Tissue effects of neodymium:YAG laser photoradiation of canine ureters

Although the entire ureter and renal collecting system are accessible for endoscopic treatment with a neodymium:YAG, (Nd:YAG) laser, specifications for safe laser application within the ureter are not established. After various doses of Nd:YAG laser energy were delivered, the midureters of six mongrel dogs were studied to determine tissue effects. Doses which are appropriate within the bladder (35 watts X 2 seconds) resulted in perforation and urine leak from the ureters. Higher doses (60-65 watts) of short duration were tolerated without problems and nonstrictured healing ensued. Further studies are necessary before Nd:YAG laser treatment of mid-ureteral tumors is recommended.