Predictors of successful erectile function using intracavernosal injection in post-prostatectomy men with erectile dysfunction.

INTRODUCTION

Intracavernosal injections (ICI) are commonly used to treat erectile dysfunction (ED) in men following radical prostatectomy (RP). Predictors of treatment success are still unclear. Our objective was to explore the relationship between various clinical and pathologic parameters and the achievement of satisfactory erections with ICI following RP.

METHODS

This is a prospective study of men following RP with bilateral neurovascular bundle preservation who experienced ED refractory to treatment with phosphodiesterase type 5 inhibitors (PDE5I) at a minimum of six months after surgery. Three escalating dosages of TRIMIX were used consecutively (5 mg papaverine, 0.5 mg phentolamine, 10 mcg alprostadil; 10 mg papaverine, 1 mg phentolamine, 20 mcg alprostadil; 17 mg papaverine, 1 mg phentolamine, and 30 mcg alprostadil). Erection Hardness Scale (EHS) and International Consultation on Incontinence Questionnaire-Short Form (ICIQ-SF) were used for functional assessments.

RESULTS

Thirty-four patients were stratified by their EHS scores and Trimix dosages: low-dose full responders (n=12), intermediate-dose full responders (n=10), high-dose partial responders (n=7), and high-dose failures (n=5). Twenty-nine patients (85%) reported on satisfactory erectile function with ICI. The ICIQ-SF scores were the only parameter that correlated significantly with successful erectile response, with median scores of 0, 3.5, 11, and 16 for the respective groups above (p=0.001). Univariate logistic regression demonstrated a significant association between ICIQ-SF scores and partial or non-response (odds ratio 1.3, 95% confidence interval 1.1-1.5, p=0.002).

CONCLUSIONS

ICI is an efficient therapy for achieving satisfactory erections following RP in PDE5I-resistant men. Sustainable urinary incontinence is a strong predictor of poor response to therapy.