Taku Aizawa

A New Transurethral Resection System: Operating in Saline Environment Precludes Obturator Nerve Reflexes

PURPOSE We developed a transurethral resection system comprising a uniquely designed resectoscope and high frequency wave generator. The obturator nerve is free of electrical stimulation during transurethral resection since high frequency current is delivered via a resection loop to the sheath of the resectoscope in saline irrigation. Preclinical verification of the system was performed in an animal model to ensure its efficacy and operational safety. MATERIALS AND METHODS The swine bladder wall was transurethrally resected using the system in a saline environment. Results were subsequently compared with data on identical resection performed with the conventional system in sorbitol solution irrigation. Electrolyte contents were measured after resection for comparative evaluation with corresponding pre-resection data. Also, the depth of heat degeneration was measured in resected tissue. RESULTS No additional skills were required for bladder resection performed with the new system versus the conventional system. No lower limb adductor contraction was noted except minimal creeping during resection of a site close to the urethra. There were no apparent anomalies of blood electrolytes after transurethral resection. No difference was observed in the mean depth of heat degenerated tissues compared with the conventional system. CONCLUSIONS The newly developed transurethral resection system was effective in a saline irrigated environment, which inhibited the obturator nerve reflex when applied in an animal model. This finding suggests promising potential for the system as a safe and cost-effective alternative compared with conventional transurethral resection.

M1 prostate cancer with a serum level of prostate-specific antigen less than 10 ng/mL

Abstract Background: M1 prostate cancer, which is invasive, is usually associated with a serum level of prostate‐specific antigen (PSA) greater than 10 ng/mL, but cases are occurring where the serum PSA level is less than this. The present study investigated the clinical and pathologic characteristics of these cases of M1 prostate cancer.

Does transrectal ultrasound guided eight‐core prostate biopsy improve cancer detection rates in patients with prostate‐specific antigen levels of 4.1–10 ng/mL?

Background: To investigate retrospectively whether the eight‐core biopsy method improves the prostate cancer detection rate when compared with the standard sextant biopsy method in patients with prostate specific antigen (PSA) levels of 4.1–10 ng/mL.

The possibility of ‘de novo’ cancer in the prostate

Abstract  Background:  To investigate the possibility of ‘de novo’ prostate cancer by analyzing the relationship between high grade prostatic intraepithelial neoplasia (HGPIN) and latent prostate cancer.