Application of hollow glass waveguides in urological treatment

The application of specially designed delivery system consisted of cyclic olefin polymer coated silver hollow glass waveguide (inner/outer diameter 700/850 μm) with protector in one side and sealed cap in the output is shown for treatment of ureter wall perforation by Er:YAG laser radiation. For this purpose Er:YAG laser system (wavelength 2.94 μm) working in free-running and Q-switched regime was utilized. The basic characteristic of the interaction of Er:YAG laser radiation with the ureter surface and its deep structures was found. Maximum interaction pulse energy and length in free-running regime were 100 mJ and 200 μs, respectively (corresponding intensity 130kW.cm-2). Maximum interaction pulse energy and length in Q-switched regime were 30 mJ and 70 ns, respectively (corresponding intensity 111 MW.cm-2). From the histological evaluation it follows that the application of Q-switched Er:YAG laser radiation on ureter tissue resulted in minimum tissue alteration without any influence on the deeper layers.

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