[Pulmonary hypertensive vascular disease in patients with interventricular defect or complete atrioventricular canal]. / La malattia vascolare ipertensiva polmonare nei pazienti con difetto interventricolare o con canale atrioventricolare completo.

In 34 patients operated on the morphological and morphometric patterns of the pulmonary vascular bed on lung biopsies, performed during the operation for ventricular septal defect or complete atrio-ventricular septal defect were studied. These patterns were related to the preoperative hemodynamic data. Ages ranged from 2 to 20 months. There were 16 ventricular septal defect (mean age 10 +/- 4 months) and 18 complete atrio-ventricular septal defect (mean age 9.8 +/- 1.2 months). Furthermore, of the latter 15/18 (83%) patients had Down's syndrome. The following hemodynamic data were considered: a) ratio between the pulmonary systolic artery pressure and the systemic systolic artery pressure; b) diastolic pulmonary artery pressure; c) pulmonary vascular resistance; d) ratio between pulmonary and systemic flow. The lung specimens obtained at surgery were routinely processed and embedded in paraffin. Sections measuring 4 microns were stained with hematoxylin-eosin, Masson's thricrome and Miller's elastin. The status of the small pulmonary arteries was assessed according to the Heath-Edwards classification and to the morphometric parameters proposed by Rabinovitch and coll. Ratio between the pulmonary systolic artery pressure and the systemic systolic artery pressure ranged from 0.48 to 1 (mean 0.8 +/- 0.23) in patients with ventricular septal defect, whereas in complete atrio-ventricular septal defects it ranged from 0.42 to 1 (mean 0.86 +/- 0.21). The mean diastolic pulmonary artery pressure was 20 +/- 10 mmHg (range 8-40 mmHg) in ventricular septal defects and 19.5 +/- 2.3 mmHg (range 10-35 mmHg) in complete atrio-ventricular septal defects.(ABSTRACT TRUNCATED AT 250 WORDS)