OBJECTIVETo investigate the effects of cryoablation on different bronchi of normal pigs and provide experimental bases for the potential clinical application of this technique.

METHODSSix normal pigs were divided into two groups and subjected to percutaneous cryoablation of the lung tissues. Three pigs were sacrificed on day 3 (group A) and another 3 on day 28 (group B) after the ablation, and the morphology and volume of the ablated areas and the pathological changes in different bronchi.

RESULTSIn group A, examination of the biopsy samples taken 3 days after the ablation revealed significantly greater maximal longitudinal (t=9.789, P=0.000) and transverse (t=3.253, P=0.023) diameters of the area of freezing damage than those observed immediately after the cryoablation. The diameters of the freezing damage area in group B were significantly smaller than those in group A (t=7.227, P=0.000; t=6.006, P=0.001). The freezing damages to the bronchi worsened with the reduction of the bronchial lumen; the damages to the major bronchi and the second-order bronchi were relatively slight, which also showed better recovery 28 days after the ablation.

CONCLUSIONCT-guided percutaneous cryoablation does not produce serious effects on the major bronchi and the second-order bronchus, and can be a minimally invasive therapy for lung tumors with good tolerance and safety.