Variant anatomy of the internal iliac vein and its applications

The article analyzed data from relevant literature that focused on anatomical variations of the internal iliac vein (IIV), its structure, and morphometric characteristics. P.A. LePage et al. (1991), D. Venieratos et al. (2012), and P. Kanjanasilp et al. (2019) have previously evaluated anatomical variations of the IIV using postvital materials. M. Shin et al. (2015) extensively analyzed the architectonics of the main trunk of the IIV according to vestibular methods (n=2488) and identified eight variants. This approach formed the basis of a similar work (n=1071) by A. Hekimoglu and O. Ergun (2021). D. Sat-Muñoz et al. (2020) and M.G. Shkvarko et al. (2021) also conducted a morphometric study of IIVs. D. Sat-Muñoz et al. categorized variants of IIV formation into three types, according to the classification of R. Gregoire (2007), based on the relationship of the IIV with its artery. According to D. Kachlik et al. (2010), in approximately 50% of cases, the root of the IIV is the internal genital vein, which penetrates the pelvis through the subclavian orifice; in 30%, the anterior and posterior trunks can be identified in the architectonics of the IIV by analogy with the internal iliac artery, which are the roots; in 20%, the IIV trunk is formed by many small tributaries, and roots and trunks could not be identified. Our data revealed that the typical IIV variant is the one in which its roots and tributaries (except for the umbilical vein) correspond to the branches of the artery of the same name, and a typical variant of IIV architectonics should be considered the fusion of the anterior and posterior trunks, with the internal genital vein and superior gluteal vein as the roots, respectively. All visceral tributaries flow into the anterior trunk, and nearly all extramural tributaries accompanying branches of the internal iliac artery flow into the posterior trunk. The majority of authors studied the architectonics of the main trunk of the IIV without the systematization of its tributaries. Based on the review of available literature, no modern clinically oriented classification of the variability of IIV architectonics has been established, satisfying the needs of modern surgery during interventions on the pelvic organs. Knowledge of the IIV anatomical variants and its tributaries is necessary when performing surgical interventions in the small pelvis, particularly during evisceration, to prevent blood loss. This article outlined promising directions in the study of the IIV and its tributaries, namely, methods of three-dimensional modeling, including the use of augmented reality technology, at various stages of surgical treatment of locally advanced pelvic tumors.