Hiroaki Shiozawa

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.

Efficacy of transurethral needle ablation of the prostate for the treatment of benign prostatic hyperplasia

Background: We evaluated the efficacy and safety of transurethral needle ablation (TUNATM) of the prostate for treatment of symptomatic benign prostatic hyperplasia (BPH) as one institute participating in a Japanese clinical trial.

Transurethral needle ablation of the prostate: An initial Japanese clinical trial

Abstract Objectives: Transurethral needle ablation of the prostate is a new alternative endoscopic thermal therapy that uses a low‐energy radio frequency delivered into the prostatic adenoma. Herein is reported the initial clinical experience by multiple institutes in Japan of transurethral needle ablation of the prostate for the treatment of symptomatic benign prostatic hyperplasia.

Perirenal Pseudolymphoma: A Case Report

A right nephrectomy was performed on a 51 year‐old female with a tumor surrounding the right kidney since the possibility of malignant lymphoma could not be excluded based on radiography or a needle biopsy. An immunohistological examination of the surgically‐resected specimen confirmed a diagnosis of pseudolymphoma. A pseudolymphoma involving the urinary tract is rare, and this is only the second reported case of pseudolymphoma in the perirenal space.

Endoscopic Ultrasonic Aspiration of Superficial Bladder Tumors

The gold standard of surgical treatment for superficial bladder tumor is transurethral resection (TUR). However, the procedure has drawbacks: it needs skill to avoid perforation of the bladder wall, while burns on the resected tissue are disadvantageous for histological examination. We developed an endoscopic ultrasonic aspiration system which is easy to manipulate and makes no burns on aspirated tissue. Furthermore, the equipment includes a coagulating system. Transurethral ultrasonic aspiration was performed in 19 cases of superficial bladder tumor with a prototype 24Fr Y-shaped rigid endoscope. The efficacy of bladder tumor aspiration was evaluated and ultrasonic aspiration was compared to the conventional TUR procedure. Bladder tumors less than 2 cm were aspirated very rapidly. Blood loss was minimal and the largest tumor aspirated in this series weighed 6.5 grams. Aspirated tissue was large enough for histological examination. Compared to conventional TUR, the ultrasonic aspiration has advantages of no burns on aspirated tissue and easy manipulation. Transurethral ultrasonic aspiration may be an alternative procedure for the treatment of superficial bladder tumor.

Basic Study on Transurethral Electrosurgical Vaporization of the Prostate

To clarify the best conditions for the most effective prostate vaporization, the electrode pressure on the tissue surface, the depths of the vaporization cavity and the desiccated layer of tissue, the formation of bubbles, the electrical voltage, and the resistance of the tissue were examined employing different types of electrodes.