Author + information
- Received May 8, 2017
- Revision received May 24, 2017
- Accepted May 30, 2017
- Published online August 10, 2017.
- Sandeep A. Saha, MD, MSa,
- Kousik Krishnan, MDa,
- Clifford J. Kavinsky, MDb,
- Neeraj Jolly, MDb,
- Keyur Parekh, MDc and
- Dinesh K. Kalra, MDd,∗ ()
- aSection of Cardiac Electrophysiology, Rush University Medical Center, Chicago, Illinois
- bInterventional Cardiology, Rush University Medical Center, Chicago, Illinois
- cAdvanced Cardiac Imaging, Division of Cardiology, Department of Medicine, Rush University Medical Center, Chicago, Illinois
- dDepartment of Radiology, Rush University Medical Center, Chicago, Illinois
- ↵∗Address for correspondence:
Dr. Dinesh K. Kalra, Advanced Cardiac Imaging, Rush University Medical Center, Division of Cardiology, 1717 West Congress Parkway, Kellogg Suite 320, Chicago, Illinois 60612.
A 76-year-old woman with paroxysmal atrial fibrillation (CHA2DS2-VASc score 4) and recurrent nose and gastrointestinal bleeds was referred for a Watchman left atrial appendage closure device (Boston Scientific, Natick, Massachusetts) implantation. Transthoracic echocardiography showed a mildly dilated left atrium, but no other abnormalities. Right femoral vein access was obtained and a 0.032-inch guidewire tip was advanced to the superior vena cava (SVC). An SL1 sheath and dilator were advanced over the wire, and a transseptal needle inserted through the dilator. The sheath-dilator-needle assembly was slowly pulled down from the SVC into the right atrium under fluoroscopic guidance. On transesophageal echocardiography, despite multiplanar views, we could neither visualize the sheath within the right atrium nor any tenting of the interatrial septum. Contrast injection through the dilator showed staining that extended beyond the cardiac silhouette (Online Video 1), and showed delayed opacification of the right atrium (Online Video 2). Transesophageal echocardiography showed a dilated azygous vein coursing adjacent to the descending thoracic aorta (Online Video 3). The SL1 sheath was exchanged for a pigtail catheter. Contrast injection demonstrated a large venous channel with a posterior, leftward course and delayed opacification of the right atrium via the SVC (Online Video 4). Based on these findings, a venous anomaly was suspected, and the procedure was aborted. Cardiac computed tomography angiography revealed interruption of the suprarenal inferior vena cava (IVC), with a dilated azygous vein continuation that drained into the SVC (Figures 1, 2, 3, and 4).
Left atrial access via transseptal puncture is becoming commonplace for many structural heart interventions and ablation procedures. Knowledge of this rare venous anatomic variant is important, because it may impact pre-procedural decision making including choice of femoral versus other access routes, as well as in planning access for cardiopulmonary bypass or liver transplantation (1). Previously, this rare entity was thought to be associated with other congenital heart defects and polysplenia. However, it is now evident that it can occur in isolation and can be asymptomatic such as in our patient. Rarely, the IVC may be duplicated, but in the usual form, the IVC is interrupted above the level of the renal veins. There is an absence of the hepatic segment of the IVC, and the post-renal IVC continues as azygous and hemiazygous veins. Embryologically, there is a failure to form right subcardinal–hepatic anastomosis, resulting in atrophy of the right subcardinal vein (2). Plain chest x-rays will show a soft tissue density at junction of the trachea and right main bronchus where the dilated azygous vein joins the SVC. This may be mistaken for mediastinal lymphadenopathy or a right-sided aortic arch. However, computed tomography or magnetic resonance imaging can readily establish the diagnosis.
For supplemental videos and their legends, please see the online version of this article.
The authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- Received May 8, 2017.
- Revision received May 24, 2017.
- Accepted May 30, 2017.
- 2017 American College of Cardiology Foundation