Yoshimi Mamiya

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.

Outpatient ESWL in 500 kidneys

Between March 1989 and January 1992, 600 cases (636 kidneys) with upper urinary tract stones were treated with ESWL, using a Lithostar. Of these, 78.6% were carried out in our outpatient service, and in the last two years approximately 90% of cases have been treated as outpatient. We evaluated first 500 kidneys, treated with ESWL as outpatient. There were 481 cases involving 500 kidneys (19 bilateral cases). The ages of the 367 men and 114 women ranged from 16 to 77 years. There were 227 kidney stones and 273 ureter stones. Most of the stones were less than 20 mm. The average number of sessions and shock waves for each patient were 1.4 times and 6,988 waves, respectively. While 74% of the patients could be treated in only one session, 9% of them needed 3 sessions or more. Auxiliary measures were needed in 23 cases (D-J stent insertion in 5 cases and ureteral catheterization in 18 cases) and 474 cases (94.8%) were treated by in-situ procedures. At 3 months after treatment, 470 cases were evaluated and the stone-free rates of kidney stones and ureter stones were 70.3% and 84.5%, respectively with an overall stone-free rate of 78.1%. With regard to complications, the rate of the clinic visit because of pain after treatment was observed in 4.6% and higher than 38 degrees C in 2.5%. However, no serious perioperative complications occurred. From these results, outpatient ESWL was considered to be safe and efficient without serious complications.(ABSTRACT TRUNCATED AT 250 WORDS)

Peculiarity of pulsed dye laser lithotriptor and its clinical application

Ultrasound lithotriptors (USL) and electrohydraulic lithotriptors (EHL) are representative lithotriptors for endoscopic elimination of upper urinary tract stones. However, they have some disadvantages. For example, USL can not be used with flexible scopes and EHL can cause unexpected tissue injury. To overcome these problems, the pulsed dye laser lithotriptor (MDL-1, Candera Co.) was developed. The characteristics of this laser lithotriptor and its direct effects on tissue was investigated. This pulsed dye laser lithotriptor generates a 504 nm wavelength green light beam by using a combination of a xenon flash lamp and the greenish dye composed of coumarin solution. The maximum output energy is 60 mJ/pulse and the pulse duration is 1.5 microsecond. The pulse rate can be varied from 1 to 20 Hz. First, the intensity of the shock wave was measured by using a combination of a piezoelectric element and an oscilloscope, and then, the results were compaired with those obtained by a similar experiment with an EHL. The average intensity of the shock wave was 54.4 mW under the conditions of 40 mJ/pulse of output energy and 10 Hz of pulse duration. On the other hand, the EHL generated an average of 54.7 W under the conditions of 400 mJ/pulse output energy. Then, fragmentation of various kinds of urinary stones in saline solution was performed. The results showed that this lithotriptor could fragment almost all kinds of stones except cystine stones. Then, hens eggs were used to observe the effect if laser bean influenced on the organism immediately behind the photoradiated object. Only the egg shell was demolished but the egg membrane below the eggshell did not undergo any change. After these experiments, skin, liver, kidney and urinary bladder of nude mice and human prostatic urethral mucosa in case of TUR-P were irradiated by this laser. The results showed that laser energy caused slight penetration and localized hemorrhage from the surface of epithelium to subcutaneous tissue. It was confirmed that these effects were generated when the tip of the quartz fiber was in direct contact with the object.(ABSTRACT TRUNCATED AT 250 WORDS)