In vitro comparison between argon beam coagulator and Nd:YAG laser in lung contraction therapy

Background. The Argon Beam Coagulator (ABC) and neodymium: yttrium-aluminum garnet (Nd:YAG) laser are used for lung tissue contraction. Assessing the damage of treated lung tissue is helpful in choosing devices for pulmonary volume reduction by pneumoplastic procedures. Methods. We assessed the damage of in vitro lung lobes resected at operation for pulmonary carcinoma. Samples were irradiated with noncontact Nd: YAG laser and ABC. One hundred forty-four samples obtained from 24 lobes were examined by light microscopy. The lung tissue showing destructive degeneration at the pleura and slight coagulation at the residual parenchyma was defined as showing “air leak pattern” based on a previously reported experiment of the air inflation test. Results. At the power of clinical use (Nd: YAG, 15 W; ABC, 80 W), most of the visceral pleura treated with the Nd: YAG laser was classified as presenting amorphous degeneration, and that treated with ABC showed destructive degeneration. Air leak pattern occurred in all samples treated with ABC. At the power of 40 W, ten (42%) of 24 visceral pleuras irradiated with the Nd: YAG laser were classified as presenting destructive degeneration, and of those irradiated with the ABC, 18 (75%) showed destructive degeneration (p < 0.05). Air leak patterns were found in 3 (13%) of the samples treated with the Nd: YAG laser and in 16 (63%) of those treated with the ABC (p < 0.05). Conclusions. The ABC had more potential to damage the pleura and less potential to produce underlying parenchymal coagulation in the lung tissue than did the Nd: YAG laser. This information may be useful in the selection of devices for pulmonary volume reduction by pneumoplastic procedures.