Postoperative changes of pulmonary vascular resistance in patients with complete atrioventricular canal defect. Relation to the age at primary repair.

Abstract

The postoperative changes of pulmonary vascular resistance (PVR) of two age groups of children with complete atrioventricular canal (CAVC) were compared. Patients were divided by age at the time of primary repair; Group-1 (G-1, n = 4) with age below 2 years (average 13.8 mo.) and Group-2 (G-2, n = 5) with age over 2 years (average 44.0 mo.). All except one were Down's syndrome. Preoperatively, pulmonary to systemic resistance ratio (Rp/Rs) were 0.87 +/- 0.50 in G-1 and 0.41 +/- 0.13 in G-2 (n.s.), and postoperative study (average 6.5 mo.) showed no significant falls in Rp/Rs in both groups. However, G-2 showed significantly lower Rp/Rs postoperatively (0.79 +/- 0.19 in G-1 vs 0.27 +/- 0.12 in G-2, p less than 0.05). Mean pulmonary artery pressure (mPA) showed significant fall after surgery in only G-2 (66.8 +/- 6.6 to 31.8 +/- 11.6 mmHg, p less than 0.005). Anatomically, type-A showed better postoperative change in mPA compared to type-C. This study summarized the early progression of pulmonary vascular obstructive disease with poor postoperative improvement even the primary repair was done before 2 years of age. The less advanced pulmonary vascular disease in G-2 might have some relations to the natural selection of the disease.