Endoscopic injection of the vasoconstrictor ornithine-8-vasopressin in transurethral resection

A simple technique to inject the synthetic vasoconstrictor agent ornithine-8-vasopressin endoscopically into the prostate has been developed. The method has been assessed by two prospective randomised controlled trials on patients undergoing transurethral resection of the prostate. Results from the first trial, involving 56 patients who had general anaesthesia, were that the mean operative blood loss was 48% less in the treated group, a significant difference (P = 0.05). Results from the second trial, involving 57 patients who had spinal anaesthesia, were that the mean operative blood loss was 75% less in the treated group, a highly significant difference (P = 0.01). The pharmacology of the drug is reviewed, and it seems to be a safe agent which aids transurethral resection. It frequently causes a modest and transient elevation in blood pressure shortly after injection and, although not encountered by the author, it is possible that a more severe elevation necessitating treatment may rarely occur.