Bubble contrast echocardiography in detecting pulmonary arteriovenous malformations after modified Fontan operations

The development of pulmonary arteriovenous malformations is a well-known co mplication after Fontan operations, and may result in significant morbidity due to increasing arterial desaturation. We compared the use of bubble con trast echocardiography and pulmonary angiography in detecting such malforma tions. We also examined which anatomical and haemodynamic variables were as sociated with their development. Our study includes 20 patients who had und ergone modified Fontan procedures, 10 with atriopulmonary and 10 with total cavopulmonary connections, in Gothenburg between 1980 and 1991. All patien ts underwent cardiac catheterisation and pulmonary angiography. Bubble cont rast echocardiography was performed at the same time, with injection of agi tated polygelin colloid solution (Haemaccel, Hoechst) into the right and le ft pulmonary arteries, respectively. Transoesophageal echocardiography was used to detect the appearance of bubble contrast in the pulmonary venous at rium. The aim was also to evaluate the role of hepatic venous blood. Of the 20 patients, 9 (45%) had a positive contrast echocardiography study, compa red with only 2 (10%) detected by pulmonary angiography. Patients with posi tive contrast echocardiography had a significantly lower arterial oxygen sa turation than those with negative studies, both at rest (88% vs 95%, p < 0. 01) and during exercise testing (78% vs 89%, p = 0.01). Bubble contrast ech ocardiography is much more sensitive in detecting pulmonary arteriovenous m alformations than pulmonary angiography. By injecting echo contrast into th e right and left pulmonary arteries, the method can be made highly selectiv e. Pulmonary arteriovenous malformations develop much more frequently in pa tients with the Fontan circulation than previously reported.