Pulmonary arteriovenous fistulas in patients with left isomerism and cardiac malformations.

OVER THE PAST DECADE, VARIOUS FORMS OF cavopulmonary anastomoses (the bidirectional Glenn shunt, the hemi-Fontan procedure) have become the palliative procedure of choice for the treatment of hearts with a functionally single ventricle. Significantly, the occurrence of pulmonary arteriovenous fistulas had been noted as an important 'late' complication after construction of the classic Glenn anastomosis, with a reported incidence of 25%.' In contrast to the experience with the classic anastomosis, the incidence of fistulas after construction of bidirectional cavopulmonary anastomoses seems to be quite low. These observations, however, may simply be the consequence of the short natural history of the bidirectional shunt. In most instances, it is performed as a part of a two-stage approach, with most patients proceeding relatively quickly to the Fontan operation, which then incorporates the inferior caval and hepatic venous flows into the pulmonary circulation. An exception to this two-stage strategy for total cavopulmonary connection is in patients with left isomerism, interruption of the inferior caval vein, and azygos continuation to the superior caval vein, in which the hepatic veins drain directly into the atrium. In these cases, construction of a bidirectional cavopulmonary anastomosis directs all venous return to the pulmonary bed except for the coronary and the hepatic venous blood. This, typically, results in arterial oxygen desaturation in the range of 85% to 90%, and was initially considered to provide definitive palliation. Several years ago, however, some cases of fistulous communications were reported in patients