Kazumi Etori

Microwave surgical treatment of diseases of prostate

A new transurethral probe for microwave radiation of the prostate has been developed. As a preliminary experiment, sliced ham was radiated with microwaves using this probe in order to evaluate the extent of thermal effect. Using mongrel male dogs, microwave coagulation of the prostate was examined. These animal experiments showed marked destruction of the prostate gland. Furthermore, the safety of this method was confirmed on the basis of results from the experiments. Prostatic bladder neck obstruction also has been treated in 6 patients with benign prostatic hypertrophy or carcinoma of the prostate by this technique. There has been no mortality and also no complications. The results of this preliminary clinical trial have been excellent.

Microwave Surgical Treatment of the Prostate: Clinical Application of Microwave Surgery as a Tool for Improved Prostatic Electroresection

Microwave surgery as a tool for improved prostatic electroresection is introduced. Prior to electroresection the prostate was coagulated with 2,450 MHz of microwave which was emitted from the bipolar electrode of a specially designed probe. We conducted a comparative study of 35 patients with bladder neck obstruction. There was a microwave coagulation group treated with subsequent transurethral resection (TUR) and a conventional TUR group. Both groups were analyzed for the amount of blood loss, irrigant absorption and the frequency of complications. Both during and following surgery, the former group had a significant reduction in blood loss and had no complications. We conclude that the combination procedure of microwave coagulation and TUR can minimize the disadvantage of formal TUR and may be of value in the treatment of patients with both prostatic obstruction and of hemorrhagic diathesis as well as in high risk patients.

Microwave Coagulation Therapy for Urinary Bladder Tumors

A new device has been developed for microwave coagulation of urinary bladder tumors. Twenty-one patients with urinary bladder tumors were treated by irradiation with microwave energy of 2,450 MHz. Results were obtained as follows: (1) microwave coagulation was performed in 21 patients with transitional cell carcinoma of the urinary bladder. Excluding 4 patients who subsequently received radical cystectomy, 17 patients showed a complete response, although 2 patients subsequently developed recurrences in different parts of the bladder within the following several months. Histological examination of the excised specimen revealed complete eradication of the tumor in 2 patients. In the remaining 2 patients with high-stage tumor (T4), viable tumor cells were noted in the urethra or vaginal wall. (2) Although neither technical difficulties nor severe complications were encountered, transient urinary frequency and calcification of the bladder wall were noted. The results of this study indicate that microwave coagulation may be used in the treatment of both superficial and invasive tumors.

Intraoperative real-time ultrasonic scanning for microwave coagulation of the prostate

Nine patients with severe dysuria caused by prostatic cancer received prostatic microwave coagulation under intraoperative real-time ultrasonic scanning. During the procedure, the microwave applicator was clearly observed, and the coagulation region appeared as an hyperechoic area compared to the noncoagulated region. Intraoperative real-time ultrasonic scanning allowed safer and more efficacious application of prostatic microwave coagulation.

Remote Afterloading Transurethral Radiotherapy for Prostatic Cancer

We have developed a technique of transurethral radiotherapy for prostatic cancer using a remote after-loading system. The radioactive source is a cobalt-60 pellet with 3.7-Ci activity. Four patients with adenocarcinoma of the prostate were treated. In all patients, the local tumor response was rapid and satisfactory as judged by physical examination as well as ultrasonography. Serious complications were not seen. A new technique and preliminary clinical results are reported.

Combination Therapy with Microwave Coagulation and Intracavitary Irradiation for Bladder Cancer

Twenty-five patients with transitional cell carcinoma of the bladder have been treated with combined therapy consisting of microwave regional coagulation and intracavitary irradiation. A remote-controlled after-loading system was utilized for the radiation therapy. The follow-up period ranged from 6 to 19 months with an average of 11.4 months. Tumor stages were Tis (n = 2), Ta or T1 (n = 17), T2 (n = 2), T3 (n = 3) and T4 (n = 1), and grades were G1 (n = 10), G2 (n = 11) and G3 (n = 4). In 23 patients (92%), there was no endoscopic or histologic evidence of tumor after the initial treatment. Heterotopic recurrences were found after 2 or 3 months in 3 patients who received microwave regional coagulation or intracavitary regional irradiation. Additional intracavitary whole bladder mucosal irradiation was performed for 10 patients with multiple tumors and frequent recurrent tumors. Nine patients had no recurrence (average follow-up 11 months). Our preliminary findings indicate that combination therapy of microwave coagulation and intracavitary irradiation is a useful treatment for bladder cancer.

Microwave regional coagulation therapy for outpatients with recurrent, superficial bladder cancer

From April 1988 to June 1995, we performed microwave regional coagulation therapy (MRCT) with suspicious recurrent bladder tumors, immediately after bladder biopsy under epidural anesthesia 24 times in 17 outpatients. Of the 17 cases, both clinical and pathological examinations revealed that 14 cases were of recurrent, superficial bladder cancer. Tumors were completely eradicated both endoscopically and histologically in all patients. Four had a slight hematuria or lower abdominal pain after MRCT. These complications, however, improved in a few days after medication. Furthermore, the cost of outpatient MRCT was one third that of the transurethral resection of bladder tumor in hospital treatment, which required a 3 day admission. Outpatient MRCT could be one of several safe and useful treatments for patients with recurrent bladder cancer.

[Urethral compliance and cross sectional area measurement--clinical study of male patients with lower urinary tract dysfunction].

Distributions of urethral compliance, closure pressure and cross sectional area were measured in 12 male patients with lower urinaly tract dysfunction, including 5 individuals without urological disorder, through a new instrument based on a field gradient principle. The following results were obtained. 1) Normal male;the urethral compliances were 0. 071-0. 11 cm 3/mmHg at the proximal segment higher than the other segment, 0. 034-0. 056 cm3/mmHg at the external sphincteric urethra and 0. 0280. 036 at the distal segment. The urethral closure pressure was 40. 4-52. 7 mmHg at the external sphincteric urethra, which was the highest in the urethra. The maximum urethral cross sectional area was 1. 2-1. 83 cm2 at the proximal segment, 1. 1-1. 6 cm2 at the external sphincter and 1. 1-1. 4 cm2 at the distal segment. 2) In patients with benign prostatic hypertrophy, the urethral compliance was almost the same as in normal men, but the maximum urethral cross sectional area was smaller than that of normal individuals. 3) In patients with prostatic cancer, the urethral compliance was significantly low, the cross sectional area was also small and urethral closure pressure was high. 4) The urethral closure presure was 0-25. 6 mmHg in patients with incontinence, which was lower than other individuals.

Impedance Urine Bolusmetry (bolus volumeおよびfrequency測定) による腎孟尿管機能の評価

New equipment based on field gradient principle for measurement of cross sectional area of ureteral urine bolus has been developed. Inside the probe consisted of a Fr.4 ureteral catheter, there are 4 ring impedance electrodes and a bipolar ring ureteromyographic electrode. Ex vivo experiments has proved high values in reliability and reproducibility of obtained cross sectional area of urine bolus through an impedance method. Following results have been obtained through animal and clinical experiments. As urine bolus passed through the impedance electrodes, impedance represented the cross sectional area of urine bolus. The ureteral activity corresponded to the increase of urine flow changed as follows, ureteral peristaltic frequency increased, cross sectional area of urine bolus increased, length of urine bolus increased, during maximum diuresis, peristaltic activity diminished and continuous flow presented through ureteral column. It will be useful method for experimental or clinical evaluation of ureteral function.