The effects of hilar-stripping upon pulmonary function. Experimental study

The purpose of this study is to report the effects of hilar-stripping upon pulmonary function in dogs.1) Effects upon pulmonary ventilation.It was revealed by bronchospirometry using a modified Trummer's catheter that oxygen uptake and minute ventilation by left lung normally accounted for 41 and 44% of the total, respectively. The ventilation was decreased for the first week after operation, and returned to nearly normal at the second week in the thoracotomied control dogs. However, the ventilation of the hilar-stripped lung was markedly decreased during the first and second weeks after the operation, and it slowly improved thereafter. Oxygen uptake and minute ventilation were restored to the pre-operative values 5-7 weeks and 4 weeks after operation, respectively.Hering-Breuer Reflex was abscent in all dogs during 15 months after operation.Bronchiectasis caused by hilar-stripping stored to improve at the third month and was recovered within 9th month.2) Effects upon circulation.The blood pressures of pulmonary artery and vein were slightly different between pre and post-operation.Unilateral pulmonary artery occulusion tests on the unoperated lung were performed on the 11 dogs. Five of them showed the II type reaction, and 6 showed the III type. Pulmonary arterial pressures had moderately elevated during the tests in 10 dogs, but were remained within physiological ranges. This elevation was not always related to the decrease of ventilatory function.Contralateral pneumonectomy was performed on 8 hilar-stripped dogs, 3 of which were vivid after operation. The remaining 5 dogs died in early stage. The pattern of respiration was not altered in all dogs. These results indicated that dogs were able to live only with unilateral hilar-stripped lung.