Caval Contribution to Flow in the Branch Pulmonary Arteries of Fontan Patients With a Novel Application of Magnetic Resonance Presaturation Pulse

Mark A. Fogel, Paul M. Weinberg, Jack Rychik, Anne Hubbard, Marshall Jacobs, Thomas L. Spray, John Haselgrove
1999 Circulation  
Background-A complete understanding of fluid mechanics in Fontan physiology includes knowledge of the caval contributions to right (RPA) and left (LPA) pulmonary arterial blood flow, total systemic venous return, and relative blood flow to each lung. Methods and Results-Ten Fontan patients underwent cine MRI. Three cine scans of the pulmonary arteries were performed: (1) no presaturation pulse, (2) a presaturation pulse labeling inferior vena cava (IVC) blood (signal void), and (3) a
more » ... on pulse labeling superior vena cava (SVC) blood. The relative signal decrease is proportional to the amount of blood originating from the labeled vena cava. This method was validated in a phantom. Whereas 60Ϯ6% of SVC blood flowed into the RPA, 67Ϯ12% of IVC blood flowed toward the LPA. Of the blood in the LPA and RPA, 48Ϯ14% and 31Ϯ17%, respectively, came from the IVC. IVC blood contributed 40Ϯ16% to total systemic venous return. The distributions of blood to each lung were nearly equal (RPA/LPA bloodϭ0.94Ϯ11). Conclusions-In Fontan patients with total cavopulmonary connection, SVC blood is directed toward the RPA and IVC blood is directed toward the LPA. Although the right lung volume is larger than the left, an equal amount of blood flow went to both lungs. LPA blood is composed of equal amounts of IVC and SVC blood because IVC contribution to total systemic venous return is smaller than that of the SVC. This technique and these findings can help to evaluate design changes of the systemic venous pathway to improve Fontan hemodynamics. (Circulation. 1999;99:1215-1221.)
doi:10.1161/01.cir.99.9.1215 pmid:10069790 fatcat:zdy6xqxw3vdvzdyabsitsif33m