FIRST EXPERIENCE WITH THE MEMOTHERM STENT IN THE TREATMENT OF BPH

We report our experience with a new thermosensitive stent (Memotherm), which has been invented recently as an alternative method for treatme nt of benign prostatic hyperplasia. The wall of this stent is a thermo reactive mesh made of nitinol, which reaches its maximum force of expa nsion at body temperature. Its high degree of flexibility allows the M emotherm stent to fit the natural course of the prostatic urethra. Thi s stent is available in different sizes between 2 and 8 cm to meet the demand for different lengths of prostatic urethra. Furthermore, the m eshed structure of this stent allows its atraumatic removal. From Apri l 1992 to September 1993, 54 consecutive patients with benign prostati c hyperplasia had Memotherm stents inserted. The mean patient age was 76.1 years (range 61-98 years). Patients were considered suitable for treatment with the Memotherm stent when they presented with a poor ope rative risk. Mean prostatic volume was 51.9 +/- 25 mi (20-150 mi), and on average a stent measured 32.3 +/- 9.5 mm (20-70 mm). Preoperativel y, only 14 patients (26 %) were able to void, and 40 patients (74 %) h ad had a transurethral or suprapubic catheter placed. After placement of the Memotherm stent, 53 of 54 patients were able to void. In the pa tients who were able to void preoperatively, the mean maximum flow rat e increased from 4.5 ml/s to 15.8 ml/s within the first 6 months after treatment. Within the same period of time, the mean residual urine vo lume decreased from 194.4 mi to 11.8 mi, and the AUA 6-Symptom Score i mproved from 24 to 3.5 points. All differences are statistically signi ficant (P < 0.02). In the patients who were unable to void preoperativ ely, the mean maximum flow rate was 14.8 ml/s and the mean residual ur ine volume was 14.8 mi 6 months after stent placement. The AUA 6-Sympt om Score improved from 25 to 3.9 points (P < 0.02) within the first 6 months after treatment. There was no statistically significant differe nce between the two groups of patients. Apart from 1 patient suffering from epididymitis after stent placement no significant complications have been observed. Of the 54 patients. 30 (55.5%) complained of urgen cy, which usually vanished spontaneously within 1 week. In our experie nce, insertion of the Memotherm stent is a convenient and effective me thod of treating benign prostatic hyperplasia in patients with poor op erative risk.