Mechanical valves in the pulmonary position: a reappraisal.

OBJECTIVES: To evaluate midterm results of mechanical valves in pulmonary position in patients with pulmonary regurgitation and right ventricular dysfunction as an alternative to bioprostheses. PATIENTS: Mechanical valves (six tilting disc valves and two bileaflet valves) were implanted in eight patients previously operated on for tetralogy of Fallot (n = 7) and truncus arteriosus (n = 1), with severe right ventricular dysfunction caused by massive pulmonary regurgitation. RESULTS: All patients survived prosthesis implantation and are currently well. At follow-up (3 months to 9 years), they do not show signs of valve failure, and right ventricular function has dramatically improved in all but one, who still shows moderate ventricular hypokinesia. CONCLUSION: After operative correction of congenital heart defects in selected patients who show severe dysfunction of the right ventricle caused by pulmonary regurgitation/stenosis, mechanical valves may represent an alternative to bioprosthetic valves. The selection of the valve type is still a matter of debate. However, according to literature data, complications seem to have occurred only in patients with bileaflet mechanical valves in the pulmonary position, whereas no thromboembolic episodes or valve failure is reported in subjects with tilting disc valves in the right ventricular outflow. Tilting disc valves might perform better in the right ventricular outflow than bileaflet valves.

[Relation between the heart and lungs in children and adolescents with ventricular septal defects]. / Vzt'ah srdce-pl'úca u detí a mladistvých s defektom komorového septa.

Lung function tests were performed in 39 patients with haemodynamically significant ventricular septal defect (age 3-20 years, median 10 years). We found pulmonary restriction in 47% of patients, pulmonary hyperinflation in 50% of patients, obstruction of smaller airways in 20% of patients preoperatively. Observed lung function disorders were not related to the volume of the left to right shunt and the mean pulmonary arterial pressure. The surgical correction of VSD lead only to significant improvement of hyperinflation. The rest abnormal findings persisted for several years postoperatively. We conclude that the surgical repair of significant ventricular septal defect beyond 9.5 years of age does not prevent chronic lungs changes. The clinical implications of these findings yet remain to be established.

[The importance of pulmonary angiography in the surgical treatment of congenital heart defects with a left-right shunt and pulmonary hypertension]. / Význam pulmoangiografie pre indikáciu na chirurgickú liecbu vrodených srdcových chýb s l'avo-pravým skratom a pl'úcnou hypertenziou.

The studied series consisted of 14 patients with ventricular septal defect and pulmonary hypertension aged from 3 months to 15 years. Three examination methods were compared: (1) Invasive hemodynamic examination; (2) Pulmoangiographic examination by means of wedge peripheral pulmoangiography; (3) Histological examination of bioptic samples. Direct correlation was found to exist between mean PA pressure, PAR/m2, TPR/SR and pulmoangiographic records, in which the following parameters were evaluated: (a) length of the narrowing of the peripheral branch of the PA, (b) background opacity, (c) circulation time. The histological findings obtained in the bioptic samples corresponded practically in all cases with the hemodynamic and PAG findings. Only in two patients did the histological picture display a less severe degree of affection than found by PAG and hemodynamic examination. The obtained results suggest that in light of surgical indications, PAG can be considered a suitable and valuable supplementary method in assessing borderline findings of pulmonary hypertension in children with congenital heart defects and left-to-right shunt.