Intravesicular prostatic protrusion as a predictor of silodosin response: results from an observational study

Background: Ultrasound measurement of the IPP has been previously described as an effective instrument for the evaluation of benign prostatic obstruction (BPO) and could help in clarifying the role of silodosin in patients with (BPE).Aim of our study was to investigate the efficacy of silodosin in patients with lower urinary tract symptoms (LUTS) and benign prostatic enlargement (BPE) with intravesical prostatic protrusion (IPP). Methods: In this observational study Patients with BPE and LUTS were enrolled. Intravesical prostatic protrusion was graded as grade 1 (< 5 mm), 2 (5 < IPP < 10 mm) and 3 (> 10 mm). Patients were treated with silodosin for twelve weeks. International Prostate Symptom Score (IPSS) and uroflowmetry was performed before and at the end of treatment. Patients were considered responders if a reduction of IPSS > 3 points was noted. Results: Of the sixty eight patients enrolled, two patients were excluded because of incomplete data. 26 patients showed an IPP grade 1 (group A), 27 a grade 2 (group B) and 13 grade 3 (group C). Treatment success was obtained in 80 %, 44 % and 7.5% of patients respectively; these differences (group A vs B-C and group B vs C) were highly significant. The odd ratio to obtain a treatment success was of 52 and 10 in group A and group B respectively, in comparison to group C. After a multivariate regression, the relationship between IPP grade and treatment success remained significant. Improvement of uroflowmetry parameters has been reported in all the groups especially in patients with a low grade IPP .Prostate volume seems not to influence this relationship. Conclusion: Intravesical prostatic protrusion has found to be significantly and inversely correlated with treatment success in patients with LUTS and BPE under silodosin therapy. silodosin odd ratio of success is 52 times higher in patients with a low grade IPP in comparison to patients with a high grade.