Laparoscopic interstitial contact laser ablation of renal lesions: an experimental model

Tissue ablation with the interstitial Nd:YAG contact laser is a rapidly evolving technique. The urologic applications of interstitial lasers have not been fully investigated. We developed a model to test the feasibility of using interstitial laser energy, administered under laparoscopic guidance, to ablate porcine renal tissue. Utilizing a synthetic sapphire interstitial Nd:YAG contact probe, minimal tissue effects were observed using total energies between 120 and 240 J. At energies of 480 J (8 W/60 seconds), there was predominantly coagulation necrosis of the renal parenchyma. At 720 J (12 W/60 seconds), there was pronounced tissue vaporization surrounded by a zone of coagulation necrosis approximately 1.5 cm across. This preliminary investigation demonstrates that the interstitial Nd:YAG contact laser probe can be used for both controlled coagulation necrosis and vaporization of renal parenchymal tissue. This approach may be applicable to the laparoscopic ablation of small renal lesions in selected patients.