urodynamic bàng quang đầu ra tắc nghẽn trong hơn 90% các trường hợp. Thông thường, đàn ông có triệu chứng đường tiết niệu thấp hơn là kết quả của một bàng quang hoạt động quá mức hơn là cản trở đầu ra bàng quang do để mở rộng tuyến tiền liệt lành tính có mô hình dòng chảy bình thường hoặc supranormal. | DIAGNOSIS OF PROSTATIC DISEASES Figure 99 This uroflow recording from a patient with bladder outflow obstruction secondary to benign prostatic hyperplasia shows a reduced maximum flow and prolonged voiding urodynamic bladder outlet obstruction in more than 90 of cases. Typically men with lower urinary tract symptoms that are the result of an overactive bladder rather than bladder outlet obstruction due to benign prostatic enlargement have normal or supranormal flow patterns. PRESSURE-FLOW URODYNAMICS Pressure-flow urodynamics is the term used for the investigation that involves measurement of intravesical pressure during filling and voiding and urinary flow rate. This is achieved by the insertion of a filling catheter and pressure recording device into the bladder usually by the transurethral route but sometimes by suprapubic puncture. To discount the effect of abdominal straining and thereby assess the impact of genuine bladder contractions another small tube is inserted into the rectum and this pressure is subtracted from the intravesical pressure. The normal bladder should accommodate up to 300-500 ml of fluid without undue pressure rise. As a response to prostatic obstruction bladder compliance is reduced and involuntary contractions occur during filling. During voiding bladder pressures are typically high and flow rates low. When late-stage bladder outflow obstruction occurs and in conditions such as diabetic neuropathy bladder contractions are impaired and a low-pressure low-flow scenario develops. Urodynamics provide the only reliable way of confirming this diagnosis. TRANSRECTAL ULTRASOUND IMAGING Transrectal ultrasound TRUS imaging of the prostate serves several purposes Imaging the internal architecture of the gland and periprostatic tissues including seminal vesicles Estimation of prostate volume Facilitation and targeting of ultrasound-guided prostate biopsy. A 7-MHz endocavity ultrasound probe is commonly used and the prostate viewed in both .
