Right coronary artery from the left aortic sinus of Valsalva

Anomalous right coronary artery arising from the left aortic sinus of Valsalva is the most common of all coronary anomalies.Reference Mavroudis, Dodge-Khatami, Backer and Lorber²⁸ Anginal symptoms, myocardial ischaemia/infarction, syncope, and atrioventricular block can occur in these patients owing to a slit-like stenotic orifice within the left coronary sinus, and it is often associated with an intramural course within the wall of the aorta before it eventually exits via the right coronary sinus en route to the epicardial surface of the heart. Coronary hypoperfusion and ischaemia ensue owing to intermittent stenosis/closure of the anomalous ostium within the aortic wall during exercise or hypertensive crises. Left ventricular dysfunction occurs during exertion owing to enlargement of the aortic root and pulmonary artery. Most authors ascribe to the idea that the ischaemic perturbation is a result of the stenotic arterial course. A minority believe that there is compression of the coronary artery between the aorta and pulmonary artery. Others postulate that both mechanisms are operative.Reference Mainwaring, Reddy and Reinhartz^19, Reference Gulati, Reddy and Culbertson^20, Reference Rodefeld, Culbertson, Rosenfeld, Hanley and Thompson^22, Reference Mavroudis and Backer²⁷

The course taken by the anomalous right coronary artery generally traverses above or downstream of the commissure between the left and right coronary sinuses of Valsalva. For the most part, the course of the intramural coronary artery is within 1–2 mms of the commissure and generally denotes no risk to aortic valve function during the unroofing operation. Rarely, the intramural course will traverse from one sinus to the other below or upstream to the commissure. The repair of this anatomical entity requires more challenging manoeuvres.

The repair of anomalous aortic origins of the coronary arteries generally requires aortobicaval cardiopulmonary bypass, left ventricular venting, cold cardioplegia, antegrade and retrograde, and aortic transection or subtotal transection (Fig 1a).Reference Mavroudis and Backer¹⁶ When aortic transection is elected, corresponding marking sutures are placed in the ascending and proximal aorta to re-align the re-anastomosis after the repair. After proper exposure is accomplished, the anomalous coronary orifice is measured by calibrated probes and recorded. A dilator is carefully advanced into the tunnel to confirm the intramural course to the right coronary cusp. The unroofing procedure is demonstrated in Fig 1b that can be accomplished by dissection using a sharp scalpel or scissors.Reference Mavroudis and Backer¹⁶ The incision into the slit-like orifice is started with a scalpel or scissors and progresses across the commissure to the coronary artery exit location, most often found in the right coronary cusp. There is no need to rush this part of the operation; extending the incision to the neo-ostium should be made gradually and stopped when the orifice is identified and will allow an appropriately sized dilator without difficulty. Measuring multiple times and cutting only once is the preferred technique. This tenet is especially important when the unroofing incision nears the point where the coronary artery exits the aorta as it courses to the epicardial surface of the heart. If the surgeon discovers that he/she extended the incision through the aortic wall, the coronary and aortic intimal surfaces must be re-attached using interrupted monofilament suture before the operation can continue. When intimal disruption occurs, care must be taken to ensure a competent and secure re-anastomotic suture line, as a poorly reconstructed orifice can result in dissection, bleeding, and coronary occlusion. This situation and the solution thereto pertaining will be reviewed in a subsequent section of this manuscript.

Figure 1 Drawing (a) shows the transected aorta with an intramural and interarterial right coronary artery originating from the left coronary sinus above the involved aortic valve commissure. The dotted lines represent the intramural course. The tunica media (common wall) forms the intramural portion of the vessel. (b) The completed unroofing procedure, which can be accomplished using a blade (shown) or fine scissors. The tunica media can be incised or excised with special care being taken to avoid an unwanted extraaortic (extracardiac) transmural incision. Drawing (c) shows tacking sutures to approximate the intimal edges to prevent dissection at the right coronary sinus neo-orifice. The tacking sutures can be placed at the neo-orifice or the entire length of the unroofed segment. In the event that the tunica media is excised, tacking sutures are generally placed the entire length of the excision similar to the way that was done after performing an endarterectomy. Reproduced with permission from Mavroudis et al. Technical tips for three congenital heart operations: modified Ross–Konno procedure, optimal ventricular septal defect exposure by tricuspid valve incision, coronary unroofing and endarterectomy for anomalous aortic origin of the coronary artery. Oper Tech Thorac Cardiovasc Surg. 2010; 15:18–40. Copyright © 2010, with permission from Elsevier and the American Association for Thoracic Surgery.Reference Mavroudis and Backer¹⁶

