Description of the features of blood supply of intramural and intramural-subserous myomatous nodes of various sizes using the Virtual Organ Computer-aided Analysis (VOCAL)

Background: Uterine fibroids are a common benign tumor that negatively affects reproductive function. The criteria for tumor evolution have not yet been determined. It is assumed that tumor growth and the number of growth points are associated with the transformation of blood circulation in the uterus and myomatous node. Recently, data have appeared on the prospects for three-dimensional ultrasound to be used with a specialized program that allows for describing the characteristics of blood supply throughout the entire tumor volume at the level of the microvasculature, which has low speed parameters, namely Virtual Organ Computer-aided Analysis (VOCAL).

Aim: The aim of this study was to assess the characteristics of the blood supply to intramural and intramural-subserous myomatous nodes of various sizes using ultrasound and power Doppler in three-dimensional mode using specialized VOCAL software.

Materials and methods: This study included 40 patients with uterine fibroids with a single myomatous node of intramural-subserous or intramural localization (International Federation of Gynecology and Obstetrics types 4–6). Four study groups were formed. Group I consisted of ten patients with uterine fibroids with a node diameter of up to 4.0 cm inclusive. Group II comprised ten patients with a node diameter from 4.0 to 5.0 cm inclusive. Group III included ten patients with a node diameter from 5.0 to 8.0 cm inclusive. And Group IV included ten patients with a node diameter of more than 8.0 cm. Ultrasound examination was carried out using a W10-RUS ultrasound scanner (Samsung Medison Co., Ltd., South Korea) on days 5–7 of the menstrual cycle.

Results: We found that the most vascularized were myomatous nodes with a diameter of up to 4.0 cm. With an increase in the diameter of myomatous nodes, vascular resistance increased, which in turn indicates a decrease in vascularization. In addition, a decrease in resistance in the central vessels of the tumor compared to its peripheral vessels indicates the characteristic development of the vascular network of the myoma. This is characterized by the formation of new blood vessels mainly from the periphery of the tumor, which form a highly vascularized vascular capsule, while the center of the myomatous node is a hypovascular core.

Conclusions: Evaluation of uterine vascularization and uterine fibroids using the specialized VOCAL program allows us to describe the features of blood supply and re-evaluate the mechanisms of tumor development. The use of power Doppler in 3D mode with the use of the specialized VOCAL program makes it possible to further study the vascularization of tumor tissue and establish “hemodynamic variants” of the intramural form of uterine myoma to search for the relationship between tumor growth and the transformation of the associated myometrium.