Penile rehabilitation with a vacuum erectile device in an animal model is related to an antihypoxic mechanism: blood gas evidence

Abstract

Our previous study showed that vacuum erectile device (VED) therapy has improved erectile function in rats with bilateral cavernous nerve crush (BCNC) injuries. This study was designed to explore the mechanism of VED in penile rehabilitation by analyzing cavernous oxygen saturation (SO2) and to examine the effect of VED therapy on preventing penile shrinkage after BCNC. Thirty adult Sprague-Dawley rats were randomly assigned into three groups: group 1, sham surgery; group 2, BCNC; and group 3, BCNC+VED. Penile length and diameter were measured on a weekly basis. After 4 weeks of therapy, the penile blood was extracted by three methods for blood gas analysis (BGA): method 1, cavernous blood was aspirated at the flaccid state; method 2, cavernous blood was aspirated at the traction state; and method 3, cavernous blood was aspirated immediately after applying VED. SO2 values were tested by the blood gas analyzer. The results showed that VED therapy is effective in preventing penile shrinkage induced by BCNC (Penile shortening: BCNC group 1.9±1.1 mm; VED group 0.3±1.0 mm; P<0.01. Penile diameter reduction: BCNC group 0.28±0.14 mm; VED group 0.04±0.14 mm; P<0.01). The mean SO2±s.d. values were increased by VED application (88.25%±4.94%) compared to the flaccid (76.53%±4.16%) or traction groups (78.93%±2.56%) (P<0.05). The calculated blood constructs in the corpus cavernosum right after VED application were 62% arterial and 38% venous blood. These findings suggest that VED therapy can effectively preserve penile size in rats with BCNC injury. The beneficial effect of VED therapy is related to antihypoxia by increasing cavernous blood SO2.