After the intramural segment is successfully unroofed, the length is measured and recorded. Careful evaluation will determine whether further courses of action are necessary. Occasionally, the common wall (tunica media) is thick and potentially obstructive. Leaving it in place could threaten the integrity of the newly established orifice. Under these circumstances, one should consider removing the common wall using sharp dissection. The unroofed segment will result in an intimal gap between the coronary artery wall and the aortic wall requiring “tacking sutures” to re-approximate the intimal edges, and thus avoiding dissection and bleeding after separation from cardiopulmonary bypass. Figure 1c shows the tacking sutures that are placed at the neo-orifice of the right coronary artery in the right coronary cusp.Reference Mavroudis and Backer¹⁶ The rest of the unroofed segment usually requires tacking sutures to prevent the aforementioned complications.

Rarely, the anomalous aortic origins of the coronary arteries traverses from the left coronary cusp to the right coronary cusp upstream or below the involved commissure. This anatomical entity requires more creative reparative techniques. Aortic root exposure is shown in Figure 2a after the appropriate cardiopulmonary bypass and cardioplegic manoeuvers have been performed.Reference Mavroudis and Backer¹⁶ A calibrated probe defines the orifice diameter. When advanced further into the tunnel, the probe defines the area of the shared wall between the coronary artery and the aorta that can be incised and unroofed. Figure 2b shows the unroofed proximal intramural segment within the left coronary sinus and the unroofed segment within the right coronary sinus, which effectively creates a neo-orifice.Reference Mavroudis and Backer¹⁶ Caution is observed to avoid injury to the aortic valve leaflets and to avoid any incisions through to the epicardial surface of the heart. Tacking sutures are placed (Fig 2c) to avoid the potential complications of dissection, haemorrhage, and coronary occlusion.Reference Mavroudis and Backer¹⁶

Figure 2 Drawing (a) shows the transected aorta with an intramural and interarterial right coronary artery originating from the left coronary sinus upstream to the height of the commissure (below the involved aortic valve commissure). The dotted lines represent the intramural course. The tunica media (common wall) forms the intramural portion of the vessel. Drawing B shows the completed unroofing procedure and creation of new coronary ostium in the correct sinus, which can be accomplished using a blade (shown) or fine scissors after the common wall in the correct sinus has been located and incised/uncovered. The tunica media can be excised with special care being taken to avoid an unwanted extraaortic (extracardiac) transmural incision. Drawing (c) shows tacking sutures to approximate the intimal edges to prevent dissection at the right coronary sinus neo-orifice. The tacking sutures can be placed at the neo-orifice or the entire length of the unroofed segment taking into consideration the aortic valve commissure, which should be preserved for this type of procedure. Under these circumstances, tacking sutures are generally placed to ensure the integrity of the neo-orifice. Reproduced with permission from Mavroudis et al. Technical tips for three congenital heart operations: modified Ross–Konno procedure, optimal ventricular septal defect exposure by tricuspid valve incision, coronary unroofing and endarterectomy for anomalous aortic origin of the coronary artery. Oper Tech Thorac Cardiovasc Surg. 2010; 15:18–40. Copyright © 2010, with permission from Elsevier and the American Association for Thoracic Surgery.Reference Mavroudis and Backer¹⁶

At the conclusion of the operation, the aorta can be closed and the patient can be separated from cardiopulmonary bypass. Unexpected bleeding or ventricular dysfunction by echocardiography necessitates recommencement of cardiopulmonary bypass and exploration to rule out dissection, anastomotic disruption, and coronary artery occlusion. In general, clinical outcomes with this operation are excellent.

In rare cases, the intramural orifice can be camouflaged behind the commissure between the right and left coronary cusps. This condition will be discussed in a subsequent section.

