RU2826989C1 - Method for ultrasonic diagnosis of aorto-mesenteric compression of left renal vein in left-sided varicocele in children - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention relates to pediatric surgery, urology and ultrasound diagnostics, and can be used for ultrasound diagnostics of aorto-mesenteric compression of the left renal vein in left-sided varicocele in children. Performing the examination with the patient lying on his/her back, determining the maximum diameter of the dilated portion of the left renal vein and measuring its anteroposterior size, maximally narrowed area is determined proximally and its anteroposterior size is measured. Ratio of the diameter of the maximally expanded section to the diameter of the maximally narrowed section is calculated, and the maximum blood flow rate in the narrowed section is determined. After that, the sensor is installed in the upper one-third of the scrotum, during the Valsalva test and measuring in cross section anteroposterior size of maximally dilated vein of ungulate plexus of scrotum, blood flow direction is determined, and blood flow velocity or direction change is assessed during Valsalva test for 10 seconds. If the flow increases, but the direction does not change, an antegrade flow is established, if the flow increases in the opposite direction, retrograde flow is established, time of amplification or change of flow direction is measured in the obtained spectrogram and points are assigned to the obtained diagnostic parameters. Obtained points are summed up, and if the total score is from 8 to 10, the presence of aorto-mesenteric compression of the left renal in children with left-sided varicocele is diagnosed.

EFFECT: method enables diagnosing aorto-mesenteric compression of the left renal vein in left-sided varicocele in children by selecting the most significant renal blood flow values in various positions and using the Valsalva test.

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Description

The proposed invention relates to medicine, namely to pediatric surgery, pediatric urology, ultrasound diagnostics, and can be used in the study of the left renal vein in the area of the aorto-mesenteric junction and the veins of the pampiniform plexus of the veins of the scrotum in case of left-sided varicocele in children.

The following criteria and methods for diagnosing aorto-mesenteric compression based on ultrasound examination (US) data are known:

1. The patient is in a vertical position. The maximum flow velocity in the narrowing zone of the left renal vein (LRV) and in the hilar segment of the LRV is calculated. Соотношения в диапазоне от 4,0:1 до 5,0:1 значимы в диагностике компрессии ЛПВ (Kim S.H. et al. Nutcracker syndrome: diagnosis with Doppler US. Radiology 1996; 198:93-7. Cheon J.E., Kim W.S., Kim I.O., et al. Nutcracker syndrome in children with gross haematuria: doppler sonographic evaluation of the left renal vein. Pediatr Radiol 2006; 36(7):682-6. Shin J.I. et al. Morphologically improved nutcracker syndrome in an 11-year-old girl with hematuria. Pediatr Int 2007; 49: 677-9. Kolber M.K, Cui Z., Chen C.K. et al. Nutcracker syndrome: diagnosis and therapy. Cardiovasc Diagn Ther 2021; 11(5): 1140-1149. http://dx.doi.org/10.21037/cdt-20-160).

2. The patient is in an upright position. The ratio of the anteroposterior diameter measured in the stretched hilar and narrowed aortomesenteric parts of the left renal vein is calculated; threshold values are greater than 4.2. The maximum flow velocity in the narrowing zone of the left renal vein and in the hilar segment of the left renal vein is also calculated. A ratio of greater than 4.0 is a diagnostic criterion for aortomesenteric compression in children (Park S.J. et al. Nutcracker syndrome in children with orthostatic proteinuria: diagnosis on the basis of Doppler sonography. J Ultrasound Med 2002; 21:39-45; quiz 46).

3. Criteria for hemodynamically significant compression of the left renal vein using ultrasound: anteroposterior size of the renal vein in the narrowing zone is 1.5-2.5 mm or less, local increase in blood flow velocity is more than 110 cm/s (Strakhov S.N., Pryadko S.I., Bondar Z.M., Kosyreva N.B. Variants of the architectonics, hemodynamics of the left renal and testicular veins and the choice of a pathogenetically substantiated method of surgical treatment of left-sided varicocele // Annals of surgery. - 2014. - No. 3. - P. 32-40).

4. The examination is performed with the patient in the following positions: "supine", "lying on the left side" and "standing in front of the researcher". The criterion for aorto-mesenteric compression is the diameter of the left renal vein in the aorto-mesenteric region of less than 3.5 mm and the linear blood flow velocity in this area of more than 100 cm/s (Berlizeva O.Yu., Aboyan I.A., Usenko E.E. et al. A method for differential diagnosis of primary and secondary varicose veins of the pelvic veins in men. Patent RU 2713800 C1., 2020. Berlizeva O.Yu., Aboyan I.A., Amosov A.V. et al. Methodology of complex ultrasound examination in the diagnosis of varicose veins of the pelvis in men // Modern problems of science and education. - 2021. - No. 2. - P. 118-127).

