Anatomical Validation of Internal Iliac Vessels Assessed by Three-dimensional Angiographic Analysis

Objectives: Anatomical understanding of the internal iliac vessels is important with the increasing frequency of minimally-invasive pelvic surgery. We aimed to investigate the branch patterns of internal iliac vessels, especially the veins.Methods: This study included 30 patients with 60 half-pelvises who underwent minimally-invasive pelvic surgery. Branch patterns were assessed on surgical videos with a multi-detector computed tomographybased three-dimensional simulation. Branch patterns of the superior gluteal artery and vein (SGA and SGV), inferior gluteal artery and vein (IGA and IGV), internal pudendal artery and vein (IPA and IPV), and obturator artery and vein (ObA and ObV) were investigated.Results: In the most frequent internal iliac vein (IIV) branch pattern, 67% of SGV branched from the IIV, 95% of the IGV branched from the IPV and 82% of the ObV branched from the IPV. According to Adachi's classification, 62% of IIVs were Type I and 33% Type IV. Although IIV branch patterns are heterogeneous, in individual patients with the most frequent branch patterns, good correlation (75-100%) of the branch patterns was observed between the internal iliac artery (IIA) and IIV, and between the right and left IIVs.Conclusions: This study clarified the branch patterns of IIV. In patients with the most frequent branch patterns, good correlation of the branch patterns was observed between the IIA and IIV, and between right and left IIV. We believe this helps secure the safety and standardization of minimally-invasive pelvic surgery.