Left coronary artery from the right aortic sinus of Valsalva

The most serious anomaly of coronary origin is the left main coronary artery arising from the right aortic sinus of Valsalva. It is associated with the highest incidence of symptoms and sudden death.Reference Basso, Maron, Corrado and Thiene⁷ The anatomical characteristics that cause ischaemic complications in “left from right” anomalous aortic origins of the coronary arteries are analogous to those noted in the previous section – “right from left” anomalous aortic origin of the coronary arteries. Similar to “right from left” anomalous aortic origins of the coronary arteries, the intramural course can be above the commissure – that is, downstream to the commissure – between the left and right coronary cusps or below the commissure – that is, upstream to the commissure.

Operative exposure is similar to that previously described. The anatomical particulars for “left from right” anomalous aortic origins of the coronary arteries are demonstrated in Figure 3a.¹⁶ The left coronary orifice is usually small and slit-like; the dashed lines show the course across the commissure into the left coronary cusp. Figure 3b shows the unroofing procedure with a scalpel.Reference Mavroudis and Backer¹⁶ The same precautions are observed as in the previous section to avoid an errant transaortic/transcoronary incision to the epicardial surface of the heart. Such an unwanted occurrence will require accurate identification and repair. Figure 3c demonstrates the unroofing procedure with tacking sutures at the neo-orifice of the left main coronary artery.Reference Mavroudis and Backer¹⁶ Tacking sutures (not shown) are also placed throughout the entire length of the incised tunica media.

Figure 3 Drawing (a) shows the transected aorta with an intramural and interarterial left coronary artery originating from the right coronary sinus above the involved aortic valve commissure. The dotted lines represent the intramural course. The tunica media (common wall) forms the intramural portion of the vessel. Drawing (b) shows the completed unroofing procedure, which can be accomplished using a blade (shown) or fine scissors. The tunica media can be incised or excised with special care being taken to avoid an unwanted extraaortic (extracardiac) transmural incision. Drawing (c) shows tacking sutures to approximate the intimal edges to prevent dissection at the left coronary sinus neo-orifice. The tacking sutures can be placed at the neo-orifice or the entire length of the unroofed segment. In the event that the tunica media is excised, tacking sutures are generally placed the entire length of the excision, similar to the way that was done after performing an endarterectomy. Reproduced with permission from Mavroudis et al. Technical tips for three congenital heart operations: modified Ross–Konno procedure, optimal ventricular septal defect exposure by tricuspid valve incision, coronary unroofing and endarterectomy for anomalous aortic origin of the coronary artery. Oper Tech Thorac Cardiovasc Surg. 2010; 15:18–40. Copyright © 2010, with permission from Elsevier and the American Association for Thoracic Surgery.Reference Mavroudis and Backer¹⁶

In cases where the left main coronary artery arises from the right coronary sinus and courses below or upstream of the commissure to the left coronary sinus, the same techniques are used to unroof this anomalous artery as has been described for the “right from left” subcommissural intramural coronary artery. Figure 4a shows the “left from right” anomalous aortic origins of the coronary arteries as it traverses below the commissure.Reference Mavroudis and Backer¹⁶ The unroofing procedure is accomplished in both sinuses of Valsalva as noted in Figure 4b.¹⁶Figure 4c shows the tacking sutures that form the neo-orifice.Reference Mavroudis and Backer¹⁶

Figure 4 Drawing (a) shows the transected aorta with an intramural and interarterial left coronary artery originating from the right coronary sinus upstream to the height of the commissure (below the involved aortic valve commissure). The dotted lines represent the intramural course. The tunica media (common wall) forms the intramural portion of the vessel. Drawing (b) shows the completed unroofing procedure and creation of a new coronary ostium in the correct sinus, which can be accomplished using a blade (shown) or fine scissors after the common wall in the correct sinus has been located and incised/uncovered. The tunica media can be excised with special care being taken to avoid an unwanted extraaortic (extracardiac) transmural incision. Drawing (c) shows tacking sutures to approximate the intimal edges to prevent dissection at the left coronary sinus neo-orifice. The tacking sutures can be placed at the neo-orifice or the entire length of the unroofed segment taking into consideration the aortic valve commissure, which should be preserved with this type of procedure. Under these circumstances, tacking sutures are generally placed to ensure the integrity of the neo-orifice. Reproduced with permission from Mavroudis et al. Technical tips for three congenital heart operations: modified Ross–Konno procedure, optimal ventricular septal defect exposure by tricuspid valve incision, coronary unroofing and endarterectomy for anomalous aortic origin of the coronary artery. Oper Tech Thorac Cardiovasc Surg. 2010; 15:18–40. Copyright © 2010, with permission from Elsevier and the American Association for Thoracic Surgery.Reference Mavroudis and Backer¹⁶

