| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
J Thorac Cardiovasc Surg 1994;108:589-590
© 1994 Mosby, Inc.
LETTERS TO THE EDITOR |
Department of Cardiovascular Surgery
Southern Railway Headquarters Hospital
Ayanavaram, Perambur
Madras 600023, India
To the Editor:
The tetralogy of Fallot is known to be associated with anomalous origin of the left anterior descending artery (LAD) from the right coronary artery in about 5% of patients 
1,2 This abnormality is important surgically because the anomalous LAD courses across the right ventricular outflow tract, where a subpulmonic incision is usually made during a surgical repair. Also, postmortem study has shown that the anomalous artery may be buried in the myocardium. 3 The anomalous LAD may be divided during attempts to enlarge the outflow tract, and results of this injury have been adequately detailed by numerous reports. 4-6 We report a case of tetralogy of Fallot in which an anomalously arising LAD was transected inadvertently during intracardiac repair. Blood supply distal to the transection was restored by a left internal mammary artery (IMA) graft, which was dissected with the aid of cardiopulmonary bypass.
Tetralogy of Fallot with an LAD arising from the right coronary artery was diagnosed in an 18-year-old boy. The intracardiac repair was done with the aid of cardiopulmonary bypass with core cooling to 25° C and blood cardioplegia. The infundibular resection and pulmonary valvotomy were performed through a right atriotomy and pulmonary arteriotomy, respectively. During extension of the pulmonary arteriotomy across the anulus to the infundibulum to repair the hypoplastic anulus, the LAD was divided accidentally. After closure of the ventricular septal defect, a pericardial patch was placed on the right ventricular outflow tract with the heart beating during rewarming. The left IMA was dissected with the aid of cardiopulmonary bypass and grafted to the LAD distal to the site of transection with the aid of cardioplegic arrest. The patient was weaned from cardiopulmonary bypass with dopamine 5µg/kg per minute, started electively.
His early stay in the intensive care unit was uneventful, with good hemodynamics. A tracheostomy was done on the second postoperative day for right-sided diaphragmatic paresis caused by phrenic nerve palsy that resulted from the use of iced slush. The tracheostomy was closed on the ninth postoperative day and the patient was discharged 2 days after tracheostomy closure.
The patient was seen 3 months after the operation and is attending college. He is free of symptoms and has no evidence of infarction or ischemia on the electrocardiogram. Simultaneous IMA injection and right ventricular angiography done at 3 months show a patent left IMA, right ventricular outflow tract, and distal pulmonary arteries (Fig. 1). The left ventriculogram and echocardiogram show good left ventricular function, as well.
|
7 in 1976 described the method of dissecting the coronary artery off the outflow tract with placement of an outflow patch beneath the artery. This technique carries the risk of stretching with resultant ischemia caused by right ventricular dilatation, which is not uncommon immediately after the operation. The ventricular septal defect can be closed through the aorta if an outflow patch is not required. 8 A transverse ventriculotomy below the LAD can be used for relief of infundibular stenosis and closure of the ventricular septal defect. 6 A separate ventriculotomy can be made at or near the pulmonary anulus if a transverse ventriculotomy is inadequate. 5 Hurwitz and coworkers 9 recommended a separate pulmonary artery incision for relief of pulmonary stenosis and enlargement with a patch if necessary. Humes and coworkers 10 suggested using either patch reconstruction or conduit placement in this situation depending on the exact location and tortuosity of the anomalous artery and the level and severity of the right ventricular outflow tract obstruction. Castaneda and colleagues 11 considered this additional anomaly to be a contraindication to primary repair in infancy. The complete repair can be deferred until the child is 5 to 6 years old. The transatrial approach may be useful in the presence of this anomaly. 12 However, its effectiveness and usefulness are limited if the obstruction is primarily infundibular and the pulmonary valve anulus is of adequate size for body weight and surface area.
Bypass grafting is the only method of restoring blood supply distal to an inadvertently transected LAD. Berry and McGoon 5 were the first to report aorta-coronary bypass grafting with autologous saphenous vein in 1973. Shaffer, Berman, and Waldhausen 13 reported another case of saphenous vein grafting for divided anomalous LAD in a 13-year-old boy. Although di Carlo and colleagues 14 reported aorta-coronary bypass with a polytetraflouroethylene graft in a 17-month-old boy, the graft was for a transected left coronary artery. Our case represents the first use of a left IMA graft for inadvertent transection of an anomalous LAD. On the basis of various reports of use of the IMA for coronary artery disease, we predict that the patient will do well.
Preoperative angiography is important to delineate the coronary artery anomalies in tetralogy of Fallot. Various modifications may be used to prevent injury to an anomalously arising LAD. If it is damaged, the blood supply distal to the site of injury or transection can be successfully restored by bypass grafting with polytetrafluoroethylene, saphenous vein, or a left IMA graft.
References
This article has been cited by other articles:
|
|
 |
|
  S. Kalra, R. Sharma, S. K. Choudhary, B. Airan, A. Bhan, A. Saxena, S. S. Kothari, and P. Venugopal Right ventricular outflow tract after non-conduit repair of tetralogy of Fallot with coronary anomaly Ann. Thorac. Surg., September 1, 2000; 70(3): 723 - 726. [Abstract] [Full Text] [PDF]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| ANN THORAC SURG | ASIAN CARDIOVASC THORAC ANN | EUR J CARDIOTHORAC SURG |
| J THORAC CARDIOVASC SURG | ICVTS | ALL CTSNet JOURNALS |
