ADRIAMYCIN ABSORPTION AFTER ND-YAG LASER COAGULATION COMPARED TO ELECTROSURGICAL RESECTION OF THE BLADDER WALL

The toxicity of intravesical drugs used for the treatment of bladder cancer is increased by systemic absorption. Therefore, treatment is often delayed several weeks after transurethral resection until sufficient healing occurs. Since a neodymium:YAG laser causes tissue injury by thermal coagulation, we investigated differences in bladder permeability after laser treatment compared to TUR. Comparable 2.5 cm in diameter areas of tissue injury were created in the bladder of mongrel dogs either by Nd:YAG laser coagulation or transurethral electrocautery resection (TUR). Subsequently, 30 mg. of adriamycin were instilled intravesically. A control group consisted of animals receiving adriamycin alone. Blood was taken at 10, 30, 60, and 120 minutes after instillation and the serum concentration of adriamycin measured quantitatively by high performance liquid chromatography (HPLC) with fluorescence detection. The maximum serum ADM concentration during 120 minutes for the control group was 28.0 +/- 12.9 ng/ml compared to 38.9 +/- 4.8 for the laser group and 102.9 +/- 29.9 for TUR. The area under the curve was 35.1 +/- 10.2 ng x hours/ml for control, 43.5 +/- 3.9 for laser and 127.7 +/- 49.9 for TUR. Using a two-tailed Student's test, the difference between the TUR and the laser group was significant (p < 0.01). There was no difference between laser and control. These results suggest that laser treatment has minimal effect on the absorption of drugs from the bladder. The clinical practice of delaying intravesical therapy after TUR is verified but a similar policy may not be necessary after laser treatment.