An infant with primary pulmonary vein stenosis, associated with fatal occlusion of intraparenchymal small pulmonary veins

Abstract

Primary pulmonary vein stenosis (PVS) is rare within the pediatric population and its pathophysiology remains unclear, especially as to how the histopathology relates to its refractoriness to treatment. We report the case of a 4-month-old girl with primary PVS. The lesion in this patient was characterized by fatal obstruction of intraparenchymal small pulmonary veins, associated with localized stenosis at the four pulmonary veno-atrial junctions. All four localized stenoses underwent transcatheter stent implantation. Although the procedure was technically successful, her clinical status failed to improve, and she died 2 months after stenting. Histopathological examination of lung specimens showed severe luminal obstruction by marked intimal proliferation with fibrosis in the intraparenchymal small pulmonary veins, and these findings were present in every lobe. To the best of our knowledge, the histopathological findings and clinical course in this case, including the response to treatments, are extremely rare. We suggest that the histological findings of the small pulmonary veins are important in deciding the indication and appropriate timing of intervention. <Learning objective: The outcome of primary pulmonary vein stenosis has remained poor despite aggressive treatment, while the indication and appropriate timing of intervention has not been clarified. The histological findings of small pulmonary veins are important to predict the response to treatment and outcome, and early intervention might prevent the secondary progression of this disease.>.

Keywords: Pediatric interventional cardiology; Primary pulmonary vein stenosis; Pulmonary hypertension; Pulmonary vein obstruction.

Fig. 1

Chest X-ray on admission (a), after inhaled nitric oxide and epoprostenol were started (b).

Fig. 2

Echocardiogram on admission, short-axis view (a), four-chamber view (b). LV, left ventricle; RV, right ventricle; TR, tricuspid regurgitation.

Fig. 3

Computed tomography of pulmonary venous connection to the left. White arrow shows the narrowest points. RUPV, right upper pulmonary vein; RLPV, right lower pulmonary vein; LUPV, left upper pulmonary vein; LLPV, left lower pulmonary vein; LA, left atrium. atrium.

Fig. 4

Pulmonary venogram before (a) and after stent implantation (b). RUPV, right upper pulmonary vein; RLPV, right lower pulmonary vein; LUPV, left upper pulmonary vein; LLPV, left lower pulmonary vein; 4Fr JR, 4 French Right Judkins catheter.

Fig. 5

Histopathological findings of small pulmonary vein (a), (b).