Correlation of Computed Tomography Measured Presacral Thickness with Body Mass Index

Sacral colpopexy is often chosen as a reliable approach that effectively resolves vaginal vault prolapse. Advancements in minimally invasive technology, robotic and laparoscopic surgery, have helped facilitate surgical dissection and operation when performing this procedure. An increased presacral thickness can potentially present a surgical challenge when operating in the presacral space. We hypothesize that there is a correlation between body mass index and presacral thickness. Computed Tomography (CT) images of 241 patients were reviewed in this retrospective study. The presacral thickness was measured by taking the cross sectional distance from the sacral promontory to the upper aspect of the iliac arteries. The corresponding demographic information of age, body mass index (BMI), and comorbidities were evaluated using univariate analysis, linear regression, and multiple regression analysis. The mean age was 56.6 years, and BMI was 27.6. The mean presacral thickness measurement based on the CT scan was 21.08 mm. Univariate linear regression models demonstrated a positive correlation between presacral thickness and BMI and a negative correlation with age. When adjusting for both age and BMI on multivariate analysis, a positive correlation with hypertension was found. The surgeon should be aware of this potential change in anatomy when operating in the presacral space.