TY - JOUR
T1 - Relationship Between Prostatic Urethral Angle and Urinary Flow Rate
T2 - Its Implication in Benign Prostatic Hyperplasia Pathogenesis
AU - Cho, Kang Su
AU - Kim, Joo Han
AU - Kim, Dong Jun
AU - Choi, Young Deuk
AU - Kim, Jang Hwan
AU - Hong, Sung Joon
N1 - Funding Information:
This work was supported in part by the Strategic Industry Innovation Cluster Program of the Seoul Metropolitan Government.
PY - 2008/5
Y1 - 2008/5
N2 - Objectives: The prostatic urethra is a bent tube, and the clinical significance of the prostatic urethral angle (PUA) is poorly understood. We investigated the effect of the PUA on the urinary flow rate in men without benign prostatic obstruction. Methods: In a theoretical model, the urinary flow rate at the end of the prostatic urethra was formulated according to some principles of fluid dynamics, including the Navier-Storkes equation, Bernoulli's equation, and the loss of coefficient at bends. The change in the urinary flow rate according to the PUA was also calculated through mathematical simulations. In addition, the relationship between the PUA and the peak flow rate was evaluated in 65 healthy men without benign prostatic obstruction (age 50 to 59 years, prostate volume less than 30 cm3, peak flow rate greater than 15 mL/s). The prostate volume and PUA were determined by transrectal ultrasonography. Results: Using the fluid dynamic model, the urinary flow rate increased in proportion to the urethral diameter and was inversely associated with the PUA. The mathematical simulations showed that the urinary flow rate decreased by more than 27% as the PUA increased from 35° to 90°. In the clinical setting, the peak flow rate was significantly associated with the PUA by linear regression analysis (R = 0.34, β = -0.342, P = 0.005), but it was not associated with the total prostate volume (R = 0.18, β = -0.181, P = 0.150). Conclusions: The PUA was inversely associated with the urinary flow rate in this theoretical model and preliminary clinical study. This relationship could be an important factor in the pathogenesis of benign prostatic hyperplasia/lower urinary tract symptoms.
AB - Objectives: The prostatic urethra is a bent tube, and the clinical significance of the prostatic urethral angle (PUA) is poorly understood. We investigated the effect of the PUA on the urinary flow rate in men without benign prostatic obstruction. Methods: In a theoretical model, the urinary flow rate at the end of the prostatic urethra was formulated according to some principles of fluid dynamics, including the Navier-Storkes equation, Bernoulli's equation, and the loss of coefficient at bends. The change in the urinary flow rate according to the PUA was also calculated through mathematical simulations. In addition, the relationship between the PUA and the peak flow rate was evaluated in 65 healthy men without benign prostatic obstruction (age 50 to 59 years, prostate volume less than 30 cm3, peak flow rate greater than 15 mL/s). The prostate volume and PUA were determined by transrectal ultrasonography. Results: Using the fluid dynamic model, the urinary flow rate increased in proportion to the urethral diameter and was inversely associated with the PUA. The mathematical simulations showed that the urinary flow rate decreased by more than 27% as the PUA increased from 35° to 90°. In the clinical setting, the peak flow rate was significantly associated with the PUA by linear regression analysis (R = 0.34, β = -0.342, P = 0.005), but it was not associated with the total prostate volume (R = 0.18, β = -0.181, P = 0.150). Conclusions: The PUA was inversely associated with the urinary flow rate in this theoretical model and preliminary clinical study. This relationship could be an important factor in the pathogenesis of benign prostatic hyperplasia/lower urinary tract symptoms.
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U2 - 10.1016/j.urology.2008.01.019
DO - 10.1016/j.urology.2008.01.019
M3 - Article
C2 - 18343484
AN - SCOPUS:42749083413
VL - 71
SP - 858
EP - 862
JO - Urology
JF - Urology
SN - 0090-4295
IS - 5
ER -