RÉSUMÉ
Objective To evaluate the relationship between ultrasound-assayed detrusor thickness and bladder outlet obstruction (BOO) in old men with benign prostatic hyperplasia (BPH).Methods The 106 BPH patients underwent the urodynamic examination on which the diagnosis of BOO was dependent. The obstruction was defined as the Abrams-Griffiths nomogram (A-G index)≥40 and the grade of linear passive urethral resistance relation (LinPURR)≥Ⅱ . When bladder capacity reached 150 ml, the detrusor thickness was measured by abdominal ultrasound. Results Compared with unobstructed group, the maximum flow rate and average flow rate were both lower in obstructed group [(10.1±3.0) ml/s vs. (17.4±3.1) ml/s, (5.5±2.2) ml/s vs. (11.2±2.2) ml/s, t= 10.26and 11.03, both P＜0.01]. And the residual urine volume and maximum detrusor pressure were significantly higher in obstructed group than in unobstructed group [(47.6 ± 24.3) ml vs. (17.0 ±5.6) ml, (39.3±14.4) cm H2Ovs. (26.8±8.0) cm H2O, t=6.32 and 4.07, P＜0.01 or 0.05].Detrusor thickness was positively correlated with maximum detrusor pressure (r= 0.419, P＜0.01),but negatively correlated with maximum flow rate (r =- 0.749, P＜ 0.01 ), mean flow rate (r=-0.853, P＜0.01) and voided volume (r=-0.556, P＜0.01). There was significant difference in detrusor thickness between obstructed group and unobstructed group [(3.0± 0.2) mm vs. (2.5 ±0.2) mm, t= 11.2,P＜0.05]. According to the diagnostic standard of detrusor thickness≥3.0 mm,it had a sensitivity of 90% and a specificity of 84.6%, a positive predictive value of 93.1% and a negative predictive value of 78.6%. Conclusions Detrusor thickness of 3.0 mm or greater has a certain predictive value for BOO in old men.