The effects of extracorporeal cardiopulmonary circulation on serum total and free prostate specific antigen levels.

The aim of this study was to investigate whether or not there is an increase in serum total and free prostate specific antigen levels (t-PSA, f-PSA) in patients with and without benign prostatic hyperplasia (BPH) undergoing extracorporeal circulation during cardiovascular bypass. The study included a total of 50 men. Of these, 35 patients underwent elective coronary artery bypass grafting with extracorporeal circulation [with (n=20, group I) and without (n=15, group II) BPH]. Another 15 patients underwent renal or ureteral surgery (group III) and served as a control group. Serum t-PSA and f-PSA levels were measured before surgery and 3 h and 3 days after surgery. All patients underwent urethral catheterization 24 h before surgery. In groups I and II, patients had an increase in t-PSA 3 h after surgery compared to baseline values (p=0.0001 and p=0.011, respectively). Also, 3 days after surgery, mean t-PSA levels were higher than baseline levels (p=0.004) in group I. Serum t-PSA levels were higher at 3 h than at day 3 in groups I and II (p=0.003 and p=0.02, respectively). Mean serum f-PSA levels obtained 3 h after surgery were increased in both groups I and II when compared to baseline values (p=0.0001 and p=0.001, respectively). There was no significant difference between f-PSA values before and 3 days after surgery in all groups. In the control group, there was no significant increase in either serum t-PSA or f-PSA levels obtained at different times. There was a modest increase in the percentage of free prostate specific antigen (% f-PSA) 3 h after the operation in group II (p=0.025); the values returned to baseline within 3 days. It was suggested that t-PSA and f-PSA serum levels increase due to extracorporeal cardiopulmonary circulation as a consequence of ischemic damage to the prostate. In patients with BPH, this rise may be higher than in those without BPH, because BPH patients generally have larger prostate volumes that may be more vulnerable to ischemic damage. Because f-PSA has a shorter half-life, postsurgical levels of f-PSA may not show this ischemic damage to the prostate during the late postoperative period and f-PSA appears to be cleared more rapidly than t-PSA.