C 1% to 2% of the population [l]. In addition to

Transcription

1 Congenital Malformations of the Coronary Arteries: The Texas Heart Institute Experience Eugene D. Fernandes, MD, Hooshang Kadivar, MD, Grady L. Hallman, MD, George J. Reul, MD, David A. Ott, MD, and Denton A. Cooley, MD Department of Cardiovascular Surgery, Texas Heart Institute, Houston, Texas Coronary artery anomalies, some of which are considered clinically insignificant, can be associated with other congenital heart defects, myocardial ischemia, and reduced life expectancy. We conducted a retrospective study to determine the efficacy of surgical treatment in 191 patients who had a total of 202 coronary artery anomalies, which were classified as anomalies of origin (88 patients), termination (93), or distribution (10). Of the 88 patients with anomalies of origin, 60 had a coronary artery arising from the pulmonary artery, 18 had a right coronary artery arising from the left anterior descending artery, and 10 had a coronary artery arising from the contralateral sinus of Valsalva. All patients with an anomaly of termination had a coronary arteriovenous fistula, and all patients with an anomaly of origin had a single coronary artery. The diagnostic and operative techniques for each of the defects are evaluated. Based on our experience, early diagnosis and surgical intervention can yield satisfactory results in patients with coronary artery anomalies, with most experiencing relief of symptoms. The operative procedures were associated with a low early and late mortality; in addition, few patients experienced complications. (Ann Thorac Surg 1992;54:732-40) ongenital anomalies of the coronary arteries occur in C 1% to 2% of the population [l]. In addition to making angiographic visualization of the coronary circulation more difficult, these congenital anomalies may increase the risk of coronary artery trauma during surgical procedures. Moreover, certain types of anomalies may also produce myocardial ischemia [2]. Nonetheless, stateof-the-art echocardiography and angiography make early detection and accurate delineation of these rare coronary anomalies easier, and modern surgical techniques, including the routine use of cardioplegia, allow most of these anomalies to be corrected. Patients and Methods This retrospective study reviews major and certain clinically significant minor anomalies of the coronary arteries diagnosed and treated by the Texas Heart Institute physicians at Texas Children s Hospital and St. Luke s Episcopal Hospital from 1964 to One hundred ninetyone patients with 202 anomalies were studied. Anomalies were classified into three groups: anomalies of origin, anomalies of termination, and anomalies of distribution (Table 1). Anomalies of Origin Eighty-eight patients had anomalies of origin, which included origin of a coronary artery from the pulmonary Accepted for publication Feb 20, Address reprint requests to Dr Hallman, PO Box 20345, Houston, TX artery (PA), origin of the left anterior descending artery (LAD) from the right coronary artery (RCA), and origin of a coronary artery from the contralateral sinus of Valsalva. Patients ages ranged from 1 month to 53 years, and the group was almost evenly split between the sexes. Of the 60 cases in which a coronary artery originated from the PA or one of its major branches, 56 (93.3%) involved the left coronary artery (LCA) (Table 2). Two patients (3.57%) were totally asymptomatic and had only a continuous murmur and electrocardiographic (ECG) changes. In the remaining patients, the predominant symptoms were dyspnea (78.57%) and angina (62.50%). Sixteen patients (28.57%) had congestive cardiac failure. Fourteen of these patients (87.50%) were less than 10 years old, and 7 (43.75%) were less than 1 year old. In neonates and infants, angina was observed to occur at the time of feeding, the so-called angina of feeding induced by the effort of sucking [3]. Ten patients (17.85%) had arrhythmias. Thirteen patients were found to have associated cardiac lesions: mitral regurgitation (7 patients), ventricular septa1 defect (2), tetralogy of Fallot (2), aortic stenosis (l), and occlusion of the iliac veins resulting from cardiac catheterization (1). On physical examination, 23 patients (41.07%) had a continuous murmur along the left sternal border, heard best in the second and third intercostal spaces. In 15 patients (26.79%), only a systolic murmur was heard. Ischemic changes (ST depression and T-wave inversion) were observed in the anterior and lateral leads in 36 patients (64.28%). Twenty patients showed an infarction pattern with Q waves, with or without ST-T by The Society of Thoracic Surgeons /92/$5.00

2 Ann Thorac Surg 1992;54:73240 FERNANDES ET AL 733 Table 1. Con,qenital Anomalies of the Coronary Arteries Patients Anomaly Type (n = 191) Origin Origin of a coronary artery from the pulmonary artery Origin of the left anterior descending artery from the right coronary artery Origin of a coronary artery from the contralateral sinus of Valsalva Termination Coronary arteriovenous fistula Distribution Single coronary artery changes, and 10 of these had cardiac failure. Chest roentgenographic examination revealed in 24 patients (42.85%) evidence of cardiomegaly (cardiothoracic ratio range, 0.51 to 0.73). Echocardiography indicated dilated left ventricles with poor contractility and wall-motion abnormalities in 19 patients (33.92%). Five patients (8.92%) had dilated left atria and left ventricular hypertrophy. In 3 patients (5.30%), echocardiography detected a dilated and tortuous RCA with collaterals to the LCA. Preoperative cardiac catheterization and coronary angiography were done in all cases and documented elevated preangiographic left ventricular end-diastolic pressure in 18 patients (32.14%), with values ranging from 8 to 26 mm Hg. In 36 patients (64.2%), there was an increase in the oxygen saturation of the PA, indicating a left-to-right shunt. In these 36 patients, angiography revealed a large, dilated RCA with tortuous dilated collaterals and retrograde filling of the LAD. In 4 patients, the collaterals were profuse and large, appearing angiomatous. Mitral incompetence was seen in 7 patients (12.5%); in 