title: Pulmonary vascular morphology in shunted and nonshunted patients with tetralogy of Fallot.
abstract: The pulmonary vascular morphology of 20 patients with tetralogy of Fallot (TOF), aged 2 months to 29 years, was studied by lung biopsy. In eight patients, systemic-to-pulmonary anastomosis had been performed prior to the lung biopsy and repair. The findings were compared to control data obtained by biopsy (n = 8) or necropsy (n = 23). On comparison to control subjects, patients with TOF displayed increased wall thickness of the intra-acinar arteries, extensive extension of smooth muscle to the alveolar wall (AW) and alveolar duct (AD) arteries, and increased diameter of the AW vessels. Intimal proliferation and fibrosis was observed in two patients. Large right-to-left shunt (Q p/Qs less than or equal to 0.75) was associated with an increased number of arteries, whereas left-to-right shunt (Q p/Q s greater than or equal to 1) was associated with a decreased number of vessels. The severity of the pulmonary vascular changes were similar in the shunted (N = 8) and nonshunted (n = 12) groups and in the ipsilateral and contralateral lungs of four shunted patients having bilateral biopsy. We conclude that some pulmonary morphologic features characteristic of pulmonary vascular obstructive disease are present in all patients with TOF surviving operation. An appropriate shunt causes no additional detrimental effect on the pulmonary vasculature. Thus, although early repair may be desirable for a variety of reasons, it is not preferable over a staged repair with respect to the pulmonary vasculature.
mesh_terms: D000293:Adolescent; D000328:Adult; D001706:Biopsy; D002648:Child; D002675:Child, Preschool; D006801:Humans; D007223:Infant; D008168:Lung / Q000473:pathology; D011650:Pulmonary Alveoli / Q000473:pathology; D011651:Pulmonary Artery / Q000473:pathology* / Q000601:surgery; D013771:Tetralogy of Fallot / Q000473:pathology* / Q000601:surgery