- 作者：Navroop JOHAL ; Sotiris BOGRIS ; Peter CUCKOW ; Chris FRY
- 刊名：Journal of Pediatric Urology
- 出版年：2008
- 出版时间：April 2008
- 年：2008
- 卷：4
- 期：Supplement 1
- 页码：S46
- 全文大小：36 K
PURPOSEWe have shown the paediatric exstrophy bladder is significantly hypocontractile in comparison to the normal paediatric bladder despite isolated single detrusor cells functioning normally. The aim of this study was to test the hypothesis that the visco-elastic properties of the paediatric bladder contribute to this observed difference in contractility.MATERIAL AND METHODS
Ethical committee approval and patient consent were obtained. Full thickness bladder samples were obtained from patients with a bladder exstrophy and from normal bladders (control) during open surgery (n = 9,11 respectively). Detrusor strips were superfused with a buffered physiological solution. One end of the muscle strip was tied to an isometric force transducer; the other end to a hook, the position of which could be adjusted in the horizontal plane by a voltage-operated solenoid. Incremental changes in muscle strain were generated by imposing square voltage waves on the solenoid for 50 seconds duration, then returning to steady state length with continuous force measurement during this period. The resultant changes to muscle stress were recorded and the viscous and elastic workload was calculated. Significance of differences (p < 0.05) between means were examined by Student's t-test.
RESULTS
The lengths were not significantly different between groups. The elastic and viscous component (mN.s/mg) was significantly greater in the exstrophy group at every strain when compared to the control group. The time constant was not significantly different between groups.
CONCLUSIONS
The elastic and viscous workload is increased and the tissue is mechanically stiffer in bladder exstrophy. This corroborates clinical urodynamic data that the exstrophy bladder is poorly compliant.