3 patients it was severe. In 2 patients, the proximal LCA was dilated with a membranous obstruction at the origin of the circumflex coronary artery. Of the 4 remaining cases in which a coronary artery originated in a PA, 2 were cases in which the RCA arose from the PA, and 2 were cases in which a branch of the LCA arose from the right PA. In the first 2 cases, both patients were men in their twenties, and both had exertional chest pain and Table 2. Origin of a Coronay Artey From the Pulmonary Artery: Patient and Sex Distribution Anomaly No. Male Female (n = 60) (n = 26) (n = 34) Left coronary artery arising from pulmonary artery Right coronary artery arising from pulmonary artery Left atrial branch arising from right pulmonary artery Circumflex coronary artery arising from right pulmonary artery dyspnea, with no evidence of congestive cardiac failure. A continuous murmur, indicating good collateral flow from the LCA into the RCA, was heard in both, and electrocardiograms showed evidence of myocardial ischemia in the right-sided and inferior leads. Selective coronary angiography revealed an RCA originating from the main PA with large collaterals filling retrogradely from the LCA. Of the 2 patients in whom a branch of the LCA arose from the right PA, 1 had tetralogy of Fallot and had an atrial branch of the LCA arising from the right PA. In the other patient, who also had aortic stenosis, the circumflex branch of the LCA arose from the right PA at its departure from the main PA. The second largest subset of patients with congenital anomalies in the origin of coronary arteries was made up of 18 patients in whom the LAD originated from the RCA. These patients, all children ranging in age from 1 month to 10 years, also had an associated and usually complex congenital heart defect. Of these 12 boys and 6 girls, 15 (83.33%) had tetralogy of Fallot. The remaining 3 had ventricular septal defect and pulmonary stenosis, 1 with atrial septal defect and the other 2 with double-outlet right ventricle. Finally, there were 10 patients, ranging in age from 2 to 45 years, whose coronary artery arose from the contralatera1 sinus of Valsalva. In 6, the RCA arose from the left coronary sinus from a separate ostium. Four of these patients were male and 2 were female. In 5, the RCA ran posterior to the aorta to reach the atrioventricular groove, and in 1 it ran between the aorta and the PA. All patients chief complaint was exertional chest pain, and all had ECG evidence of myocardial ischemia. In the other 4 patients (3 men and 1 woman), the circumflex coronary branch of the LCA arose from the right coronary sinus from a separate ostium. From this anomalous origin, the vessel ran between the aorta and pulmonary artery to reach the atrioventricular groove and the posterior aspect of the left ventricle, where it was distributed normally. Two of these patients had, in addition, ostial stenosis. One patient had third-degree mitral regurgitation. All complained of angina, especially precipitated by sudden exertion, and all had evidence of ECG changes. Anomalies of Termination Ninety-three patients were treated for 104 coronary arteriovenous fistulas (CAVFs) during the 25-year period. The youngest of the 41 male and 52 female patients was 4 days old, and the oldest was 78 years old. A single fistula was present in 83 patients (89.25%), and multiple fistulas were present in 10 (10.75%). The RCA was the most common vessel of origin, and the most frequent drainage site was the right ventricle (Table 3). The rarest drainage sites were the coronary sinus and the bronchial vein. Three patients suffered aneurysmal dilatations, and in 3 other cases, the fistula became angiomatous. In 1 patient, bacterial endocarditis developed between the RCA and the right ventricle. This group was divided for purposes of this review into two subsets: those 56 patients (60.22%) who had CAVFs

3 734 FERNANDES ET AL Ann Thorac Surg 1992:54: Table 3. Coronary Arteriovenous Fistulas: Sites of Origin and Drainape Drainage Site Origin RV PA RA LV LA CS BV Total RCA LAD Circumflex I 1 19 Diagonal Obtuse marginal LCA Total BV = bronchial vein; CS = coronary sinus; LA = left atrium; LAD = left anterior descending artery; LCA = left coronary artery; LV = left ventricle; PA = pulmonary artery; RA = right atrium; RCA = right coronary artery; RV = right ventricle. alone and those 37 patients (39.78%) who had, in addition to a CAVF, an associated congenital or acquired cardiac lesion. Of the 56 patients diagnosed as having a CAVF alone, 41 (73.21%) were symptomatic. Sixty percent of the patients with symptoms reported angina, 34.14% reported dyspnea, and 26.83% reported palpitations (arrhythmias). Congestive cardiac failure was the presenting feature in 14.63% of patients with symptoms. Fifteen of the 56 were totally asymptomatic and were diagnosed only by virtue of a continuous murmur. All asymptomatic patients were less than 30 years of age. Physical examination revealed the characteristic hallmark of a CAVF-the continuous machinery murmur, usually superficial in character, heard along the left sternal border in the second and third intercostal spaces. Twenty-one patients (37.50%)(including the 15 who were asymptomatic) had this characteristic murmur. In addition, a systolic murmur alone was heard in 6 patients and a diastolic murmur, in 4. Thirty-six patients (64.29%) had ECG changes. The predominant ECG finding in these 36 was ischemia or chamber overload (66.67%). Infarction was experienced by only 4 patients (11.11%). Arrhythmias were present in 8 patients (22.22%), including ventricular premature contraction in 4 (ll.ll%), atrial tachyarrhythmias in 2 (5.56%), and conduction defects (bundle-branch block and first-degree atrioventricular block) in 2 (5.56%). Chest roentgenographic examination revealed cardiomegaly in 38 patients (67.86%) (cardiothoracic ratios, 0.53 to 0.68). Twelve patients (16.50%) had radiologic evidence of a left-to-right shunt (pulmonary plethora). Cardiac catheterization and angiography were done in all patients. Not only did these tests give accurate estimates of the left-to-right shunt, but they also gave the exact anatomic diagnosis-the location and the type