Detrusor contractility in women: Influence of ageing and clinical conditions.
OBJECTIVE
We assume that the voiding process in women is governed by the detrusor contractility and a "urethral resistance". The value of these 2 parameters, respectively named k and U in the VBN (Valentini-Besson-Nelson) mathematical model of micturition is deduced from the VBN analysis of pressure-flow recordings (PFs). Our objectives were to search for a correlation between these 2 parameters and clinically relevant variables such as chief complaint, urodynamic diagnosis (UD), and age by decades.


METHODS
PFs from 125 non-neurogenic women (mean age 58.0±17.2years [range 20-90years]) were retrospectively analyzed using the VBN model. VBN criteria for inclusion were maximum flow rate>2mL/s, voided volume>100mL, and non-interrupted flow. Evaluated parameters were k (without unit) and U (unit: cm H2O). Standard values were k=1.0 and U=0.


RESULTS
VBN parameter ranges were k [0.14-1.55] and U [0.0-73.0cm H2O]. There was a significant correlation between k and U for the whole population (P<0.0001) with k=(.259+0.015*U) (R(2)=0.723) and each chief complaint. For UD, significant difference comparing k and U in phasic detrusor overactivity with intrinsic sphincter deficiency and urodynamic stress incontinence was noted. In sub-groups defined according to decades of age, the values of k and U remained similar in sub-groups for those who are less than 50years old and decreased regularly with ageing.


CONCLUSIONS
The detrusor contractility can be easily evaluated in women; lower than in men, its range is less spread out but also adjusted to compensate a "urethral resistance". Phasic detrusor overactivity and post-menopausal age significantly affect detrusor force value.


METHODS
3.
Service de médecine physique et de réadaptation, hôpital Rothschild, université Pierre-et-Marie-Curie, 5, rue Santerre, 75012 Paris, France. Electronic address: francoise.valentini@rth.aphp.fr.
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FA
Valentini
Service de médecine physique et de réadaptation, hôpital Rothschild, université Pierre-et-Marie-Curie, 5, rue Santerre, 75012 Paris, France.
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Nelson
University of Texas Southwestern, TX 75390 Dallas, USA.
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Zimmern
Service de médecine physique et de réadaptation, hôpital Rothschild, université Pierre-et-Marie-Curie, 5, rue Santerre, 75012 Paris, France.
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Robain
D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D005260:Female; D006801:Humans; D008875:Middle Aged; D009119:Muscle Contraction; D009130:Muscle, Smooth / Q000502:physiology*; D012189:Retrospective Studies; D001743:Urinary Bladder / Q000502:physiology*; D014555:Urination Disorders / Q000503:physiopathology*; D014563:Urodynamics; D055815:Young Adult
Contractilité du détrusor; Detrusor contractility; Femme; Modèle VBN; Urodynamics; Urodynamique; VBN modelling; Women