Canter C E, Gutierrez F R, Molina P, Hartmann A F, Spray T L
Division of Pediatric Cardiology, St. Louis Children's Hospital, MO 63110.
J Thorac Cardiovasc Surg. 1991 Apr;101(4):724-31.
Right-sided extracardiac conduits are frequently complicated by obstruction over time. We compared the utility of two-dimensional and Doppler echocardiography and magnetic resonance imaging in the diagnosis of postoperative right-sided obstruction with cardiac catheterization and angiography in 10 patients with xenograft or homograft conduits. Correlation (r = 0.95) between continuous-wave Doppler estimates and catheter pullback pressure gradients across the conduits was excellent. Echocardiography could only visualize five of 10 conduits in their entirety. Magnetic resonance imaging visualized all conduits and showed statistically significant (kappa = 0.58) agreement with angiography in the localization and estimation of severity of a variety of right-sided obstructions in these patients. However, flow voids created by the metallic ring around xenograft valves led to a false negative diagnosis of valvular stenosis in four patients when magnetic resonance imaging was used alone. Doppler studies correctly indicated obstruction in these patients. The combination of magnetic resonance imaging studies and continuous-wave Doppler echocardiography can be useful to noninvasively evaluate right-sided obstruction in postoperative patients with right-sided extracardiac conduits.
随着时间的推移，右侧心外管道常常会出现梗阻并发症。我们比较了二维和多普勒超声心动图以及磁共振成像在诊断10例使用异种移植物或同种移植物管道的患者术后右侧梗阻方面的效用，并与心导管检查和血管造影进行了对比。连续波多普勒估计值与通过管道的导管回撤压力梯度之间的相关性（r = 0.95）非常好。超声心动图仅能完整显示10根管道中的5根。磁共振成像能显示所有管道，并且在这些患者各种右侧梗阻的定位和严重程度评估方面，与血管造影显示出具有统计学意义的一致性（kappa = 0.58）。然而，异种移植物瓣膜周围金属环产生的血流信号缺失，导致在单独使用磁共振成像时，4例患者出现瓣膜狭窄的假阴性诊断。多普勒研究正确地指出了这些患者存在梗阻。磁共振成像研究与连续波多普勒超声心动图相结合，有助于对术后右侧心外管道患者的右侧梗阻进行无创评估。