of fistula. Oximetry measured left-to-right shunts (range, 1.36:l to 2.3:l). There were 37 patients with a CAVF who had an associated congenital or acquired cardiac lesion. Although coronary artery occlusive disease was the most frequent (in 35.14% of patients), no associated lesions occurred with sufficient frequency to establish a statistically signif- icant relationship to CAVF. The patients in this category had predominantly symptoms and signs of the primary lesion; however, 8 patients also had a continuous lowpitched machinery murmur along the left sternal border. Anomalies of Distribution Ten patients were diagnosed as having an anomaly of distribution. These 6 male and 4 female patients ranged from 2 to 48 years in age. In 6 patients, the LCA system arose from the RCA, and in 4, the RCA system arose from the LCA. In 6 cases, there was an associated cardiac lesion. These included tetralogy of Fallot, ventricular septa1 defect and pulmonary stenosis with double-outlet right ventricle or with tricuspid regurgitation and mitral regurgitation, and mitral regurgitation alone. The clinical presentation of this anomaly depends on two factors: any associated cardiac lesion and the presence or absence of atherosclerosis. Three patients complained of angina, and 4 patients appeared cyanotic. Tests found ECG changes suggestive of ischemia in 5 patients, arrhythmias in 3, and cardiomegaly in 4. Surgical Techniques Surgical treatment for coronary anomalies of origin was governed by the site of origin and coexisting cardiac lesions. On the 60 patients in whom coronary arteries originated in the PA, four basic surgical techniques were used: reimplantation (70% of patients), ligation and aortocoronary bypass (25%), ligation alone (3.33%), and the tunnel (Takeuchi) technique (1.67%). Fifty-six of these 60 had the LCA arising from the PA. Of the remaining 4, 2 had the RCA arising from the PA. In 1, reimplantation was used, but in the other, suspicion of ostial stenosis of the RCA made ligation with aortocoronary bypass using the saphenous vein the technique of choice. For the 2 patients in whom a branch of the LCA arose anomalously from the right PA, surgical correction of their associated lesions was also undertaken. In 1, surgeons corrected coexisting tetralogy of Fallot and ligated the anomalously arising left atrial branch. The other patient underwent aortic valve replacement to correct aortic stenosis, as well as reimplantation of the circumflex coronary artery into the aorta. In the 18 patients in whom the LAD originated in the RCA, the anomalously arising LAD crossed the anterior aspect of the right ventricular outflow tract (RVOT), posing a problem in patching the RVOT for relief of infundibular pulmonic stenosis. To circumvent this limitation, surgeons mobilized the LAD artery and placed the outflow patch under the mobilized artery (44.44% of patients), used a right ventricle-to-pa conduit (38.89%), or ligated the anomalous artery and performed aortocoronary bypass to the distal LAD (16.67%). In this third method, surgeons used the saphenous vein in 2 patients and the left internal mammary artery in the third. In the 10 patients in whom a coronary artery originated from the contralateral sinus of Valsalva, a combination of the four surgical methods was used. In 4 of the 6 patients whose RCA arose from the left sinus of Valsalva, surgeons excised the ostium of the RCA along with a cuff of

4 Ann Thorac Surg 1992;54:73240 FERNANDES ET AL 735 aortic wall, then reimplanted it into the right anterior aortic wall. Care was taken to ensure that there was no angulation at the newly created ostium or in any part of the newly implanted vessel. Surgeons carefully closed the defect created in the aortic wall in the region of the left sinus of Valsalva with a patch of pericardium, making sure not to compromise the ostium of the LCA. In the 2 remaining patients, the RCA was ligated and aortocoronary bypass using saphenous vein was performed. Of the 4 patients whose circumflex coronary artery arose from the right sinus of Valsalva, 2 with ostial stenosis underwent aortocoronary bypass to the obtuse marginal branch of the circumflex, and the other 2 underwent ligation of the anomalous artery just distal to its origin at the right sinus of Valsalva and aortocoronary bypass to the obtuse marginal branch of the circumflex. The aim of the ligation was preventing competition of flow. In both cases, saphenous vein grafts were used. Typically, CAVFs are surgically corrected; however, in cases in which associated cardiac lesions exist, a CAVF may be closed or left intact, depending on the physiologic significance of the shunt through the fistula, when the primary defect is corrected. The goal of surgical treatment is interruption of the fistulous tract-usually obliterating it totally-without compromise of normal coronary vessel flow. In this series, surgical treatment of the 104 CAVFs included internal closure (46.15% of fistulas), tangential arteriorrhaphy (28.85%), distal ligation alone (11.54%), proximal and distal ligation (6.73%), ligation and bypass grafting (3.85%), and closure from within a vessel dilated by an aneurysm (2.88%). Internal closure was used most frequently for fistulas that drained into a cardiac chamber, for fistulas whose identification on the surface of the heart was difficult, and for multiple fistulas. The second most frequently used technique, tangential arteriorrhaphy, was used for lateral fistulas. The fistula was first located by palpating for a thrill over the involved vessel. The fistula was then obliterated using multiple horizontal mattress sutures placed under the coronary artery. Complete obliteration was indicated by the disappearance of the thrill, reduction in the size of the recipient chamber, and failure of oximetry to show an oxygen saturation increase in the recipient chamber. Of the 10 patients who had anomalies of distribution, 8 patients underwent operation. In 4 of these, surgeons corrected underlying cardiac lesions, as well as used a right ventricle-to-pa conduit to prevent trauma to the LAD crossing the anterior aspect of the RVOT. Three others, who were symptomatic and had ECG evidence of