CLINICAL AND DIAGNOSTIC ASPECTS OF THE NUTCRACKER PHENOMENON AND SYNDROME USING BIOMEDICAL VISUALIZATION METHODS

Background. Varicose veins of the pelvic veins remain an insufficiently studied disease and the causes of its development are not always obvious. Anomalies in the structure, shape and location of the renal vessels occur during the embryonic development of the vascular system. Congenital changes in the renal veins are most often associated with developmental disorders of the inferior vena cava into which they flow. Compression stenosis of the left renal vein (LRV) can exist in two clinical and morphological forms: the Nutcracker phenomenon and syndrome. Nutcracker syndrome is a rare disease, and according to clinical manifestations, it is not diagnosed enough to determine the difference between the "syndrome" and the "phenomenon". In addition to laboratory and urological diagnostics of the disease, biomedical imaging methods play a significant role in diagnosing the disease. Purpose. To acquaint medical specialists with the clinical and diagnostic aspects of the Nutcracker phenomenon and syndrome using biomedical imaging methods. Materials and methods. The Internet search was used to select literature. The analysis included 21 articles, 11 of which belong to foreign authors. Results. Upper-level arteriovenous conflicts, in particular the Nutcracker syndrome, can lead to pelvic venous congestion and the development of varicose veins of the pelvis. Timely detection of arteriovenous compression syndromes using biomedical imaging, as well as an assessment of their hemodynamic and clinical significance, will allow for bypass surgery, which will prevent the development of complications, improve the quality of life of patients and reduce the burden on the healthcare system. Conclusions. Using biomedical imaging methods, it is possible to identify congenital anomalies of the renal vessels, determine the relative position of the LPV relative to the aorta and superior mesenteric artery (SMA), and measure the angle of departure of the SMA. Currently, the following biomedical imaging methods are used to diagnose and assess the significance of arteriovenous conflicts, in particular, the Nutcracker syndrome: ultrasound angioscanning (including with contrast enhancement, as well as intravascular ultrasound); CT and CT angiography; MRI and MR angiography; direct X-ray phlebography (including with phlebotonometry).