Method for assessing functional state of patient's upper urinary tract in real time

Abstract

FIELD: urology; radiology.SUBSTANCE: used to assess the functional state of a patient's upper urinary tract in real time. The patient lies in a supine position on a stationary table between the x-ray tube and the detector. The contrast agent Ultravist is administered intravenously at a rate of 1 ml / kg of body weight. Scanning begins 3 minutes after administration. The source and detector are moved along the patient's body from the projection of the renal pelvis and the upper third of the ureter to the middle and lower third. Scanning cycles are repeated 3 to 5 times. A series of sequential images are obtained, converted into a digital video file. It is used to evaluate the spread of the contractile wave of smooth muscles, the movement of the contrast agent, the size, contours and shape of the calyces, pelvis and ureters. If the renal pelvis is dilated in comparison with the opposite one, the movement of the contrast agent is asymmetrical, its strip narrows in the area of the ureter, or its atony appears as a widening of the contrast strip, a clinically significant latent disorder of the contractile function of the upper urinary tract is diagnosed.EFFECT: method provides visualization of peristaltic waves of the renal pelvis and ureter in real time with reduced radiation exposure and ensuring reproducibility of the study due to cyclic movement of the radiation source and detector along the urinary tract.1 cl, 2 dwg, 1 ex

Description

[0001] The invention relates to medicine, namely to diagnostics in urology, and can be used to assess the functional state of a patient's upper urinary tract in real time, in particular the contractility of the ureter when there is a suspicion of a violation of the tone of the upper urinary tract.

[0002] The ureter exhibits pronounced automaticity. Pacemaker zones (rhythm drivers) are located in its wall, primarily in the proximal section—the ureteropelvic junction. In these areas, spontaneous electrical oscillations of the membrane occur, triggering smooth muscle contractions. These contraction waves are called cestoids. They propagate along the ureter from top to bottom at a speed of 2–6 cm / s, causing urine to move in portions toward the bladder. The normal rate of cestoids is 2–6 per minute, but may increase with increased diuresis.

[0003] Urine movement is primarily due to peristalsis. Each contraction wave causes a local narrowing of the ureteral lumen and distal movement of the contents. At rest, intraureteral pressure is approximately 5–10 mm H2O. During the passage of a peristaltic wave, it increases to 20–80 mm H2O. A clear gradient is observed: the pressure is lower in the proximal portion. The pressure increases toward the distal portion, particularly in the intramural segment.

[0004] The need to assess the contractility of the ureter is due to cases where a violation of the tone of the upper urinary tract is suspected; this is especially relevant when deciding on the need for surgical treatment for hydronephrosis and hydroureteronephrosis.

[0005] In the current stage of urology development, clinical situations arise that require an assessment of the contractility of the upper urinary tract (pelvis, ureter), particularly during surgical interventions for infiltrative endometriosis involving the lower third of the ureter. Traditionally, this procedure involves shaving the endometriotic area from the ureter and inserting a ureteral stent, which is removed after 21 days. If hydronephrosis persists, an assessment of the upper urinary tract using specialized diagnostic methods is indicated. Below is a list of well-known and widely used diagnostic methods for the urinary tract, including their advantages and disadvantages.

[0006] Excretory urography, a static imaging method, allows for visualization of the anatomy and patency of the urinary tract but does not provide objective information on motility. Invasive retrograde pyelography provides high-resolution imaging of anatomical changes but does not reflect the dynamics of renal pelvis and ureter contractions. Dynamic nephroscintigraphy allows for assessment of urine flow rate and the functional state of the renal parenchyma, but is characterized by low spatial resolution and limited visualization of ureteral motility.

[0007] Ultrasound examination with Dopplerography is a safe and non-invasive method, however, the reliability of the results of this method is largely determined by the qualifications of the operator, which does not allow for an objective assessment of the contractility of the ureter.

[0008] Magnetic resonance urography (MRI) without ionizing radiation provides high anatomical detail, but is limited in its applicability for analyzing rapid contractions of the renal pelvis and ureter. Computed tomography (CT), which is characterized by high radiation exposure, allows for highly accurate visualization of the anatomy and detection of pathological changes in the urinary tract, but does not provide an objective assessment of ureteral motor activity.

[0009] Urokymography, a method first proposed in 1933 by J. Holland, is used to assess the contractility of the upper urinary tract [Pytel, A. Ya. X-ray diagnostics of urological diseases / A. Ya. Pytel, Yu. A. Pytel. - Moscow: Meditsina, 1966. - 12 p.]. The essence of this urokymography method is the sequential execution of a series of X-ray images using a movable kymographic grid located between the patient and the X-ray film.

