Uroflowmetry, trans rectal ultra sonography and power doppler to develop a less invasive bladder outlet obstruction score in benign prostatic hyperplasia: A prospective analysis

OBJECTIVE : To evaluate the ability of transrectal power doppler sonography (TRPDS) in combination with conventional grey scale transrectal ultrasonography (TRUS), uroflowmetry and clinical parameters, to predict bladder outlet obstruction (BOO) in benign prostatic hyperplasia (BPH). MATERIALS AND METHODS : Sixty-nine male patients with more than 50 years of age, presenting with lower urinary tract symptoms were evaluated prospectively for BOO secondary to BPH. TRUS was done to estimate prostate volume (PV), transition zone volume (TZV), median lobe projection in the bladder (ML) and bladder wall thickness (BWT). TRPDS was done to measure resistive index (RI) of transition zone vessels. All patients also underwent PFS and depending upon its results, the patients were divided into Group 1 [Abram-Griffiths (AG) number < 40] and Group 2 (AG number> 40). Mean values of TRUS and TRPDS parameters and uroflowmetry in the two groups were compared to identify predictive factors for BOO. RESULTS : Demographic profile of Group 1 (n= 42) was similar to that of Group 2 (n= 27). Significant independent factors for prediction of BOO were maximum flow rate, resistive index of transition zone, median lobe projection into the bladder and post void residue. BOO scoring system was developed based on these 4 factors, which showed a specificity of 77.8% and a sensitivity of 85.7%, with an overall predictive value of 82.6%. CONCLUSIONS : Transrectal power doppler ultrasonography (resistive index) in combination with uroflowmetry, median lobe projection in bladder and post void residue measurement can predict BOO with a high specificity and sensitivity