2129. Correlation of CT Derived Biomarkers of Presacral Adiposity with Body Mass Index in Pelvic Floor Dysfunction
Authors * Denotes Presenting Author
  1. Dema Jaber *; University of Wisconsin School of Medicine and Public Health
  2. Jon Pennycuff; University of Wisconsin School of Medicine and Public Health
  3. Perry Pickhardt; University of Wisconsin School of Medicine and Public Health
  4. Giuseppe Toia; University of Wisconsin School of Medicine and Public Health
Sacrocolpopexy (SC) is a reconstructive gynecological surgery involving the attachment of synthetic mesh to the vaginal and sacral promontory regions for treating pelvic floor prolapse. Both open and minimally invasive techniques are utilized for SC, but difficulties can arise due to challenging sacral dissection, particularly in cases with increased presacral fat. This study aims to investigate whether CT-derived biomarkers, such as presacral thickness and volume, are correlated with specific factors like body mass index (BMI), age, or certain medical conditions.

Materials and Methods:
We examined CT images from 143 female patients with suspected or clinically diagnosed pelvic floor dysfunction. Presacral thickness (PT) was measured on axial CT images at the sacral promontory level by drawing a transverse line tangent to the anterior borders of the external or common iliac arteries, followed by measuring a perpendicular line drawn to the anterior sacral promontory at L5-S1. The presacral volume (PV) was manually measured using advanced volumetric visualization software (Vitrea, Canon Medical Systems, USA) from the sacral promontory to S3. From the medical record we extracted demographic information including age, race, and BMI and pertinent medical history (lipid disorder, hypertension, diabetes, thyroid disorder, prior hysterectomy, and defecography studies). BMI was stratified into underweight, normal, overweight, and obese categories. Statistical analysis included t-tests, one-way ANOVA, and multivariate linear regression to explore associations and predictive factors for PT and PV.

Among the 143 patients, mean ± standard error of age, BMI, PT, and PV were 58 ± 1.2 years, 28 ± 0.6, 16 ± 0.5 mm, and 18 ± 0.6 mL, respectively. BMI exhibited a significant positive correlation with PT (<em>rho</em> = 0.210, <em>p</em> < .001) and PV (<em>rho</em> = 0.168, <em>p</em> = .05). Age was positively correlated with PV (<em>rho</em> = +0.169, p = 0.44), but not PT (<em>rho</em> = -0.023, <em>p</em> = .71). Univariate analysis indicated that PT significantly increased with higher BMI (<em>p</em> = .008), whereas PV did not. Larger PT and PV were associated with thyroid disease (<em>p</em> < 0.04), while race, lipid disorder, hypertension, diabetes, hysterectomy, and defecography study were not linked to PT or PV differences. In multivariate regression, BMI (<em>p</em> < .001) and thyroid disorder (<em>p</em> < .007) each remained the sole significant predictors for PT and PV, respectively.

This preliminary study establishes a positive correlation between CT-derived PT measurements and BMI. While the relationship between PV and BMI showed positive correlation, this relationship was not statistically significant with univariate or multivariate analysis. Our findings indirectly suggest an increased likelihood of requiring more intricate pre-sacral dissection during SC for pelvic organ prolapse. By identifying patients who might necessitate enhanced dissection pre-operatively, surgeons can better plan and execute surgeries to achieve optimal outcomes.