Evaluation of vasculogenic impotence by monitoring of cavernous oxygen tension

Color coded duplex sonography, regarded as the gold standard in penile vascular evaluation, does not yield data on cavernous oxygenation itself. In addition to using color coded duplex sonography to measure peak flow velocity in cavernous arteries after injection of 20 micrograms. prostaglandin E1 in 34 unselected patients with impotence, we monitored cavernous oxygen tension with oxygen-sensitive Eppendorf needle electrode. During flaccidity the mean cavernous oxygen tension of 38 mm. Hg increased to 61 mm. Hg after injection of prostaglandin E1. Peak flow shown with color coded duplex sonography and maximal oxygen tension correlated well in 24 men (71%). However, in 10 men (29%) normal peak flow did not result in a cavernous oxygen tension of greater than 65 mm. Hg, so this might have been isolated cavernous perfusion defects. In contrast, there was no case of impaired arterial inflow and high oxygen tension. Monitoring of cavernous oxygen tension allows for characterization of patients with cavernous perfusion deficiency. This new and simple diagnostic method might help to improve diagnosis and followup after penile vascular surgery. However, more data on patients and controls will be required to define normal ranges.