Post-operative blood loss after transurethral prostatectomy is dependent on in situ fibrinolysis.

OBJECTIVE: To evaluate whether post-operative blood loss in patients with benign prostatic hyperplasia, undergoing transurethral resection of the prostate (TURP), depends on in situ fibrinolysis in urine, and to determine the relative contributions of the urokinase and tissue-type plasminogen activator systems. PATIENTS AND METHODS: TURP was performed in 24 men (median age 68.5 years, range 52-78) and the weight of resected tissue, the operative and post-operative blood loss determined. The concentrations of the urokinase- (u-PA) and tissue-type plasminogen activator (t-PA)-related fibrinolysis in their urine was followed using sensitive and specific assays, and the changes related to post-operative blood loss. Measurements of the urinary concentrations of free t-PA activity, t-PA antigen, free u-PA activity, u-PA antigen and fibrin degradation products (FbDP) were determined and the area under the curve for each of these quantities correlated with the post-operative blood loss.
RESULTS: The post-operative blood loss correlated significantly with the per-operative loss (P = 0.047) and the weight of resected tissue (P = 0.029). There was a highly significant correlation between the area under the curve of FbDP in the urine and the post-operative blood loss (P < 0.005), while there was no significant positive correlation between the PA concentration or activity in the urine and post-operative blood loss. There was a significant correlation between the urinary t-PA activity and the amount of FbDP in the urine (P = 0.047), and a significant correlation between the weight of resected tissue and the amount of FbDP in the urine (P = 0.014).
CONCLUSION: The post-operative blood loss after TURP is significantly related to an increase of the urinary fibrinolytic activity and the enhanced fibrinolytic activity is probably caused by t-PA.