5. The patient is positioned on the side. During shallow breathing, the vascular pedicle of the kidney is visualized. Flow curves are recorded on the main (distal) section of the renal vein. During ultrasound Dopplerography (USDG), the difference (ΔVven) between the maximum blood flow velocity (Vven-max) and the minimum blood flow velocity (Vven-min) during one cardiac cycle is determined in the main section of the renal vein. An increase in the difference between the maximum and minimum velocity in the renal vein of at least 22 cm/sec reflected the presence of phlebostasis in the main venous vessels of the kidneys (Alekseenko S.N. A method for early diagnosis of venous outflow disorders from the renal vein "pool", 2020. Tonyan A.G., Khan V.V. The role of aorto-mesenteric "tweezers" in the development of disorders of the main venous blood flow of the left kidney. // Hospital medicine: science and practice. - 2021. - Vol. 4, No. 1. - P. 17-25).

6. The diameter of the LSV (between the aorta and the superior mesenteric artery (SMA) is 1.7-2.3 mm. The diameter of the LSV (distal segment) is 5.8-10.3 mm. The maximum flow velocity in the LSV between the aorta and the SMA is 80.9-158.6 cm / s. (Fomina E.E., Akhmetzyanov R.V., Tukhbatullin M.G. Ultrasound diagnostics of the pelvic veins in women of reproductive age. Outpatient surgery. 2022; 19 (1): 113-123. https://doi.org/10.21518/1995-1477-2022-19-1-113-123).

7. The closest to the proposed method in terms of the set of essential features is the following method. The study is performed in the patient's positions "lying on the back" and "standing in front of the researcher". The ratio of the LPV diameter in the stretched, maximally expanded perihilar zone to the LPV diameter at the site of narrowing (aorto-mesenteric part of the LPV) is calculated. The threshold value of this indicator is 3.8 in the lying position and 5.58 in the standing position. The ratio of the maximum flow velocity at the site of narrowing of the LPV (aorto-mesenteric part) to the maximum flow velocity at the site of its expansion (perhilar part) is calculated. The threshold value of this indicator is 4.23 in the lying position and 5.14 in the standing position (Fitoz S., Ekim M., Ozcakar Z.B., Elhan A.N., Yalcinkaya F. Nutcracker syndrome in children: the role of upright position examination and superior mesenteric artery angle measurement in the diagnosis. J Ultrasound Med. 2007; 26(5): 573-580. Kurklinsky A.K., Rooke T.W. Nutcracker phenomenon and nutcracker syndrome. Mayo Clin Proc. 2010 Jun; 85(6):552-9. doi: 10.4065/mcp.2009.0586).

The listed methods of diagnosing aorto-mesenteric compression of the LPV have significant discrepancies in the parameters studied. The same criteria may or may not correspond to aorto-mesenteric compression. When assessing several parameters, disagreements also arise. If one criterion is defined as positive and the other as negative, then it is impossible to reliably diagnose compression of the LPV. Thus, the listed methods are ambiguous and entail diagnostic errors.

The objective of the present invention is to develop a safe and non-invasive method for diagnosing aorto-mesenteric compression of the left renal vein in left-sided varicocele in children.

The technical result of using the claimed method consists in increasing the accuracy of determining aorto-mesenteric compression of the left renal vein in left-sided varicocele in children.

The problem is solved as follows. For accurate ultrasound diagnostics of aorto-mesenteric compression of the left renal vein in left-sided varicocele in children, a method is proposed for ultrasound diagnostics of aorto-mesenteric compression of the left renal vein in left-sided varicocele in children and assigning a point assessment to the obtained diagnostic criteria and indicators using a scale (Table 1).

where D1/D2 is the ratio of the diameter of the left renal vein (LRV) distal to the aortomesenteric junction (maximum dilated diameter of the LRV, in millimeters, D1) to the diameter of the LRV proximal to the aortomesenteric junction (maximum narrowed diameter of the LRV, in millimeters, D2);

Vmax LPV - maximum blood flow velocity in the narrowed area of the LPV (Vmax, cm/sec);

Dmax VM - maximum diameter of the veins of the pampiniform plexus of the scrotum during the Valsalva maneuver (in millimeters);

V flow of VM - change in the speed or direction of flow in the pampiniformly dilated veins of the scrotum during the Valsalva maneuver;

T is the time of change in the speed or direction of flow in the pampiniformly dilated veins of the scrotum during the Valsalva maneuver (in seconds).

