**5.1 Orifices**

A normal coronary orifice is more or less round, or slightly ovoid. Our knowledge about orifices of ANOCOR is mostly taken from postmortem (Frescura et al., 1998, Kragel et al., 1988) and individual peroperative examinations. The invasive coronary arteriography has understandable limitations for the visualization of the orifice shape. More recently, qualitative and quantitative assessment of the orifices and initial paths of ANOCOR has been documented by IVUS during conventional coronary angiography (Angelini et al., 2003). It is important to consider that an anomalous origin of a coronary artery does not imply systematically an abnormal shape of its orifice. The ANOCOR connected with the contralateral artery must have, in theory, a normal coronary orifice. Indeed, the initial segment, the first millimetres at least, of the ectopic coronary has a normal angulation (>45°) with the contralateral artery. On the contrary, the anomalous origins from the inappropriate sinus with an initial course tangential to aorta are most often associated with an abnormal orifice. A slit-like ostium is generally described in the postmortem descriptions. A similar feature is found by surgeons through an intra aortic view (figure 8). Rare selective coronary angiograms suggest the presence of a membrane-like ostial stenosis (Angelini et al., 2006). As mentioned above, an abnormal orifice of a coronary artery connected with the usual site of the appropriate sinus has been described, but rarely (Frescura et al., 1998).

Fig. 8. Peroperative view showing an ectopic origin of the right coronary artery (arrow) from the left sinus close to the origin of the left coronary artery (arrowhead).

#### **5.2 Initial courses**

194 Congenital Heart Disease – Selected Aspects

An exact analysis of the orifices and courses of ANOCOR is of crucial importance, while the pathophysiological mechanisms of cardiac adverse events are mainly based on anatomical

A normal coronary orifice is more or less round, or slightly ovoid. Our knowledge about orifices of ANOCOR is mostly taken from postmortem (Frescura et al., 1998, Kragel et al., 1988) and individual peroperative examinations. The invasive coronary arteriography has understandable limitations for the visualization of the orifice shape. More recently, qualitative and quantitative assessment of the orifices and initial paths of ANOCOR has been documented by IVUS during conventional coronary angiography (Angelini et al., 2003). It is important to consider that an anomalous origin of a coronary artery does not imply systematically an abnormal shape of its orifice. The ANOCOR connected with the contralateral artery must have, in theory, a normal coronary orifice. Indeed, the initial segment, the first millimetres at least, of the ectopic coronary has a normal angulation (>45°) with the contralateral artery. On the contrary, the anomalous origins from the inappropriate sinus with an initial course tangential to aorta are most often associated with an abnormal orifice. A slit-like ostium is generally described in the postmortem descriptions. A similar feature is found by surgeons through an intra aortic view (figure 8). Rare selective coronary angiograms suggest the presence of a membrane-like ostial stenosis (Angelini et al., 2006). As mentioned above, an abnormal orifice of a coronary artery connected with the usual site

of the appropriate sinus has been described, but rarely (Frescura et al., 1998).

Fig. 8. Peroperative view showing an ectopic origin of the right coronary artery (arrow) from

the left sinus close to the origin of the left coronary artery (arrowhead).

**5. Orifices, initial and ectopic courses** 

findings.

**5.1 Orifices** 

It is admitted that a slit-like orifice, almost without exception, is associated with an intramural course. The latter means a course of the first millimetres of the ectopic vessel in the aortic media. Therefore, no adventitia exists between the coronary media and aortic media. The length of the intramural path is ranged from 5 to 25 mm, much longer for the left ANOCOR (Angelini & Flamm, 2007). An intramural course is not synonymous with a preaortic course, and inversely (Houyel & Planché, 2008). The ANOCOR arising from the opposite sinus, and without a preaortic or retroaortic course, have generally a normal orifice, while they move quickly from the aorta, and their initial courses are therefore extramural. The ANOCOR with a retroaortic course have in most cases a juxtamural course regarding the aorta, although rare observations with abnormal orifice and/or intramural course have been reported. The ANOCOR with a high take-off above the sinotubular junction may have an abnormal orifice with a vertical intramural initial course. Generally, the orifice of the anomalous connections with the pulmonary artery is circular with an extramural or juxtamural initial course. Coronary IVUS, now easily available, gives important quantitative parameters regarding the orifices and initial courses of ANOCOR (Angelini & Flamm 2007). The ellipsoid shape of an ectopic orifice is well visualized. Also important, coronary IVUS highlighted systematically a hypoplasia of the intramural segment in comparison with the more distal, extramural segment.

#### **5.3 Ectopic courses**

The ectopic course of an ANOCOR may be defined as the coronary path between the orifice and the point where the ectopic artery meet up with an appropriate myocardial area. The length of the ectopic course varies considerably regarding the site of ectopic ostium and relationships with the adjacent structures. The definitions of different ectopic courses are still used in an ambiguous fashion. Usually, 4 subgroups of anomalous origin of the LCA from the opposite sinus are described: anterior to pulmonary trunk, between aorta and pulmonary trunk, in ventricular septum, and posterior to aorta courses (Roberts & Shirani, 1992). For the purpose of being close to the anatomical descriptions and recent imaging contributions, we classify the ANOCOR into 7 courses relating to their links with the great vessels and/or ventricles (table 6). We chose to define each course according to the closest adjacent cardiac structure (figure 9).


Table 6. Different courses of anomalous origins of the coronary arteries.

Proximal Anomalous Connections of Coronary Arteries in Adults 197

subpulmonic or intraseptal or intraconal course. The nomenclature used in this review appears more appropriate regarding the cardiac anatomy. The left coronary artery (LMCA or LAD) with retroinfundibular course provide always one or more septal branches in the

Fig. 10. Computed tomography imaging of an ectopic left main coronary artery (arrow) arising from the right sinus with a retroinfundibular course. AO: aorta, SPI: subpulmonary

**AO**

The typical preaortic course is tangential to the aorta through the fibroadipose tissue separating the arterial roots, (figure 11). Nomenclatures using the so-called interarterial course, in other words between the aorta and the pulmonary artery, may be ambiguous. In fact, a LCA connected in the opposite sinus or contralateral artery, and coursing anterior to the aorta, is in contact first with the subpulmonary infundibulum. A close contact with the pulmonary trunk is also possible because a LCA arising from the opposite sinus with a preaortic path, courses distally near the usual origin of the vessel before to join the interventricular groove. Conversely, an ectopic RCA is in contact first with the pulmonary trunk and then with the subpulmonary infundibulum before to join the atrioventricular groove. ANOCOR with high take-off from the aorta above the sinuses have, by definition, a preaortic course. The presence of an intramural segment, as defined above, must be

**5.3.3 Preaortic course with intramural segment (type C)** 

**SPI** 

systematically looked for in order to stratify the risk.

floor of the right ventricular outflow tract.

infundibulum.

Fig. 9. Anatomic representation of the courses of an anomalous left coronary artery arising from the right sinus. A: preinfundibular course, B: retroinfundibular course, C: preaortic course, D: retroaortic course. LS: left sinus, RS: right sinus.

#### **5.3.1 Preinfundibular course (type A)**

The prepulmonary course involves the ectopic paths coursing on the surface of the pulmonary trunk or subpulmonary infundibulum. The latter is mostly concerned. In case of a long and sinuous course, both pulmonary trunk and subpulmonary infundibulum may be in contact with the ectopic vessel. The vessel coursing with a prepulmonary path, almost without exception, is the left coronary artery (LMCA or LAD or septal branch arising from the opposite sinus or the RCA).
