DEVELOPMENT OF NONINVASIVE VELOCITY FLOW VIDEO URODYNAMICS USING DOPPLER SONOGRAPHY - PART II - CLINICAL-APPLICATION IN BLADDER OUTLET OBSTRUCTION

Objectives: We have developed a totally noninvasive urodynamic techniq ue based on the concept of Doppler sonography, which was tested in men with and without bladder outlet obstruction. Materials and Methods: A n ultrasonic image directed Doppler system with a 3.75 MHz. micro-conv ex electro-probe was operated transperineally using a specially devise d remote control robotic holder. Uroflow rates from the urethral meatu s were also measured with a flowmeter. The color Doppler ultrasound im age and digital now velocity data were processed by a personal compute r. Color scale data were analyzed by customized software. Multiple rec tangle sample volumes could be set in any size in any position, and th e resulting color encoded data were averaged. Calculation was performe d every 0.5 second and a flow velocity curve in the region of interest was obtained. A total of 12 men, 6 without (controls) and 6 with blad der outlet obstruction, were evaluated by conventional pressure flow s tudy and the new Doppler ultrasound urodynamic system. Bladder outlet obstruction was determined using the nomogram of Abrams and Griffiths. The sample volume for a flow velocity curve was set only in the prost atic urethra and, thus, maximum flow velocity in and functional cross- sectional area of the prostatic urethra were determined. Results: Urin ary stream in the male urethra was clearly detected and flow velocity in the prostatic urethra could be measured in all cases. Maximum flow rate measured by a flowmeter was significantly lower in the bladder ou tlet obstruction group. Maximum flow velocity by Doppler study was alm ost the same in the obstructed and control groups. Functional cross-se ctional area, which was calculated by dividing maximum flow rate by ma ximum flow velocity, was lower in the bladder outlet obstruction (mean plus or minus standard deviation 0.31 +/- 0.16 cm.(2)) than control g roup (0.78 +/- 0.23 cm.(2)) (p = 0.006). Velocity flow plots were poss ible in both groups. Conclusions: The concept of noninvasive pressure flow-like urodynamic evaluation based on Doppler ultrasound is feasibl e. Parameters of flow velocity as well as functional cross-sectional a rea can be used in the diagnosis of bladder outlet obstruction and to localize the site of obstruction.