The points obtained are summed up. It is considered that if the sum of points obtained during the calculation is equal to:

- 8-10 points - there is aorto-mesenteric compression of the left pelvic vertebra. Renospermatic form of varicocele is detected. Sensitivity 96.2%, specificity 94.7%.

- 6-7 points - aorto-mesenteric compression of the left pelvic vertebra is not precisely established. Renospermatic form of varicocele is revealed. Sensitivity 50%, specificity 82.4%.

- 5 points or less - no aorto-mesenteric compression of the left pelvic vertebra. Ileospermatic form of varicocele is detected.

Using this scale, a study of 45 patients with left-sided varicocele was conducted. The study included patients with primary treatment who had not previously undergone surgery. The age was (Me) 14.5 years (Q1 14.0; Q3 15.0). In 91.1% of cases, patients had grade 2 varicocele. In 26 patients, a left testicular vein dilated by more than 3 mm was detected during laparoscopy, which served as a criterion for compression of the left renal vein as a cause of varicocele. The sensitivity and specificity of the scale assessment in the diagnosis of aortomesenteric compression of the left renal vein in left-sided varicocele in children were assessed:

1. 8-10 points - 96.2% sensitivity, 94.7% specificity (Table 2).

2. 6-7 points - 50% sensitivity, 82.4% specificity (table 3)

3. 5 points or less - sensitivity 0% and specificity 0%, no aorto-mesenteric compression of the left posterior ventricle.

The method is illustrated by the following drawings:

Fig. 1 shows a transverse scan of the left renal vein, where 1 is the superior mesenteric artery (SMA); 2 is the left renal vein, the maximally dilated section (LRV, D1); 3 is the aorta; 4 is the inferior vena cava (IVC); 5 is the left renal vein, the maximally narrowed section (LRV, D2).

Fig. 2 shows a visual display of the mode for determining the maximum blood flow velocity in the narrowed area of the LPV (Vmax, cm/sec).

Fig. 3 shows a visual display of the mode for determining the time of change in the speed or direction of flow in the pampiniformly dilated veins of the scrotum during the Valsalva maneuver (T, sec).

The method is carried out as follows.

The first stage of the examination is performed with the patient in the supine position. Convex ultrasound sensors with a frequency of 3.5 MHz to 7.5 MHz are used. The scanning depth is 10-12 cm. The sensor is installed under the xiphoid process in the epigastrium. Scanning is performed in cross-section. The aorta and inferior vena cava are visualized. Then the sensor is shifted downwards until the superior mesenteric artery (SMA) is visualized in cross-section, shifting the direction of the scanning beam, the left renal vein (LRV) is visualized. The maximum diameter of the LRV is determined distal to the aorto-mesenteric junction, its anteroposterior size is measured in millimeters (D1 indicator). Proximal to the aorto-mesenteric junction, the LSV is visualized until it enters the inferior vena cava (IVC), and the anteroposterior size of the maximally narrowed section of the LSV is measured in millimeters (D2 indicator) (Fig. 1).

In the color Doppler mapping (CDM) mode, the blood flow in the LPV is visually assessed in all areas. In the pulse-wave Doppler mode, the flow is assessed. The control volume is set at 2/3 of the vessel diameter. The flow characteristic is determined at an angle of -60° for the dilated section of the LPV and at an angle of +60° for the narrowed section of the LPV. In the resulting spectrogram, the maximum flow velocity (Vmax LPV) is measured according to the intensely colored spectrum (Fig. 2).

The second stage of the study is performed with the patient in a standing position. Linear sensors with a frequency of 10 MHz to 14 MHz are used. The scanning depth is 2-3 cm. The sensor is placed in the upper third of the scrotum. During the Valsalva maneuver, the anteroposterior size (in millimeters) of the maximally dilated vein of the pampiniform plexus of veins of the scrotum (Dmax VM indicator) is measured in cross section. In the color Doppler mode, the blood flow in the dilated veins of the scrotum is visually assessed. In the pulsed-wave Doppler mode without a correction angle, the direction of the flow is determined and, during the Valsalva maneuver, a change in the velocity or direction of the flow is assessed for 10 seconds (antegrade - the flow increases, but the direction does not change; retrograde - the flow increases in the opposite direction). In the resulting spectrogram, the time of change in the velocity or direction of the flow is measured in seconds (T indicator) (Fig. 3).

The obtained indicators are then assigned points according to the proposed scale for determining aorto-mesenteric compression.

