Thakappa Narayanrao Gachchi1, Ramalingaiah Karadakere Hanumegowda2, Jagruthi Sundar3, Keshavamurthy Rammaiah4, Mahohar Chikkamoga Siddaiah5
A filled bladder acts as an acoustic window for transabdominal ultrasound measurements of intravesical prostatic protrusion and volume. The incidence of BPE is 18%, 29%, 40% and 56% of men in their 40s, 50s, 60s and 70s, respectively, having moderate-to-severe Lower Urinary Tract Symptoms (LUTS).1 The size of the prostate are determined by Digital Rectal Examination (DRE), Transabdominal Ultrasound and Transracial Ultrasound (TRUS). DRE tends to underestimate true prostate size as determined by transabdominal ultrasound and TRUS. The magnitude of the underestimation increases with increasing prostate size from 25% up to 50% or more.2 TRUS volume measurements using the prostate ellipsoid volume formula (maximum width x height x length /6) are the most widely accepted measure of prostate volume.3 Ultrasound has been increasingly used in the evaluation of patients with Benign Prostatic Enlargement (BPE). It defines prostatic size, shape and volume, which maybe correlated with the degree of bladder outlet obstruction in BPE. Ultrasound also be used to assess the effects of BPE on the upper urinary tracts and bladder.4,5 For transabdominal ultrasound imaging of the prostate, a filled bladder is essential. It acts as an acoustic window, which readily transmits ultrasound waves and effectively serves as a conduit to the postero-caudally situated prostate. The loss of this acoustic window (an empty bladder) and over distended bladder makes ultrasound imaging and measurement of prostate difficult and unreliable.6
The aim of this study is to compare prostate volume measured by transabdominal ultrasound and by transrectal ultrasonography correlating with bladder volume.
MATERIALS AND METHODS
One hundred patients presenting with lower urinary tract symptoms due to benign prostatic enlargement were studied prospectively in Uroradiology Department, Institute of Nephro-Urology, Bengaluru, from May 2016 to October 2016.
Inclusion Criteria- Male patients aged more than 50 years presenting with Lower Urinary Tract Symptoms (LUTS) and suggestive of Benign Prostatic Enlargement (BPE) were selected for the study.
Exclusion Criteria- Patients with symptoms of LUTS due to bladder outlet obstruction other than benign prostatic enlargement, urinary tract infections, neurogenic bladder, trauma, chronic kidney diseases and patients with carcinoma prostate are excluded. Prostate volume determined by transabdominal ultrasound at pre-void and post-void bladder volume and then TRUS measurement of prostate volume was obtained.
There was an obvious trend of decreasing mean transabdominal prostatic volume with increasing bladder volume. The mean transabdominal prostatic volume at bladder volumes 200-300, 300-400,400-500 and 500-600 mL was 51.8, 52.3, 53.8 and 50.0 respectively and these were correlated to transrectal prostate volume, particularly when the bladder volume was less than 400 mL.
Transabdominal ultrasound measurement of prostatic volume correlates well with the transrectal measurement of the same parameter when the bladder volume is less than 400 mL.