Second place--Resident Clinical Science Award 1990. A porcine model of chronic endobronchial obstruction

To elucidate the effects of both prolonged lobar atelectasis and subsequent re-expansion in a non-thoracotomized animal, we have developed a chronic, reversible porcine model of endobronchial obstruction. Eight adolescent pigs underwent the bronchoscopic placement of a left lower lobe bronchial plug. The obstruction was left in place for 24 hours. Four pigs then had the balloon bronchoscopically removed, while four controls underwent sham removal of the balloon. All animals showed significant atelectasis of the obstructed lobe compared to non-obstructed lobes at 24 hours. Pulmonary blood flow decreased significantly 24 hours after obstruction compared to pre-obstruction values in the collapsed lobe in all animals. Re-expansion was followed by arterial hypoxemia, which was accompanied by an increase in relative blood flow to the partially re-expanded lobe in the experimental group. No significant changes in lung water content occurred in the study group compared to controls.