The Influence Of Functional Pulmonary Lobectomy On Hemodynamics In Dogs

Objective To establish animal model of functional pulmonary lobectomy(FPLT) and to study the influence of FPLT on hemodynamics in dogs and to investigate its pathogenesis by observing the changes of hemodynamics and morphology of the lungs in dogs after procedure.Methods To select randomly the one side diaphragmatic lobes of four mongrel healthy dogs (12-18 months old ) as target pulmonary lobes and compare with the other sides at the same level. The target pulmonary lobes were filled with bleomycin-lipiodol emulsion, and then the target bronchi were occluded by polymethyhnerthacrylate (PMMA). The non-target pulmonary lobes were done with nothing. The hemodynamic parameters, such as systole pulmonary artery pressure(SPAP),diastole pulmonary artery pressure(DPAP), mean pulmonary artery pressure(mPAP), target segment pulmonary artery pressure(TSPAP) , non-target segment pulmonary artery pressure (NTSPAP). pulmonary artery wedge pressure(PAWP), systole right ventricle pressure(SRVP), diastole right ventricle pressure(DRVP), mean right ventricle pressure(mRVP),centrial venous pressure(CVP), were observed pre-procedure and post-procedure and then 7~th , 14~th, 21~st, 28~th and 56~th day respectively. On 56th day the four dogs were sacrificed by bleeding. Cutting down all the lungs and irrigating the pulmonary arteries by 0.9% heparinized sodium chloride solution. After marinated in 10% formalin for 24 hours, the bronchi or pulmonary arteries were filled in with blue or red ABS glue respectively. Three days later, putting all of the lungs into 38% hydrochloric acid, and about 1-2 weeks later, washing them out carefully and gently, then their morphological characters were observed. The diameter of 1-5 grade pulmonary arteries of both target and non-target lobes were measured and compared.Results (l)The statistically significant elevation was seen in mean pulmonary artery pressure(mPAP), non-target segment pulmonary artery pressure (NTSPAP), pulmonary artery wedge pressure(PAWP), mean right ventricle pressure(mRVP) and centrial venous pressure(CVP) one hour later after procedure .Target segmentpulmonary artery pressure(TSPAP) was elevated slightly.(2)On 7-14 days , CVP, mRVP, mPAP, PAWP, TSPAP and NTSPAP were going on upward, but NTSPAP was statistically higher comparing to TSPAP. (3)On 21-56 days, mRVP, mPAP, TSPAP and NTSPAP became low gradually, but Yet CVP and PAWP kept in normal. (4) Three dogs' target pulmonary boncbi and one dog's target segment bronchus were obstructed completely by PMMA plugs, in these bronchi and a part of target lobe tissue the PMMA plugs could be seen.(5)Pulmonary arteries of 4 target lobes were sparse,slim,atrophied and the main branches of target pulmonary arteries were crooded toword each other.Conclusion (1) animal model of FPLT can be established successfully by filling the target lung lobe with bleomycin-lipiodol emulsion and occluding the target bronchus. (2) FPLT has not harmful influence on hemodynamic parameters such as SPAP, DPAP, mPAP, TSPAP , NTSPAP, PAWP, SRVP, DRVP, mRVP and CVP. (3)The twig branches of target pulmonary artery atrophied obviously. (4) FPLT may be a safe and effective therapical method to many pulmonary diseases in the future.