Contact laser-assisted neuroendoscopy can be performed safely by using pretreated 'black' fibre tips: Experimental data

Background and Objective: Laser-assisted endoscopic neurosurgery by using c onventional fibres requires the use of high-power laser light. Because this is potentially hazardous, we developed a pretreated fibre tip and evaluate d tissue effects in vitro and in vivo. Study Design/Materials and Methods: By applying a highly absorbing coating to the front of the ball tip, almost all laser light is transformed into th ermal energy, instantly producing ablative temperatures at the tip itself. The temperature distribution was examined by using an in vitro thermal imag ing technique. The in vivo effect on rabbit cerebral tissue was examined ma croscopically and histologically. Results: By using a conventional fibre tip, ablation was not observed, desp ite the use of high energy and power (20 W for 10 seconds), whereas histolo gy and thermal imaging demonstrated deleterious effects deeply into the cer ebral tissue. By using the coated fibre tip, ablation was observed at low e nergy and power(1 W for 1 second) with thermal effects restricted to superf icial structures. Conclusions: We show that laser-assisted neuroendoscopy can only be conside red to be safe when pretreated "black" fibre tips are used, as laser light damages deep structures. Lasers Surg. Med. 28:324-329, 2001. (C) 2001 Wiley -Liss, Inc.