RU2400144C1 - Triplex scanning method for blood flow assessment in inferior mesenteric artery in colon cancer patients - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention refers to medicine, namely to ultrasonic diagnostics, and aims at preoperative diagnosis of colon cancer. It involves Doppler ultrasound of the mesenteric artery to assess a Doppler curve shape, qualitative spectral characteristics, a group of quantitative characteristics. If observing an increasing diastolic spectral component combined with an increasing diastolic velocity, a decreasing resistivity index and a pulse index as compared to a norm, a malignant pathology is determined in an intestinal wall.

EFFECT: method is noninvasive; it ensures colon cancer diagnostic criteria by blood flow spectral characteristics in the inferior mesenteric artery.

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Description

The present invention relates to medicine, namely to ultrasound diagnostics, and can be used to assess blood flow in the inferior mesenteric artery in colorectal cancer.

The volume of surgical interventions in patients with colorectal cancer (CRC) is determined by the size of the tumor, the presence of invasion of the surrounding organs, the general condition of the patient. Rectum resection with sigma reduction is one of the “gold standards” in the surgical treatment of colorectal cancer. In the case of the formation of an anastomosis between the intestinal loops, the assessment of blood supply to the reduced intestinal loop, which is supplied from the system of the inferior mesenteric artery (NBA), is of great importance.

Currently existing methods for studying blood flow in the arteries of the left half of the colon — radiopaque angiography and ultrasonic flowmetry — are performed while the patient is on the operating table.

X-ray contrast angiography of the inferior mesenteric artery (NBA) is performed by injecting a contrast agent directly through a needle or intra-arterial catheter (General Guide to Radiology. Part 11, Chapter 20. Medical Imaging Series. NICER Institute, 1995). The rate of administration of the contrast medium should be commensurate with the technique of radiographic imaging and with the speed of blood flow in the test vessel. This examination is carried out intraoperatively.

The disadvantages of X-ray contrast angiography are the invasiveness of the technique, the presence of radiation exposure and the possibility of developing complications that can be caused by puncture (bleeding, spasm, thrombosis, peripheral embolization), catheter manipulations (perforation, embolization of plaque components, air) or an allergic reaction to a contrast medium.

For NBA ultrasonic flowmetry, an NT 101 device (Transonic Sistems Inc., USA) is used, which emits ultrasound, and a sensor with a piezoelectric generator of various types and sizes, which are selected according to the diameter of the vessel (Yu.A. Kazakov, VV Bobkov. Forecasting the risk of ischemia of the left half of the colon during reconstruction of the abdominal aorta. Methodology of flowmetry. 1999). The volumetric blood flow in the vessels during surgery is measured. Volumetric blood flow is estimated from a functioning NBA, which averages 138 + 16.5 ml / min. Range of fluctuations is from 110 to 180 ml / min. With NBA stenosis, the volumetric flow is not recorded or is extremely low. The disadvantage of this method is to conduct research only intraoperatively. This method is taken as a prototype.

The objective of the invention is to develop a method for assessing the spectral characteristics of blood flow in the NBA.

EFFECT: obtaining criteria for the diagnosis of colorectal cancer by assessing the spectral characteristics of blood flow in the NBA.

The proposed method is as follows.

Indications: cancer of the descending colon, sigmoid and rectum.

Contraindications: no.

Execution technique

On the eve of the examination, a well-known gas-free diet is observed for preparation for ultrasound. The patient is examined on an empty stomach, laid on a couch while lying on his back. An ultrasonic convex sensor with a frequency of 3-5 MHz is applied to the patient's anterior abdominal wall in the projection of the abdominal aorta. Stage 1 of the study includes aortic assessment in B-mode. Aortic cross section is derived. The mouth of the NBA is located 3-5 cm below the mouth of the renal arteries and 2-3 cm above the aortic bifurcation. An artery is defined as an oval structure with hyperechoic walls and anechoic cavity lumen. The average diameter is 3.5 mm.

The next step is to study in Doppler mode. Initially, a study is conducted in the color Doppler mapping (CDC) mode and a color signal (locus) is determined that is additional to the color chart from the aorta at a distance of 3-5 cm below the mouth of the renal arteries or 2-3 cm above the aortic bifurcation. When detecting blood flow in the NBA in the CDC mode, they switch to a spectral analysis of blood flow in the pulse-wave Doppler mode. In order to assess the state of blood flow in the vessel, the following conditions are met:

1) the control volume is set with an insonation angle of 45 degrees;

2) the size of the control window is at least 2/3 of the diameter of the lumen of the vessel.

When assessing the spectrum of the Doppler frequency shift, quantitative and qualitative parameters are determined. Among the qualitative parameters, the shape of the Doppler curve, the type of spectrum of Doppler frequencies and the belonging to arteries with high or low peripheral resistance, the presence of a spectral window are evaluated.

After determining the qualitative characteristics of the spectrum, quantitative parameters are evaluated: final diastolic blood flow velocity (Vmin), peripheral blood flow resistance index (resistance index, RI), pulsation index (PI). If an increase in the diastolic component of the spectrum is detected, while the final diastolic velocity increases, the resistance index and the pulsation index decrease, the presence of a malignant tumor in the walls of the descending colon, sigmoid or rectum supplied from the NBA system is determined.

