Artificial sapphire contact probes in Nd:YAG endometrial ablation: a quantitative in vitro and in vivo study

Artificial sapphire contact probes offer theoretical advantages in Nd:YAG endometrial ablation. To examine this, an in vitro and in vivo study of laser-tissue interaction was performed. In vitro, a linear correlation was found between applied energy and total depth of effect, that is, photovaporization and photocoagulation. Using a Round (MTR 1.5) contact probe, an applied energy of 30 joules gave a depth of myometrial effect of 3.3 mm. In vivo, there was a significant reduction in tissue effect (p less than 0.001) compared to in vitro. Difficulty of manipulation of the contact laser probe within the uterus also caused a significant reduction (p less than 0.001) in depth of tissue ablation achieved on the posterior uterine wall compared with that achievable at the uterine fundus, but this may be counteracted by increasing applied energy.