mm, Vl = 0.07 m / s, UO = 70 ml, heart rate = 90 beats / min, SD = 120 mm Hg. The portal vein coefficient calculated by the formula (8), CVI = 122.45918, corresponds to the third group of patients (table 4) - with a worsening of the disease clinic. The obtained value is significantly higher than in the group of healthy patients.

Thus, the proposed method for non-invasive diagnosis of GHG using the portal vein coefficient, which reflects an increase in the vascular resistance of the portal vein and is determined by a number of hemodynamic parameters of the portal system and the cardiovascular system, can improve the accuracy and reliability of diagnosis, as well as provide the possibility of monitoring postoperative treatment of patients.

Table 1 No pp D mm Vl m / s UO ml SD mmHg Heart rate beats / min HWB one 11.3 0.73 69.8 114 71 12,4761 2 11.0 0.39 51 152 61 11.6026 3 10.3 0.37 41 124 64 14,4217 four 9.0 0.38 45 120 62 20,2071 5 10.9 0.32 55.9 140 86 24.1618 6 11.1 0.47 45 120 82 14,2053 7 11.0 0.44 46.7 120 84 16,4250 8 9.3 0.28 35.5 144 68 18,5182 9 12.0 0.19 42 130 84 26,5351 10 13.5 0.27 47 125 83 16.9662 eleven 10.0 0.29 48 112 60 23,7206 12 9.0 0.25 47.5 144 64 27,7891 13 10.9 0.35 58.3 120 93 29,0668 fourteen 11.6 0.31 42.1 142 78 14.8307 fifteen 12.0 0.25 49 122 76 22.6829 16 10.8 0.37 50,4 126 80 19,8358 17 12.5 0.31 53.6 138 91 19,5207 eighteen 9.0 0.29 23.3 129 93 19.1301 19 10.7 0.48 83,4 132 72 22.1440 twenty 9.6 0.37 38 143 74 15,4271 21 8.0 0.49 36 118 73 19,9984 22 9.6 0.28 37 119 76 24,4972 23 10.0 0.25 28 120 78 19,4751 24 8.0 0.45 37 118 73 21,2617 25 11.0 0.31 53 140 89 24,0292 26 9.0 0.29 25 130 91 19.9298 27 10.6 0.41 82 132 72 25.9732 28 11.0 0.72 65 120 72 11.9755 29th 9.8 0.32 45 140 62 17.3469 thirty 10.8 0.38 51 130 82 19,4159

table 2 No pp D mm Vl m / s UO ml SD mmHg Heart rate beats / min HWB one 9.9 0.23 56 140 68 32,279327 2 14.2 0.32 65 110 82 20.08902 3 13.8 0.29 90 120 66 23,97727 four 13.6 0.26 70 120 70 22,7151 5 12,2 0.25 45 118 71 19,46616 6 12.3 0.18 44 135 68 21.771837 7 11.5 0.17 fifty 120 70 34,704 Table 3 No pp D mm Vl m / s UO ml SD mmHg Heart rate bpm HWB one 11.2 0.12 55 120 80 65.16334 2 11.0 0.14 65 120 88 75,27612 3 14.2 0.16 85 120 78 45.8129 four 12.8 0,07 70 120 90 122,45918 5 6.5 0.15 90 120 80 253.269513 6 6.0 0.13 60 120 80 228.646088 7 7.0 0.18 70 120 80 141.54605 Table 4 Patient group The average value of the HW Almost healthy patients 19.4 ± 1.71 Patients with a satisfactory clinic of the disease 25,0003 ± 2.28 Patients with worsening clinical disease 133.1675 ± 28.8

Claims (1)

A method of evaluating a portal hypertension clinic after splenorenal bypass surgery by measuring hemodynamic parameters in the portal vein using ultrasound dopplerography, characterized in that it additionally measures the cardiovascular system and determines the coefficient of hydrodynamic resistance in the portal vein (CVE)

where heart rate - heart rate, beats / min; UO - stroke volume of the heart, ml; Vl - average linear blood flow velocity in the portal vein, m / s; D is the diameter of the portal vein, mm; SD - systolic blood pressure, mm RT. Art. and with a value of CVB = 25,0003 ± 2.28, a satisfactory clinic of portal hypertension is diagnosed after splenorenal bypass surgery, and with CVB = 133.1675 ± 28.8, its deterioration.

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