Persistent localized pulmonary interstitial emphysema and lymphangiectasia: a causal relationship?

The mechanism responsible for persistent regional pulmonary interstitial emphysema under tension, which occasionally complicates assisted ventilation, has not been explained. It is difficult to comprehend how interstitial air may cause lobar hyperinflation and not escape to the mediastinum or pleura. Histologic examination of resected emphysematous lung in two neonates with this type of interstitial emphysema revealed air dissecting from the interstitial connective tissue into markedly dilated lymphatics. It is proposed that intralymphatic air dissection causing emphysematous lymphangiectasia may be responsible for fixation of the lung in the emphysematous state.