Type B Left Circumflex Coronary Artery With Anomalous Origin Overlooked during Catheter Angiography.
Coronary artery anomalies are vascular anatomical differences seen in less than 1% of the population. The more common abnormal anatomical changes may be classified as the variations of normal (1, 2).Coronary artery anomalies are classified in various ways. When classified anatomically, the ostium, the origin and course of the artery are examined (3). The retro-aortic course of the left circumflex (LCX) artery is considered to be one of the most common coronary artery anomalies with a frequency of up to 0.67% (1, 4-6).
In this case, we present the computed tomography (CT) angiographic images of a patient with Type B anomalous LCX artery, which is relatively rare. Especially, CT angiographic images are rare in the literature because this anomaly has been mostly detected by catheter angiography in studies with large patient populations.
A 63 year-old female patient had angina pectoris caused by physical activity. She had been referred to the radiology clinic for cardiac CT angiography. Written consent was obtained from the patient before the examination. The examination was performed in the 256-detector multislice CT scanner (Somatom Definition Flash, Siemens Healthcare, Erlangen, Germany) with a cross-sectional thickness of 0.6250625 mm using the ECG gating method. The images were evaluated using syngo.via VB10B (Siemens Healthcare GmbH, Erlangen, Germany). Overall, 95 mL intravenous iodinated-contrast agent (iohexol, Omnipaque 350 mg/mL, GE Healthcare, Princeton, New Jersey) was administered to visualize the coronary arteries. Catheter angiography was performed in another medical center abroad five months before the CT angiography examination in our clinic. The prior examination failed to show the abnormal LCX artery. CT angiography showed the LCX artery with thin calibration originating from the right sinus valsalva with the right coronary artery (RCA) (Figure 1). Retro-aortic course of the abnormal LCX artery was well visualized on both cross-sectional and volume-rendered images (Figure 2-3). The origin of this artery was very close to that of RCA. Abnormal LCX artery was assessed as a branch that separated from the proximal of RCA. The proximal segment of the left main coronary artery (LMCA) was longer than anticipated and the bifurcation to LCX and left anterior descending (LAD) arteries was not seen (Figure 4). In this hypoplastic LCX artery case, the lateral wall of the left ventricle was vascularized by the well-developed diagonal branches of LAD and posterolateral branches of RCA.
The anomalous origin of LCX artery and its retro-aortic course is usually considered as one of the benign anomalies of the coronary artery tree in the absence of atherosclerosis (1, 4). Non-visualization of the abnormal LCX artery in catheter angiography in this case did not result in any undesirable results for the patient. Because CT angiography showed no significant atherosclerotic changes in this thin-calibrated artery. However, the fact that coronary artery anomalies are not known before the operation, especially in patients undergoing cardiac valve surgery, may lead to iatrogenic damage to these arterial structures (3, 7). Suspicious findings in terms of abnormal LCX artery are the absence of its visualization, lack of perfusion in the left lateral wall, and a LMCA with a non-branching, long proximal segment after the injection of the contrast medium into LMCA in catheter angiography (4, 5). Contrast medium injections into RCA may sometimes not show an abnormal LCX artery, as in our patient. To avoid this, the tip of the catheter needs to be moved closer to the ostium or to the more posterior part of the sinus valsalva (4, 8). In a study analyzing 20 abnormally originating LCX arteries, this anomaly was classified into three types (5). In type A, RCA and LCX have separate ostiums in right sinus of valsalva, whereas in type B, the LCX artery is a discrete branch of RCA. In type C, two arteries have a common ostium. The anomaly in our case matches to the type B. In our case, contrast filling in the abnormal LCX artery may have been prevented by the catheter itself because of location of origin as very close to the RCA ostium. In addition, a slight contrast enhancement may have not been recognized in the two-dimensional views because of its hypoplastic structure. It may be difficult to distinguish between the absence of LCX artery and the LCX artery with anomalous origin by catheter angiography in such types because in the case of hypoplastic LCX artery, the left ventricle lateral wall may be vascularized by branches from the RCA and LAD, as in the absence of LCX artery (7). As shown in our case, CT angiography is a non-invasive and successful imaging modality for detecting such troublesome or complex anomalies (9). In a published case, catheter angiography showed the LCX artery arising from the right sinus of valsalva; however, the proximal course of the artery was not assessed precisely and CT angiography was performed (10).
