Nocturnal penile tumescence activity unchanged after long-term intracavernous injection therapy

Purpose: Anecdotal evidence suggests that some men have restored erectile function after long-term intracavernous injection therapy for erectile dysfunction. We objectively assessed this phenomenon using nocturnal penile tumescence testing. Materials and Methods: In our retrospective study 19 men with a mean age of 53.5 years who had organic erectile dysfunction underwent nocturnal penile tumescence testing before and after prostaglandin E1 based intracavernous injection at least 6 months in duration. The nocturnal penile tumescence parameters measured included the number of erectile episodes, base and tip tumescence, and percent of time with rigidity greater than 70% at the penile base and tip. A 5-item questionnaire was given to all patients after the intracavernous injection period to assess subjective changes in erectile quality. Results: Mean time on intracavernous injection was 2.42 years and mean injection frequency was 3.74 times monthly. Prostaglandin E1 only, and combined prostaglandin E1, phentolamine and papaverine were used in 7 and 9 cases, respectively. Nine patients believed that unaided erection improved after intracavernous injection and 6 achieved intercourse without injection who were unable to do so before injection. No statistically significant changes were noted in any of the 5 objectively measured nocturnal penile tumescence parameters. Conclusions: Long-term prostaglandin E1 based intracavernous injection may provide subjective improvement in erectile function in some men. However, as measured by nocturnal penile tumescence testing, no objective improvement in spontaneous erectile function occurs.