Critical Anatomy Relative to the Sacral Suture: A Postoperative Imaging Study After Robotic Sacrocolpopexy

Objective: This study aimed to characterize pertinent anatomy relative to the sacral suture placed at time of robotic sacrocolpopexy using postoperative computed tomography and magnetic resonance imaging. Methods: A vascular clip was placed at the base of the sacral suture at the time of robotic sacrocolpopexy. Six weeks postoperatively, subjects returned for a computed tomography scan and magnetic resonance imaging. Results: Ten subjects completed the study. The middle sacral artery and vein coursed midline or to the left of midline in all the subjects. The left common iliac vein was an average of 26 mm from the sacral suture. To the right of the suture, the right common iliac artery was 18 mm away. Following the right common iliac artery to its bifurcation, the right internal iliac was on average 10 mm from the suture. The bifurcations of the inferior vena cava and the aorta were 33 mm and 54 mm further cephalad, respectively. The right ureter, on average, was 18 mm from the suture. The thickness of the anterior longitudinal ligament was 2 mm. The mean angle of descent of the sacrum was 70 degrees. Lastly, we found that 70% of the time, a vertebral body was directly below the suture; the disc was noted in 30%. Conclusions: We describe critical anatomy surrounding the sacral suture placed during robotic sacrocolpopexy. Proximity of both vascular and urologic structures within 10 to 18 mm, as well as anterior ligament thickness of only 2 mm highlights the importance of adequate exposure, careful dissection, and surgeon expertise.