S18 DIAGNOSTIC VALUES OF DETRUSOR WALL THICKNESS, POSTVOID RESIDUAL URINE AND PROSTATE VOLUME TO EVALUATE LOWER URINARY TRACT SYMPTOMS IN MEN

Abstract

277 L ower urinary tract symptoms (LUTS) are common, affecting approximately 40% of older men (1). LUTS is a recent term for what used to be known as prostatism (2). However, obstructive disorders of the lower urinary tract may also be caused by other diseases, such as bladder neck contractures, urethral valves, or external sphincter dyssynergia. However, for the majority of cases in the male population, the etiology is benign prostatic hyperplasia (BPH). Various animal and human studies have revealed that a significant enlargement of the bladder wall is attributable to smooth muscle cell hypertrophy, fibrocyte hyperplasia, and collagen deposition in the detrusor (3, 4). From a clinical perspective, thickening of the bladder wall should be considered as a sign of significant subvesical obstruction (5). The best way to visualize this detrusor muscle hypertrophy in a noninvasive manner is to measure the detrusor wall thickness (DWT) by suprapubic ultrasonography. In 2006, Belal and Abrams (6) evaluated noninvasive methods used to diagnose bladder outlet obstruction (BOO) in a meta-analysis and observed that ultrasound measurements of the DWT and bladder weight were the only predictors of subvesical obstruction in LUTS patients. It is widely accepted that DWT decreases continuously while the bladder fills to 50% of its capacity and then remains constant until 100%. Therefore, the detrusor wall measurements are performed on patients when the bladder is filled to maximum capacity only (7). However, no study has been published that evaluates the diagnostic accuracy of DWT when the bladder is empty. In our study, we investigated the association between the LUTS severity and DWT. In addition, the parameter “DWT when the bladder was empty” was also evaluated as a noninvasive diagnostic tool to predict LUTS in men. An ideal assessment tool to detect LUTS must be noninvasive, quick, inexpensive, and reproducible with high diagnostic accuracy. Ultrasonography has all of these criteria with additional advantages (no contrast material and no ionizing radiation). In uro-radiology practice, conventional ultrasound-derived noninvasive tests for the evaluation of LUTS severity can achieve measurements of DWT, postvoid residual urine volume (PVR), and prostate and bladder volumes. Hence, our primary aim in this prospective, controlled clinical study was to analyze the diagnostic accuracy of these ultrasound-derived noninvasive tools (i.e., DWT when the bladder is full and empty, PVR, and bladder and prostate volumes) in healthy, mildly symptomatic, and moderately-toseverely symptomatic men, and compare the outcomes in each group. In addition, their correlation according to International Prostate Symptom Score (IPSS) and age groups as well as differences in DWT values were also investigated. Our hypothesis was that these tests would accurately discriminate symptomatic cases from healthy subjects and would ABDOMINAL IMAGING