Another form of anomalous aortic origins of the coronary arteries “left from right” is demonstrated in Figure 5a.¹⁶ Ischaemic clinical episodes are thought to be due to acute angulation of the left main coronary artery at its origin from the right coronary sinus with a long course to the arterial bifurcation. There is no intramural course with this particular anomaly. Figure 5b shows the side-to-side anastomosis between the coronary artery and the aortic wall in the left sinus of Valsalva in progress with fine running suture technique.Reference Mavroudis and Backer¹⁶Figure 5c demonstrates the completed side-to-side anastomosis.Reference Mavroudis and Backer¹⁶ The distal left main coronary artery is shown with the dotted line en route to the arterial bifurcation.

Figure 5 Drawing (a) shows a rare form of anomalous aortic origin of the coronary arteries involving the left coronary artery arising from the right coronary sinus and traversing to the right of the aorta and posteriorly en route to bifurcation into the left anterior descending coronary artery and circumflex coronary artery posterior to the pulmonary artery. (b) How a side-to-side anastomosis can be achieved using fine suture technique without distortion. The completed anastomosis is shown in (c). Reproduced with permission from Mavroudis et al. Technical tips for three congenital heart operations: modified Ross–Konno procedure, optimal ventricular septal defect exposure by tricuspid valve incision, coronary unroofing and endarterectomy for anomalous aortic origin of the coronary artery. Oper Tech Thorac Cardiovasc Surg. 2010; 15:18–40. Copyright © 2010, with permission from Elsevier and the American Association for Thoracic Surgery.Reference Mavroudis and Backer¹⁶

Right coronary artery from the left coronary cusp complicated by unwanted transaortic/transcoronary incision

In general, transaortic repair of an intramural coronary artery is a safe and reproducible operation. Infrequently, the unroofing procedure may result in an unwanted incision through the intimal layers of the aorta and coronary artery, the outcome of which is a disrupted or near-disrupted coronary–aortic connection. These circumstances can have important and serious consequences. They require conscientious evaluation during the unroofing procedure. Figure 6 shows the characteristic intramural course of a right coronary artery with a slit-like opening arising from the left coronary cusp.Reference Mavroudis and Backer²⁷Figure 7 demonstrates the unroofing procedure performed using scissors.Reference Mavroudis and Backer²⁷ When the incision is carried too far, even for 1 mm, intimal coronary-aortic disruption can occur and may be transmural – hole to the epicardial surface of the aorta – or effectively transmural – the disruption being held together by a veil of epicardial tissue with no vascular integrity. Figure 8 demonstrates intimal repair of the coronary-aortic disruption from within the aorta with multiple fine sutures.Reference Mavroudis and Backer²⁷ For the most part, these sutures successfully manage this potential problem. After cross-clamp removal, the repair can be evaluated. If the integrity of the repair is unacceptable, further measures can be undertaken. What is meant by “unacceptable” is problematic and challenging in these situations. Visible blood swirling through the epicardial surface of the repair is clearly an obvious and ominous sign of impending disruption. Other problems are generally obvious and include kinking, stenosis, or suspected intimal integrity. This should result in a re-exploration of the anastomotic repair. Figure 9 demonstrates multiple external fine sutures on the epicardial surface in an attempted repair of the disrupted suture.Reference Mavroudis and Backer²⁷ This should be performed with the cross-clamp and cardioplegic arrest, which is not shown in the drawing. Although this intervention may resolve the problem, internal and external forces on the suture line can disrupt the integrity of the repair and result in bleeding as shown in Figure 10.Reference Mavroudis and Backer²⁷ Additional suture placement will not resolve the problem and in fact will make it worse. Another cross-clamp and cardioplegia administration will be required with removal of all the previously placed sutures. Suture line debridement is required to remove the uneven edges as shown in Figure 11.Reference Mavroudis and Backer²⁷ In most cases, this leaves a large defect; direct anastomosis under these circumstances is ill advised. Some patch material will be required to perform a tension-free anastomotic suture line. A variety of patch material can be used and include polytetrafluoroethylene, autologous pericardium, and other biological substances. Autologous pulmonary artery wall is an ideal patch material for arterial and aortic reconstruction. Figure 12 shows how a piece of pulmonary artery wall is harvested for the coronary-aortic disruption, as demonstrated in Figure 13.Reference Mavroudis and Backer²⁷ This technique ensures a tension-free reconstruction with excellent flow characteristics.

