Transurethral prostatectomy with computer-monitored resectoscope.

Based on the difference in electrical conductivity between hyperplastic prostatic tissue and tissue of the surgical capsule, we have developed a monitoring computer that distinguishes the former from the latter. The computer sounds an alarm when the cutting loop of the resectoscope touches the capsule, followed by an automatic cut-off of the power source 0.4 s later; thus inadvertent perforation of the surgical capsule can be avoided in most cases. The function of the computer has been tested in 73 patients with benign prostatic hyperplasia. The results show that, with Nesbit's technique of transurethral resection, tiny perforations of the surgical capsule, usually 1 to 2 mm in diameter, occurred in all 30 patients operated on without computer monitoring, but only 3 of 73 computer-monitored patients had such an occurrence. There was a slight increase in the weight of resected prostatic tissue among the computer-monitored patients, but the difference between the time spent on the procedure between the two groups of patients was not significant. Apart from its monitoring function, the computer may reduce eye strain and mental stress in the surgeon, especially when resecting a large hyperplastic prostate.