RELATIONSHIP BETWEEN BLADDER NECK DIAMETER AND HYDRAULIC ENERGY AT MAXIMUM FLOW

Citation
M. Tojo et al., RELATIONSHIP BETWEEN BLADDER NECK DIAMETER AND HYDRAULIC ENERGY AT MAXIMUM FLOW, The Journal of urology, 152(1), 1994, pp. 144-149
Citations number
19
Categorie Soggetti
Urology & Nephrology
Journal title
ISSN journal
00225347
Volume
152
Issue
1
Year of publication
1994
Pages
144 - 149
Database
ISI
SICI code
0022-5347(1994)152:1<144:RBBNDA>2.0.ZU;2-H
Abstract
A pressure-flow study was performed with a 5-micro-tip transducer cath eter in 6 normal male volunteers (bladder neck diameters 0.80 cm. or l arger) and 13 male subjects suspected of having bladder neck contractu re. Intraurethral pressure was measured at various sites in the urethr a at maximum flow to calculate hydraulic energy at these sites using t he 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 th e former than in the latter group. Therefore, the ''flow rate controll ing zone'' lies at the external urethral sphincter in the former group and at the bladder neck in the latter group.