Transurethral Laser Surgery of Prostate using Lateral Firing Fiber

Abstract

Animal experiment was performed with seven male dogs weighing between 21 and 25 kg, under general anesthesia, with pentobarbital sodium (25mg/kg). A midline lower abdominal incision was made to expose the urinary bladder. 23Fr conventional cystoscope was introduced into the prostatic urethra via cystostomy. The entire operative procedure was observed under TV monitor. Laser irradiation was begun linearly from proximal to the apex of the prostate using Hercules 5060U^TM and Model 6000^TM Nd: YAG laser (LaserSonics) and UltraLine^TM (LaserSonics) fiber which delivered 50 watts of power for 20, 30, 40 and 60 seconds at 3, 9 o'clock. Animals were killed immediately, and at 2, 4, and 6 weeks after the operation. The bladder, prostate and urethra were carefully examined and removed. Specimens were cut into transverse step-section. As the results, thermal coagulation necrosis and delayed sloughing were observed usually several weeks after the procedure. The prostatic urethral cavity was covered with transitional epithelium in the later stage. Clinically 27 male patients underwent laser operation. Their ages ranged from 53 to 80 years of age. The present study selected the patient with below 15 ml/sec in peak flow rate (uroflometry), above 20 gram prostate volume (transrectal ultrasound) and above 15 points in AUA Symptom Score, and excluded the patient with prostatic cancer and neurogenic bladder. The used instrument was the same as those used in the animal experiment. The laser prostatectomy was carried out with standard lithotomy position under spinal anesthesia. The laser was employed at four radial regions (2,4,8 and 10 o'clock positions), additionally to 3,5,7 and 9 o'clock position, with the fiber being dragged from the bladder neck to the verumontanum. The laser was set at 50 watts power on continuous wave. The drag rate was from 30 to 60 seconds. Clinical efficiency was determined by peak flow rate, residual urine, AUA Symptom Score, prostatic volume and side effect. The total evaluation was divided into 3 grades (useful, slightly useful, not useful). According to the criteria, laser surgery was classified as useful in 11 (68.8%). As the side effect, 13 patients revealed urinary retention and one patient showed acute epididymitis after the operation.