ischemia, underwent aortocoronary bypass grafting, including 2 who had an RCA system with the LCA running between the aorta and the PA. One patient underwent an aortocoronary bypass with mitral annuloplasty (No. 25 Duran ring). Surgeons used the internal mammary artery or bilateral mammary arteries. Operation was not recommended for 2 patients: 1 had multiple cardiac lesions and was in congestive cardiac failure, and the other was asymptomatic and scheduled for follow-up. Table 4. Surgical Technique and Mortality for Treating Anomalous Origin of a Coronary Artey From the Pulmonary Artey Mortality (%) Technique n LCA RCA Reimplantation 42 2 (4.76) 0 Ligation and bypass 15 l(6.67) 0 Ligation 2 l(50.00) 0 Tunnel (Takeuchi) Total 60 4 (6.67) 0 LCA = left coronary artery; RCA = right coronary artery Results Of the 60 patients who underwent surgical treatment for a coronary artery arising anomalously from the PA, 4 (age range, 5 to 10 months) died in the immediate postoperative period (mortality, 6.60%) (Table 4). There were no delayed postoperative deaths. Two of the patients who underwent reimplantation and whose conditions were classified as being high risk died. All patients had serial electrocardiograms on postoperative day 1, day 2, day 7, and just before discharge. Left ventricular function was assessed with echocardiography in the immediate postoperative period (within 24 hours) and just before discharge. Postoperative selective coronary angiography was not performed unless there was reason to believe that the patient still had myocardial ischemia or unless the patient was not progressing well postoperatively and it was thought that there was a possible mechanical reason (eg, kinking or torsion of the reimplanted artery or occlusion of a graft). Eighty-five percent had total relief from angina (symptomatically and on electrocardiograms) and improvement in left ventricular function (as assessed by echocardiography). In 3 patients (5%), cardiac failure persisted; in 5 patients (8.38%), postcardiotomy syndrome developed but responded to indomethacin and steroids. Two patients (3.33%) had residual ischemia, and in 1 patient (1.67%), a residual fistula persisted that required reoperation. One other patient (1.67%) had heart block. Of the 60 patients treated for this anomaly, 50 (83.33%) have been regularly followed up. Duration of follow-up ranges from 2 to 17 years. In the 18 patients who underwent operation to correct an LAD originating in the RCA, there were two immediate postoperative deaths (11.11%). One of these patients was a 1-month-old girl who had had a right ventricleto-pa conduit. She, in addition, had an anomalous retroesophageal subclavian artery, and her superior vena cava was on the left side. The other patient was a 5-year-old child who had undergone bypass with the left internal mammary to the distal LAD and could not be weaned from cardiopulmonary bypass. There were no delayed postoperative deaths. One patient had postcardiotomy syndrome that responded to antiinflammatory drugs. All patients have been regularly followed up,

5 736 FERNANDES ET AL Ann Thorac Surg 1992;54: including 2 for 15 years. One patient has undergone reoperation for conduit stenosis and calcification. In the 10 patients treated for origin of a coronary artery from the contralateral sinus of Valsalva, there were no immediate or delayed postoperative deaths. Regular follow-up was maintained with 8 patients. Follow-up ranges from 1 year to 12 years. One patient underwent reoperation for coronary artery occlusive disease. In the group of 56 patients with CAVF only, there were no immediate or delayed deaths, and only 7.14% had complications. Two patients suffered myocardial infarction after proximal and distal ligation and had a stormy postoperative period, but survived. Another had a residual fistula that persisted after tangential arteriorrhaphy but underwent reoperation successfully. A 72-year-old woman had hemiparesis on the left side after closure of a CAVF on cardiopulmonary bypass; however, after 2 months, she was discharged from the hospital with minimal deficit. Of these 56 patients, only 6 (10.71%) were lost to follow-up. In the group of 37 patients having a CAVF associated with other cardiac lesions, there were two postoperative deaths (5.41%), and 2 patients (5.41%) had complications after discharge from the hospital: one needed sternal debridement and rewiring for mediastinitis; the other required permanent pacemaker implantation to overcome persistent complete heart block. Unfortunately, follow-up has been possible only with 26 patients (70.27%), ranging from 10 months to 12 years. In the 10 patients with anomalies of distribution, there were no postoperative in-hospital deaths. All 8 patients who underwent operation progressed well postoperatively, showing no evidence of residual ischemia. Five patients took a stress test 8 weeks after discharge from the hospital, and none had positive results. Follow-up, ranging from 1 year to 13 years, was maintained in 6 of the 10 patients. One patient, who had double-outlet right ventricle, ventricular septa1 defect, and pulmonary stenosis, had a reoperation for conduit stenosis. Comment Congenital anomalies of the coronary arteries form a rare but important subset of nonatherosclerotic coronary artery disease. Despite their rare occurrence (1% to 2% of the population) [l], these anomalies often are seen in patients in whom ischemic heart disease is uncommon and unsuspected. Moreover, they may occur along with and complicate other congenital heart defects, and as a result of abnormal course or distribution, increase the risk of coronary artery trauma during cardiac operations [2]. In addition, in most instances the natural history of these lesions is not associated with a normal life expectancy (with the exception of congenital origin of the RCA from the PA). Today, these anomalies can be easily diagnosed, accurately located, and safely corrected with gratifying long-term results, and for these reasons, surgical intervention should be strongly recommended once a precise diagnosis is established. Anomalies of Origin Origin of the LCA from the PA is rare, estimated to occur in 2.5% to 4.6% of patients