1. Gateways to the heart – Incidental CT findings of anomalous systemic venous connections and the clinical challenges they present
Hanzhou Li, Christopher Williamson, Matthew Brown, William Bates, Jayanth Keshavamurthy Department of Radiology, Medical College of Georgia at Augusta University
Introduction
During the development of the fetus, cardinal veins remodel to drain blood into the heart from the body and extremities. Due to anomalies in venous development, circulation of blood can become inefficient and in some cases, obstructed. Because venous developmental anomalies are rare, they can be difficult to diagnose. In most cases, patients are asymptomatic and present with complaints of chest pain and respiratory distress. These symptoms usually can lead to a diagnosis focused on myocardial infarction or pulmonary embolisms. The use of CT imaging and 3D reconstruction can aid in the accurate diagnosis of venous anomalies and enable physicians to better prepare for surgical intervention.
Case 2: 41 year old female undergoing a chest CT for suspected pulmonary embolism.
As seen in the anterior-posterior volume rendered (VR), coronal CT, and left anterior oblique VR imaging (Panels A, B, and D), the left innominate vein splits into a superior portion (black arrow) coursing anterior to the arch as well as an inferior portion (red arrow) traveling posterior to the arch. The axial CT (C) depicts contrast flowing through both branches of the anomalous left innominate, encircling the aorta before forming the superior vena cava.
Case 5: 70-year-old female presented with shortness of breath. She had an elevated d-dimer and had contrast injected in the left cephalic vein for a chest CTA.
Axial (A) demonstrates the course of the persistent left SVC (PLSVC) as it continues superior to inferior (arrows). There is no bridging innominate vein that connects the PLSVC to the RSVC throughout the downward course. Panel B is a coronal view of the PLSVC as it drains into the coronary sinus and eventually the right atrium (arrow). Panel C is a sagittal view of the descending course of the PLSVC. There is a moderate dilatation of the coronary sinus.
Anomalous vasculature cases A B
Case 4: 79 year old male underwent a chest CTA for investigating his shortness of breath.
Axial (A, B) demonstrate the persistent left SVC (PLSVC) lateral to the aortic arch (arrows). The PLSVC curves posteriorly as it descends and eventually drains into the right atrium. Panels C and D demonstrate the right SVC (RSVC) draining into the left atrium in axial and coronal views (arrows showing the junction of the RSVC and left atrium). Panel E is a volume-rendered image where the arrow points to the RSVC. Panel F is an oblique view of the CTA showing the RSVC draining into the left atrium as it curves posteriorly. C D
Conclusion
Though systemic venous anomalies are rare, obtaining CTs for patients with a history of pulmonary and cardiac distress could reveal defects in vascular development. CT scans have the resolution and 3D modeling capabilities to help physicians recognize and diagnose abnormal vessel connections and enable the tracing of blood flow. This knowledge will allow physicians to accurately diagnose and better prepare for potential corrective surgery or interventional procedures.
Case 1: 43 year old male with a chest CT.
Various computerized tomographic views of the aberrant retroaortic left innominate vein. Volume-rendered image (A) demonstrating the retroaortic course. Panel B demonstrates axial imaging of the variant joining with right innominate. Panels C and D demonstrate the full course in coronal view (panel D depicts its origin and continuation under the aortic arch to join, in panel C, the right innominate vein forming the SVC and draining into the right atrium). The white arrows point to the retroaortic left innominate vein. The black arrows point to the right innominate vein. AA – ascending aorta; DA – descending aorta; Z – azygous vein; S – superior vena cava.
Case 3: 39 year-old female presented with chest pain, palpitations, and syncope. She received a coronary CTA.
Axial (A) and coronal (B) demonstrate the levoatrial cardinal vein in the interatrial space (arrows). Panel C demonstrates the full course of the levoatrial cardinal vein in axial views (Upper left is the origin of the vein, branching from the left atrium, upper right and bottom left demonstrate the course in the interatrial space and the bottom right demonstrates the drainage into the distal superior vena cava). Panel D is a volume-rendered image. The arrow points to the levoatrial cardinal vein.