Relationship between bladder neck diameter and hydraulic energy at maximum flow.

A pressure-flow study was performed with a 5-micro-tip transducer catheter in 6 normal male volunteers (bladder neck diameters 0.80 cm. or larger) and 13 male subjects suspected of having bladder neck contracture. Intraurethral pressure was measured at various sites in the urethra at maximum flow to calculate hydraulic energy at these sites using the Bernoulli equation. When the subjects were divided into 2 groups (1 group with a bladder neck diameter of 0.73 cm. or larger and 1 with a bladder neck diameter of 0.60 cm. or smaller), the relative value of energy (ratios to the initial energy generated in the bladder) at the external urethral sphincter was significantly (p < 0.01) greater in the former than in the latter group. Therefore, the "flow rate controlling zone" lies at the external urethral sphincter in the former group and at the bladder neck in the latter group.

[1]  B. Von.  Analysis of micturition; a new method of recording the voiding of the bladder. , 1957 .

[2]  W. Schäfer.  Urethral resistance? Urodynamic concepts of physiological and pathological bladder outlet function during voiding , 1985 .

[3]  J. Andersen,et al.  Functional bladder neck obstruction. Late results after endoscopic bladder neck incision. , 1980, Scandinavian journal of urology and nephrology.

[4]  A. Rossier,et al.  5-microtransducer catheter in evaluation of neurogenic bladder function. , 1986, Urology.

[5]  E. Arnold,et al.  The nature of the abnormality in bladder neck obstruction. , 1975, British journal of urology.

[6]  N. Resnick,et al.  Elastic jump in male urethra during voiding: clinical observations in male subjects and experimental studies in dogs. , 1985, The Journal of urology.

[7]  C. Whiteside,et al.  A urodynamic view of the clinical problems associated with bladder neck dysfunction and its treatment by endoscopic incision and trans-trigonal posterior prostatectomy. , 1973, British journal of urology.

[8]  D. Lenaghan.  The diagnosis of prostatic obstruction by measurement of urethral resistance to flow. , 1970, The Journal of urology.

[9]  A. Rossier,et al.  Urodynamics in spinal shock patients. , 1979, The Journal of urology.

[10]  G. Webster,et al.  The evaluation of bladder neck dysfunction. , 1980, The Journal of urology.

[11]  M. Claridge,et al.  THE DYNAMICS OF OBSTRUCTED MICTURITION. , 1964, Investigative urology.

[12]  D. J. Griffiths,et al.  Urodynamics: The Mechanics and Hydrodynamics of the Lower Urinary Tract , 1980 .

[13]  D. Griffiths,et al.  Third report on the standardisation of terminology of lower urinary tract function. Procedures related to the evaluation of micturition: pressure-flow relationships. Residual urine. , 1980, Scandinavian journal of urology and nephrology.