with congenital cardiac anomalies. Though the anomaly was first reported by Brooks [4] in 1886, the clinical and hemodynamic syndrome was first described by Bland, White, and Garland [5] in 1933; hence, this anomaly is sometimes referred to as the Bland-White-Garland syndrome. In more than 90% of cases, it is the LCA that originates anomalously from the PA, generally from the left posterior sinus [2]. In this series, 56 of 60 (93.3%) cases involved the LCA arising from the PA; however, the RCA alone may arise from the PA (2 cases in this series), both coronary arteries may arise from the PA, or, rarely, a portion of the LCA system may arise from the PA (eg, the LAD or circumflex artery). Two such cases were found in this series. In 1, it was the circumflex branch, and in the other, it was the left atrial branch of the LCA that originated from the right PA. This anomaly, if left untreated, results in a high mortality, particularly in symptomatic infants. If the child survives infancy, a risk of sudden death still persists, inasmuch as 80% to 90% of those affected die suddenly by a mean age of 35 years. The pathophysiology of this syndrome was described by Edwards [6]. In a few cases, collateral circulation may develop fairly rapidly so that left ventricular myocardial perfusion is adequate. Myocardial ischemia and the later effects of fibrosis and mitral regurgitation do not occur then. Such patients survive and are seen later on in life with symptoms and signs proportional to the extent of intercoronary collaterals. In infants in whom adequate collateral circulation develops, a left-to-right shunt results, and blood flows from the RCA through the collaterals into the LCA and, thence, into the PA. It has been suggested that this may, in some cases, produce a sizable left-to-right shunt. However, in most cases of this adult-type syndrome, the shunt is of small volume and causes only a minimal hemodynamic effect on the left ventricle [6]. Patients with this syndrome have symptomatic angina. This results from either an inadequate RCA-to-LCA collateral flow or the "steal" phenomenon in which an adequate or excessive collateral flows into the lowpressure PA. Sudden and unexpected death is not an unusual result under these circumstances. Anomalous origin of the RCA from the PA is a much rarer malformation, and the clinical manifestations of this condition are usually minimal or absent. Death is extremely rare. Nonetheless, this benign and rare anomaly can lead to myocardial ischemia, congestive heart failure, and myocardial fibrosis. Because it can be completely corrected once diagnosed, surgical correction is indicated. Origin of both coronary arteries from the PA has been reported but is extremely rare and fatal. In the reported cases, survival ranged from 9 hours to 5 months. The goal of surgical therapy in anomalous origin of the LCA from the PA is to establish adequate left ventricular myocardial perfusion, and there appears little doubt that achieving anterograde flow of oxygenated blood into the LCA is the best treatment [7]. How the latter can be

6 Ann Thorac Surg 1992;54:73240 FERNANDES ET AL 737 achieved is rather controversial, and several ingenious techniques have been described. In the current series, reimplantation was performed in 75% of the patients with good results. There were only two postoperative deaths, and both of these patients had other cardiac lesions corrected simultaneously (left ventricular aneurysm repair, and ventricular septa1 defect and coarctation repair), greatly increasing their risk. In cases in which reimplantation was not technically feasible from an anatomical standpoint (when the anomalous ostium was located anteriorly) [7], if the proximal LCA was aneurysmal, or if there existed membranous obstruction or ostial stenosis of the LAD or circumflex artery, surgeons resorted to ligation of the anomalous LCA with distal aortocoronary bypass using either the saphenous vein or the internal mammary artery. This technique was originally described by Cooley and coworkers [8] in 1966 and has the advantage of establishing a two-coronary artery system. The main disadvantage of this technique is the high rate of graft occlusion, especially in infants and children. We, along with others [8], do not favor the use of simple ligation as a technique for correcting this anomaly because it can be safely used only if there exist adequate intercoronary collaterals. Also, it results in a one-coronary artery system, which poses a greater risk in the face of subsequent atherosclerosis. Furthermore, the incidence of sudden death has been found to be significantly higher in patients who have had ligation than in those who have a two-coronary artery system. At the Texas Heart Institute, simple ligation, though used fairly frequently before 1966, was used in only 2 cases thereafter-one was an emergency ligation of the anomalous LCA in a neonate with intractable heart failure, and the other was a ligation of a left atrial branch that arose from the PA that was performed without any consequence. Meyer and associates [9] in 1968 used the turned-down left subclavian artery and anastomosed it to the LCA. Though this is an ingenious idea, graft occlusion remains a major drawback. Moreover, there have been reports that the left subclavian artery has a tendency to kink at its origin. Experience at the Texas Heart Institute with this technique is very limited. Finally, there is the novel tunnel technique described by Takeuchi and colleagues [lo] in The advantages of this technique include establishing a two-coronary artery system, without mobilizing the LCA, and definite potential for growth with the in situ tissues that are used; the disadvantages are late complications of aortic incompetence and supravalvar pulmonic stenosis. Although technically the anomaly of an LAD arising from the RCA is grouped under secondary anomalies [ll], it has been considered and discussed here because of its frequent occurrence and because of its singularly important surgical implication. This anomaly is usually associated with other congenital heart defects, most commonly tetralogy of Fallot. (In this series, 15 of 18 patients [83.33%] had tetralogy