ORIGINAL ARTICLE

ANOMALOUS LEFT CORONARY ARTERY

TREATMENT

Gregor Wollenek, MD

Department of Cardiothoracic Surgery,

University and General Hospital of Vienna, Austria

ABSTRACT

Over the last decades, the Bland-White-Garland syndrome has been treated with various surgical approaches, ranging from simple ligation to anatomic revascularization, usually creating a two coronary artery system. In Vienna, between 1965 and 1999, 20 patients underwent an operation (ligation in 3, revascularization techniques in 17). Total mortality was 67 % in the group with ligation and 24 % following revascularization. Out of 14 survivors with a mean follow-up of 11 years, 12 have an excellent functional result; only one required reoperation with mitral valve repair and bypass grafting. The state of the art in surgical treatment is discussed, including mitral valve sequelae, presentation in adults and the option of transplantation. So far, in the literature the incidence of the syndrome seems to be underestimated. According to the Vienna experience, the Bland-White-Garland syndrome may be expected in one of every 25,000 live births. (Heart Views. 2000;1(7): 251-257). © 2000 Hamad Medical Corporation

Key Words: ®Bland-White-Garland syndrome ®ALCAPA ®coronary artery anomaly ®congenital heart defect

Introduction

The anomalous origin of the left coronary artery from the pulmonary artery, known as Bland-White-Garland syndrome, is a rare congenital cardiac malformation that usually occurs as an isolated lesion, though with a broad spectrum of variations. First described by Brooks in 1886 (1) and Abbott in 1908 (2), the clinical phenotype was reported by Bland, White, and Garland in 1933 (3). If not diagnosed and treated, the syndrome has a very poor natural prognosis with a high mortality rate (4). Without treatment, up to 90% of patients develop congestive heart failure due to severe myocardial ischemia and die in infancy (5,6). Patients presenting as adolescents or adults carry the risk of suffering sudden cardiac death (7,8). The onset of symptoms and consequently even survival is decisively determined by function of collaterals between the right coronary artery and the anomalous left system. Since 1958 various surgical techniques are available.

This article reviews our experience concerning early and late results obtained with some of the methods used in a consecutive series over the last 35 years.

Patients and methods

Between 1965 and 1999, 20 patients with equal gender distribution underwent operative treatment at the Department of Cardiothoracic Surgery of the University of Vienna, Austria. The median age at operation was 29 months, ranging from 6 weeks to 28 years. The diagnosis was confirmed by cardiac catheterization. Within the last few years, however, echocardiography has started to play a role of increasing importance.

Two patients showed no clinical symptoms and only minimal congestive heart failure, obviously due to a well-developed collateral circulation corresponding with the so-called adult type of the lesion. In these patients, non-specific systolic murmur was noticed and led to the final diagnosis. All other patients had persistent symptoms of congestive heart failure despite aggressive medical therapy; some were in end-stage left ventricular failure. In all children, electrocardiography showed signs of ischemic myocardial lesion. Mitral regurgitation was present in all, in 10 mild and in 10 moderate-to-severe.

We have used extracorporeal membrane oxygenation, (ECMO), in three, and left ventricular assist device, (LVAD), in one patient.

The indication for surgical procedure has changed over time and is far more aggressive nowadays. As soon as the diagnosis is established in symptomatic neonates, they are referred for urgent operation within the next days. In older patients without severe symptoms, surgical intervention is planned electively for the earliest convenient date, usually within a few weeks. In principle, it is our policy that diagnosis of Bland-White-Garland syndrome is equivalent to indication for surgical treatment.

