[Criteria of Rigiscan normalcy in aged men]

To define the changes in penile tumescence and rigidity in normally potent older men before a nerve-sparing radical retropubic prostatectomy (NS-RRP) and to establish a base-line for investigating erectile dysfunction in that age group.

75 patients used the Rigiscan for 2-3 nights before undergoing a NS-RRP procedure. Rigiscan data were analyzed visually using Kaneko & Bradley criteria, and by computerized analysis. The computerized data were compared to the patient self-evaluation of potency (questionnaire), patient's age (above and below 60 years old), peak cavernosal artery velocity measured by Duplex Doppler scanning, and to the visual analysis of the Rigiscan data.

55 of 75 men (73%) completed three sessions. 42 men had at least 2 normal sessions, and when compared to the 33 with abnormal visual tracings, only age was significantly characteristic (p < 0.05). Tip event rigidity (%) in < 60 year-old men was greater than in older men (p < 0.01). Nearly all men had erections lasting more than 2 minutes, while only 29 of 74 had 10 minutes erections with rigidity > 70%. The best correlation between visual and computerized analyses was noted in the group of 54 men who experienced > 70% rigidity for more than 2 minutes.

This large prospective series of potent older men studied by Rigiscan and other subjective and objective parameters helps establishing normative data in the diagnosis of erectile dysfunction. An important observation is clearly the lack of correlation between the patient's questionnaire or the Doppler findings and the Rigiscan data.