of Fallot.) The LAD, after arising from the RCA, crosses over the anterior surface of the RVOT and eventually continues in its normal course. As a result of this abnormal course, the LAD is particularly vulnerable to injury when an incision is made in the right ventricle for relief and repair of RVOT obstruction. Injury to the LAD is an important cause of low-output syndrome after total correction of tetralogy of Fallot. Trauma to the LAD can be avoided by making a transverse or oblique ventriculotomy and fashioning it so as to avoid the LAD or by mobilizing the LAD and placing a transannular patch under it. Sometimes a right ventricle-to-pa conduit may be used. Rarely, the LAD is ligated and a distal aortocoronary bypass graft is done. It must be emphasized that surgeons must consider and treat each case on the basis of the existing anatomy and employ the most suitable technique. When one coronary artery arises from the contralateral sinus of Valsalva, this vessel must traverse the base of the heart to reach its territory of distribution, passing anterior to, posterior to, or between the aorta and the right ventricular infundibulum. The importance of this seemingly benign anomaly is that it may result in sudden death, which usually occurs during or immediately after exercise. Such a tragic and fatal outcome is characteristic of the LCA arising from the right sinus of Valsalva [12]. The exact mechanism of sudden death is not clearly known, and several theories have been postulated. Benson and Lack (131 and Cohen and Shaw [14] initially postulated that the LCA was compressed between the aorta and PA as a result of an increase in cardiac output during exertion. This resulted in acute ischemia and ventricular fibrillation; however, it is difficult to comprehend how the low-pressure PA could compress a coronary artery whose pressure is systemic. Another hypothesis is that acute kinking disables a long left main artery and a congenitally small left coronary system [13]. The most reasonable explanation was proposed by Cheitlin, McAllister, and de Castro [15], who suggested that as the LCA arises from the right sinus of Valsalva, it forms an acute angle at its origin that may compromise its lumen as it passes anteriorly and leftward along the contour of the aorta posteriorly. Whatever the mechanism, this anomaly should always be suspected in young patients, particularly male patients with exertional chest pain of syncope [121. We agree with other workers in recommending an immediate prophylactic bypass operation in all patients diagnosed as having the LCA arising from the right sinus of Valsalva. The high incidence of sudden death should support this approach [2, 121. Because the patients are usually young, we prefer to use the mammary artery (one or both) for bypass grafting. On the other hand, in cases of the RCA arising from the left sinus of Valsalva, we advocate operation only if the patient is symptomatic, because angina-not sudden death-has been reported with this anomaly. A special reference must be made regarding coronary anomalies associated with transposition of the great arteries. Variations in origin and branching of the coronary arteries in transposition have been well documented. Coronary anatomy must be thoroughly known before

7 738 FERNANDES ET AL Ann Thorac Surg 1992;54: anatomic correction is undertaken. In almost all cases of transposition, the coronary arteries arise from one or both of the facing sinuses of the aorta [16]. Many ways of classifying these anomalies exist, but the system proposed by Yacoub and Radley-Smith [17] is the most useful from the surgical standpoint. Of importance are cases in which the coronary arteries take an intramural course. Intramural indicates an intimate relationship between the aortic and coronary artery walls [16]. Such coronary arteries are usually acutely angled at their origin; thus, excision of such an artery from the aortic wall and anastomosis to the pulmonary artery would cause kinking of the coronary artery. Hence, transferring an intramural coronary artery is not recommended (161. Anomalies of Termination Coronary arteriovenous fistula, first described by Krause [18] in 1865, constitutes the most common hemodynamically significant coronary artery anomaly [12, 13, 151. It may be accurately defined as a direct precapillary anastomosis between a major coronary artery and a cardiac chamber or major vessel (coronary sinus, superior vena cava, or pulmonary artery) [2]. In this series, almost half of the total patients had this anomaly. Although most commonly congenital in origin, this anomaly may also (but rarely) be acquired as a result of trauma. Recently, CAVFs have been reported in recipients of orthotopic heart transplants. These acquired fistulas usually involve the right ventricle and are thought to arise as a complication of endomyocardial biopsy. Anatomically, the RCA is the most frequent site of origin and the right ventricle, the most common recipient chamber. Bilateral fistulas (involving both coronary systems in the same patient) are reported in 4% to 5% of patients [19]. In this series also, the RCA was the most common site of origin (52.8%), and the right ventricle the most frequent recipient chamber (40.38%). Bilateral fistulas were seen in only 4 patients (4.3%). There were also 2 cases in this series in which the fistula drained into the bronchial veins. Fistulas draining into the left side are relatively rare (less than 10%) [19]. The age of the patient is very significant in identifying the anomaly [12]. Younger patients are generally asymptomatic. In this group, 15 patients were totally asymptomatic; all were less than 30 years of age. Flow from the high-pressure artery into the lowpressure chamber or systemic vein occurs both during systole and diastole, producing the characteristic continuous murmur, and symptoms vary in magnitude directly in proportion to the size of the shunt. Angina, in the absence of coronary artery disease (atherosclerosis), was the predominant symptom in this series and is thought to arise from an effect called coronary steal, which produces ischemia by diverting blood from the high-resistance myocardial capillary bed into