Morphological studies of pulmonary arteriovenous shunting in a lamb model of superior cavopulmonary anastomosis.
We sought to identify and characterize the abnormal vascular structures responsible for pulmonary arteriovenous shunting following the Glenn cavopulmonary shunt. Superior cavopulmonary shunt is commonly performed as part of the staged pathway to total cavopulmonary shunt to treat univentricular forms of congenital heart disease, however, clinically significant pulmonary arteriovenous malformations develop in some patients after the procedure. The causes of pulmonary arteriovenous malformations and other pulmonary vascular changes that occur after cavopulmonary shunt are not known. Using a juvenile lamb model of superior cavopulmonary anastomosis that reliably produces pulmonary arteriovenous malformations, we performed echocardiography and morphological analyses to determine the anatomic site of shunting and to identify the vascular structures involved. Pulmonary arteriovenous shunting was identified by contrast echocardiography in all surviving animals (n = 40) following superior cavopulmonary anastomosis. Pulmonary vascular corrosion casts revealed abnormal tortuous vessels joining pulmonary arteries and veins in cavopulmonary shunt animals but not control animals. In conclusion, unusual channels that bridged pulmonary arteries and veins were identified. These may represent the vascular structures responsible for arteriovenous shunting following the classic Glenn cavopulmonary shunt. Detailed analysis of these structures may elucidate factors responsible for their development.
Department of Pediatric Cardiac Surgery, Children's Hospital & Regional Medical Center, Seattle, WA, 98105, USA. michael.mcmullan@seattlechildrens.org
David Michael
DM
McMullan
Vadiyala Mohan
VM
Reddy
William M
WM
Gottliebson
Norman H
NH
Silverman
Stanton B
SB
Perry
Frandics
F
Chan
Frank Louis
FL
Hanley
Robert Kirk
RK
Riemer
D000714:Anastomosis, Surgical / Q000009:adverse effects; D000818:Animals; D001165:Arteriovenous Malformations / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000209:etiology* / Q000503:physiopathology; D016319:Corrosion Casting; D004195:Disease Models, Animal; D021621:Imaging, Three-Dimensional; D008953:Models, Anatomic; D011651:Pulmonary Artery / Q000002:abnormalities* / Q000601:surgery*; D012117:Resins, Synthetic; D012756:Sheep; D014463:Ultrasonography; D014683:Vena Cava, Superior / Q000601:surgery*
D012117:Resins, Synthetic