Objectives: To document the penile vascular and erectile response to intracavernous injection (ICI) of vasoactive agent in hypogonadal men with micropenis.
Methods: A total of 15, previously untreated, hypogonadal men with micropenis (stretched penis length less than 2.5 SD below the mean of the normal population) underwent a detailed urologic and endocrinologic evaluation. Their mean age was 21.2 +/- 4.2 years. Penile hemodynamics were assessed by color Doppler ultrasonography before and after ICI of 5 microg of prostaglandin E(1) combined with manual genital self-stimulation.
Results: Endocrinologic evaluation revealed that hypogonadism was hypogonadotropic in 10 (66.7%) and hypergonadotropic in 5 (33.3%). Karyotype analysis showed 46XY in all. Their mean stretched penile length was 6.2 +/- 1.4 cm (range 3 to 7.5) and increased to a mean of 6.96 +/- 1.5 cm (range 4 to 8.5) after ICI. The serum free testosterone levels ranged from 0.2 to 3.2 pg/mL (mean 1.9 +/- 0.92). None had had any previous sexual experience, and 14 (93.3%) reported a history of nocturnal erections. Penile color Doppler ultrasonography demonstrated a normal penile vascular system in 7 (46.7%) and penile arterial insufficiency in 4 (28.6%). All 11 of these patients (73.3%) achieved an adequate erectile response to ICI combined with manual stimulation. Mixed vascular disease was observed in the remaining 4 patients (28.8%), and they did not have a sufficient erectile response to ICI. Color Doppler ultrasonography revealed similar results in the hypogonadotropic and hypergonadotropic men.
Conclusions: Our data suggest that the erectile response to ICI combined with manual genital self-stimulation is effective in most hypogonadal men having a micropenis with low serum androgen levels.