[Hemodynamics and histology of lung blood vessels in 191 patients with atrioventricular canal].

The correlation between hemodynamic and histological changes of the small lung arteries was examined in 191 patients with atrio-ventricular canal. Lung biopsies were taken during palliative or corrective surgery. The histological findings were classified according to the Heath and Edwards-grading. The haemodynamic data were obtained within 3-4 months before operation (pulmonary/systemic ratios of systolic pressure, flow, and resistance as well as mean pulmonary artery pressure). The results indicated that the term atrioventricular canal must be divided into three different subgroups with regard of the development of HPVD: I. The incomplete atrio-ventricular canal (IAVC) showed a strong correlation between pulmonary hypertension and histological changes. II. The VSD-III (endocushion defect) developes HPVD in the first month of life similar to the complete av-canal. In about all children of this subgroup a serve pulmonary hypertension was found, therefore a correlation to the variety of histological findings could not be established. III. The CAVC was the largest subgroup of our patients. These patients had relatively the highest incidence of high-grade histological alterations. In 87% of the children with CACV we found histologically changes of the structure of the small arteries of the lungs mostly a hypertrophy of the media, but also alterations of the intima as proliferation of fibrosis. 88% of the children within the subgroup CAVC also hat a pulmonary hypertension with a systolic pressure ratio above 0.8.(ABSTRACT TRUNCATED AT 250 WORDS)