Indian Journal of Urology (Jan 2004)
Diagnosing bladder outlet obstruction can we do away with pressureflow studies?
Abstract
Objective: To compare pressure-flow study on one hand with BWT, prostate volume, urine flow rate PVR and IPSS index in the other arm for diagnosis of BOO. Materials and methods: A prospective cross-sectional study was carried out in 48 men with lower urinary tract symptoms (LUTS). International prostate symptom score was completed by the patient who then underwent free urine flow study. Pressure-Flow study was performed as per recommendations of International continence Society. Abrams-Griffiths nomogram and number were used to diagnose BOO. Patients with diabetes, neurovesical dysfunction, acute urinary retention, prior pelvic surgery and known prostate cancer were excluded. Suprapubic ultrasonography was performed independently by a consultant radiologist, who was blinded to findings of Pressure-Flow study. Prevoid bladder volume, postvoid residue (PVR), prostate volume and bladder wall thickness (BWT) were noted. Results: Based on objective evidence from Pressure-Flow study, 35 patients were obstructed, 13 were not. Multivariate analysis was performed using Backward Stepwise Logistic Regression Model. Bladder wall thickness, prostate volume and urine flow rate had statistically significant relationship with BOO. Their coefficients of correlation were +0.794, +0.084 and 0.393 respectively. Bladder outlet obstruction could be defined by using a mathematical formula as detailed in the text (Positive Predictive Value 96.97%). Post-void residue and IPSS index were statistically insignificant. Conclusion: In a select group of patients presenting with LUTS, it should be possible to diagnose BOO without the use of Pressure-Flow study.