Address correspondence to: Prof. Dr. Gregor Wollenek Department of Cardiothoracic Surgery, University and General Hospital of Vienna, Währinger Gürtel 18-20 A-1090 Vienna, Austria Fax, 0043-1-40400-6794 E-mail, wollenek@aon.at

Pat Op Year Age Gender Technique Mortality Postop problems or reoperations

1 1965 4,0 male ligature day of operation

2 1971 1,0 female ligature    

3 1977 0,3 male ligature 9 months postop

4 1980 0,3 female reimplantation    

5 1982 0,5 male reimplantation    

6 1983 0,2 male reimplantation day of operation

7 1983 0,6 female reimplantation 1 day postop

8 1987 0,7 male subclavian BP    

9 1987 1,8 male tunnelling    

10 1988 1,3 female reimplantation    

11 1992 11,0 female mammaria BP    

12 1992 0,2 male reimplantation  

13 1992 4,0 male reimplantation   1988: LIMA + valvuloplasty

14 1993 1,5 female reimplantation 1 week postop LVAD

15 1993 0,6 male reimplantation    

16 1994 0,1 female reimplantation    

17 1995 0,4 female reimplantation    

18 1996 28,3 female reimplantation    

19 1997 0,4 male reimplantation   ECMO

20 1998 0,6 female reimplantation 3 weeks postop ECMO

Bland-White-Garland syndrome in Vienna, Austria

Diagnosis only by autopsy

21 1965 3,5 female repair of ASD I 1 day postop

22 1990 22,1 male no operation sudden death

OP year = year of operation; age = age in years; mortality = time of death; postop. problems or reoperations = early and long-term complications, BP = bypass, Tunnelling = elongation of coronary artery according to Vigneswaran, LIMA = internal thoracic artery bypass, LVAD = left ventricular assist device, ECMO = extracorporeal membrane oxygenation

Surgical management

Over the period of 35 years, 5 different surgical techniques were used, all performed with median sternotomy approach.

Three patients underwent suture ligation of the left coronary artery close to the pulmonary vessel to stop the coronary-steal-phenomenon but leaving the heart with a mono-coronary perfusion system.

Seventeen patients underwent revascularization establishing a dual coronary artery system. These procedures were performed using cardiopulmonary bypass with special care taken to myocardial protection. In recent years, cardioplegia was applied initially to both the aortic and the pulmonary trunk during the further course of the procedure given either continuously or as a multidose application via the aorta and in the last cases, retrograde cardioplegia was applied.

Direct implantation of the coronary artery into the ascending aorta was chosen in 14 patients. After complete transection of the pulmonary trunk so as to obtain good exposure of the left coronary artery and the aortic site of implantation, the left ostium was excised with a sizable button of surrounding pulmonary artery wall and transferred to an opening created in the adjacent left-sided aortic wall. After mobilization of the pulmonary bifurcation and division of the ligamentum arteriosum, end-to-end anastomosis of the pulmonary trunk was easily feasible without tension or compression of the reimplanted coronary artery.

In one child with the ostium in a very lateral position within the left posterior sinus, the ostium was excised together with a broad strip of the dorsal pulmonary vessel wall. This wall strip was sutured to form a tunnel, thus elongating the coronary and bridging a distance of about 15 millimeters. After completing the aorto-tunnel anastomosis, direct pulmonary reconstruction was possible.

Bypass techniques were used in 3 children: in one the left subclavian artery, in two the left internal mammary artery was anastomosed to the left anterior descending artery, in one of them at reoperation.

In accordance with our policy, neither mitral valve procedures nor resection of dyskinetic left ventricular wall segments nor heart transplantation were performed. Only in one child of 6 months was the mitral valve reconstructed; in a 28-year- old patient, a mitral ring was implanted. In 2 children, sternal closure was delayed in the hope to provide better conditions for treating low cardiac output.

Perioperatively 5 patients died, all of them with a left ventricular ejection fraction of less than 10%. As demonstrated preoperatively, at autopsy very poorly developed collaterals were noted. Preoperatively one of the non-survivors had been resuscitated, another had been put on the mechanical assist device before surgery. One early and one late death occurred after ligation procedure, thus raising the mortality for the ligation group to 67%, as compared to 24% in the revascularization-group. Thus in our hands, early mortality was 25% and overall mortality was 30%.

