Erectile Dysfunction: Anatomical Parameters, Etiology, Diagnosis, and Therapy

Abstract

Functional anatomy of the human penis involves various parameters: cavernous tissue, covering integument, prepuce foreskin, corpora cavernosa, corpus spongiosum, glans, facia, arterial supply, venous drainage, lymph drainage, musculature, and nerve supply. Several factors affect the expression/degree of erectile dysfunction (ED) endocrine profile, aging/senescence, demyelinating diseases, and surgery. Risk factors of ED are: age, vascular factors, metabolic diseases (diabetes mellitus), neurologic diseases, and HIV/AIDS. Several drugs are associated with ED: antiandrogenic, anticholinergic, antidepressants, antihypertensive, major tranquilizers, anxiolytics, and certain medicines/metabolites. The International Index of Erectile Function (IIEF) is a multidimensional scale for assessment of erectile dysfunction. The main structures mediating erection are the corpora cavernosa or "erectile bodies," which are fused distally for approximately three-quarters of their length. They separate proximally to fuse with each ischial tuberosity of the pelvis. On their ventral surface lies the corpus spongiosum, which surrounds the urethra. Coital dysfunction is classified into "erectile dysfunction" (psychosexual and endocrine/neuro-endocrine) and "ejaculatory dysfunction" (psychosexual, and genitourinary surgery). Vasculogenic impotence was evaluated by high-resolution ultrasonography and pulsed Doppler spectrum analysis. Cavernosal, alpha-blockade is a technique used to evaluate and treat ED. Another diagnostic procedure for ED involves color floro and spectural Doppler imaging after papaverine-induced erection in impotent men. Color Doppler and duplex ultrasonography are used to evaluate Peyronie's disease. Sildenafil cilrate (Viagra) is an effective therapy of ED in men. Vardenavil is a highly selective phosphodiesterase 5 (PDE5) inhibitor which improved ED. Prostagland E1, vasoactive intestinal polypeptide (VIP), and phentolamine mesylate (administered by autoinjectors) have been applied to treat ED in patients resistant to other intracavernosal agents. Clinical trials were conducted on self-injection of vasoactive drugs, apomorphine SL, and tadalafil in diabetic men. Medical therapy of ED includes: medicated urethral system for erection (MUSE), intravenous pharmacotherapy, arterial revascularization, vacuum devices, two- and three-component inflatable penile prosthesis, semi-rigid penile prosthesis in situ, and inflatable one-piece penile prosthesis. Surgical therapy include procedures to correct Peyronie's penile deformity and penile deformity, procedures to avoid inevitable shortening accompanying Nesbit's disease, and for penile lengthening.