Stone incrustation: a relevant complication of the intraprostatic spiral

Six high operative risk patients with urinary retention caused by benign prostatic hyperplasia were managed with an intraprostatic spiral at our hospital. Three of them had severe coronary artery disease, 1 had uremia, 1 had cerebral stroke and 1 had poorly controlled diabetes mellitus. The urinary retention was successfully relieved by the intraprostatic spiral in all patients. No operative mortality or severe complication was encountered. One patient experienced a repeat attack of urinary retention due to proximal migration of the spiral. Four patients complained of urgency, which was relieved by anticholinergic agents. Stone incrustation was found on 2 out of 3 spirals removed (66%), and the stone turned out to be calcium phosphate and struvite by scanning electron microscopy and infrared spectrophotometry. In 1 patient, stone formation was so abundant that it almost obstructed the lumen of the redundant tip of the spiral. From our preliminary results, the intraprostatic spiral seems to be a good alternative to an indwelling catheter for patients awaiting prostatectomy. Nevertheless, the potential complication of stone incrustation should be anticipated and it is suggested to remove the device as soon as possible or to replace it at regular intervals.