Only the nose knows: penile hemodynamic study of the perineum-saddle interface in men with erectile dysfunction utilizing bicycle saddles and seats with and without nose extensions.

PURPOSE: To investigate the differential impact of straddles (A(ns) and B(ns)) and noseless two-cheek seats (A(ntcs) and B(ntcs)) on penile hemodynamics and perineal compressive forces in subjects who cycle in a stationary bicycle. MATERIALS AND METHODS: Subjects underwent cavernosal artery peak systolic velocity (CAPSV) measurements after intracavernosal injection of vasoactive agents while supine, sitting upright on an examination table, straddling a saddle, sitting on a seat, and again supine. Mean perineal compression pressures recorded while straddling the saddles were compared with those while sitting upright. RESULTS: No differences were found in right and left CAPSV values while supine, sitting upright on an examination table, sitting on a seat, and supine again. Right/left CAPSV (cm/second) values straddling A(ns) and saddle B(ns) (0.7 +/- 2.9/1.5 +/- 6.2 and 0/0, respectively) were significantly lower than values obtained while sitting on A(ntcs) and B(ntcs) (25.6 +/- 13.4/23.8 +/- 12.0 and 17.3 +/- 6.4/18.3 +/- 6.5, respectively) (P < 0.001). Mean perineal compression pressures (mm Hg) on A(ns) and saddle B(ns) (315.2 +/- 39 and 387.9 +/- 64.3, respectively) were significantly higher than values obtained while sitting upright on an examination table (47.6 +/- 5.2 and 46.0 +/- 8.1, respectively) (P < 0.001). CONCLUSIONS: We have identified an objective test to assess if an individual bicycle rider, sitting on a certain shape of bicycle saddle or seat generates sufficient compressive forces at the perineal-saddle interface to obstruct cavernosal arterial inflow. This study also demonstrated that straddling bicycle saddles with nose extensions is associated with perineum-saddle interface compressive pressures that exceed systolic perfusion pressures, significantly diminishing penile hemodynamics.