Chromophore-enhanced 805 nm laser therapy for gastrointestinal neoplasia

Background: A new technique of 805 nm semiconductor diode laser-tissue inte raction potentiation using indocyanine green (ICG) as an exogenous chromoph ore has been assessed for use in the palliation of advanced gastrointestina l malignancy Materials and Methods: The tissue effects of ICG potentiated 805 nm laser w ere assessed both in-vivo using rat stomach and colon, and in vitro using n ormal and neoplastic human gastric and colonic mucosa. Results: Intravenous ICG did not potentiate the laser-tissue effects of the 805 nm laser in in-vivo studies. Local techniques of ICG application (subm ucosal injection +/- surface painting of [CG solution) enhanced the total d epth and diameter of laser induced thermal injury in all in-vitro tissues. Without ICG enhancement thermal tissue injury was minimal in normal gastric and colonic mucosa. Conclusion: Local techniques of ICG application enhance laser induced therm al injury in normal and neoplastic gastric and colonic mucosa, This may per mit targeting of 805 nm laser-tissue effects with minimal collateral damage during endoscopic laser palliation of advanced gastrointestinal malignancy . (C) 2001 Harcourt publishers Ltd