Serial changes in proximal urethral function after transurethral balloon laser hyperthermia of the prostate (TUBAL-H) in a canine model

Abstract

雑種犬6頭のTUBAL-H後の近位尿道機能の変化を評価する為に, 尿道内圧と尿道断面積(CSA, cm2)を同時測定し, これらからコンプライアンス(Comp, cm3/cmH2O)を算出し経時的に検討した.TUBAL-H前にはComp, 最大尿道断面積(MCSA)の平均は, それぞれ0.013, 0.66であった.8週後には, それぞれ0.038, 1.39と増加した.16週後には, それぞれ0.026, 1.21とやや減少した.αブロッカーに対する反応性では, TUBAL-H前ではフェントラミン投与で, Comp, MCSAの平均はそれぞれ0.46, 1.40と増加した.16週後には, フェントラミン投与でCompのみ, 0.033と増加した

We performed transurethral balloon laser hyperthermia of the prostate (TUBAL-H) in 6 mongrel dogs. To evaluate the changes in proximal urethral function after TUBAL-H, the urethral cross sectional area (CSA, cm2) and urethral pressure (Pu, cmH2O) were measured using a balloon probe that allows their simultaneous measurement, and the urethral compliance (Comp, cm3/cmH2O) was calculated from these parameters and serially evaluated. In addition, the changes in Pu, CSA and Comp after administration of an alpha-adrenoceptor antagonist were evaluated before and 16 weeks after TUBAL-H. Before TUBAL-H, the mean Comp was 0.013, and the mean maximum CSA (MCSA) was 0.66. Eight weeks after TUBAL-H, the mean Comp was 0.038, and the mean MCSA was 1.39, showing a significant increase (p < 0.01). Sixteen weeks, after TUBAL-H, the mean Comp was 0.026, and the mean MCSA was 1.21, being lower than those at 8 weeks after TUBAL-H, but significantly higher than those before TUBAL-H (p < 0.05). After administration of the alpha-adrenoceptor antagonist, phentolamine (1 mg/kg), before TUBAL-H, the mean Comp significantly increased to 0.046 (p < 0.05), and the mean MCSA to 1.40 (p < 0.01). The mean Comp was significantly increased to 0.033 (p < 0.05), by phentolamine administration 16 weeks after TUBAL-H, but no other changes were observed. After TUBAL-H, urethral elasticity increased, and this increase persisted for 4 months. The responses of Comp and MCSA to alpha-adrenoceptor antagonist administration before and 16 weeks after TUBAL-H suggested that part of the effects of TUBAL-H is due to damage to alpha-adrenoceptors.