Vascular Supply of Pulmonary Metastases

Abstract

Four tumors (Walker 256 sarcoma, fibrosarcoma, adenocarcinoma and rhabdomyosarcoma) were implanted into the tails of four groups of rats and pulmonary metastases were induced by injecting cells from the primary tumors into the rat's tail vein. When pulmonary metastases had developed, the circulatory patterns of primary and secondary tumors were compared and the source of vascular supply to the pulmonary metastases identified by “lethal” microangiography. The pulmonary metastases were supplied by pulmonary circulation in 48%, bronchial circulation alone in 16% and by mixed pulmonary and bronchial circulation in 36%. Highly vascularized primaries had very vascular metastases. Where the metastases had apulmonarycirculation, the circulatory pattern duplicated that of the primary but no characteristic circulatory pattern could be found in metastases supplied by the bronchial circulation alone.