ED is the inability to develop and maintain an erection for satisfactory sexual intercourse or activity. ED after nerve-sparing RP is related to a certain degree with functional impairment of cavernous nerves (CN) that travel along the prostate to the penis. This neuropraxia can last as long as 2 years. Pro-erectile nerve stimulus is vital for replenishment of corporal oxygen supply and other metabolic needs. Several histological analyses have demonstrated decreased smooth muscle number, cell-cell contact, venous leakage, collagen deposition, and additional harmful effects to corporal tissue after injury to CN.