[0010] Urokymography was performed both during retrograde pyelography and excretory urography, and made it possible to identify organic motor disorders of the upper urinary tract, as well as functional diseases (dyskinesia), which were not detected by other methods. In addition, the method made it possible to differentiate the nature of the urinary tract dilation: atony (absence of contractions on the urokymogram) and tonic dilation (preserved motor function in the presence of an obstructive factor) [Shestopalova O. Yu., Amosov V. I., Yakovenko A. A. History of the development of radiological research methods in urology / / Urological News. - 2012. - Vol. 2, No. 1. - P. 6-11].

[0011] Urokymography allows for the detection of a wide range of urinary tract motility disorders, both those caused by organic changes (strictures, obstructions) and functional pathologies—dyskinesias—that are not identified by other standard urological examinations.

[0012] The particular value of this method lies in its ability to assess the nature of the patient's urinary tract dilation. For example, with atony, there are no contractions of the renal pelvis and ureter, which is reflected on the urokymogram as the complete disappearance of the waves. In the case of tonic dilation, motor function is preserved, but the contractions have a different character; in the presence of an obstructive factor, stenotic waves are recorded, visualized as tall waves.

[0013] Thus, urokymography, as a research method, the radiation load of which is significantly less than that of CT, can provide information not only on the presence or absence of contractions of the pelvis and ureter, but also assess the direction of propagation of the peristaltic wave, its magnitude and speed.

[0014] However, the above-described urokymography method, known since 1933, is not used in modern clinical practice. The primary information carrier in this method is X-ray film with multiple X-ray images, which precludes the possibility of digital recording of the X-ray image, its subsequent processing, as well as transmission and dynamic analysis of the resulting images.

[0015] The technical problem solved by the invention consists in developing a method for assessing the functional state of the patient's upper urinary tract in real time, which would preserve the diagnostic capabilities of urokymography while eliminating its main disadvantages.

[0016] For this purpose, a method for assessing the functional state of the patient's upper urinary tract in real time is proposed, including the use of a stationary X-ray unit, characterized in that the patient is in a supine position on a stationary table of the unit between an X-ray source in the form of an X-ray tube and an X-ray detector, a contrast agent is introduced - the drug "Ultravist" at the rate of 1 ml / kg of the patient's body weight, scanning begins 3 minutes after the intravenous administration of the drug, the X-ray source and detector are moved along the patient's body from the projection of the renal pelvis and the upper third of the ureter to the middle and lower third of the ureter, scanning cycles are repeated from 3 to 5 times, a series of sequentially taken X-ray images are obtained, converted into a digital video file, which is used to evaluate the propagation of the contractile wave of the smooth muscles of the upper urinary tract of the patient,the movement of the contrast agent down the urinary tract, the size of the calyces, renal pelvis and ureters, as well as their contours and shape, and with expansion of the pelvis in comparison with the opposite one, asymmetry of the release and movement of the contrast agent, narrowing of the strip of the contrast agent in the area of ​​the ureter or atony of the ureter in the form of expansion of the strip of the contrast agent, a clinically significant latent disorder of the contractile function of the upper urinary tract is diagnosed.

[0017] The proposed method is urokymography performed on a modern X-ray machine using an algorithm that is optimal for visualizing the upper urinary tract, including the start time of scanning and the frequency of repetitions of this scanning using an intravenous radiocontrast agent and the ability to record the obtained data on a digital medium convenient for repeated viewing.

[0018] The new technical result achieved by the invention consists in visualizing the peristaltic pelvis and ureter in real time with reduced radiation exposure while recording the obtained data on a digital medium for reproducibility of the study.

[0019] The invention is illustrated by drawings, where Fig. 1 shows an X-ray image of the first scanning cycle, where the absence of movement of the contrast agent and peristaltic waves of the smooth muscles of the renal pelvis and ureter on the right (indicated by green arrows) is visible; Fig. 2 is an X-ray image of the second scanning cycle, where a thin strip of contrast agent is visible in the pelvic section of the ureter and the absence of contractile waves of the smooth muscles of the right renal pelvis and ureter (indicated by green arrows), indicating dyskinesia of this area.

[0020] A method for assessing the functional state of a patient's upper urinary tract in real time using urokymography was implemented in the diagnosis of strictures of the lower third of the ureter (observation or surgical treatment) in patients after surgery for extragenital endometriosis involving the ureter or both ureters and persistent urinary flow disturbances along the ureters, which were confirmed by ultrasound scanning of the kidneys and computed tomography of the kidneys with intravenous contrast. Visual dynamic assessment of the contractility of the renal pelvis and ureter in these patients was performed on a GE Innova 3100 (2004) X-ray angiography system from General Electric, which is currently used in cardiology and vascular surgery for examining blood vessels and the heart.