the lowresistance fistula [2]. The same phenomenon would precipitate angina if the flow in the involved vessel is borderline because of the presence of minimal occlusive disease, which does not show up on selective angiography. The relative incidence of symptoms in older patients could also be explained by the increased incidence of coronary occlusive disease with age and the long-term effects of volume overload [20]. In addition, CAVFs draining into the chambers on the right side may result in a left-to-right shunt, causing overload not only of the chambers, but also of the pulmonary circulation and the left ventricle. Left untreated, CAVFs may result in several complications, and the incidence of complications increases with age [12]. Noteworthy are congestive cardiac failure, a common cause of death in untreated cases [ll], bacterial endocarditis, and-though rare-mild to moderate pulmonary hypertension [21]. Finally, aneurysmal dilatation of the involved vessel and rupture of the fistula have been reported. Although the surgical management of CAVFs has been controversial, now, with the knowledge of their complications and the ability to delineate them accurately, all hemodynamically significant CAVFs should be repaired whenever diagnosed [12, 221. Correction in childhood constitutes optimal management and prevents the development of symptoms and complications [12]. The median sternotomy approach is the preferred surgical technique because it gives optimal exposure of the total coronary vascular tree. Moreover, it allows correction of other associated defects and permits the institution of cardiopulmonary bypass with ease. Although many fistulas can be repaired without cardiopulmonary bypass, the Texas Heart Institute has used it during the last few years in almost all cases. The current approach is internal closure of the distal end of fistulas draining into the right ventricle or PA from within the recipient cavity. Localization can be improved immensely by releasing the cross-clamp or by infusing cardioplegia. For lateral fistulas, especially those on the surface of the right ventricle, tangential arteriorrhaphy (first described by Cooley and Ellis [20] in 1962) has been the technique of choice. Proximal and distal ligation, a technique first described by Bjork and Crafoord [21] in 1947 and used extensively in the past, has been largely abandoned because of the risk of permanent myocardial ischemia or even infarction. Currently, this technique has been reserved for terminal fistulas from a main coronary trunk or those arising from secondary or accessory branches. Finally, when the involved vessel has become aneurysmal, the vessel itself can be opened and the fistula closed from within. The arteriotomy can then be trimmed and repaired. It must be emphasized that the goal of surgical therapy should be complete obliteration of the fistulous tract with preservation of flow through the normal vessel. Anomalies of Distribution Having a single coronary artery is a very rare anomaly. Sharbaugh and White [23] found an incidence of 0.04%. Approximately 40% of patients with this anomaly have an associated congenital cardiac defect (eg, tetralogy of Fallot, transposition, or truncus arteriosus). Six of the 10 patients with this anomaly had associated congenital cardiac defects. There is no clear sex predominance in this

8 Ann Thorac Surg 1992;54: FERNANDES ET AL 739 condition, and the frequency of occurrence of single left and single right coronary arteries is approximately equal. As in the case of anomalous origin from the contralatera1 sinus of Valsalva, one or more components of the coronary circulation must cross the base of the heart to reach the territory of distribution passing anterior to, posterior to, or between the great vessels. These transposed vessels may thereby be exposed to the risks of angulation or compression. On its own, this anomaly has been considered to be a benign anomaly because cardiac function is normal, provided all portions of the myocardium are perfused adequately; however, atherosclerosis is more prone to develop in the single coronary artery than in two normally arising arteries [6, 111. When atherosclerosis develops, the consequences are severe because collateral circulation from a secondary coronary artery is not present. Because of this, occlusion of the proximal portion of a single coronary artery carries a grave prognosis. The management of this anomaly alone is a problem. Some patients remain asymptomatic whereas some experience angina, infarction, or even sudden death. If the patient is severely symptomatic and no other associated disease is present to account for the symptoms, a bypass operation should be considered [2]. If the patient has mild symptoms but no atherosclerosis, then additional tests for myocardial ischemia may be helpful: atrial pacing with lactate metabolism determination, maximal treadmill exercise, or thallium stress testing. If test results are abnormal, then conventional therapy for ischemia should be advised, and the patient should be scheduled for close follow-up. Conclusion It must be reemphasized that the major anomalies and some of the clinically significant minor anomalies are all associated with a reduced life expectancy and even sudden death. It is imperative that they are diagnosed early and treated appropriately. A high index of suspicion, in a physician evaluating a young individual thought to have coronary artery disease, is the cornerstone for a successful outcome. As highlighted earlier, anomalous origin of the LCA from the PA is a very important cause of ventricular dysfunction, intractable cardiopulmonary failure, and even death in infants. Infants with this anomaly require immediate intervention. It is always preferable to establish an anterograde flow of oxygenated blood through the coronary arteries and to maintain a two-coronary artery system. Reimplantation of the anomalous LCA into the aorta achieves both these objectives. In cases in which this was not possible in this series, good results were obtained with ligation of the anomalous vessel with distal aortocoronary bypass. Coronary arteriovenous fistula was the most common anomaly in this series. It