Transurethral balloon laser thermotherapy for symptomatic benign prostatic hyperplasia: preliminary clinical results

Enhancement of tissue lesion depth by dual wavelength irradiation with the Nd-YAG/KTP laser: Perspectives for laser prostatectomy

The Nd-YAG/KTP laser coagulates and vaporizes prostate tissue. The objective of this study was to investigate the combined effects of both wavelengths and to determine the irradiation parameters allowing the largest lesion volume. Chicken breast tissue was irradiated ex vivo. Consecutive 1064 and 532 nm Nd-YAG/KTP laser irradiations were performed for different combinations (30 W/10 W, 20 W/20 W, 10 W/30 W) with variable total fluence (1200 J, 2400 J, 3600 J) and compared to isofluent single wavelengths at 40 W irradiation. The depths, diameters and volumes of the total lesion as well as the vaporization effects of the 532 nm wavelength on normal and on priorly coagulated tissue were analysed. Maximum total lesion depths (p< 0.001) were found under combined Nd-YAG/KTP (20 W/20 W) irradiation conditions. Ablation efficacy of the 532 nm wavelength was reduced after prior 1064 nm irradiation, but crater depths were increased. Dual wavelength irradiation with the Nd-YAG/KTP laser induces a specific denaturation process. This may represent a new approach to increase the depth of coagulation necrosis, and thus the treated volume, thereby improving long-term results.

Transurethral balloon laser thermotherapy for urinary retention in patients with benign prostatic hyperplasia who are at high surgical risk

BACKGROUND

Twelve patients with benign prostatic hyperplasia and urinary retention, who were considered to be poor candidates for prostatectomy, were treated by transurethral balloon laser thermotherapy (TUBAL-T). The mean patient age was 78.9 years (range, 66 to 93 years) and the mean duration of bladder catheterization was 11 weeks (range, 2 to 48 weeks).

METHODS

Irradiation into the prostatic tissue was done through 360 degrees with a neodymium: yttrium aluminum garnet (Nd:YAG) laser balloon placed in the prostatic urethra, with pain relief provided by using local topical anesthesia. The total laser dose was from 45,000 to 123,376 J, with an average of 73,089 J. The irradiation time was from 40 to 54 minutes, with an average of 45.2 minutes.

RESULTS

Spontaneous voiding became possible in all patients at a mean of 2.8 days (range, 1 to 7 days) after irradiation. The mean catheter-free period was 20.5 months (range, 6 to 34 months), with the longest being 34 months. The international prostatic symptom scores, quality-of-life scores, and peak uroflow rates showed substantial improvement after laser thermotherapy. To date, long-term resumption of spontaneous voiding was successfully achieved in 9 of 12 cases (75%).

CONCLUSION

TUBAL-T is safe and effective alternative for treatment of urinary retention in patients with benign prostatic hyperplasia who are considered to be at high surgical risk.