Developing a 3d Quantification Strategy to Evaluate Vaginal Apical Fixation Alternation After Apical Suspension Procedures
American Journal of Obstetrics and Gynecology
OBJECTIVES: The goal of reconstructive prolapse surgeries is to restore the three levels of pelvic support structures by resuspension and/or enforcement. We have created a biomechanical model POPSIM that allows the theoretical structural changes expected from reconstructive prolapse surgery to be simulated to analyze their effect on overall support. To expand POP-SIM’s utility in predicting surgical outcomes with different operative approaches, it is necessary to know what each operation would achieve. The aim of this study is to develop strategies to quantify the achieved surgical correction and their variations for two common apical resuspension procedure based on post-operative MRI. MATERIALS AND METHODS: This is a secondary analysis of MRIs from an ongoing study that aims to understand and simulate the surgical effect on pelvic floor support. Ten patients had a Michigan-four-wall sacrospinous ligament suspension surgery (SSLS) and 5 women had high uterosacral ligament suspension (USLS) performed by board certified urogynecologists as standard care for their prolapse surgery. Each women underwent rest and 3D stress MRI at maximal Valsalva preoperatively and three months postoperatively. For women who underwent SSLS, sacrospinous ligament fixation location where the vagina was in proximity to the ligament was identified on the post-operative axial and sagittal MRI. The 3D distance of fixation relative to the right ischial spine were reported for both rest and maximal Valsalva. For USLS surgery, we measured the mid-sagittal distance of the cervix or vaginal apex to the middle of S3 as functional uterosacral ligament length (USL length) for both at rest and at maximum Valsalva. The median and range were reported for both surgical procedures corrections. The Leven’s test for equal variance was used to compare the correction variation achieved by SSLS and USLS. RESULTS: The distance from SSLS fixation points to ischial spine has the median of 2.3 cm and ranges from 1.6 cm to 3.1 cm at rest and median of 2.8 cm ranging from 1.9 cm to 4.7 cm at maximum Valsalva. In all individuals, the vaginal wall was seen in direct contact with the ligament. The post-operative USL length has a median of 6.5 cm and range from 4.2cm to 7.8cm at rest and median 8.2cm and ranged from 5.7 cm to 10.1 cm at maximum Valsalva. Leven’s test for equal variance demonstrated that there is a significantly larger variance in post-operative USL length than SSLS fixation location at rest (p¼0.0052). CONCLUSION: We have developed a strategy to evaluate what two common apical suspension procedures accomplish. Our MRI-based evaluation showed that SSLS procedure has lesser variation in surgically achieved fixation location while the USLS procedure demonstrate larger variations in post-operative USL functional length. Comments: These data could guide future biomechanical studies using surgical simulation platform (POPSIM) to predict the surgical success rate with different apical procedure choice.
Chen L, Schmidt P, Cheng W, DeLancey JO. Developing a 3d quantification strategy to evaluate vaginal apical fixation alternation after apical suspension procedures. Am J Obstet Gynecol. 2023 Mar;228(3 Suppl.):S874-S875. doi:10.1016/j.ajog.2022.12.130