Figure 6 A typical anomalous aortic origin of the coronary arteries, right from left, is shown with an intramural and interarterial course after operative exposure and before any repair techniques are used. Reprinted with permission from Mavroudis et al.Reference Mavroudis and Backer²⁷

Figure 7 The unroofing procedure using scissors is shown with extension to the orifice of the coronary artery where it emerges from the aorta. This is the location where the incision can be taken too far and may result in transluminal extension and disruption. (LCA, left coronary artery; RCA, right coronary artery) Reprinted with permission from Mavroudis et al.Reference Mavroudis and Backer²⁷

Figure 8 Tacking sutures are placed whether or not an unwanted external transmural incision is made. If the incision is transmural, care must be taken to include all the layers of the coronary-aortic junction within the repair. This is the potential site of vascular disruption and can cause, bleeding, dissection, and poor perfusion. (LCA, left coronary artery; RCA, right coronary artery) Reprinted with permission from Mavroudis et al.Reference Mavroudis and Backer²⁷

Figure 9 Shows the attempted reparative sutures being placed at the site of previous disruption and internal attempted repair. Care is taken to ensure a tension-free anastomosis. Otherwise, delayed disruption can occur and cause haemorrhage. Reprinted with permission from Mavroudis et al.Reference Mavroudis and Backer²⁷

Figure 10 The delayed haemorrhage that was predicted in Figure 9 is shown in this drawing. This condition should be treated by re-institution of cardiopulmonary bypass, aortic cross-clamping, and patch repair of the anastomosis. Reprinted with permission from Mavroudis et al.Reference Mavroudis and Backer²⁷

Figure 11 The disrupted anastomotic site is controlled and the edges are debrided after the sutures are removed. This creates a moiety that will require patch material. Reprinted with permission from Mavroudis et al.Reference Mavroudis and Backer²⁷

Figure 12 A piece of pulmonary artery wall is an excellent autograft for the anastomotic repair. The moiety left in the pulmonary artery can be closed with pericardium or polytetrafluoroethylene. Reprinted with permission from Mavroudis et al.Reference Mavroudis and Backer²⁷

Figure 13 The complete repair of the disrupted coronary artery is shown using the pulmonary artery wall as the patch material. Reprinted with permission from Mavroudis et al.Reference Mavroudis and Backer²⁷

The camouflaged coronary intramural orifice by the aortic commissure

In rare circumstances, as alluded to in a previous section, the orifice of an intramural coronary artery may arise at the commissure between the right and left coronary cusps that can obstruct the surgeon’s view of the slit-like opening. Unless, an accurate pre-operative determination is made, the folds and unsupported wall of the aorta may cause the surgeon to miss the course of the intramural coronary artery. This state of affair can cause particular dismay, as the pre-operative diagnosis may not be confirmed despite all efforts to identify the anatomical characteristics of the intramural coronary artery. The unsuspecting surgeon may conclude that there is proximal coronary orifice atresia. This situation is noted in Figure 14.Reference Mavroudis and Backer²⁷ The intramural course of the anomalous right coronary artery with the slit-like orifice is camouflaged by the aortic commissure as noted by the dotted/dashed lines. Exploration of the epicardial surface reveals the right coronary artery, which apparently arises from the right coronary cusp (Fig 15), but could be misconstrued as an orifice atresia as the orifice is not found in the right coronary cusp;Reference Mavroudis and Backer²⁷ however, as the dotted/dashed lines indicate, the epicardial right coronary artery is the continuation of the intramural portion from the left coronary cusp that is camouflaged by the associated commissure. Failure to identify this anatomical configuration can be managed in the same manner as is performed for proximal coronary artery atresia. The dotted line in Figure 15 indicates a proposed incision from the top of the transected aorta to the epicardial surface of the right coronary artery on the epicardial surface.Reference Mavroudis and Backer²⁷ The proposed incision will unite the aorta and the coronary artery in preparation for the final repair. Figure 16 demonstrates the incision onto the epicardial surface of the right coronary artery.Reference Mavroudis and Backer²⁷ The surgeon can now detect the intramural course of the right coronary artery and with a probe can demonstrate the camouflaged origin behind the commissure. Obviously, the placement of a patch will be necessary to create a tension-free neo-orifice. A piece of autologous pulmonary trunk is harvested for the eventual repair (Fig 17).Reference Mavroudis and Backer²⁷ The patch is used to augment the orifice of the right coronary artery with anastomotic extension to the aortic wall, thereby forming the neo-orifice as demonstrated in Figure 18.Reference Mavroudis and Backer²⁷ The moiety that was created by the unroofing procedure is treated by multiple tacking sutures. The neo-orifice is completed as shown in Figure 19.Reference Mavroudis and Backer²⁷ After separation from cardiopulmonary bypass, the concluded reconstruction is shown in Figure 20.Reference Mavroudis and Backer²⁷

