Functional anatomy of cavernous helicine arterioles in potent subjects

Purpose: We investigated the morphological and functional features of cavernous helicine arterioles in male potent subjects. Materials and Methods: Ten young men reporting normal rigid erections which were confirmed by polysomnographic recording underwent power Doppler sonography of the cavernous helicine arterioles during flaccidity, after intracavernous injection of alprostadil, and after subsequent genital and audiovisual sexual stimulation. Results: During flaccidity the helicine arterioles were never detected by power Doppler imaging while they became evident in all cases after alprostadil injection, They usually originated from the cavernous artery forming an acute angle and showed 3 orders of ramifications, Systolic and diastolic flow was present. After genital and audiovisual sexual stimulation, and achievement of maximum rigidity, the helicine arterioles were still evident but with only 1 or 2 orders of distal ramifications, Only systolic flow was present. During penile tumescence the helicine arterioles disappeared in all cases. Conclusions: Using power Doppler sonography it is possible to investigate the functional anatomy of the cavernous helicine arterioles during the various phases of the erectile cycle. Our preliminary study suggests that the helicine arterioles are functionally inactive during penile flaccidity while they are activated during penile tumescence and continue to supply blood to the corpora also during maximum penile rigidity.