Within the postoperative course, 2 survivors suffered episodes of ventricular fibrillation, 2 had a period of respiratory insufficiency, one had to be resuscitated after sudden cardiac arrest, probably due to a rhythm disorder. In the child with subclavian bypass, the coronary ostium had been closed by suture from the inside of the pulmonary trunk. Intraoperative echocardiography confirmed a residual leak, which was closed in a second procedure.

Mean stay at the intensive care unit was 3 days (range 1 to 10 days). Patients were discharged 21 days postoperatively (range 14 to 47 days), all with digitalis medication.

Follow-up

Mean follow-up of 14 survivors, both short- and long-term, is 11 years, ranging from 20 months to 29 years.

With the exception of one child after sublavian-left coronary artery anastomosis and another after reoperation who both were in chronic left ventricular failure and treated with digoxin, currently all other patients are asymptomatic according to functional class NYHA I and without medication; all are in sinus rhythm.

In all patients chest roentgenogram reveals either normal cardiac silhouette or persisting mild cardiomegaly. On echocardiography, pre-existing signs of myocardial ischemia have either disappeared or improved significantly following successful reestablishment of a dual coronary system. In 2 children left ventricular function remained depressed. In all other patients, the ejection fraction is within normal range.

Although mitral regurgitation nearly always lessens after successful revascularization, residual mitral incompetence may remain a source of concern: mild regurgitation was found in 7, mild-to-moderate in 5 children, and one had been reoperated.

As a remnant of preexisting valvular malformation one child had mild pulmonary insufficiency, while another developed supravalvular stenosis at the site of anastomosis. All patients had some degree of visible endocardial fibrosis.

Eight patients underwent postoperative cardiac catheterization. In all but one, there was no angiographic evidence of anastomotic stenosis or major local impairment of ventricular performance. That patient was reoperated and received an internal thoracic artery bypass. In 5 patients who underwent thallium stress tests, there were small areas of irreversible reduced perfusion in the left ventricular and septal myocardium. In all these findings, no differences were noticed as a result of different techniques or surgical management.

Fig. 1. Sector-echocardiogram in the short left parasternal axis view shows the left coronary artery (LCA) passing abnormally between aorta (AO) and pulmonary trunk (PA) and emptying into pulmonary artery. With color flow the run off from the coronary vessel into the pulmonary artery is

According to the literature, Bland-White-Garland sysndrome is expected to occur once in 300,000 live births and thus constitutes approximately between 0.24% and 0.46% of all congenital cardiac anomalies (9,10). Reviewing our data, the published incidence may be an underestimation. In our experience, considering the number of live deliveries in the referring area of our hospital, there was a local incidence rate of 1 in 70,000 with an increase over the last decade to 1 in 25,000 live births. We assume that this trend is not a consequence of changing incidence but of improving successful diagnosis as a result of improved diagnostic tools together with a close-matched neonatal diagnostic network and, last but not least, improved knowledge and experience in the pediatric medical field in general.

Diagnosis should be established prior to the onset of myocardial damage. Even in our experience, at least one case was not identified in time. In 1965, a child underwent surgical repair for primum atrial septal defect but deteriorated for unknown reasons. The diagnosis was established only at postoperative autopsy. Angiography including selective right coronary injection visualizing the enlarged coronaries and the blush of opacification into the pulmonary trunk is the most sensitive imaging technique for definitive diagnosis (9,11). More recently, increasing experience with echocardiography including two-dimensional, pulsed and color flow Doppler (Fig. 1) has led to excellent diagnostic quality. Today, catheterization and angiography are mandatory only if the diagnosis cannot be made with certainty. 

