Non-invasive diagnosis of bladder outlet obstruction (BOO) in male patients with lower urinary tract symptoms (LUTS)

The thesis summarizes nine published articles and deals with the diagnostic value of morphological changes in the lower urinary tract in adult men with LUTS associated with BOO. Until recently, no morphological change of the lower urinary tract could safely diagnose BOO. Therefore, the value of ultrasound measurement of detrusor wall thickness (DWT) for the detection of BOO was investigated. The results of the studies demonstrate that suprapubic measurement of DWT should be performed at the anterior bladder wall with a bladder filling of ≥250 ml or a bladder capacity of ≥50%. Measurements in healthy men are significantly thicker than in healthy women. Ultrasound measurement DWT values ≥2 mm indicate BOO. The more severely BOO is the thicker DWT becomes. Compared to pressure-flow studies, ultrasound DWT measurement for the evaluation of BOO has a positive predictive value of 94-95%, negative predictive value of 75-86%, sensitivity of 64-83%, specificity of 95-97%, and a likelihood ratio of a positive test result of 17.6-21.3. The prospective evaluation of ultrasound DWT measurements demonstrated that this test is superior to other tests which are frequently used in clinical practice (measurement of the maximum or average urinary flow rate of free uroflowmetry, measurement of post-void residual urine, or transrectal ultrasound measurement of the prostate). Ultrasound DWT measurement has recently been mentioned in the EAU Guidelines for the Assessment and Treatment of Male LUTS and can be used as a screening test for BOO.