Background: The cavopulmonary shunt procedure is now used for palliation of complex congenital heart lesions in infants. While pulmonary arteriovenous fistulae (PAVF) are a well-known complication of this surgery in older patients, no study of the prevalence of this condition in children and young infants has been reported.
Methods and results: We compared 29 patients with cavopulmonary shunts or total caval exclusion with 53 control subjects evaluated by contrast echocardiography at the University of California, San Francisco. The primary cardiac lesion, age at the time of surgery, type of right heart bypass procedure, provision of auxiliary pulmonary blood flow, and changes in oxygen saturation over time were compared. The prevalence of PAVF in children after cavopulmonary anastomosis is 60%, higher than previously reported. The prevalence is significantly higher in infants < 6 months old and in those with a heterotaxy syndrome. The provision of an additional source of pulsatile, pulmonary blood flow appears to have little effect on the development of PAVF. Patients who developed PAVF had arterial oxygen saturations at the time of discharge from surgery similar to those who did not develop them. Those with PAVF had significantly lower arterial and pulmonary venous oxygen saturations at follow-up as a result of their intrapulmonary shunt.
Conclusions: Contrast echocardiography provides a sensitive method for the detection of PAVF. While the origins, natural history, and ultimate clinical significance of PAVF in children after cavopulmonary anastomosis are unclear, surveillance by contrast echocardiography is indicated for all patients who have had this procedure because PAVF may cause significant intrapulmonary right-to-left shunting in some patients.