A total of 46 cases underwent 66 treatments with extracorporeal microexplosive
lithotripsy (EML) for upper urinary tract
calculi between March 10, 1987 and May 28, 1987. The efficacy of EML
therapy was investigated in all cases over 3 months. The lithotripter of EML made by the Yachiyoda Co. Ltd (SZ-1) was adapted to a microexplosion (10 mg
silver azide) as the source of energy for underwater
shock wave generation. Fifteen cases (32.6%) had a history of previous open lithotomy of the same upper urinary tract as being treated by EML. Pre-treatments with
ureteral catheters and ureteral
stents were performed in 4 and 4 cases (8.7% and 8.7%), respectively. The microexplosions were conducted in syncronization with patient exhalation from 100 to 400 times during 1 session, depending upon the size of the stone. The patients felt pressure only on their back at the pulse of explosion and complained occasionally a dull
pain, but this
pain was mild and tolerable, and no patients required
anesthesia. When stone disintegration was judged to be unsatisfactory, that is the stone remained unfragment or the size of the residual stone fragments was greater than 5 mm., an additional session was performed, usually 1 week after the previous session. On the
X-ray film obtained three months after EML treatment, 26 cases (57%) were completely free from stone concerments, 17 cases (37%) had stone fragments of equal to or less than 5 mm and 3 cases (6%) had ones of greater than 5 mm. Treatment of EML alone was performed in 44 cases (96%), while 2 cases (4%) required transurethral stone manipulation following EML.(ABSTRACT TRUNCATED AT 250 WORDS)