Coronary Cannulation Through Mirror-Image Right Aortic Arch During Right Transradial Approach: A Rare Case Report With Review of Literature

Abstract: Although right aortic arch (RAA) is a rare developmental anomaly, it can create a challenging anatomical situation while cannulating coronaries working through right transradial approach (TRA). We describe a rare adult patient with mirror-image RAA, whose coronary angiogram was performed through right TRA. We have also discussed the challenges encountered because of RAA and technique to enter the ascending aorta.

J INVASIVE CARDIOL 2012;24(5):234-235

Key words: transradial approach, right aortic arch, coronary cannulation

______________________________________________

Case Report

A 58-year-old male patient with history of diabetes (10 years) and hypertension (15 years) was admitted for coronary angiography. He gave history of effort angina and positive stress test. Patient was prepared for coronary angiogram through right transradial approach (TRA). Radial artery puncture was done and a 5 Fr Radifocus introducer sheath (Terumo) was deployed using standard technique. A 5 Fr Optitorque Tig catheter (Terumo) was introduced with a 0.032˝ standard exchange-length guidewire.

In this patient, the catheter had a tendency to dive repeatedly into the descending thoracic aorta, maintaining right paraspinal position (Figure 1A). It was initially misinterpreted as entry into the right atrium through the superior vena cava. However, pressure tracing was suggestive of arterial pressure. Angiogram with pigtail catheter was done to define anatomy, and confirmed the right paraspinal position of the descending thoracic aorta (Figure 1B). Another angiogram in aortic arch position confirmed innominate artery origin at an acute angle from right aortic arch (RAA; Figure 1C). Keeping curvilinear calcification as a roadmap, the ascending aorta was entered with some difficulty (Figures 1D and 1E). Aortic root angiogram showed a faintly opacified right coronary artery (RCA) that was nondominant and normal (Figure 1F). Selective left coronary artery (LCA) injection was performed after exchanging the Pigtail catheter to a 5 Fr Optitorque Tig catheter (Figure 1G).

Discussion

The incidence of RAA in radiology and autopsy series is approximately 0.1%.^1-3 RAA type-I with mirror-image branching is the most common variant.^1-3 Although uncommon, RAA is an important variant to understand for a radialist because working through right TRA entry in the ascending aorta becomes challenging due to the acute angle of the innominate artery with the RAA (Figure 2). This leads to selective diving of the catheter in the descending thoracic aorta. The problem is quite similar to that encountered while working through arteria lusoria (anomalous origin of right subclavian artery from aortic arch-descending thoracic aorta junction) during right TRA.^4-7 However, anatomically with left aortic arch the descending thoracic aorta usually traverses in front of the spinal column, whereas it transverses in continuity with the right paraspinal region in mirror-image RAA. This is a subtle point to differentiate RAA from arteria lusoria, which is also a challenging and difficult anatomy for a radial operator.^4-7 Catheter course through left aortic arch, right aortic arch, and arteria lusoria have been demonstrated (Figure 3).

Repeated entry of a guidewire and/or catheter in the descending aorta while working through right TRA usually prompts an operator to rule out arteria lusoria.^4-6 However, the possibility of RAA should always be kept in mind because a number of patients with tetralogy of Fallot who have undergone total correction surgery during their childhood may present with coronary artery disease in their later age. The incidence of mirror-image RAA in this patient population is approximately 25% and while working through right TRA, this challenging situation may be encountered.³

Acknowledgment. Authors acknowledge the help extended by Mr Yash Soni and Mr Chidambaram Iyer during preparation of this manuscript.

References

1. Natsis KI, Tsitomidis IA, Didagelos MV, et al. Anatomical variations in the branches of human aortic arch in 833 angiographies: clinical significance and literature review. Surg Radiol Anat. 2009;31(5):319-323.
2. Jaffe RB. Radiographic manifestations of congenital anomalies of the aortic arch. Radiol Clin North Am. 1991;29(2):319-334.
3. Knight L, Edwards JE. Right aortic arch: types and associated cardiac anomalies. Circulation. 1974;50(5):1047-1051.
4. Abhaichand R, Louvard Y, Gobeil J, et al. The problem of arteria lusoria in right transradial coronary angiography and angioplasty. Catheter Cardiovasc Interv. 2001;54(2):196-201.
5. Gilchrist I. Transradial technical tips. Catheter Cardiovasc Interv. 2000;49(3):353-354.
6. Patel T. Right trans-radial approach-working through arteria lusoria. Indian Heart J. 2006;58(4):301.
7. Yiu K, Chan W, Jim M, et al. Arteria lusoria diagnosed by transradial coronary catheterization. JACC Cardiovasc Interv. 2010;3(8):880-881.

______________________________________________

From the ¹Total Cardiovascular Solutions Private Limited, Ahmedabad, India, ²Department of Cardiology, Sheth V.S. General Hospital and Smt. N.H.L. Municipal Medical College, Ahmedabad, India, and ³Department of Cardiology, Mercy Hospital and Community Medical Center, Scranton, Pennsylvania.
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 submitted December 1, 2011, provisional acceptance given December 14, 2011, final version accepted January 2, 2012.
Address for correspondence: Tejas Patel, MD, FACC, FSCAI, FESC, Professor and Head, Department of Cardiology, Sheth V.S. General Hospital and Smt. N.H.L. Municipal Medical College, Ahmedabad-380 006, India. Email: tejaspatel@tcvsgroup.org