Cutting characteristics of the Nd: YAG contact technique using a laser with tissue effect control, conical fibres and a normal bare fibre: First results of a physical, morphometrical and clinical study

Summary

In the present study, a Nd : YAG laser with tissue effect control (MediLas 4060-N-Fibertom, Dornier-Medizintechnik, Munich) and two newly developed conical bare fibres (Sharplase Conical Fibers, Sharplan Lasers, Freising) were used and the cutting effect compared to that of a conventional bare fibre. Methodology: The two conical fibres had a body diameter of 600 and 800 μm, a 400 μm bare fibre served as a reference. In the first step, radiation geometry was physically measured. Subsequently, in an in vivo experiment, linear uterotomies were performed on Wistar rats with the three types of fibres and the tissue effect control system at an initial power output of 10, 15 and 20 W. Serial cuts were HE-stained and the zones of tissue damage evaluated with the Cue-2 Image Analysis System. In the third step, operative hysteroscopies and laparoscopies were performed. Results: Physical measurements showed a characteristic radiation profile for each fibre. The tissue effect control system prevents melting of the distal end of the fibre in case of non-contact handling, but does not significantly improve tissue effect (P lt; 0.001). Both conical bare fibres resulted in considerably increased cutting depth while the zones of tissue lesion were significantly reduced as compared to the 400 μm control fibre (P lt; 0.001). Clinical application confirmed the cutting properties established in the experimental phase.

Key Words:

• Nd: YAG laser
• contact technique
• tissue effect control
• conical fibre
• thermal tissue damage