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.
Schmidlin
F
F
Clinic of Urology, Department of Surgery, University Hospital of Geneva (HCUG), Geneva, Switzerland.
Delacrètaz
G
G
Oswald
M
M
Iselin
C
C
Jichlinski
P
P
Mermillod
B
B
Lemoine
R
R
Leisinger
H J
HJ
Graber
P
P
Urology. 1994 Jun;43(6):813-20
7515205
J Urol. 1993 Jul;150(1):95-9
7685429
J Urol. 1995 Jan;153(1):94-7; discussion 97-8
7526006
J Endourol. 1993 Aug;7(4):333-6
7504551
Br J Urol. 1992 Jun;69(6):603-8
1379101
J Urol. 1990 Feb;143(2):398-401
2299739
J Endourol. 1995 Apr;9(2):199-203
7633479
Lasers Surg Med. 1995;17(1):49-58
7564856
Br J Urol. 1994 Mar;73(3):225-30
7512883
Eur Urol. 1993;23 Suppl 1:60-2
7685699
J Endourol. 1995 Apr;9(2):145-9
7543325