The effect of cardiopulmonary bypass in coronary artery bypass surgeries (on-pump versus off-pump) on erectile function and endothelium-derived nitric oxide levels.

Purpose: To investigate the effects of on-pump and off-pump coronary artery bypass grafting (CABG) on the erectile function and endothelium-derived nitric oxide (eNO) levels.

Materials And Methods: Twenty-eight consecutive patients were randomized into two groups depending on use of cardiopulmonary bypass in CABG surgery. The erectile function was evaluated by using the IIEF-5 questionnaire. The plasma eNO levels were determined at baseline and after reactive hyperemia before and after surgery. Blood was collected in one minute after cuff deflation from the radial artery on the same side.

Results: After CABG surgery the mean IIEF-5 score increased insignificantly over baseline from 14.8 to 15.8 (p = 0.29) and 12.4 to 14.3 (p = 0.11) after on-pump and off-pump CABG surgeries, respectively. The baseline plasma NO levels before surgery were 18.16 ± 7.63 nmol/L in on-pump and 21.76 ± 11.08 nmol/L in off-pump CABG. After reactive hyperemia the plasma NO levels were 22.14 ± 10.52 nmol/L in on-pump and 21.49 ± 9.13 nmol/L in off-pump CABG before the surgery. The difference in the plasma NO levels before surgery was not significant (p = 0.51). Two hours after surgery, the difference of the plasma NO levels at baseline (24.44 ± 12.31 on -pump and 20.58 ± 6.74 nmol/L off-pump CABG) and after reactive hyperemia (35.55 ± 23.54 nmol/L on-pump and 23.00 ± 15.40 nmol/L off-pump CABG) were not significantly different from each other (p = 0.11).

Conclusions: Patients who had on-pump or off-pump CABG surgeries had higher IIEF-5 scores. Nevertheless, the improvement was insignificant in both groups. Meanwhile, on-pump or off-pump CABG surgeries did not have significant effect on plasma eNO levels.