The D1/D2 index is calculated - the ratio of the left renal vein (LRV) diameter distal to the aorto-mesenteric junction (maximum dilated LRV diameter, in millimeters, D1) to the LRV diameter proximal to the aorto-mesenteric junction (maximum constricted LRV diameter, in millimeters, D2). If the D1/D2 value is less than 3.5, the index is assigned 0 points, if the D1/D2 value is in the range of 3.5-4.0, 1 point is assigned, and if the value is greater than 4.0, 2 points are assigned.

Points are assigned to the previously determined indicator of the maximum blood flow velocity in the narrowed area of the LPV (Vmax, cm/sec). If the Vmax value is less than 100 cm/sec, 0 points are assigned, if the value is in the range of 100-130 cm/sec, 1 point is assigned, and if the value is more than 130 cm/sec, 2 points are assigned.

Points are assigned to the previously determined Dmax VM indicator - the maximum diameter of the veins of the pampiniform plexus of the scrotum during the Valsalva maneuver (in millimeters). If the Dmax VM value is less than 3.0 mm, 0 points are assigned, if the value is in the range of 3-4 mm - 1 point, if the value is more than 4.0 mm - 2 points.

Points are assigned to the previously determined indicator of change in the speed or direction of flow in the pampiniformly dilated veins of the scrotum during the Valsalva maneuver (V flow VM). In this case, if there is no change in the speed or direction of blood flow, 0 points are assigned, with antegrade flow (the flow increases, but the direction does not change) 1 point is assigned, with retrograde flow (increase in flow in the opposite direction) 2 points are assigned.

Points are assigned to the previously determined T indicator - the time of change in the speed or direction of flow in the pampiniformly dilated veins of the scrotum during the Valsalva maneuver, in seconds. If the T indicator is less than 1.0 seconds, 0 points are assigned, if the value is 1-2 seconds - 1 point, if the value is more than 2.0 seconds - 2 points.

The obtained points are summed up. It is considered that if the sum is 8-10 points, then aorto-mesenteric compression of the left renal vein (LRV) is diagnosed. Renospermatic form of varicocele is detected.

At 6-7 points, aorto-mesenteric compression of the left pelvic vertebra is not precisely established. Renospermatic form of varicocele is revealed. At 5 points and less, there is no aorto-mesenteric compression of the left pelvic vertebra. Ileospermatic form of varicocele is revealed.

The proposed method is illustrated by the following clinical examples.

Clinical example No. 1.

Patient K., 17 years old, was treated at the State Children's Hospital of Irkutsk with a diagnosis of: Varicocele on the left (I 86.1)

From the anamnesis: the child had periodic pain in the left half of the scrotum after physical exertion for 6 months. He contacted a surgeon at his place of residence and was referred for planned surgical treatment.

During examination at the upper pole of the left testicle, grape-shaped dilated veins of the scrotum are detected by palpation.

The OAM did not reveal proteinuria or hematuria.

The child underwent ultrasound examination using the proposed method. The following parameters were revealed. The left renal vein distal to the aortomesenteric junction has a diameter (D1) of 9.5 mm, the maximum flow velocity is 26.5 cm/sec. The left renal vein proximal to the aortomesenteric junction has a diameter (D2) of 1.6 mm, the maximum flow velocity (Vmax LRV) is 132 cm/sec. The veins of the pampiniform plexus of the scrotum at rest are 4.8 mm. During the Valsalva maneuver, the diameter of the veins of the pampiniform plexus of the scrotum increases to (Dmax VM, mm) 5.5 mm, retrograde flow is observed for 3.2 seconds. The revealed parameters were assigned the following points in accordance with the proposed method:

D1ZD2 = 5.9 (more than 4.0) - 2 points;

Vmax LPV = 132 cm/sec (more than 130 cm/sec) - 2 points;

Dmax VM = 5.5 mm (more than 4.0 mm) - 2 points;

Retrograde flow (V flow VM - retrograde) - 2 points;

Time to change flow direction (T indicator) = 3.2 sec. (more than 2 sec) - 2 points.

Based on the examination results, the patient received a total of 10 points, which indicated aorto-mesenteric compression as the cause of varicocele. The child underwent surgical treatment: laparoscopic ligation of the left testicular vein. During the operation, the left testicular vein was dilated by more than 3 mm, after ligation, the testicular vein in the distal parts collapsed.

The postoperative period was uneventful. The pain was relieved. The child was discharged as a recovered patient.

Clinical example No. 2.

Patient III., 16 years old, was treated at the State Children's Hospital of Irkutsk with a diagnosis of: Varicocele on the left (I 86.1)

From the anamnesis: the diagnosis was made during a routine preventive medical examination at the place of residence. Referral for planned surgical treatment.

