[Choice of YAG-Nd mode for conduction of interstitial laser coagulation in benign prostatic hyperplasia]

Basing on the results of fundamental and experimental investigations, we have selected the YAG-Nd laser mode for interstitial laser coagulation (ILC) of the prostate using laser unit LAMIN-1 made in Russia. The experiments were performed on cadaver prostates (3 macropreparations of human prostate 50-80 cm3 in volume). The samples were exposed to laser radiation after their immersion into 5% glucose solution. Laser worked with impulse frequency 30 Hz, power 30-50 W, time of exposure 20-50 s. In exposure 30-40 or 20 s recommended power is 30 or 40-50 W, respectively. The resultant coagulation necrosis covers 2.8-2.9 cm3, carbonized layer is absent. The above mode was used in 10 operations in 65-85-year-olds. The duration of the intervention was 10-15 min maximum. The sites were 3-5 in the lateral lobe and 2 in the middle lobe of the prostatic gland. The outcomes were followed up for 12 months. The comparison of the mean control values with those before the procedure provided the following picture after 12 months: preoperative IPSS 21.9 vs 9.3 scores postoperatively; residual urine 140 vs 30 cm3; maximum urination rate 6.7 ml/s vs 13.5 ml/s, respectively. For interstitial laser coagulation we think it valid to use high laser power and short exposure because short duration of the operation, complete hemostasis, minor lesion of the urothelium, unnecessary long-term drainage of the urinary bladder minimize the risk of intra- and postoperative complications.