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Year : 2018  |  Volume : 1  |  Issue : 1  |  Page : 59-61

Intercoronary communication associated with chronic total occlusion: A rare combination

Department of Cardiology, Government Medical College, Kozhikode, Kerala, India

Date of Web Publication24-Aug-2018

Correspondence Address:
Dr. Kailash Kumar Goyal
Department of Cardiology, Super‑Specialty Block, Government Medical College, Kozhikode - 673 008, Kerala
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/IHJI.IHJI_8_17

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Intercoronary communication (ICC) is a rare coronary artery anomaly which may occur with or without associated obstructive coronary artery disease. Lack of awareness of this entity often leads to them being misinterpreted as functioning collaterals in patients with chronic total occlusion. However, if identified, these vessels may act as an important channel in an attempt to open such vessels through retrograde approach. We herein report a case of ICC associated with chronic total occlusion which was identified following a successful percutaneous transluminal coronary angioplasty.

Keywords: Chronic total occlusion, intercoronary communication, milking phenomenon, open-ended circulation

How to cite this article:
Goyal KK, Muneer K, Sajeev CG. Intercoronary communication associated with chronic total occlusion: A rare combination. Indian Heart J Interv 2018;1:59-61

How to cite this URL:
Goyal KK, Muneer K, Sajeev CG. Intercoronary communication associated with chronic total occlusion: A rare combination. Indian Heart J Interv [serial online] 2018 [cited 2019 May 22];1:59-61. Available from: http://www.ihji.org/text.asp?2018/1/1/59/239784

  Introduction Top

Intercoronary communication (ICC) is a rare congenital anomaly and defined as an open-ended circulation in which there is uni-directional or bi-directional blood flow between two coronary arteries. Initially described by Cheng in 1972,[1] very few cases have been reported in the literature. The true incidence of ICC is unknown but reported to be around 0.05%.[2] They are different from collateral vessels anatomically, histologically as well as clinically. These may have a protective role if one of the connecting vessels develop an obstruction or may cause a coronary steal phenomenon resulting in myocardial ischemia in patients with otherwise normal coronary arteries. We herein report a case where an ICC between the right coronary artery (RCA) and left circumflex (LCX) arteries was identified following angioplasty of RCA.

  Case Report Top

A 65-year-old diabetic and the hypertensive male patient was admitted with exertional angina Grade III for the past 3 months. He was a chronic smoker and had a history of nonST-elevation myocardial infarction, 6 months back which was managed medically. The patient was taken for elective coronary angiography via a right femoral approach which showed a totally obstructed left anterior descending (LAD) artery and near-total obstruction of the RCA, whereas the LCX artery was normal. Retrograde filling of RCA up to crux was seen on left injection [Figure 1]. After discussing with the patient and his relatives, he was posted for elective percutaneous transluminal coronary angioplasty of LAD and RCA lesions.
Figure 1: (a) LAO caudal view showing normal LMCA(left main coronary artery), mild disease in ostioproximal LAD and normal LCX artery. (b) RAO caudal view showing normal LCX and total occlusion of LAD artery. (c) PA cranial view showing total obstruction of mid LAD artery. (d) LAO cranial view showing LAD total and RCA filling upto crux retrogradely. (e) LAO caudal view showing near total occlusion of RCA. (f) PA cranial view showing near total occlusion of RCA

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LAD lesion was crossed with a run-through NS wire, predilated and then stented with a 2.75mm × 23mm xience prime drug-eluting stent at a pressure of 8 atmosphere to a diameter of 2.75mm. Following this, RCA was stented using a 2.75mm × 24mm endeavor resolute drug-eluting stent at a pressure of 9 atmosphere to a diameter of 2.80mm, and the posterior descending artery was stented using a 2.25mm × 23mm xience prime stent to a diameter of 2.27mm. Check injection following RCA stenting showed retrograde filling of the LCX artery along with a typical milking phenomenon which is classical for an ICC [Video 1]. Further, a detailed and careful analysis of the angiogram showed that the connection between RCA and LCX was formed by a single vessel which had a larger diameter and a relatively straighter course [Figure 2]. Thus, an ICC between RCA and LCX was considered. The patient was shifted to CCU where he was kept for 24h and then to cardiology ward. There were no postprocedure complications and patient was discharged on the 3rd postoperative day.
Figure 2: Intercoronary communication between right coronary artery and left circumflex

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  Discussion Top

ICC is a rare coronary artery anomaly in which direct communication is present between two main coronary arteries. True prevalence is not known. However, this is the second case identified by us among the 14,852 coronary angiograms performed at our institute over the past 6 years (0.013%).[3] Two types have been described in the literature: communication between the anterior and posterior interventricular arteries in the distal interventricular groove and between the LCX and the RCA (as described in our case).[4] The second type with communication between LCX and RCA appears to be more common as most of the cases described are of this type.

Collateral vessels, which develop in the presence of obstructive coronary artery disease are usually <1mm in diameter, multiple, tortuous with a corkscrew shape and intramural. ICC, in contrast, is large diameter vessels, generally single, straight or gently curved and extramural with an epicardial course. Histologically, collaterals are composed of endothelium supported by poorly organized collagen and elastic fibers, whereas ICCs have a well-defined muscular layer.[5] Since the histological structure of an ICC is comparable to that of a normal artery, it is assumed that persistence of fetal coronary circulation is the mechanism responsible for its presence in individuals with otherwise normal coronary arteries. Milking phenomenon is an interesting observation seen in patients with ICC. It is believed to be due to competitive blood flow between the vessels connected through an ICC. This phenomenon is not seen with collaterals as they are smaller in size and blood flow through them is limited.

Functional significance of an ICC is not known. It is believed to have a protective role if one of the vessels connected by it develops significant stenosis. On the contrary, a unidirectional ICC may cause myocardial ischemia through coronary steal phenomenon in patients with normal coronary arteries.[4] Due to its large size and histological similarity to the normal artery, an ICC may also serve as a good channel for the retrograde approach in patients with chronic total occlusion in case the anterograde approach fails. Thus, the awareness of this rare congenital anomaly is important to avoid misinterpretation of a coronary angiogram as well as to identify its potential role in the retrograde approach for opening a chronic totally occluded artery.

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Conflicts of interest

There are no conflicts of interest.

  References Top

Cheng TO. Arteriographic demonstration of intercoronary arterial anastomosis in a living man without coronary artery disease. Angiology 1972;1:76–88.  Back to cited text no. 1
Hines BA, Brandt PW, Agnew TM. Unusual intercoronary artery communication: A case report. Cardiovasc Intervent Radiol 1981;1:259–63.  Back to cited text no. 2
Rajesh KF, Ranjith MP, Sajeev CG, Krishnan MN. Intercoronary communication between the circumflex and right coronary artery. Heart Asia 2013;1:252.  Back to cited text no. 3
Gur M, Yilmaz R, Demirbag R. Unidirectional communication between the circumflex and right coronary arteries: A very rare coronary anomaly and cause of ischemia. Int J Cardiovasc Imaging 2006;1:339–42.  Back to cited text no. 4
Panayiotou H, Perry JM, Norris JW. Intercoronary connection and apical left ventricular hypertrophy: Case report and review of the literature. Cathet Cardiovasc Diagn 1991;1:55–7.  Back to cited text no. 5


  [Figure 1], [Figure 2]


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