[Initial experiences with the Memotherm Stent in treatment of benign prostatic hyperplasia].

We report our experience with a new thermosensitive stent (Memotherm), which has been invented recently as an alternative method for treatment of benign prostatic hyperplasia. The wall of this stent is a thermoreactive mesh made of nitinol, which reaches its maximum force of expansion at body temperature. Its high degree of flexibility allows the Memotherm stent to fit the natural course of the prostatic urethra. This stent is available in different sizes between 2 and 8 cm to meet the demand for different lengths of prostatic urethra. Furthermore, the meshed structure of this stent allows its atraumatic removal. From April 1992 to September 1993, 54 consecutive patients with benign prostatic hyperplasia and 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 operative risk. Mean prostatic volume was 51.9 +/- 25 ml (20-150 ml), and on average a stent measured 32.3 +/- 9.5 mm (20-70 mm). Preoperatively, only 14 patients (26%) were able to void, and 40 patients (74%) had had a transurethral or suprapubic catheter placed. After placement of the Memotherm stent, 53 of 54 patients were able to void. In the patients who were able to void preoperatively, the mean maximum flow rate 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 volume decreased from 194.4 ml to 11.8 ml, and the AUA 6-Symptom Score improved from 24 to 3.5 points. All differences are statistically significant (P < 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)