Pulmonary Arterial Bed Reperfusion Induces Regression of Distal Vasculopathy in a Chronic Thromboembolic Pulmonary Hypertension Piglet Model

Abstract

Purpose Chronic Thromboembolic Pulmonary Hypertension (CTEPH) is due to occlusion of pulmonary arteries (PA) and to distal pulmonary vasculopathy in occluded and non-occluded territories. Persistent pulmonary hypertension, the main complication after pulmonary endarterectomy, may be due to remaining distal pulmonary vasculopathy.The aim was to assess whether distal pulmonary vasculopathy regresses in occluded and non-occluded territories after pulmonary endarterectomy. Methods and Materials CTEPH was induced in piglets 5 weeks after left PA ligation followed by weekly right lower lobe artery embolization. Animals were studied 5 weeks later, after reperfusion of the left PA mimicking pulmonary endarterectomy (R-HYPPE group, n=5) or not (HYPPE group, n=5). Left lung (LL) was studied as occluded territories and right upper lobe (RUL) as non-occluded territories. All groups were compared to Sham operated animals (n=5). Results At 5 weeks, mean PA pressure (mPAP) and indexed total pulmonary resistances (iTPR) increased in HYPPE and R-HYPPE groups when compared to baseline values (p Conclusions Distal pulmonary vasculopathy regresses after surgical treatment of CTEPH in previously occluded and non-occluded territories.