Analysis of anatomical variations of intrapelvic vessels for advanced pelvic surgery

Abstract

Background: In pelvic surgery, it is important to anticipate potential anatomic variations, which may be unknown, and inter-relationships among intrapelvic vessels. Here, we comprehensively analyzed intrapelvic vessel patterns. Method: This retrospective analysis included 81 patients that underwent colorectal surgery in our institution in 2016. A total of 162 half-pelvises were imaged with contrast-enhanced computed tomography. We scrutinized thinslice images. Results: We found variations in the number of internal iliac veins. In 47.5% of cases, one internal iliac vein drained into the ipsilateral common iliac vein in both halves of the pelvis. In the other cases, several internal iliac veins were observed in one or both halves of the pelvis. We analyzed the inter-relationships between the superior gluteal artery and the sacral nerve plexus in pelvic halves. Superior gluteal arteries ran between the 5th lumbar nerve and 1st sacral nerves, in 82% of halves, and lateral to the 5th lumbar nerve, in 17% of halves. Dorsally, the superior gluteal artery ran on the medial side of the internal iliac vein in 15% of halves. In 28% of half-pelvises, two superior gluteal veins were observed. Superior gluteal veins passed through the sacral nerve plexus lateral to 5th lumbar, between 5th lumbar and 1st sacral, and between 1st and 2nd sacral nerve, in 42.0, 47.5, and 37.7% of halves, respectively. We evaluated the rate of symmetric pelvic anatomies, and found that all anatomic variations formed symmetrically, except the number of internal iliac veins.Conclusion: This study clarified the anatomical variations of intrapelvic vessels and their inter-relationships. These findings will benefit our understanding of pelvic anatomy and enhance the safety of radical surgery for treating pelvic diseases.

Retroperitoneal Sentinel Lymph Node Biopsy by Vaginally Assisted Natural Orifices Endoscopic Transluminal Endoscopic Surgery in Early Stage Endometrial Cancer: Description of Technique and Surgeon’s Perspectives after the First Experience

“…In case of vNOTES sentinel node biopsy or lymphadenectomy, the spatial orientation of the anatomical structures is different compared to the standard laparoscopy or the open surgery. However, because of the very little anatomical variation of pelvic vessels and nerves, an experimented surgeon adapts without difficulty to the new point of view [20]. Main limitations of vNOTES are the restricted surgical access in case of a narrowed vagina, instrument-optic conflicts, and difficult triangulation that may be circumvented by a curved scope or instruments [2].…”

Artificial intelligence‐based technology to make a three‐dimensional pelvic model for preoperative simulation of rectal cancer surgery using MRI

“…In the surgeries for advanced rectal cancer, comprehension of the interrelationships between the vessels and sacral plexus is crucial, and this algorithm would play an important role. 1 Regarding the extraction of vessels, the veins are apt to blur on CT‐based segmentation because the contrast density in veins cannot reach as high a value as in the artery; thus, the venous contour is forced to be indistinct. However, this algorithm does not depend on the difference in CT values and, therefore, the administration of contrast medium is not required in the acquisition of MRI and this algorithm is not affected by the contrast density.…”

“…Furthermore, these structures, especially vessels, are associated with abundant anatomical variations. 1 , 2 , 3 , 4 We need to comprehend these complexities during surgery for locally advanced rectal cancers, especially technically demanding surgery including lateral lymph node dissection (LLND) or total pelvic exenteration, not only rectal resections, because they are a difficult hurdle for surgeons to overcome.…”

Sacral Dysmorphism Increases the Risk of Superior Gluteal Artery Injury in Percutaneous Sacroiliac Joint Fusion: Case Report and Literature Review

“…Hamabe et al looked at 81 patients using contrast-enhanced CT. In their study, they found 82% of the SGAs ran between the L5 and S1 spinal nerve branches and 17% of SGAs ran lateral to the L5 branch [ 13 ]. Interestingly, they also found patients with variations of how two internal iliac veins communicate and form a venous loop around the SGA before continuing dorsally.…”