离体尿道流率对兔尿道狭窄程度的评价意义

Significance of urethral flow rate in evaluating severity of urethral stricture

目的探讨离体尿道流率对兔尿道狭窄严重程度的评价意义。方法15只成年雄性新西兰大白兔,内镜直视下尿道粘膜电凝法制作尿道狭窄模型。30d后,逆行尿道造影、尿道镜检观察尿道狭窄形态。设计制作简易装置测定离体尿道流率。分析离体尿道流率与球部狭窄段尿道直径的相关性。结果15只动物死亡2只,余动物顺利完成实验。狭窄处直径(4.08±0.84)mm,狭窄段长(7.73±1.07)mm,尿道管腔缩窄(78.45±7.59)%;离体尿道流率(11.45±4.83)mL/s。离体尿道流率与狭窄段尿道直径具有显著相关性(Spearman相关分析,r=0.680,P=0.011)。结论本实验自行设计装置进行兔离体尿道流率测定,可从流体力学角度准确反映尿道狭窄所致的排尿阻力增加情况,结合尿道造影和尿道镜检,可全面、准确评价模型尿道狭窄的严重程度。

Objective To explore the significance of flow rate of isolated urethra in evaluating the severity of urethral stricture. Methods A total of 15 adult male New Zealand rabbits were involved and urethral stricture was induced by visual endoscopic electrocoagulation. 30 days after coagulation, stricture formation was evaluated by retrograde urethrogram and urethroscopy. Meanwhile, a simple device was invented to detect the flow rate of isolated urethra and to evaluate the urine flow resistance from strictured urethra. The correlation between urethral flow rate and urethral diameter was studied. Results 2 rabbits died and the others survived the observation. The stricture was （4.08 ± 0.84） mm wide and （7.73 ± 1.07） mm long, with urethral lumen decreasing by （78.45 ± 7. 95）%. The mean flow rate was （11.45± 4. 83）mL/s. There was a significant correlation between urethral flow rate and urethral diameter, demonstrated by Spearman correlative analysis （r =0.642, P=0.018）. Conclusion In this study, a simple device was designed to detect flow rate of isolated urethra. It was firstly proved from hydrodynamics that urethral flow rate could exactly reflect flow resistance of strictured urethra. Combined with urethrogram and urethroscopy, urethral flow rate could exactly evaluate severity of urethral stricture.