THE TITANIUM INTRAPROSTATIC STENT - THE UNITED-STATES EXPERIENCE

This multicenter, cooperative study represents, the initial United States experience using an expandable, titanium intraprostatic stent in 68 patients (60 to 93 years old). The stents were inserted under direct vision and expanded to 33F using a balloon catheter. All patients had a symptom score analysis, and underwent measurement of peak urine flow and rate and post-void residual urine volume as part of the initial evaluation. Patients were seen at approximately 1, 3, 6 and 18 months after stent insertion (mean followup 16 months). Of the 68 patients 38 presented in urinary retention. The type of anesthesia used included general anesthesia in 6 patients, spinal or epidural anesthesia in 24, intravenous sedation in 20 and intraurethral lidocaine only in 18. All patients were able to void spontaneously within 36 hours after stent insertion. Symptom scores decreased from 16.8 to 3.9, 6.3, 5.0, 5.7 and 3.2 at approximately 1, 3, 6, 12 and 18 months, respectively. Peak urine flow rate increased from 3.9 to 13.8, 11.5, 11.2, 12.4 and 14.4 ml. per second at approximately 1, 3, 6, 12 and 18 months, respectively. Post-void residual urine volume decreased from 74.4 to 30.1, 29.2, 19.8 and 40.2 ml. at approximately 1, 3, 6 and 12 months, respectively. Of the initial 68 patients 5 died of the underlying disorder (all voiding satisfactorily with the stent in place) and 17 underwent uneventful stent removal (10 for technical failure and 7 for treatment failure). Technical failures were secondary to either inaccurate positioning or improper stent sizing. Of the 58 patients with proper placement of the stent and no technical failures 46 (79%) had improvement in symptom scores and urine flow rate. Transient hematuria was noted in 43 patients (63%) and usually resolved within 48 hours. None of the 6 urinary tract infections (9%) was recurrent. In conclusion, the titanium intraprostatic stent, when properly placed, is a promising therapeutic alternative to prostatectomy or long-term catheterization in high risk obstructed patients or those in urinary retention. Studies are currently in progress to determine the long-term efficacy of this therapeutic modality.