Postoperative pulmonary flow dynamics after Fontan surgery: assessment with nuclear magnetic resonance velocity mapping

Department of Diagnostic Radiology, University Hospital, Leiden, The Netherlands.

OBJECTIVES. This study was performed to assess the value of nuclear magnetic resonance (NMR) velocity mapping for the measurement of pulmonary blood flow after Fontan surgery. BACKGROUND. Echocardiographic studies of pulmonary flow after Fontan surgery are not always satisfactory. The newly developed technique of NMR velocity mapping may contribute to the elucidation of the Fontan circulation. METHODS. At frequent intervals during the cardiac cycle, forward and backward flow volumes in the pulmonary arteries of nine volunteers were measured, summed and compared with right ventricular stroke volume to validate the velocity mapping technique. In 14 patients after Fontan surgery, assessment of pulmonary flow volumes enabled the evaluation of atriopulmonary and atrioventricular (AV) Fontan connections. The findings were correlated with precordial echocardiography. RESULTS. Validation of the NMR technique, obtained from volunteer experiments, showed a high correlation (r = 0.97) between right ventricular stroke volume and volumetric pulmonary stroke flow. In all patients with an atriopulmonary Fontan connection (n = 8), forward flow in the pulmonary artery was biphasic, similar to normal venous flow. Monophasic systolic pulmonary flow curves indicating right ventricle-dependent pulmonary blood flow were found in three of six patients with an AV Fontan connection. In the remaining three patients, the pulmonary flow pattern did not reflect right ventricular contraction. Measurement of flow velocity alone may give a false impression of forward flow and thus of right ventricular contribution. Pulmonary regurgitation was demonstrated in six of eight patients with an atriopulmonary connection. CONCLUSIONS. Nuclear magnetic resonance velocity mapping provides accurate and valuable information on pulmonary flow volume and velocity after Fontan surgery. The success of AV Fontan surgery can be deduced from the presence of a monophasic systolic pulmonary flow pattern as demonstrated by NMR velocity mapping. With NMR flow volume analysis, substantial pulmonary regurgitation occurring after atriopulmonary Fontan surgery can be measured.

This article has been cited by other articles:

				M. I. Boechat, O. Ratib, P. L. Williams, A. S. Gomes, J. S. Child, and V. Allada Cardiac MR Imaging and MR Angiography for Assessment of Complex Tetralogy of Fallot and Pulmonary Atresia RadioGraphics, November 1, 2005; 25(6): 1535 - 1546. [Abstract] [Full Text] [PDF]

				D. J. Pennell, U. P. Sechtem, C. B. Higgins, W. J. Manning, G. M. Pohost, F. E. Rademakers, A. C. van Rossum, L. J. Shaw, and E. K. Yucel Clinical indications for cardiovascular magnetic resonance (CMR): Consensus Panel report Eur. Heart J., November 1, 2004; 25(21): 1940 - 1965. [Full Text] [PDF]

				S. Fratz, J. Hess, M. Schwaiger, S. Martinoff, and H. C. Stern More Accurate Quantification of Pulmonary Blood Flow by Magnetic Resonance Imaging Than by Lung Perfusion Scintigraphy in Patients With Fontan Circulation Circulation, September 17, 2002; 106(12): 1510 - 1513. [Abstract] [Full Text] [PDF]

				G. A. Varaprasathan, P. A. Araoz, C. B. Higgins, and G. P. Reddy Quantification of Flow Dynamics in Congenital Heart Disease: Applications of Velocity-encoded Cine MR Imaging RadioGraphics, July 1, 2002; 22(4): 895 - 905. [Abstract] [Full Text] [PDF]

				E M Pedersen, E V Stenbog, T Frund, K Houlind, O Kromann, K E Sorensen, K Emmertsen, and V E Hjortdal Flow during exercise in the total cavopulmonary connection measured by magnetic resonance velocity mapping Heart, June 1, 2002; 87(6): 554 - 558. [Abstract] [Full Text] [PDF]

				J. M. Chu, Q. Y. Wu, and W. M. Wang Pulmonary Blood Distribution After Total Cavopulmonary Connection Asian Cardiovasc Thorac Ann, December 1, 2001; 9(4): 282 - 285. [Abstract] [Full Text] [PDF]

				S. Sharma, A. E. Ensley, K. Hopkins, G. P. Chatzimavroudis, T. M. Healy, V. K.H. Tam, K. R. Kanter, and A. P. Yoganathan In vivo flow dynamics of the total cavopulmonary connection from three-dimensional multislice magnetic resonance imaging Ann. Thorac. Surg., March 1, 2001; 71(3): 889 - 898. [Abstract] [Full Text] [PDF]

				P. G. Walker, T. T. Howe, R. L. Davies, J. Fisher, and K. G. Watterson Distribution of hepatic venous blood in the total cavo-pulmonary connection: an in vitro study Eur. J. Cardiothorac. Surg., June 1, 2000; 17(6): 658 - 665. [Abstract] [Full Text] [PDF]

				R.M.F. Berger Possibilities and impossibilities in the evaluation of pulmonary vascular disease in congenital heart defects Eur. Heart J., January 1, 2000; 21(1): 17 - 27. [PDF]

				A. E. Ensley, P. Lynch, G. P. Chatzimavroudis, C. Lucas, S. Sharma, and A. P. Yoganathan Toward designing the optimal total cavopulmonary connection: an in vitro study Ann. Thorac. Surg., October 1, 1999; 68(4): 1384 - 1390. [Abstract] [Full Text] [PDF]

				M. A. Fogel, P. M. Weinberg, J. Rychik, A. Hubbard, M. Jacobs, T. L. Spray, and J. Haselgrove Caval Contribution to Flow in the Branch Pulmonary Arteries of Fontan Patients With a Novel Application of Magnetic Resonance Presaturation Pulse Circulation, March 9, 1999; 99(9): 1215 - 1221. [Abstract] [Full Text] [PDF]

				K Houlind, E V Stenbøg, K E Sørensen, K Emmertsen, O K Hansen, L Rybro, and V E Hjortdal Pulmonary and caval flow dynamics after total cavopulmonary connection Heart, January 1, 1999; 81(1): 67 - 72. [Abstract] [Full Text]

				M. A. Fogel, P. M. Weinberg, A. Hoydu, A. Hubbard, J. Rychik, M. Jacobs, K. E. Fellows, and J. Haselgrove THE NATURE OF FLOW IN THE SYSTEMIC VENOUS PATHWAY MEASURED BY MAGNETIC RESONANCE BLOOD TAGGING IN PATIENTS HAVING THE FONTAN OPERATION J. Thorac. Cardiovasc. Surg., December 1, 1997; 114(6): 1032 - 1041. [Abstract] [Full Text]

				M. R. de Leval, G. Dubini, F. Migliavacca, H. Jalali, G. Camporini, A. Redington, and R. Pietrabissa USE OF COMPUTATIONAL FLUID DYNAMICS IN THE DESIGN OF SURGICAL PROCEDURES: APPLICATION TO THE STUDY OF COMPETITIVE FLOWS IN CAVOPULMONARY CONNECTIONS J. Thorac. Cardiovasc. Surg., March 1, 1996; 111(3): 502 - 513. [Abstract] [Full Text]