Due to the risks of transvaginal mesh and the recognized failure rate of some native tissue repairs, the number of abdominal sacrocolpopexy procedures performed is increasing. The mesh is generally secured to the anterior longitudinal ligament. However, the anatomy of this presacral space can be variable and closely surrounded by critical structures, including the left common iliac vein, right ureter, right common iliac artery, middle sacral vein and artery, sacral venous plexus, and the hypogastric nerves. [1]

Our video presents fours cases and surgical video clips from three robotic-assisted sacrocolpopexy procedures, which highlight our experience with aberrant or challenging anatomy in the presacral space. In particular, we highlight how preoperative MRI with defecography assisted in identifying these anatomic challenges preoperatively thus informing patient counseling and assisting with operative planning.

This video presents a series of MRI and intraoperative findings in four women to illustrate challenging anatomic variations around the sacral promontory.

The first patient is a 70-year-old female with symptomatic vault prolapse with associated cystocele and rectocele. Her pre-operative MRI with defecography found a bulging disc at L5-S1 and a large amount of fat overlying the promontory. During the procedure, the pre-sacral space was gradually entered. With the help of the suction tip and the tip of the robotic scissors, the area of the promontory was finally identified and exposed, despite bleeding and difficulty due to the thickness of the adjacent fatty meso-colon.

The second patient is a 74-year-old female with symptomatic recurrent vault prolapse post-hysterectomy, with an associated cystocele and rectocele. Her MRI prior to defecation illustrates a very large amount of fat between the sacrum and the bowel loops. During the robotic procedure, we were unable to identify the precise location of the promontory due to excess fatty tissue despite probing with the suction tip and the tip of the scissors. Due to these challenges, our dissection location was too medial. We encountered the left common iliac vein, which, fortunately, was not injured. However, this anatomic landmark did help us redirect our dissection more medially and caudally. Finally, after deeper dissection, we were able to identify the white shiny surface of the anterior longitudinal ligament. 

In our third patient, a 77-year-old female with vault eversion, her pre-operative MRI defecography study demonstrated a loop of colon in front of the promontory. During the robotic procedure, the colon was identified to be directly over the promontory. In the video, we had to gently dissect and retract the colon with the Prograsp to adequately expose the anterior longitudinal ligament underneath. 

Finally, our last patient was a 69-year-old female with very symptomatic vault prolapse and recurrent cystocele with a history notable for prior spinal hardware from a back fusion at L3 to L5. Unfortunately, no operative notes to confirm the exact location of her plates and screws were available. Pre-operative discussion with our orthopedic colleagues reviewing her plain films concluded that the anterior longitudinal ligament would likely not be intact in this area. This impression was reinforced by the MRI which revealed artifact from the hardware in the exact area of the dissection over the promontory. In such a scenario, one could consider a lower presacral anchoring site or an alternative fixation technique such as the peritoneal colpopexy using v-lock sutures, as previously described [2].

Knowledge of the presacral anatomy, and the potential variants, is critical to safely perform a robotic-assisted sacrocolpopexy.  MRI with defecography is an important tool in both defining the pelvic floor support defects prior to surgery, but also in highlighting difficult anatomy at the sacral promontory to assist with patient counseling and operative planning.

Florian-Rodriguez, Maria E. et al. First sacral nerve and anterior longitudinal ligament anatomy: clinical applications during sacrocolpopexy. American Journal of Obstetrics & Gynecology, Volume 217, Issue 5, 607.e1 - 607.e4
Lee D, Zimmern PE. Abdominal mesh sacrocolpopexy without promontory fixation: initial results of the peritoneocolpopexy technique. J Urol. 2015 Jun;193(6):2089-93. doi: 10.1016/j.juro.2015.01.085