Atypical Extravenous Compression of Inferior Vena Cava System

The May—Thurner syndrome is the most typical variant of venous compression. Less common variants of venous compression by whether adjacent arteries or other paravascular structures and organs are of no less clinical significance. Objective. To describe possible variants of vein compression in the inferior vena cava (IVC) system based on the results of multispiral computed tomography with phlebography (CTP). Material and methods. We analyzed the causes of IVC and its branches compression based on CTP findings in patients presenting with clinical signs of chronic or pelvic venous insufficiency and suspected venous compression. Results. This analysis allowed us to categorize the primary causes of rare venous compression into distinct subgroups. Normally developed iliac veins and the IVC may be subject to compression by various factors. These include vascular structures, which can be either pathologically altered or anatomically normal. Furthermore, venous compression may be caused by non-vascular structures, such as abnormal organs or tissues within the abdominal cavity, pelvis, or retroperitoneal space. In addition, the compressing substrate may be of extrinsic origin, such as metallic hardware, etc. A distinct type of compression involves anomalously formed IVC and iliac veins. Conclusion. The diversity of causes for venous compression within the IVC system underscores the need for a comprehensive classification system aimed at developing tactical approaches to patient management.