With the drop in pulmonary vascular resistance and pulmonary artery pressure after birth, the left coronary artery perfusion is reversed, thus draining into the pulmonary artery. The quality of collateral supply from the right coronary artery is decisive for the further natural history, mainly for the onset of symptoms. With inadequate collaterals, the left-to-right shunt into the pulmonary circulation with the consequent "coronary steal" phenomenon is even more deleterious for the left ventricular myocardium. Even today, correction of Bland-White-Garland syndrome remains a high-risk surgery, with a perioperative mortality rate up to 23% (12,13,14). These experiences have emphasized the necessity of early corrective surgery as soon as the diagnosis is established, regardless of the age of the patient (12,13,14). The most important risk factor is preoperative left ventricular dysfunction (7,14,15).

As the natural history is one of progressive deterioration of left ventricular function with resultant pump failure and often dysfunction of the mitral valve, operative treatment provides the only hope for extended survival.

There are basically 2 concepts to establish an adequate coronary flow: a) ligation of the anomalous left coronary artery thus stopping the steal phenomenon and leaving the heart with a monocoronary perfusion system, and b) the creation of a two coronary system.

Ligation of the anomalous coronary artery was the first successful procedure for correction, and was formerly generally accepted as the procedure of choice (16). This very simple technique was performed after median sternotomy or left thoracotomy on the beating heart without extracorporeal bypass. There is no doubt that despite the high mortality in symptomatic infants many patients did benefit from this technique, at least in the short-term follow-up. The disadvantage of ligation is that the entire myocardium is left at the mercy of a single coronary artery. Theoretically, a single-coronary system after ligation may increase the risk in the long-term that may result in late sudden death (6,7,17).

In our series, 2 of three patients undergoing ligation died, one of them late, which is comparable to published data, with an expected late mortality of about 25% (6,17).

Discussion

Comparing some of the numerous publications, it becomes clear that the corrective surgical treatment still carries a relevant risk concerning early mortality. The numbers presented show similar range regardless of the technique used. Although revascularization seems to have a minor risk (18), this tendency is relative and should be considered with care since: a) most studies cover about two decades including all medical progress and the much-cited learning curve and b) revascularization techniques are the historically younger ones. With regard to early mortality, the extent of ischemic myocardial damage is the most important determinant of outcome after a corrective procedure (14,17).

The main difference to be expected is in the long-term outcome: there is a high rate of myocardial ischemia and consequently death from cardiac reasons in patients with coronary ligation. In particular, asymptomatic patients with so-called silent myocardial ischemia and with a subjective feeling of being free from complaints are at risk, as they may not realize the problem and refuse diagnostic procedures. On the other hand, late mortality in the revascularization group is almost nil (18).

Restoration of a two-coronary system, which aims at antegrade perfusion thus creating a physiologically normal coronary perfusion is currently preferred. These procedures take advantage of the still existing myocardial potential for recovery. This can be achieved by a number of techniques: direct implantation of the aberrant artery into the ascending aorta, aortopulmonary tunnel operation (19), bypass grafting with the left subclavian artery, the internal thoracic artery, or a vein graft (14,17).

In our experience, at least in infants, direct reimplantation is technically feasible without surgical difficulties as infant tissue is distinguished by high-grade elasticity. In older patients the tissue may not be that flexible to bridge longer distances. For these patients, we suggest either mammary bypass or the creation of an elongating pulmonary wall tunnell to the aorta. One of our children who had the repair at the age of 4 years required reoperation 6 years thereafter, showing thread-shaped stenosis of the proximal left coronary artery, possibly as a consequence of too extensive tension after reimplantation.

Because preservation of the residual ventricular function optimizes the chances of recovery, operating on a beating heart may prevent myocardial damage and yield better results (20).

In one patient, indirect implantation to the aorta was performed by making a tube extension of the left coronary artery with the pulmonary arterial wall (21). With this technique late complications such as supravalvular stenosis, baffle obstruction, and any impairment of the pulmonary valve are avoided (17,19,22).

