The Velocity Profile of the Human Urethra: Measurement and Significance

Zinner, Norman R.; Sterling, Arthur M.; Ritter, R. C.; Harris, J. H.; Gessner, F. B.; Reid, J. M.; Hedges, J.C.; Chow, Drin; Barber, Frank E.

doi:10.1007/978-3-642-65640-8_39

Cited by 8 publications

(4 citation statements)

References 2 publications

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“…In males a pressure disparity of greater than 5 cm H 2 O in the supramembranous urethra is considered suspicious for obstruction [12]. A specific pressure disparity in females has not been absolutely established, although it is known that normally the female urethra is isobaric with the bladder until there is a pressure drop in the distal 1 cm [13,14]. The exact magnitude of this pressure drop is difficult to measure because of the short segment between the pressure drop and the meatus.…”

Section: Prevalence and Definition Of Bladder Outlet Obstruction In Wmentioning

confidence: 99%

Bladder outlet obstruction in women: Prevalence, recognition, and management

Patel

Νitti

2001

Curr Urol Rep

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Bladder outlet obstruction in women is an infrequently diagnosed urological condition. Its prevalence has been estimated to be between 2.7% and 29%. The large variation in prevalence is likely a result of the lack of standard diagnostic definition for the evaluation of female bladder outlet obstruction. A combination of history taking; physical examination; and diagnostic tests, including simple pressure void studies, radiographic imaging, endoscopic visualization, and multichannel videourodynamics provides a consistent way to accurately recognize and diagnose bladder outlet obstruction. Causes of obstruction are varied and numerous but generally fall within two broad categories: functional and anatomic. Treatment options are tailored to individual causes of obstruction and range from conservative pharmacologic and behavioral options to more-invasive surgical procedures.

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Section: Prevalence and Definition Of Bladder Outlet Obstruction In Wmentioning

confidence: 99%

Bladder outlet obstruction in women: Prevalence, recognition, and management

Patel

Νitti

2001

Curr Urol Rep

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“…The maximum urinary pressure was 4kPa [26,32]. In the literature, this value appears many times, hence, it is possible to compare the results obtained by other authors in the experimental and model studies [23,32,[37][38][39]. In the scope of the CFD flow dynamics analysis, the methodology of calculations, appropriate boundary and beginning conditions as well as the structure and fluid properties were proposed.…”

Section: Cijmentioning

confidence: 99%

“…Reconstruction of the urethral lumen geometry itself and separation of the individual tissues that are part of the histological structure is a difficult but at the same time necessary issue in order to declare the real boundary conditions. Imaging methods for urethra, such as computed tomography, magnetic resonance imaging [21,22] and ultrasonography [23,24] seem to be insufficient for the evaluation of three-dimensional(3D) tissue geometry with the isolated lumen of the urethra, which, in most published papers, is simplified to the shape of a duct with a circular or oval cross-section [25,26]. This is one of the reasons why it is impossible to obtain the correct urine flow conditions.…”

Section: Introductionmentioning

confidence: 99%

Numerical Analysis of Deformation and Flow in the Proximal Area of the Urethra

Rudyk

Malinowski

Mackiewicz

et al. 2020

International Journal of Applied Mechanics and Engineering

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Pathological conditions of a male urethra, including fibrosis, have a mechanical background along the entire length of the urethra. They may be caused by excessive deformation of the urethra locally or globally. The condition of prolonged overload causes abnormal tissue remodelling and, consequently, the formation of a thick layer of scar tissue differentiated from the connective tissue of the urethra. This tissue, which has higher mechanical properties, is not highly deformable and therefore, causes a decrease in the diameter of the urethra, which results in conditions that disturb the natural flow of urine. In this paper, it was decided to determine the deformation conditions in the proximal part of the urethra. The study was conducted in three main stages. Transverse sections of the animal urethral tissues were prepared in order to examine mechanical properties and perform histological examinations. On the basis of these examinations, material models which fitted best for the experimental results were sought. Material constants of the Mooney-Rivlin material model with the best fit ratio were determined for further research. On the basis of histological photographs, a geometrical and numerical model of the urethra was developed. The urethra was tested in a flat state of deformation. The strain and stress fields of the Caucha tensor were examined. The methodology of testing the dynamics of the urine flow in the highly deformable urethra was proposed. This is important for the analysis of the influence of at excessive pressure on pathological tissue remodelling leading to fibrosis.

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“…Urodynamic literature increasingly focuses on simultaneous measurement of urinary flow rate, bladder pressure, and urethral pressure during voiding. Although these measurements have been described in the past without arousing enduring interest [Zinner et al, 1963;Cass and Hinman, 1971;Murphy and Schoenberg, 19601, new applications and new theories of voiding physiology have regenerated interest in such studies. Such flow-and pressure-dependent concepts as voiding urethral profiles [Yalla et al, 1980;Rossier et al, 1982;Nunn, 19651, work functions of the bladder [Abrams et al, 1977;Abrams and Torrens, 1979;Schafer, 1982;Campbell, 19651, energy balance [Bottaccini and Gleason, 1980;Gleason et al, 1982-111 aid in the diagnosis of obstruction and other voiding and continence problems.…”

Section: Introductionmentioning

confidence: 99%

The effect of a fine urethral pressure‐measuring catheter on urinary flow in females

Gleason

Bottaccini

1984

Neurourology and Urodynamics

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Urodynamic evaluations of 221 female patients and 21 normal female subjects were performed to study the effects of a small ureteral catheter in the urethra on various voiding parameters. We found that the catheter induced a significant diminution of flow rate, interruption of flow, and stretching and flattening of the flow curves with respect to time. The most marked changes occurred in normal subjects and in patients with stress incontinence. The diminution of flow rate induced by the catheter was not strongly related to disease and varied so greatly within each statistical grouping that it was not possible to separate clearly the effects according to disease. Since the effects of the catheter were most marked on the normal population, catheter-induced reduction of flow rate could not be used as an index of urinary outflow obstruction.

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The Velocity Profile of the Human Urethra: Measurement and Significance

Cited by 8 publications

References 2 publications

Bladder outlet obstruction in women: Prevalence, recognition, and management

Bladder outlet obstruction in women: Prevalence, recognition, and management

Numerical Analysis of Deformation and Flow in the Proximal Area of the Urethra

The effect of a fine urethral pressure‐measuring catheter on urinary flow in females

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