[0021] The renowned GE Innova 3100 system consists of a C-frame, an X-ray tube with a collimator, a digital detector, a patient table, and an image control unit. The Siemens AFDSA01 collimator is designed to shape and limit the X-ray beam, reducing the radiation dose and improving image quality. The collimator is located in the X-ray unit and is closely linked to the imaging system, which is controlled from a console where projections and radiation parameters can be adjusted. During the examination, the system records a video sequence of X-ray frames, which are combined into a dynamic image, producing clear X-ray images and videos of blood vessels in real time, helping physicians perform diagnostics and various procedures, such as coronary angiography or stenting. The resulting video is saved on a computer and can be used for analysis at any time.

[0022] Clinical example

[0023] Patient K., 36 years old, consulted a urologist after undergoing treatment - laparoscopic adhesiolysis, bilateral ureterolysis. Right salpingo-ovariolysis. Removal of the right ovarian cyst capsule. Excision of infiltrating endometriosis of the vagina, rectovaginal septum, uterosacral ligaments and lateral parametria. Excision of endometriosis of the right ureter (preliminary ureteral stenting). End-to-end circular resection of the rectum. Myomectomy. The surgery was performed due to the diagnosis of endometrioid disease. Retrocervical endometriosis with penetration through the vaginal wall, cervix, rectal wall and involvement of the ureter. Endometrioid cyst of the right ovary. Medium-sized uterine fibroids (FIGO types 5 and 6). Primary infertility. Chronic constipation. Grade II hydronephrosis of the right kidney.

[0024] Hospitalized in the urology department. The stent from the right ureter was removed. CT scan of the urinary system revealed grade I-II hydronephrosis on the right, the ureter is patent along its entire length, and a pelvic stenosis is suspected. Repeat ultrasound of the kidneys revealed persistent hydronephrosis on the right. Due to persistent hydronephrosis, real-time urokymography was performed. The patient was placed in a supine position on a fixed table of a GE Innova 3100 X-ray angiography system between the X-ray source (an X-ray tube) and the X-ray detector. Ultravist contrast agent was administered intravenously at a dosage of 75 ml (patient weight 75 kg), and scanning began 3 minutes after administration. The X-ray source and detector were moved along the patient's body from the projection of the renal pelvis and the upper third of the ureters to their middle and lower thirds.

[0025] As a result, the first scanning cycle began at the 3rd minute, where a slower passage of the contrast agent from the right renal pelvis compared to the left was diagnosed. This is confirmed by the dilation of the right renal pelvis compared to the left, the absence of movement of the contrast agent along the ureter and, as a result, the absence of contractile waves of the smooth muscles of the right renal pelvis and ureter. On the left, a contractile wave of the renal pelvis and ureter and the movement of the contrast agent are visible along the entire length (Fig. 1). During the second and third scanning cycles, significant dilation of both the renal pelvis and the calyces of the right kidney were diagnosed, as well as an area in the pelvic ureter where peristaltic waves of ureteral contraction are absent (an area of ​​ureteral dyskinesia), and the contrast agent passively moves downwards as a thin strip (Fig. 2). Then, the contractility of the right ureter is restored and can be observed.

[0026] Conclusion: Grade II hydronephrosis on the right. Dyskinesia of the right ureter in the pelvic region.

[0027] The proposed method for assessing upper urinary tract contractility was tested in the urology department of 5 patients at the Sverdlovsk Region City Clinical Hospital No. 40. No complications were observed during or after the study. The average radiation dose received by the patients was 0.4 mSv, which is more than 30 times lower than that received with contrast-enhanced CT scans of the renal pelvis and ureters, which is crucial, as the radiation dose received by the patient is 13–14 mSv.

[0028] Thus, the claimed method allows for the assessment of the functional (contractile ability) state of the upper urinary tract in real time with a minor radiation load on the patient, with the possibility of reproducibility of the study due to the use of digital technologies.

Claims

A method for assessing the functional state of a patient's upper urinary tract in real time, including the use of a stationary X-ray unit, characterized in that the patient is in a supine position on a stationary table of the unit between an X-ray source in the form of an X-ray tube and an X-ray detector, a contrast agent is administered - the drug "Ultravist" at the rate of 1 ml / kg of the patient's body weight, scanning begins 3 minutes after the intravenous administration of the drug, the X-ray source and detector are moved along the patient's body from the projection of the renal pelvis and the upper third of the ureter to the middle and lower third of the ureter, scanning cycles are repeated from 3 to 5 times, a series of sequentially taken X-ray images are obtained, converted into a digital video file, which is used to evaluate the propagation of the contractile wave of the smooth muscles of the patient's upper urinary tract,the movement of the contrast agent down the urinary tract, the size of the calyces, renal pelvis and ureters, as well as their contours and shape, and with expansion of the pelvis in comparison with the opposite one, asymmetry of the release and movement of the contrast agent, narrowing of the strip of the contrast agent in the area of ​​the ureter or atony of the ureter in the form of expansion of the strip of the contrast agent, a clinically significant latent disorder of the contractile function of the upper urinary tract is diagnosed.

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