Tohoku J. Exp. Med., 1998, 185 (2)

Experimental Ablation of Emphysematous Rat Lung with Nd: YAG Laser: Lung Changes Studied by Histopathology and SEM

TSUTOMU AKAHANE,1,2 YOSHIMOCHI KUROKAWA,2 HIROSHI YAEGASHI,1 SUSUMU SATOMI2 and TOHRU TAKAHASHI1

1Department of Pathology, Institute of Development, Aging and Cancer, Tohoku University, and 2The Second Department of Surgery, Tohoku University School of Medicine, Sendai 980-8574

  • Laser ablation has been employed as a therapeutic measure for chronic pulmonary emphysema. As yet, however, its effect is not understood on firm pathological basis. We aimed to study, both histopathologically and using Scanning Electric Microscopy (SEM), the changes produced by irradiation with contact Neodymium-yttrium aluminum garnet laser (Nd: YAG laser) in rat lungs with experimentally induced emphysema. Emphysema was produced in 34 rats by instilling elastase via airways. Eight weeks after the instillation, the emphysematous left lung was irradiated under thoracotomy with contact Nd: YAG laser at a power of 5 watts. The animals were sacrificed in acute as well as chronic phase for histopathological observation of lung and scanning electron microscopy. Laser caused necrotic and inflammatory changes in the subpleural zone of lung. Immediately after irradiation, the alveolar septa were destroyed as visualized by SEM, only leaving the elastic skeleton. In a chronic phase, the necrotic zone was collapsed and replaced with a thick fibrous scar which seemed to serve more or less to keep the organ from being excessively inflated. In this model, irradiation induces subpleural dense scarring, which, by "encasing" an emphysematous lung, is expected to more or less normalize the excessive compliance.
    Key words--- laser ablation; histopathology; scanning electron microscopy; experimental emphysema
    © 1998 Tohoku University Medical Press

    Tohoku J. Exp. Med., 1998, 185, 119-129
    Address for reprints: Tsutomu Akahane, M.D., Department of Pathology, Institute of Development, Aging and Cancer, Tohoku University, 4 Seiryomachi, Aoba-ku, Sendai 980-8574, Japan.

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