Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Ga 30332-0535, USA.
J Thorac Cardiovasc Surg. 2011 May;141(5):1170-7. doi: 10.1016/j.jtcvs.2010.11.032. Epub 2011 Feb 18.
Pulmonary arteriovenous malformations caused by abnormal hepatic flow distribution can develop in patients with a single ventricle with an interrupted inferior vena cava. However, preoperatively determining the hepatic baffle design that optimizes hepatic flow distribution is far from trivial. The current study combines virtual surgery and numeric simulations to identify potential surgical strategies for patients with an interrupted inferior vena cava.
Five patients with an interrupted inferior vena cava and severe pulmonary arteriovenous malformations were enrolled. Their in vivo anatomies were reconstructed from magnetic resonance imaging (n = 4) and computed tomography (n = 1), and alternate virtual surgery options (intracardiac/extracardiac, Y-grafts, hepato-to-azygous shunts, and azygous-to-hepatic shunts) were generated for each. Hepatic flow distribution was assessed for all options using a fully validated computational flow solver.
For patients with a single superior vena cava (n = 3), intracardiac/extracardiac connections proved dangerous, because even a small left or right offset led to a highly preferential hepatic flow distribution to the associated lung. The best results were obtained with either a Y-graft spanning the Kawashima to split the flow or hepato-to-azygous shunts to promote mixing. For patients with bilateral superior vena cavae (n = 2), results depended on the balance between the left and right superior inflows. When those were equal, connecting the hepatic baffle between the superior vena cavae performed well, but other options should be pursued otherwise.
This study demonstrates how virtual surgery environments can benefit the clinical community, especially for patients with a single ventricle with an interrupted inferior vena cava. Furthermore, the sensitivity of the optimal baffle design to the superior inflows underscores the need to characterize both preoperative anatomy and flows to identify the best option.
由异常肝血流分布引起的肺动静脉畸形可在腔静脉中断的单心室患者中发展。然而，术前确定优化肝血流分布的肝隔板设计远非易事。本研究结合虚拟手术和数值模拟，为腔静脉中断的患者确定潜在的手术策略。
纳入 5 例腔静脉中断伴严重肺动静脉畸形的患者。使用磁共振成像（n=4）和计算机断层扫描（n=1）重建其体内解剖结构，并为每位患者生成了各种虚拟手术选择（心内/心外、Y 型移植物、肝-奇静脉分流术和奇静脉-肝分流术）。使用完全验证的计算血流求解器评估所有方案的肝血流分布。
对于单上腔静脉患者（n=3），心内/心外连接是危险的，因为即使是很小的左或右偏移也会导致肝血流高度偏向相关肺。最佳结果是使用 Kawashima 跨越的 Y 型移植物分流或肝-奇静脉分流术促进混合获得的。对于双侧上腔静脉患者（n=2），结果取决于左、右上腔静脉之间的流入平衡。当它们相等时，在上腔静脉之间连接肝隔板效果良好，但否则应选择其他方案。
本研究展示了虚拟手术环境如何使临床社区受益，特别是对腔静脉中断的单心室患者。此外，最佳隔板设计对上级流入的敏感性突出表明需要对术前解剖结构和血流进行特征描述，以确定最佳方案。
