Tetsuo Matsumoto

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.

Primary signet-ring cell carcinoma of the urinary bladder inducing renal failure

Abstract A case of primary signet‐ring cell carcinoma of the urinary bladder that was found to have induced renal failure is the second such case reported in the world. Primary signet‐ring cell carcinoma of the urinary bladder is a rare histologic variant of adenocarcinoma. The patient died of distant metastasis 8 months after undergoing total cystectomy. The neoplasm had a high stage at diagnosis, so the prognosis was very poor. To improve the prognosis, earlier diagnosis and establishing a regimen of chemotherapy is necessary.

HISTOLOGICAL EVALUATION OF ENUCLEATION FOR RENAL CELL CARCINOMA USING RADICAL NEPHRECTOMY SPECIMENS

Radical nephrectomy was performed in 30 cases of renal cell carcinoma in which CT scan and angiography findings had indicated the possible suitability of enucleation. The lesions were then enucleated from the operative specimens and assessed histologically to find the feasibility of tumor enucleation and to determine its indications. Histological investigation demonstrated that the tumor was completely surrounded by the pseudocapsule in only 17 cases, and even in such tumors the thickness of the pseudocapsule was not always regular and sometimes tumor invasion was seen in the pseudocapsule. It is therefore advisable to resect the tumor with no less than several mm of surrounding renal tissue when the pseudocapsule can not be clearly distinguished. Success of the enucleation was confirmed histologically in 22 out of 30 cases (73.3%). The factors related to failure of the enucleation were invasion throughout the renal capsule in 2, tumor exposure on the resected surface in 5, residual tumor in the tumor bed in 2 and venous invasion in 6 cases. Satellite tumors were not detected in any case. Favorable results were obtained in low grade, low stage tumors less than 6 cm in diameter and clearly distinct from normal renal tissue, therefore such cases were thought to be appropriate indications for enucleation. Although we selected the cases thought to be appropriate for enucleation by imaging techniques preoperatively, success was not obtained in all cases. Enucleation is a useful and recommendable operative technique for bilateral renal cell carcinoma or renal cell carcinoma in a solitary kidney.(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)