Figure 14 Rarely, an anomalous aortic origin of the coronary artery intramural coronary orifice may be camouflaged by the commissure between the right and left coronary cusps. On preliminary inspection, the surgeon may not find or appreciate the orifice. Shown in this drawing is an anomalous aortic origin of the coronary artery (right from left) with the orifice directly associated with the commissure and intramural course (dotted lines). (LCA, left coronary artery; RCA, right coronary artery) Reprinted with permission from Mavroudis et al.Reference Mavroudis and Backer²⁷

Figure 15 When the camouflaged orifice is not appreciated or diagnosed upon exposure, a tentative diagnosis of right coronary orifice atresia can be entertained and can trigger a modified surgical solution. The figure shows three dotted lines. The two parallel dotted lines depict the undiagnosed intramural right coronary artery; the other dotted line signifies the incision from the transected aorta to the epicardial coronary artery in order to connect the aorta and the coronary artery with a patch. This option takes the path of orifice atresia repair. (LCA, left coronary artery; RCA, right coronary artery) Reprinted with permission from Mavroudis et al.Reference Mavroudis and Backer²⁷

Figure 16 The drawing depicts the completed incision from the aorta to the proximal right coronary artery. Once this incision is made, the surgeon can now find more readily the intramural segment in a retrograde manner as noted by the nerve hook. The camouflaged orifice is demonstrated at the commissure. (LCA, left coronary artery; RCA, right coronary artery) Reprinted with permission from Mavroudis et al.Reference Mavroudis and Backer²⁷

Figure 17 A piece of pulmonary wall autograft is shown being harvested for the coronary artery–aorta patch repair. The resultant defect in the pulmonary artery can be repaired with autologous pericardium or a polytetrafluoroethylene patch. Reprinted with permission from Mavroudis et al.Reference Mavroudis and Backer²⁷

Figure 18 The pulmonary wall autograft is shown being anastomosed to the proximal right coronary artery with eventual anastomosis to the aortic wall to complete the neo-orifice reconstruction. (LCA, left coronary artery; RCA, right coronary artery) Reprinted with permission from Mavroudis et al.Reference Mavroudis and Backer²⁷

Figure 19 The neo-orifice reconstruction is completed. Also shown are the tacking sutures that are placed within the aorta where the unroofing procedure was performed. Reprinted with permission from Mavroudis et al.Reference Mavroudis and Backer²⁷

Figure 20 The completed operation is demonstrated after separation from cardiopulmonary bypass. Transoesophageal echocardiography will confirm flow within the neo-orifice and absence of ventricular wall motion abnormalities and electrocardiography will help establish coronary flow and preserved ventricular function. Reprinted with permission from Mavroudis et al.Reference Mavroudis and Backer²⁷

Whether this type of reconstruction is the ideal solution for this anatomical problem is not clear. Without question, the involved commissure is not manipulated, incised, or detached; thus, the possibility of resultant aortic regurgitation remains remote. In addition, the neo-orifice is large and generally not subject to stenosis. In contrast, epicardial bleeding and coronary distortion are always potential complications that may occur using this technique. Whatever operation is performed for this anomaly, peri-operative myocardial function as determined by transoesophageal echocardiography, electrocardiography, and timely cardiac catheterisation are essential to confirm adequate coronary flow and will avoid peri-operative complications.