In conclusion, the frequency of the coronary artery anomalies may be higher than the rates determined by catheter angiography. CT angiography can be used as a first-line imaging method especially in young patients suspected of coronary artery anomalies and as a supplementary imaging method to be aware of iatrogenic hazards before cardiac surgery is performed.
Informed Consent: Written informed consent was obtained from the patient who participated in this study.
Peer-review: Externally peer-reviewed.
Author contributions: Concept - M.K.; Design - S.G.; Supervision - M.K.; Data Collection and/or Processing - S.G.; Analysis and/or Interpretation - S.G.; Literature Search - S.G.; Writing - S.G.; Critical Reviews - M.K.
Conflict of Interest: No conflict of interest was declared by the authors.
Financial Disclosure: The authors declared that this study has received no financial support.
(1.) Villa AD, Sammut E, Nair A, Rajani R, Bonamini R, Chiribiri A, Coronary artery anomalies overview: The normal and the abnormal. World J Radiol, 2016; 8: 537-55. [CrossRef]
(2.) Pursnani A, Jacobs JE, Saremi F, Levisman J, Makaryus AN, Capunay C, et al. Coronary CTA assessment of coronary anomalies. J Cardiovasc Comput Tomogr 2012; 6: 48-59. [CrossRef]
(3.) Shriki JE, Shinbane JS, Rashid MA, Hindoyan A, Withey JG, DeFrance A, et al. Identifying, characterizing, and classifying congenital anomalies of the coronary arteries. Radiographics 2012; 32: 453-68. [CrossRef]
(4.) Yamanaka O, Hobbs RE, Coronary artery anomalies in 126,595 patients undergoing coronary arteriography. Cathet Cardiovasc Diagn 1990; 21: 28-40. [CrossRef]
(5.) Page HL Jr, Engel HJ, Campbell WB, Thomas CS Jr; Anomalous origin of the left circumflex coronary artery. Recognition, antiographic demonstration and clinical significance. Circulation, 1974; 50: 768-73. [CrossRef]
(6.) Angelini P, Fairchild VD, editors. Coronary artery anomalies: a comprehensive approach. Philadelphia: Lippincott Williams & Wilkins; 1999.
(7.) Ali FS, Khan SA, Tai JM, Fatimi SH, Dhakam SH, Congenital absence of left circumflex artery with a dominant right coronary artery. BMJ Case Rep 2009; 2009.
(8.) Ali M, Hanley A, McFadden EP, Vaughan CJ. Coronary artery anomalies: a practical approach to diagnosis and management. Heart Asia 2011; 3: 8-12. [CrossRef]
(9.) Kacmaz F, Ozbulbul NI, Alyan O, Maden O, Demir AD, Balbay Y, et al. Imaging of coronary artery anomalies: the role of multidetector computed tomography. Coron Artery Dis 2008; 19: 203-9. [CrossRef]
(10.) Lee Y-S, Lee J-B, and Kim K-S, Anomalous Origin of the Left Circumflex Coronary Artery from the Right Sinus of Valsalva Identified by Imaging with Multidetector Computed Tomography. Korean Circ J 2006; 36: 823-5. [CrossRef]
Sertan Gezgin [iD], Murat Kocaoglu [iD]
Department of Radiology, Near East University School of Medicine, Nicosia, Turkish Republic of Northern Cyprus
ORCID ID of the author: S.G.: 0000-0002-5936-5392, M.K.: 0000-0002-4674-8634.
Corresponding Author: Sertan Gezgin
|Printer friendly Cite/link Email Feedback|
|Title Annotation:||Case Report|
|Author:||Gezgin, Sertan; Kocaoglu, Murat|
|Publication:||Cyprus Journal of Medical Sciences|
|Date:||Apr 1, 2018|
|Previous Article:||Vaginal-Cuff Dehiscence and Evisceration after Radical Robotic Surgery for Urothelial Carcinoma of the Urinary Bladder.|
|Next Article:||Iatrogenic Huge Colon Perforation during Colonoscopy.|