Experimental study of a closed-chest pulmonary embolism-reperfusion injury canine model by means of Swan-Ganz catheter / 中华放射学杂志

ABSTRACT

Objective To establish a closed-chest pulmonary embolism-reperfusion animal model by Swan-Ganz catheter and to explore the mechanisms of pulmonary embolism(PE)-reperfusion injury(RI). Methods Experiments were made on 14 mongrel dogs,ranging in weight from 15 to 18 kg,anesthetized with 3% pentobarbital sodium.The dogs were intubated with I.D.7 endotracheal tubes.Under sterile conditions,a 7 F Swan-Ganz catheter via the external jugular vein was positioned in the unilateral pulmonary diaphragmatic lobe(DL)artery.Occlusion/reperfusion of the DL artery was controlled with 1.2 ml diluted contrast agent filled into/drawn from the balloon.After the 24 h PE,the balloon was deflated to result in 4 h reperfusion of the DL.Measurements of blood gases and tumor necrosis factor-?(TNF-?)were made at normal condition,at 24 h PE and at 4 h reperfusion.Thin-section CT scans were performed at normal condition,24 h PE,30 min,1,2,3 and 4 h reperfusion,respectively.At the end of each experiment, tissue specimens of bilateral diaphragmatic lobes were obtained for both wet/dry(W/D)weight ratio and for pathological study.Results Reperfusion pulmonary edema(RPE)was an acute,mixed,noncardiogenic edema that was observed in all 14 dogs who had been successfully established as PE/RI animal models.RPE demonstrated heterogeneous ground-glass opacifications that predominated in the areas distal to the recanalized vessels.It manifested pathologically as an edematous lung infiltrated by inflammatory cells.The mean ofPaO_2 and TNF-? of 4 h reperfusion was(81?4)mm Hg(l mm Hg=0.133 kPa)and(16.0? 2.5)pg/ml,which were significantly different(P