Grosse-Wortmann Lars, Al-Otay Abdulmajeed, Yoo Shi-Joon
The Labatt Family Heart Center and the Department of Diagnostic Imaging, The Hospital for Sick Children, The University of Toronto, Toronto, Ontario, Canada.
Circ Cardiovasc Imaging. 2009 May;2(3):219-25. doi: 10.1161/CIRCIMAGING.108.834192. Epub 2009 Mar 25.
Aortopulmonary collaterals (APCs) have been associated with increased morbidity after the Fontan operation. We aimed to quantify APC flow after bidirectional cavopulmonary connections and Fontan completions, using phase-contrast MRI, and to identify risk factors for the development of APCs.
APC blood flow was quantifiable in 24 of 36 retrospectively analyzed MRI studies. Sixteen studies were performed after the bidirectional cavopulmonary connections (group A) and 8 after the Fontan operation (group B). APC blood flow was calculated by subtracting the blood flow volume through the pulmonary arteries from that through the pulmonary veins. The ratio of pulmonary to systemic blood flow (Qp/Qs) was 0.93+/-0.26 in group A and 1.27+/-0.16 in group B. APC flow was 1.42 (0.58 to 3.83) L/min/m(2) and 0.82 (0.50 to 1.81) L/min/m(2) in groups A and B, respectively. The mean inaccuracies corresponded to 7.9+/-14.5% and 7.1+/-13.6% of ascending aortic flow in groups A and B, respectively. Qp/Qs was negatively correlated with a younger age at the time of the bidirectional cavopulmonary connections operation (r=0.62, P=0.01) and positively correlated with the age at the time of the Fontan completion (r=0.81, P=0.01). Patients with a previous right-sided modified Blalock-Taussig shunt had more collateral flow to the right lung than those without.
APC blood flow can be noninvasively measured in bidirectional cavopulmonary connections and Fontan patients, using MRI in the majority of patients and results in a significant left-to-right shunt.
主肺动脉侧支血管（APCs）与Fontan手术后发病率增加有关。我们旨在使用相位对比磁共振成像（MRI）对双向腔肺连接和Fontan手术完成后的APCs血流进行量化，并确定APCs发生的危险因素。
在36项回顾性分析的MRI研究中，24项可对APCs血流进行量化。16项研究在双向腔肺连接后进行（A组），8项在Fontan手术后进行（B组）。APCs血流通过从肺静脉的血流量中减去肺动脉的血流量来计算。A组肺循环与体循环血流量之比（Qp/Qs）为0.93±0.26，B组为1.27±0.16。A组和B组的APCs血流分别为1.42（0.58至3.83）L/min/m²和0.82（0.50至1.81）L/min/m²。平均误差分别相当于A组和B组升主动脉血流的7.9±14.5%和7.1±13.6%。Qp/Qs与双向腔肺连接手术时较年轻的年龄呈负相关（r = 0.62，P = 0.01），与Fontan手术完成时的年龄呈正相关（r = 0.81，P = 0.01）。既往有右侧改良Blalock-Taussig分流术的患者比没有的患者有更多的侧支血流至右肺。
使用MRI可在大多数双向腔肺连接和Fontan手术患者中无创测量APCs血流，且结果显示存在明显的左向右分流。