During examination at the upper pole of the left testicle, grape-shaped dilated veins of the scrotum are detected by palpation.

The OAM did not reveal proteinuria or hematuria.

The child underwent ultrasound examination using the proposed method. The following parameters were revealed. The left renal vein distal to the aortomesenteric junction has a diameter (D1) of 6.2 mm, the maximum flow velocity is 44 cm/sec. The left renal vein proximal to the aortomesenteric junction has a diameter (D2) of 3.7 mm, the maximum flow velocity (Vmax LRV) is 50.5 cm/sec. The veins of the pampiniform plexus of the scrotum at rest are 2.5 mm. During the Valsalva maneuver, the diameter of the veins of the pampiniform plexus of the scrotum increases to (Dmax VM, mm) 3.0 mm, an increase in the flow velocity is noted for 0.356 seconds.

D1/D2 = 1.68 (less than 3.5) - 0 points;

Vmax LPV = 50.5 cm/sec (less than 100 cm/sec) - 0 points;

Dmax VM = 3.0 mm (3.0-4.0 mm) - 1 point;

Antegrade flow (V flow VM - antegrade) - 1 point;

Time of change of flow velocity (T indicator) = 0.356 sec. (less than 1 sec) - 0 points

Based on the examination results, the patient received a total of 2 points, which indicated the absence of aorto-mesenteric compression. The child was diagnosed with ileospermatic varicocele, in connection with which surgical treatment was performed: suprascrotal access to the spermatic cord was achieved (Kravtsov Yu.A., Sichinava Z.A. Surgical suprascrotal access for surgical treatment of scrotal pathology.

Patent RU 2541336 C2., 2013), pathological veins of the pampiniform plexus dilated by more than 2 mm were isolated. The veins were ligated and cut off. The wound was sutured layer by layer.

The postoperative period was uneventful. The child was discharged as a recovered patient.

Claims (7)

A method for ultrasound diagnostics of aorto-mesenteric compression of the left renal vein in left-sided varicocele in children, including performing a study with the patient in a supine position, wherein the maximum diameter of the dilated section of the left renal vein (LRV) is determined distal to the aorto-mesenteric junction, its anteroposterior size is measured with the patient in a supine position (D1), the maximally narrowed section of the LRV is determined proximal to the aorto-mesenteric junction, its anteroposterior size is measured with the patient in a supine position (D2), the ratio of the diameter of the maximally dilated section of the LRV distal to the aorto-mesenteric junction to the diameter of the maximally narrowed section of the LRV proximal to the aorto-mesenteric junction (DI/D2) is calculated, the maximum blood flow velocity in the narrowed section of the LRV is determined with the patient in a supine position (Vmax LRV), characterized in that the study includes a second stage, performed with the patient in a standing position, with the sensor installed in the upper third of the scrotum, during the Valsalva maneuver, the anteroposterior dimension of the maximally dilated vein of the pampiniform plexus of the scrotum (Dmax VM) is measured in cross section, the direction of blood flow is determined in the pulsed-wave Doppler mode without a correction angle, and during the Valsalva maneuver, the change in the speed or direction of blood flow is assessed for 10 seconds, and if the flow increases but the direction does not change, antegrade flow is established, if the flow increases in the opposite direction, retrograde flow is established, in the resulting spectrogram, the time of increase or change in the direction of the flow is measured and points are assigned to the obtained diagnostic indicators: if the D1/D2 ratio is less than 3.5, the indicator is assigned 0 points, if the ratio is in the range of 3.5-4.0, 1 point is assigned, and if the ratio is more than 4.0, 2 points are assigned; if the value of the Vmax LPV indicator is less than 100 cm/sec, 0 points are assigned, if the value is in the range of 100-130 cm/sec, 1 point is assigned, and if the value is more than 130 cm/sec, 2 points are assigned; if the Dmax VM value is less than 3.0 mm, 0 points are assigned, if the value is in the range of 3-4 mm - 1 point, if the value is more than 4.0 mm - 2 points; if there is no change in the speed or direction of blood flow in the pampiniformly dilated veins of the scrotum during the Valsalva maneuver, 0 points are assigned; if an increase in the speed of antegrade flow is detected, 1 point is assigned; if a retrograde flow is detected, 2 points are assigned; if the value of the time of change in the speed or direction of flow in the pampiniformly dilated veins of the scrotum during the Valsalva maneuver is less than 1.0 second, 0 points are assigned, if the value is 1-2 seconds - 1 point, if the value is more than 2.0 seconds - 2 points; The points obtained are summed up, and if the total points are 8-10, the presence of aorto-mesenteric compression of the left lateral varicocele in children is diagnosed.