Multiple pulmonary arteriovenous fistulas in childhood.

Three cases of multiple pulmonary arteriovenous fistulas are described in children who presented at five months, two and nine years of age. Mass spectrometry was used to measure pulmonary blood flow and, in two cases, the intrapulmonary right-to-left shunt. The shunt fractions were 51% and 35%, with no significant change on breathing 100% oxygen. In one case, effective pulmonary blood flow was measured during cardiac catheterisation by the argon-freon rebreathing method and agreed closely with that found from the Fick, principle with measured oxygen consumption. Treatment consisted of surgical ligation of a lower lobe pulmonary artery in the youngest child, balloon embolisation in the second, and initial surgical oversewing of a single large fistula followed twenty months later by steel coil embolisation in the third. The last and oldest child is well and no longer cyanosed. The first two children died seven months after treatment with evidence of progression of their pulmonary arteriovenous fistulas. The first of these, who also had an atrial septal defect and discordant thoraco-abdominal arrangement, died of heart failure. Autopsies on both children confirmed extensive involvement of both lungs by arteriovenous fistulas. In one case who had a diffuse, telangiectatic form of pulmonary arteriovenous fistulas, microscopic serial reconstructions of lung tissue revealed that anastomoses occurred between arteries accompanying terminal bronchioles and intra-acinar arteries and adjacent veins. Occlusion of the pulmonary arteries supplying the fistulas led to extensive fibrosis within them, and was associated with enlargement of the corresponding bronchial arterial circulation.