Establishment of a large animal model for research on transbronchial arterial intervention for lung cancer

PURPOSEWe aimed to evaluate whether bronchial artery can supply a percutaneously inoculated canine transmissible venereal tumor (CTVT) in a lung tumor model.METHODSFresh CTVT tissue blocks were percutaneously inoculated into unilateral or bilateral lungs of six immunosuppressed dogs at the mid zone of the middle or lower lobe. Tumor growth was monitored by computed tomography (CT). Ten weeks after inoculation, pulmonary arterial digital subtraction angiography (DSA), bronchial arterial DSA, transpulmonary arterial contrast-enhanced multislice CT, transbronchial arterial contrast-enhanced multislice CT (BA-MSCT), and transpulmonary arterial lipiodol multislice CT were performed.RESULTSTumor growth was seen in all 10 inoculated sites, with a maximum diameter of 2.734±0.138 cm at 10th week. Bronchial arterial blood supply was evident in 9 nodules on DSA, and was equivocal in one which was later demonstrated on BA-MSCT. No obvious pulmonary arterial blood supply was observed in any of the nodules. Lipiodol deposition was displayed in two of the small distant metastases, which indicated that pulmonary artery was involved in the supply of the metastases.CONCLUSIONOur results demonstrated bronchial arterial blood supply in this new lung cancer model. This model may be used in further research on transbronchial arterial intervention for lung cancer.

Bronchial arterial infusion chemotherapy (BAI) for lung cancer was introduced into clinical practice 50 years ago (1–3). Theoretically, better reductions in tumor size and symptoms, and less adverse effects of anticancer drugs could be achieved with direct infusion of high-density chemotherapeutics into tumors. However, BAI for lung cancer is not widely accepted. In the last two decades, only a few small case series were published in the English literature showing favorable results (4–9). This may be explained by several reasons: the outcomes have not been confirmed, severe complications have been reported (10, 11), the pharmacokinetics of BAI has not been fully understood, the indications and the treatment protocols have not been defined (4, 12). In the near future, the role of BAI or other transbronchial arterial therapy in the combined treatment of lung cancer may be reappraised, given the poor 5-year survival rate of less than 17% despite improvements in therapeutic management (13).Unfortunately, there is currently no large animal lung cancer model for fundamental research on transbronchial arterial therapy. In 2002, Ahrar et al. (14) developed a canine lung tumor model by intra-arterial or percutaneous inoculation of canine transmissible venereal tumor (CTVT) fragments, which was later used for study on percutaneous radiofrequency ablation (15). It is well known that metastatic lung cancer receives blood supply from both pulmonary artery and bronchial artery, with peripheral tumors having a predominant pulmonary circulation and central tumors having a predominant bronchial circulation (16). Our study goal is to evaluate the blood supply of this large animal lung tumor model.