Lee Chun Yin Jonan, Chiang Jeanie Betsy, Chow Boris Chun Kei
Department of Radiology & Imaging, Queen Elizabeth Hospital, Hong Kong, Hong Kong.
Eur J Case Rep Intern Med. 2020 Feb 26;7(4):001511. doi: 10.12890/2020_001511. eCollection 2020.
Interrupted aortic arch (IAA) is an extremely rare congenital cyanotic heart disease characterized by complete disruption between the ascending and descending aorta. A patent ductus arteriosus (PDA) or other collateral pathways provide blood flow to the distal descending aorta. Mortality is extremely high at early infancy, particularly after closure of the ductus arteriosus. Survival and presentation in adulthood are extremely rare. Here, we illustrate a rare case of type B IAA in an adult who presented with secondary polycythaemia. The blood supply to the descending aorta and beyond was almost solely via a PDA. This case demonstrates the value of multimodality imaging, including CT and MRI, for diagnosis and treatment planning in these patients.
The presence of secondary polycythaemia, as a result of chronic hypoxia, should prompt a search for underlying cyanotic heart disease even in previously undiagnosed adults.Most previous case reports of IAA in adults feature type A; type B IAA in an adult is far less frequently described.MRI has incremental value compared to CT in intracardiac assessment (aortic valve assessment, RV and LV functional assessment, flow measurement) for these patients; in addition, it provides an excellent depiction of the vascular anatomy of the aorta and great vessels.
主动脉弓中断（IAA）是一种极其罕见的先天性紫绀型心脏病，其特征是升主动脉和降主动脉之间完全中断。动脉导管未闭（PDA）或其他侧支循环途径为降主动脉远端提供血流。婴儿早期死亡率极高，尤其是在动脉导管闭合后。成年期存活并出现症状极为罕见。在此，我们阐述一例成年B型IAA的罕见病例，该患者表现为继发性红细胞增多症。降主动脉及更远端的血液供应几乎完全通过动脉导管未闭。该病例展示了多模态成像（包括CT和MRI）在这些患者诊断和治疗规划中的价值。
即使在既往未诊断的成年人中，慢性缺氧导致的继发性红细胞增多症的存在也应促使寻找潜在的紫绀型心脏病。既往大多数成人IAA病例报告为A型；成人B型IAA的描述则少得多。对于这些患者，与CT相比，MRI在心脏内评估（主动脉瓣评估、右心室和左心室功能评估、血流测量）方面具有额外价值；此外，它能很好地描绘主动脉和大血管的血管解剖结构。