The proposed method is illustrated by the following figures: figure 1 shows the spectrum of blood flow in the NBA in healthy people (Vmin = 6.5 cm / sec, RI = 0.98, PI = 3.2), figure 2 shows the spectrum of blood flow in the NBA in patients with CRC (Vmin = 9.53 cm / s, RI = 0.87, PI = 2.6).

The authors conducted studies in 30 healthy patients whose age composition ranged from 30 to 77 years, the average age was 51 ± 3.3 years.

The results obtained had the following spectral characteristics. NBA has a Doppler frequency shift spectrum characteristic of arteries with high peripheral resistance. The spectrum is characterized by high systolic and low diastolic components. The ratio of systole - diastole (S / D) averages 12.7 ± 3.5, which confirms the belonging of the Doppler frequency shift spectrum to arteries with high peripheral resistance. There is a negative phase in the early diastole of the diastolic component of the spectrum, the spectral window is determined (figure 1).

The quantitative characteristics of the diastolic velocity are from 0.08 to 12.8 cm / sec, the resistance index ranged from 0.79 to 0.98, the pulsation index ranged from 0.15 to 7.1.

A study was conducted in 38 patients with colorectal cancer. Age ranged from 38 to 72 years on average 50 ± 2 years, there were 18 men, 20 women. The study group is comparable in age and gender to the control group. In patients with colorectal cancer, NBA has a low diastolic component characteristic of the artery, a negative phase in the early diastole in the diastolic component, an increase in the diastolic component of the spectrum was determined (figure 2). In sick patients, quantitative indicators were as follows: Vmin fluctuations from 4 to 31 cm / sec, RI fluctuations from 0.6 to 0.99, PI from 0.7 to 5.5. The average blood flow indicators are presented in the table. There was a significant increase in the diastolic blood flow velocity in comparison with the control group, and a decrease in the resistance index and the pulsation index.

All patients underwent laparotomy, revision of the abdominal cavity. Morphological verification of sigma and rectum tumors was performed in all patients. There was an adenocarcinoma of varying degrees of differentiation.

Example 1. Patient O., 69 years old, in the department of coloproctology was diagnosed with multiple sigma polyps. When conducting NAD ultrasound, an artery was revealed below the mouth of the renal arteries, which has a high peripheral resistance with the following quality indicators: Vmin = 5.3 cm / s, RI = 0.92, PI = 4.19. Thus, when compared with normal values, the quantitative characteristics of blood flow in the NBA corresponded to normal values. During the operation, the surgeons removed the polyps of the sigmoid colon.

Example 2. Patient E., 60 years old, was in the coloproctology department with a diagnosis of colorectal cancer. During NBA ultrasound scan, an artery 3 mm in diameter below the mouth of the renal arteries was detected, which had arterial blood flow with high peripheral resistance, with a negative phase in the early diastole near the diastolic component of the spectrum, the spectral window was determined, and an increase in the diastolic component of the spectrum was noted. Values Vmin = 10.7 cm / s, RI = 0.82, PI = 2.28. Thus, with NBA ultrasound, the qualitative indicators corresponded to the NBA trunk, there were deviations in the qualitative indicators in the form of an increase in the diastolic component of the spectrum and quantitative characteristics from the norm: an increase in Vmin, a decrease in RI and PI. Surgeons performed Hartmann surgery to remove a rectal tumor. The result of a histological examination is rectal adenocarcinoma.

Table Quantitative indicators of blood flow in the lower mesenteric artery in healthy patients and in patients with colorectal cancer Indicators Control group (n = 30) Patients (n = 38) Reliability (p) V _min 5.7 ± 0.91 cm / s 8.89 ± 1.07 cm / s <0.01 R _i 0.91 ± 0.01 0.85 ± 0.01 <0.01 P _i 3.56 ± 0.37 2.93 ± 0.19 <0.01

Claims (1)

A method for the diagnosis of colorectal cancer in the preoperative stage, including ultrasound with an assessment of the diameter of the inferior mesenteric artery (NBA) and blood flow velocity, while in the B-mode, the aortic cross section is drawn, the mouth of the NBA is found 3-5 cm below the mouth of the renal arteries and 2 -3 cm above the aortic bifurcation and assess its diameter, while the artery is defined as an oval structure with hyperechoic walls and anechoic cavity lumen; Then, NBA duplex scanning is carried out using color Doppler mapping and pulse-wave Doppler, qualitative indicators are examined: the shape of the Doppler curve, the type of spectrum of the Doppler frequencies, the presence of the spectral window, the diastolic component of the spectrum are determined, the NBA is evaluated as an artery with high peripheral resistance, as well as quantitative blood flow indicators, characterized in that when detecting an increase in the diastolic component of the spectrum and a simultaneous increase in the final diasto personal speed above the normal value of 5.69 ± 0.66 cm / s, a decrease in the resistance index below the normal value of 0.92 ± 0.01 and a pulsation index below the normal value of 4.1 ± 0.21 from the norm determine the presence of a malignant tumor in the walls descending colon, sigmoid or rectum, blood supply from the NBA system.

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