SUFU 2018: Female Pelvic Floor Mechanics: Analysis of Pressure Data and Imaging

Austin, TX ( Dr. Tova Ablove aimed to measure and map the force applied to the pelvic floor in the sitting, standing, and supine positions. Dr. Ablove and colleagues hypothesis is that the force on the pelvic floor in the standing position is lower due to deflection of the downward visceral force by lumbar lordosis of the spine. 

They used fresh female cadaver acquired from the University at Buffalo School of Medicine. A 4x8cm pressure array (Pressure Profile Systems; Los Angeles, Ca) was placed onto the pelvic floor just above the levator ani muscles and abutting the midline structures via a retroperitoneal approach. T−DOC urodynamic catheters were placed into the hollow of the sacrum and behind the pubic symphysis in the space of Retzius. A third catheter was placed at the vaginal apex, where standard vaginal pressures are known to act as a control. The cadaver was placed in the supine, sitting and standing positions and 10 measurement sets were taken. The cadaver also had CT−scans of the abdomen and pelvis in the supine positon and X−rays in the sitting and standing positions. The analysis of variance statistical test was used to compare mean pressures between groups for statistical differences. 

Their finding were interesting the pressure array values in cm H2O − supine 47.08±10.67, sitting 80.78±12.80, and standing 24.45±13.89 are all statistically different from each other with p-values <0.001. The UDS pubic symphysis values − supine 14.60±3.44, sitting 19.19±5.07, and standing 15.10±3.93; were not statistically different. The UDS sacrum values − supine 16.80±1.14, sitting 16.20±2.90, and standing 9.80±3.16; standing position was statistically lower than either of the other two p-value <0.001. Pressure at the vaginal apex sitting on a donut (to simulate the UDS chair) was 25.20±1.75. 

They concluded that the standing position has the lowest pressure measurements particularly at the sacrum supporting the hypothesis that lumbar lordosis shields the pelvic floor from intra−abdominal pressure. The pressures on the array were highest in the sitting position when lumbar lordosis is least prominent, although they recommended further research to confirm these findings

Presenter by: Tova Ablove MD

Authors: Tova Ablove MD, Scott Doyle PhD, ALexandra Marasco BS and Frank Mendal PhD, Buffalo, NY

Written by: Bilal Farhan, MD, Female Urology Fellow and Voiding Dysfunction, Department of Urology, University of California, Irvine at the Society of Urodynamics, Female Pelvic Medicine & Urogenital Reconstruction Winter Meeting (SUFU 2018), February 27-March 3, 2018, Austin, Texas