Variations of the internal pudendal artery as a congenital contributing factor to age at onset of erectile dysfunction in Japanese.

OBJECTIVE: To investigate the relationship between variations of the pelvic artery arrangement and the age at erectile dysfunction (ED) onset, as some men develop ED while relatively young, while others maintain erectile function into old age despite having cardiovascular diseases, thus congenital factors might be involved.

PATIENTS AND METHODS: We examined 290 units of internal iliac arteries (IIA) in 145 patients showing repeated incomplete erectile response to intracavernosal injections with prostaglandin E(1). Patients with cardiovascular risk factors, neurological disease or pelvic injury were excluded. The pelvic artery arrangement, evaluated by three-dimensional computed tomographic angiography, was classified anatomically into five types: Type 1 (normal or basic type), in which the internal pudendal artery (IPA) originates from the anterior trunk at the level between the linea terminalis and the major ischial notch; Type 2, the IPA originates from the anterior trunk of the IIA at the level of the major ischial notch or more distally; Type 3, the IPA originates directly from the IIA at a level proximal to the linea terminalis; Type 4, the IPA originates together with the superior and inferior gluteal artery within 1 cm of each other; and Type 5, the penile blood supply is dependent on arteries other than the IPA, such as the obturator artery.

RESULTS: Among the 290 units, eight could not be classified due to poor image quality. There were no statistically significant differences in blood flow parameters among the types of IIAs, but there was a statistically significant difference in the IPA type at the age of onset of ED. Type 1 (153 units or 53%) anatomy, was more common in patients who developed ED at an advanced age. Types 2, 3 and 4 were more common in patients with onset of ED at an early age (log-rank test P < 0.001, P = 0.044, P < 0.001, respectively). Compared with patients with the common type of IIAs bilaterally, patients with any of the variations bilaterally are at risk of early onset of ED (log-rank test: P = 0.002).

CONCLUSION: In these anatomical studies, nearly half of all internal artery units are variations in type. Congenital factors might contribute to the development of ED. If a man has bilateral variation from the common type (Type 1), he might develop ED approximately 10 years earlier than those who are identical in every way except for their IPA (Type 1) arrangements.