A follow-up study with radionuclide imaging and angiocardiography for pulmonary perfusion after Fontan operation

Abstract

Objective To study the long-term effect of total right heart bypass on pulmonary perfusion after extracardiac total cavopulmonary connection (ETCPC). Methods Fifty-three patients (29 males, 24 females; average age (10.8±6.1) years) undergoing ETCPC from March 1990 to December 2005 were retrospectively analyzed. Forty-three patients had full set of pulmonary perfusion data at 1 month and 5 years postoperation. The perfusion ratios of each lung segment were calculated based on 99Tcm-MAA radionuclide imaging. The PVR and pulmonary artery index were calculated from angiocardiography measurements. All data were compared with paired t test. Results Compared with the early postoperative data, the perfusion ratio of superior/inferior segment(0.72±0.20 vs 0.75±0.01; t=2.54, P 0.05), the total pulmonary nuclear counts ((701.91±8.26)×103vs (698.93±12.0)×103;t=0.38, P>0.05) and the perfusion ratio of inferior vena cava to the right lung (0.61±0.06 vs 0.60±0.06; t=0.74, P>0.05) were similar between the two terms of follow-up. The early angiographic and radionuclide perfusion studies did not match in 5 patients. Conclusions Hypostatic redistribution of pulmonary blood flow is the characteristics in long-term follow-up of ETCPC patients. The radionuclide imaging is superior to angiocardiography in revealing functional pulmonary blood perfusion. Key words: Heart defects, congenital; Fontan procedure; Radionuclide imaging; Angiocardiography; MAA