Author has performed experimental study on hemodynamic changes of lung following radical hilar stripping and contralateral pulmonary artery ligation.
In view of hemodynamic changes in group 1 (right pulmonary artery ligation only) and group 2(left hilar stripping+right pulmonary artery ligation). group 2 showed remarkable decrease rate in oxygen uptake ( P <0.001) and total pulmonary blood flow( P <0. 001), and the more increase rate in mean pulmonary artery pressure (P <0.02) and total pulmonary vascular resistance (P< 0.001). Meanwhile, the decrease percent of left lung vascular resistance was lower than group 1 ( P <0.001).
The hemodynamic changes in group 1 returned to control range two weeks later.
In the group 2, two dogs were expired as a result of atelectasis and pulmonary hypertension. Among aliving 8 dogs, five months after operation, follow up studies performed in two dogs, which showed normal pulmonary hemodynamics similar to preoperative data.
The altered blood gas values and decreased oxygen uptake are more remarkable in denervated lung, which may due to pulmonary hypertension and partly retained more secretion in bronchial trees than usual.
Important factors of raising pulmonary vascular resistance and pulmonary artery pressure are considered as the increased blood flow to remaining left lung and dysfunction of pulmonary vascular bed to accept the increased blood flow after denervation.
Loss of nerve innervation had a influence, to some extent, to the decrease of oxygen uptake and the increase of pulmonary vascular resistance and pulmonary artery pressure. There can be little question that denervation does impair the pulmonary hemodynamics, however, intact pulmonary nerve innervation is not absolutely essential for survival of the animal.
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