In one patient, direct anastomosis of the left subclavian artery to the left coronary artery was performed. This procedure is feasible in even very young patients; it allows growth, and should have better long-term conduit characteristics than those of vein grafts (7). The disadvantages are the tendency of the subclavian artery to kink at its origin from the aorta and inadequate length, potential ischemia of the upper left extremity particularly in older children after ligation of the artery (23), technical difficulties in performing the anastomosis, and the patency rate, which is only 60 % to 80 % (23,24). If bypass grafting is required, these considerations argue in favor of a mammary bypass, which could reduce the potential drawbacks of saphenous vein grafts and increase long-term patency.

Revascularization immediately after diagnosis provides marked recovery of left ventricular function (12). If the vascularization is sufficient for at least 18 months, the size of the right coronary artery collaterals return to normal. This suggests that even severely damaged myocardium has a great potential for recovery, presumably because there are ischemic viable myocardial cells scattered throughout the scarred ventricle. In addition to the actual area of myocardial necrosis, there remains a large zone of ischemic muscle, with potential for recovery after revascularization. As a consequence of this theory, in our patients, no surgical excision of left ventricular myocardium was performed; neither was this necessary within the period of follow-up.

Early surgery might avoid the need for mitral valve surgery. Mitral regurgitation is secondary to both left ventricular dilatation and ischemic papillary muscle dysfunction, and may decrease postoperatively depending on improvement of left ventricular function (25,26,27). Therefore, according to our policy, in infants, the mitral valve was usually not interfered with at the corrective operation. In contrast, we advocate the reconstruction or replacement of severely impaired mitral valve in adults, since in older patients the expected improvement as a consequence of ventricular recovery is less promising. The potential use of techniques of mitral valve repair are an important addition to the treatment of Bland-White-Garland syndrome. So far, only one mitral intervention was required in our pediatric group of patients, but may be necessary with longer follow-up.

 We agree with most authors, that Bland-White-Garland syndrome is not a primary indication for heart transplantation (4). There is no doubt that extremely poor ventricular performance and the postoperative need for some extracorporeal support system carry a significant mortality. The application of mechanical assist devices as a means of cardiac rescue carries a high rate of complications and limited success (28). But when these patients survive, late cardiac function may be good (4).

In conclusion, simple ligation has to be avoided, as this procedure may prove lethal in the long-term follow up. If possible, revascularisation is the method of choice.

As myocardial ischemic damage was demonstrated in all patients at the time of diagnostic evaluation and because of the unfavorable natural course and improvement in surgical techniques over the past decades, an aggressive surgical approach is desirable to avoid further myocardial damage. The optimal time for operation is the earliest one possible. We did not see young age to be a risk factor and expect early repair to be beneficial with regard to long-term results. In children, there is usually no reason to interfere with the mitral valve at the initial operation as incompetence has been shown to disappear with time.

Long-term follow-up of these patients is needed because they may have sequelae of infarction, persistent left ventricular dilatation or mitral insufficiency, or inadequate coronary perfusion requiring late bypass grafting.

 References

2. Abbott ME. Congenital heart disease. In: Osler`s Modern Medicine, New York: Lea and Febiger, 1908; IV.

3. 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; 8:787-801.

18. Vouhè PR, Tamisier D, Sidi D, Vernant F, Mauriat P, Pouard P, Leca F. Anomalous left coronary artery from the pulmonary artery: early and late results after isolated aortic reimplantation. 28^th Annual Meeting Society of Thoracic Surgeons, Orlando, FL, 1992:134.

23. Kesler KA, Pennington G, Nouri S, Boegner E, Kanter KR, Harvey L, Chen S, Juriedini S, Balfour I, Willman VL. Left subclavian-left coronary artery anastomosis for anomalous origin of the left coronary artery: long-term follow-up. J Thorac Cardiovasc Surg 1989; 98:25-29.

28. Wollenek G, Czerny M, Golej J. Surgical aspects of pediatric cardiac extracorporeal membrane oxygenation. Artif Organs 1999; 23:988-993.