Evaluation of Detrusor Contractility Parameters Help to Analyze Consequences of Steady Abdominal Pressure Changes during Voiding in Women

Introduction: Urodynamic study interpretation leading to urodynamic diagnosis is mainly based on pressure recordings and the value of detrusor pressure at maximum flow (pdet.Qmax). Detrusor pressure is calculated by subtracting the abdominal pressure (pabd) from the vesical pressure (pves). Hence, there is a critical role for pabd in this process. The goal of our study was evaluate the contribution of detrusor contractility parameters (DCP) to confirm and to correct urodynamic misdiagnosis (UmD) due to steady abdominal pressure changes during voiding in women.

Materials and Methods: Urodynamic tracings of 271 non-neurologic women referred for investigation of various LUTS were retrospectively analyzed. UmD could be bladder outlet obstruction (BOO) and normal (N) for decreased pabd, normal (N) and detrusor underactivty (DU) for increased pabd. Detrusor contractility parameters were VBN parameter k and PIP1.

Results: Among the whole population 125 women had a significant change (≥5 cmH2O) of pabd during voiding (73 decrease, 52 increase).

In the “decrease” sub-group, only 3 N became DU with decreased DCP values; in the “increase” sub-group 1 N and 1 DU patients gained BOO diagnosis with increased DCP values.

In total, analysis of changes in abdominal pressure leads to 5/271 (1.8%) changes in urodynamic diagnosis; no correlation between previous surgery of incontinence or main complaint.

Conclusion: A high percentage of the non-neurologic female population has steady changes of abdominal pressure during voiding, that condition leads to few changes in urodynamic diagnosis; evaluation of detrusor contractility parameters values help to verify the new conclusions.