3D modeling in congenital cardiac interventions
Survival rates have continually improved in patients with congenital heart disease (CHD) over the past few decades as a result of progress in medical and surgical care (Warnes, et al., J Am Coll Cardiol 37:1170-1175, 2001). Thus, most patients born today with CHD are expected to live into adulthood (Wren and O'Sullivan, Heart 85:438-443, 2001), adding to the 1.6 million adults living with CHD in the United States (Gilboa, et al., Circulation 134:101-109, 2016). This is a growing population with congenital heart disease, and despite advances in the field, death rates among adults with CHD (ACHD) 20 to >70 years old exceed that of the general population by 2 to 7 times (Bhatt, et al., Circulation 131:1884-1931, 2015). Challenges in managing this population are myriad and complex, starting with establishing a reliable history and anatomic diagnosis. Many ACHD patients, who underwent cardiac procedures as children, may present for clinical care without accurate (or available) records that provide a reliable starting point for management. From that point onward, an echocardiogram is usually the first-line imaging study for most ACHD patients to assess anatomy and physiology. Unfortunately, echocardiography may be limited by poor acoustic windows, obesity, or lung artifact. Even in patients with good acoustic windows, standard 2-dimensioanl (2D) echo may be limited when attempting to visualize distant or complex structures, such as a total anomalous pulmonary venous return (TAPVR) repair, a total cavopulmonary connection (TCPC), or an atrial baffle. In these cases, high-resolution 3-dimensional (3D) imaging with cardiac magnetic resonance imaging (MRI) or computed tomography (CT) can be helpful. These 3D imaging modalities can help establish a baseline diagnosis and clarify the surgical procedures that have been performed. Both CT and MRI can provide detailed imaging of complex anatomy in high resolution, and MRI can provide a detailed assessment of physiology, including cardiac function, hemodynamic assessment (flow and volume), and tissue characterization (inflammation, infiltrative processes, or scar assessment) (von Knobelsdorff-Brenkenhoff, et al., Eur Heart J Cardiovasc Imaging 15(3):235-248, 2013; Partington and Valente, Methodist Debakey Cardiovasc J 9:156-162, 2013; Kilner, et al., Eur Heart J 31(7):794-805, 2010; Marcotte, et al., Congenit Heart Dis 4:216-230, 2009). Retrospectively-gated CT can calculate ventricular function as well, though with a slightly different method than cardiac MRI. Finally, cardiac CT or MRI can be used for 3D modeling or printing, which may be particularly helpful in ACHD patients.
