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Vieussens’ Arterial Ring
Key words: chronic total occlusion, conus artery, Vieussens’ ring
Case Presentation
A 63-year-old male patient presented with angina for 6 months with recent aggravation of symptoms. Physical examination was unremarkable. The electrocardiogram was within normal limits, cardiac troponin levels were not elevated, and left ventricular function was normal. Due to recent worsening of symptoms, we performed a coronary angiogram. It revealed severe triple vessel disease with chronic total occlusion (CTO) of the proximal left anterior descending (LAD), 90% obstruction of the proximal circumflex with CTO of the distal circumflex, and 99% occlusion of the proximal right coronary artery (RCA). The conus artery had a separate origin and provided collateral blood supply to the entire LAD territory by the Vieussens’ arterial ring (Figure 1 and Video 1). We recommended coronary artery bypass grafting.
The Vieussens’ artery is an anastomotic communication between the conus branch of the RCA and the LAD. Vieussens’ ring is so named because it circles around the great vessels in the form of a partial ring. The course of the artery can be best understood in 2 orthogonal views. In the left oblique view, the artery appears coursing upward to the left. In the right oblique view, it courses anteriorly across the right ventricular outflow tract.
The clinical significance of Vieussens’ arterial ring lies in it being a major source of collateral blood flow to an occluded LAD. The presence of this large collateral may explain preserved ventricular function in our patient, despite severe triple-vessel disease. A significant proportion of patients with total occlusion of the LAD have prominent collateral flow from the conus. However, in nearly half of the general population, the conus branch arises directly from the aorta. Hence, selective engagement may be necessary to demonstrate retrograde filling of the LAD. The origin of the conus artery is anterior and superior to the RCA ostium and it can be engaged by slight withdrawal and counter-clockwise rotation of the catheter. Selective engagement is easier to perform with the Tiger catheter (Terumo) because of the upward bias of its tip. Precaution should be taken to monitor pressure waveform for the presence of wedging and to avoid forceful contrast injection into the conus, which can result in injury to the vessel. Prolonged contrast injections into the conus predispose to ventricular fibrillation. The presence of a side hole in the Tiger catheter allows opacification of the adjoining RCA and makes contrast injection relatively safe.
Affiliations and Disclosures
*Joint first authors.
From the Department of Cardiology, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
Disclosure: The authors have completed and returned the ICMJE Form for Disclosure of Potential Conflicts of Interest. The authors report no conflicts of interest regarding the content herein.
Manuscript accepted January 3, 2022.
Address for correspondence: Prashant Panda, MD, DM, Associate Professor, Department of Cardiology, Postgraduate Institute of Medical Education and Research, Chandigarh-160012. Email: prashantpanda85@gmail.com