Anomalous aortic origin of a coronary artery with a non-intramural malignant course between the aorta and the pulmonary artery

In particular, one of the more challenging types of anomalous aortic origin of the coronary arteries is manifested by a non-intramural malignant course between the aorta and the pulmonary artery. This type of anomalous aortic origins of the coronary arteries represents diagnostic and therapeutic intraoperative dilemmas that are worthy of discussion. The diagnostic problem involves uncertainty of the modern-day imaging techniques that distinguish between an intramural and extramural course traversing between the great vessels. In many cases, the anatomy is not confirmed until operative exposure is established. Upon identification of an extramural course, a re-implantation approach is commenced. This involves dissection and removal of the involved coronary artery button from the constrictive actions of the great vessels with eventual re-implantation to an unaffected site on the ascending aorta, thereby forming an unobstructed neo-orifice.

Figure 21 shows the characteristic course of an extramural anomalous right coronary artery arising from the left coronary sinus.Reference Mavroudis and Backer²⁷ The figure demonstrates the right coronary button harvest from the left coronary sinus. Also noted in the drawing is the proposed anastomotic site on the ascending aorta that is downstream of the right coronary cusp. This places the neo-orifice away from the constrictor effects that take place in the area between the aorta and the pulmonary artery. The construction of the neo-orifice requires careful and safe dissection with mobilisation of the affected coronary artery to the epicardial surface to avoid unwanted coronary traction or kinking. In Figure 21, the affected coronary artery reconstruction is intentionally not shown to be completely dissected and mobilised to illustrate the unfavourable reconstruction and anatomical distortion that can occur after initial repair as shown in Figure 22.Reference Mavroudis and Backer²⁷ This drawing demonstrates the unfavourable flow characteristics that follow suboptimal epicardial dissection and coronary mobilisation. Figure 23 demonstrates the reparative techniques that are used to perform a more comprehensive epicardial dissection and mobilisation that can permit optimisation of coronary flow.Reference Mavroudis and Backer²⁷

Figure 21 Occasionally, the surgeon can be confronted with an extramural (non-intramural) course of a coronary artery and is not amenable to unroofing and will require coronary transfer and neo-orifice reconstruction. The figure shows an anomalous aortic origin of the coronary artery (right from left) with a malignant course between the pulmonary artery trunk and the aorta. Sharp dissection is used to harvest the right coronary button, mobilise the coronary artery, and re-implant the coronary button into a more superior site in the right coronary cusp. A landing site is prepared by removing a small portion of the ascending aorta in preparation for neo-orifice anastomosis. Also shown, but not altogether appreciated, is the conal branch of the right coronary artery that has the possibility of causing a resultant distorted anatomical configuration. (LCA, left coronary artery; LCC, left coronary cusp; NCC, noncoronary aortic cusp; RCA, right coronary artery; RCC, right coronary cusp) Reprinted with permission from Mavroudis et al.Reference Mavroudis and Backer²⁷

Figure 22 The resultant neo-orifice anatomical configuration is shown with an acute angle of the right coronary artery course that will endanger normal flow characteristics. The original epicardial dissection was not performed extensively enough to offer an unobstructed and distortion-free course of the coronary artery. (LCA, left coronary artery; RCA, right coronary artery) Reprinted with permission from Mavroudis et al.Reference Mavroudis and Backer²⁷

Figure 23 The figure shows more epicardial dissection and coronary mobilisation that can be performed with careful blunt dissection and low-setting electrocautery control of bleeding. The coronary artery can be mobilised enough, in most cases, to allow resultant favourable flow characteristics. (LCA, left coronary artery; RCA, right coronary artery) Reprinted with permission from Mavroudis et al.Reference Mavroudis and Backer²⁷

The operative principles for coronary re-implantation and neo-orifice reconstruction for anomalous aortic origins of the coronary arteries without an intramural course involve comprehensive coronary artery mobilisation, appropriate neo-orifice location, comprehensive assessment of ventricular function, and verification of coronary flow.

Summary

The diagnostic challenges and intraoperative techniques reviewed in this article should be noted by surgeons who perform these operations. All anomalous aortic origins of the coronary arteries are not the same and all anomalous aortic origins of the coronary arteries are not subject to a simple unroofing procedure. Complications can be serious and will require accurate and sometimes more extensive solutions.