Population: Patients with histologically confirmed pTa urothelial bladder tumours Number of Subjects: Twenty patients Selection of Subjects: Patients scheduled for a trans urethral resection of bladder tumour (TUR-B) less than 1,5 cm at the operating theatre under general anaesthesia and without concomitant therapy with anticoagulants as Marevan, Marcoumar, and the new anticoagulants as Pradaxa etc. will after informed consent be included in the study.