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Contraction strength variance during pressure/flow studies
Author(s) -
Constantinou C. E.
Publication year - 1991
Publication title -
neurourology and urodynamics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.918
H-Index - 90
eISSN - 1520-6777
pISSN - 0733-2467
DOI - 10.1002/nau.1930100105
Subject(s) - medicine , urination , contraction (grammar) , urology , surgery , urinary system
The parameters of bladder pressure, urine flow rate and strength of contraction (W) during voiding were evaluated in female patients with stress urinary incontinence (SUI) and compared to non‐SUI patients. The long‐term modification in these parameters produced by endoscopic bladder neck suspension (BNS) was also evaluated in the SUI patients. Comparisons were made between the direct measurements of bladder pressure and flow rate during voiding with the indirect computations of W. The parameter, W, was evaluated at the prevoiding stage, and during micturition at 20% and 80% of voided bladder volume. The maximum W attained was also computed. Analysis was based on an algorithm of calculating the single valued variable W from detrusor pressure and flow rate information that was digitized by a real time computer. Data were obtained from a total of 80 patients; 49 patients with non‐SUI having a mean age of 50 ± 16 years (mean ± SD) and 31 patients 56 ± 12 years with SUI. The pre‐operative values of W and pressure/flow parameters in the 31 patients with SUI were compared with postoperative values obtained 26 months following (BNS). The results show that SUI patients void at a significantly lower pressure than non‐SUI patients and at approximately the same flow rate. There is no statistically significant difference between SUI and non‐SUI patients in the value of W at any stage of the voiding cycle. Comparison of pre‐operative to postoperative values of these parameters also shows that BNS did not produce significant changes in contraction strength W although the direct measurements of voiding pressure significantly increased and flow significantly decreased. It is concluded that the contractility of the bladder is maintained at a preset physiological level in the presence of physiologically or surgically changing urethral impedance.