Cavernosal arterial patency is required for normal erectile function and thus demonstration of the cavernosal arteries is the focus of penile angiography. The internal pudendal artery is one of three major branches of the anterior division of the internal iliac artery and gives rise to the common penile artery. With great variation, there are three main paired arteries to the penis arising from the common penile artery: the dorsal penile, cavernosal and spongiosal. It is the cavernosal arteries which are required for successful erection, and even with occlusions of the penile arterial supply it is quite rare not to see part of one or both cavernosal arteries[2](Fig.3A). Important variant anatomy that one must be aware of includes a unilateral origin of both cavernosal arteries. It is therefore imperative that a complete evaluation includes bilateral selective and non-selective images. [3,4].

Trauma is a well-recognized cause of impotence especially in young and otherwise healthy males. Impotence is usually due to injury to the neurovascular supply to the penis from the injury or during surgical repair. In blunt pelvic trauma, arterial injury can occur due to upward displacement of the pubic symphysis causing urethral disruption and injury to the arteries penetrating the urogenital diaphragm, particularly the internal pudendal artery as it becomes the common penile artery [5]. Other fractures to the pelvis may result in direct arterial injury such as ischial fractures causing direct injury to the internal pudendal artery.

Blunt trauma to the perineum usually is secondary to a straddle injury or kick injury. Impotence from such injuries is usually arteriogenic and results from arterial injury as the vessel is compressed against the pubic bone. The dorsal penile and cavernosal arteries are more likely to be injured in blunt perineal trauma [6]. Rarely, high-flow priapism may occur with blunt perineal trauma as a cavernosal-sinusoidal space fistula may develop.[5,7] Disruption of the veno-occlusive mechanism may occur secondary to blunt perineal trauma and contribute to impotence.

Evaluation of patients with post-traumatic impotence can include duplex ultrasonography, dynamic infusion cavernosometry and cavernosagraphy (DICC), and pharmacoangiography[5,8]. Duplex ultrasonography can evaluate the integrity of the dorsal penile and cavernosal arteries. DICC is best for evaluating veno-occlusive function and to a lesser extent arterial integrity. However, angiography should be the study of choice for evaluating arterial insufficiency especially if penile revascularization is considered as a treatment option [5,7]. Pharmacoangiography with intracavernosal injection of a vasoactive agent, such as papaverine, and selective injections will help demonstrate the exact location of the arterial lesion.

References:
1. Bookstein JJ, Valji K. Penile vascular catheterization in diagnosis and therapy
of erectile dysfunction. In: Baum S, Pentecost MJ eds. Abrams’ angiography - interventional
radiology. Boston: Little, Brown. 1997:705-725

2. Lurie AL, Bookstein JJ, Kessler WO: Post-traumatic impotence - angiographic
evaluation. Radiology 1988;166:155-199.

3. Bookstein JJ, Lang EV: Penile magnification pharmacoarteriography - details of
intrapenile arterial anatomy. AJR 1987;48:883-884.

4. Schwartz AN, Freidenberg D, Harley JD: Nonselective angiography after intracorporal
papaverine injection - an alternative technique for evaluating penile arterial integrity.
Radiology 1988;167:249-253.

5. Matthews LA, Herbener TE, Seftel AD. Impotence associated with blunt pelvic and perineal
trauma: penile revascularization as a treatment option. Semin Urol 1995;12:66-72

6. Levine FJ, Greenfield AL, Goldstein I. Arteriographically determined occlusive disease within
the hypogastric-cavernosal bed in impotent patients following blunt perineal and pelvic trauma.
J Urol 1990;140:1147-1153.

7. Witt M, Goldstein I, Saenz de Tejada I. Traumatic laceration of the cavernosal arteries:
the pathophysiology of non-ischemic high-flow priapism. J Urol 1990;143:129-132.

8. Rosen MP, Schwartz AN, Levine FJ, Greenfield AJ: Radiologic assessment of
impotence - angiography, sonography, cavernosography, and scintigraphy.
AJR 1991;157:923-931.

Return to Day #4