can be confused with many other congenital cardiac defects (patent ductus arteriosus, ventricular septa1 defect with prolapse of aortic cusp, or aorticopulmonary window); therefore, it is important to establish a correct diagnosis and accurately localize the fistula. This review revealed that young patients are usually asymptomatic, and the severity of the symptoms is proportional to the size of the shunt. In addition to chamber overload, resulting from the left-to-right shunt, CAVFs also produce angina by the phenomenon of coronary steal. Tangential arteriorrhaphy and internal closure of the fistulas are efficient techniques because they not only totally obliterate the fistula, but also preserve anterograde flow through the normal vessel. A median sternotomy for exposure and the use of cardiopulmonary bypass is preferred in all cases. Finally, three anomalies previously considered insignificant-namely, origin of a coronary artery from the contralateral sinus of Valsalva, LAD arising from the RCA, and a single coronary arteryhave now gained immense importance because they offer an explanation for sudden death in young individuals (especially a single coronary artery or a coronary artery originating from the contralateral sinus of Valsalva) and predispose the coronary arteries to surgical trauma during repair of other congenital defects affecting the blood s course and distribution. For these reasons, adequate knowledge of these anomalies and their accurate demonstration by cineangiography are essential in avoiding catastrophic outcomes. References Engel HJ, Torres C, Page L Jr. Major variations in anatomical origin of the coronary arteries: angiographic observations in 4,250 patients without associated congenital heart disease. Cathet Cardiovasc Diagn 1975;1: Levin DC, Fellows KE, Abrams HL. Hemodynamically significant primary anomalies of the coronary arteries: angiographic aspects. Circulation 1978;58: Augustsson MH, Gasul BM, Fell EH, et al. Anomalous origin of left coronary artery from pulmonary artery: diagnosis and treatment of infantile and adult types. JAMA 1962;180:1521. Brooks HStJ. Two cases of an abnormal coronary artery of the heart arising from the pulmonary artery with some remarks upon the effect of this anomaly in producing cirsoid dilation of the vessels. J Anat Physiol 1886;20:26-9. Bland EF, White PD, Garland J. Congenital anomalies of the coronary arteries: report of an unusual case associated with cardiac hypertrophy. Am Heart J 1933;8: Edwards JE. Symposium on cardiovascular diseases: functional pathology of congenital cardiac disease. Pediatr Clin North Am 1954;1:1349. Laborde F, Marchand M, Leca F, Jarreau M-M, Dequirot A, Hazan E. Surgical treatment of anomalous origin of the left coronary artery in infancy and childhood: early and late results in 20 consecutive cases. J Thorac Cardiovasc Surg 1981;82: Cooley DA, Hallman GL, Bloodwell RD. Definitive surgical treatment of anomalous origin of left coronary artery from pulmonary artery: indications and results. J Thorac Cardiovasc Surg 1966;52:79%808. Meyer BW, Stefanik MD, Stiles QR, Lindesmith GG, Jones JC. A method of definitive surgical treatment of anomalous origin of left coronary artery: J Thorac Cardiovasc Surg 1968;56: Takeuchi S, Imamura H, Katsumoto K, et al. New surgical method for repair of anomalous left coronary artery from pulmonary artery. J Thorac Cardiovasc Surg 1979;78:7-11. Ogden ]A. Congenital anomalies of the coronary arteries. Am J Cardiol 1970;25:4749. Liberthson RR, Sagar K, Berkoben JP, Weintraub RM, Levine FH. Congenital coronary arteriovenous fistula: report of 13 patients, review of literature and delineation of management. Circulation 1979;59:

9 740 FERNANDES ET AL Ann Thorac Surg 1992;54: Benson PA, Lack AR. Anomalous aortic origin of left coronary artery: report of two cases. Arch Pathol 1968;86: Cohen LS, Shaw LD. Fatal myocardial infarction in an 11 year old boy associated with a unique coronary artery anomaly. Am J Cardiol 1967;19: Cheitlin MD, McAllister HA, de Castro CM. Myocardial infarction without atherosclerosis. JAMA 1975;231: Gittenberger de Groot A, Sauer U, Quaegbeur J. Aortic intramural coronary artery in three hearts with transposition of great arteries. J Thorac Cardiovasc Surg 1986;91: Yacoub M, Radley-Smith R. Anomalies of the coronary arteries in transposition of the great arteries and methods of their transfer in anatomical correction. Thorax 1978;33: 41a Krause W. Ueber den Ursprung einer access orischen a. coronaria cordis aus der a. pulmonalis. Z Rat Med 1865; Liotta D, Hallman GL, Hall RJ, Cooley DA. Surgical treatment of congenital coronary artery fistula. Surgery 1971;70: Cooley DA, Ellis PR. Surgical considerations of coronary arterial fistula. Am J Cardiol 1962;10: Bjork G, Crafoord C. Arteriovenous aneurysm in the pulmonary artery simulative patent ductus arteriosus Botalli. Thorax 1947; Hudspeth AS, Linder JH. Congenital coronary arteriovenous fistula. Arch Surg 1968; Sharbaugh AH, White RS. Single coronary artery: analysis of the anatomic variation, clinical importance, and report of five cases. JAMA 1974;230: Notice From the Southern Thoracic Surgical Association The Thirty-ninth Annual Meeting of the Southern Thoracic Surgical Association will be held at the Saddlebrook Golf and Tennis Resort, Wesley Chapel (near Tampa), Florida, November 57,1992. Members may register upon payment of a $50 fee. There will be a $300 registration fee for nonmember physicians except for guest speakers, speakers on the program, and residents. There will be a $50 registration fee for attendees of the Postgraduate Course, which will be held the morning of Thursday, November 5, The Postgraduate Course will provide in-depth coverage of thoracic surgical topics selected primarily as a means to enhance and broaden the knowledge of practicing thoracic and cardiac surgeons. Advance registration forms, hotel reservation cards, and details regarding transportation arrangements have been mailed to Association members. Nonmembers should write to the Secretary-Treasurer, Hendrick 8. Barner, MD. Hendrick B. Barner, MD Secretary-Treasurer Southern Thoracic Surgical Association 401 North Michigan Avenue Chicago, IL (312)