Detrusor underactivity versus bladder outlet obstruction clinical and urodynamic factors

OBJECTIVES: To evaluate the lower urinary tract symptoms, classified by the International Prostate Symptom Score (IPSS), urodynamic results (Watts Factor (WF), Bladder Contractility Index (BCI), and post void residual (PVR), in order to differentiate Detrusor Underactivity (DU) from Bladder Outlet Obstruction (BOO). METHODS: Retrospective observational study performed from 2011 to 2018 at the Hospital das Clínicas of Unicamp. Two phases were done: first, to estimate sample size, and second, to evaluate the predicted parameters. Male patients with range age from 40 to 80 years were included. Patients were divided into two groups: Group 1, without BOO and with DU; Group 2, with BOO. Variables analyzed: age, comorbidities, symptoms, urodynamic data (BCI and WF) and PVR. RESULTS: Twenty-two patients were included in each group, with medians of 68 (Group 1) and 67.5 years old (Group 2) (p = 0.8416). There was no difference for comorbidities. In relation to IPSS, medians were: 16.5 and 20.5, respectively (p = 0.858). As for symptoms, there was predominance of combination of storage and voiding symptoms in the two groups (p = 0.1810). Regarding PVR, 15 patients in Group 1 and 16 in Group 2 presented PVR> 30mL (p = 0.7411). BCI presented median values of 75 and 755.50 for Group 1 and Group 2, respectively (p <0.0001), while WF had medians of 22.42 and 73.85 (p <0.0001). CONCLUSION: Isolated symptoms, classified by IPSS and PVR, could not differentiate patients with DU from those with BOO, but it was possible using urodynamic data.