Influence of anatomic correction for transposition of the great arteries on myocardial perfusion: radionuclide imaging with technetium-99m 2-methoxy isobutyl isonitrile

Long-term fate of the coronary arteries after the arterial switch operation in newborns with transposition of the great arteries

OBJECTIVE

Concern continues to be expressed about the long-term impact of coronary artery translocation after the arterial switch operation for transposition of the great arteries. This study was conducted to determine the prevalence of obstructions of the translocated coronary arteries by the use of selective coronary artery angiography.

METHODS AND RESULTS

64 children (mean age 7.6 (SD) 1.5 years) who had survived an arterial switch operation underwent evaluation. They had been operated on by one surgeon and they were followed up by a single hospital. Selective coronary artery angiography was possible in 58 patients. Five patients showed occlusion or stenosis of a coronary artery: one occlusion and two stenoses of the left coronary trunk, two occlusions of the circumflex artery. The prevalence of late coronary artery complications was 7.8 (SD) 6.6% (95% CI 1.2 to -14.4%). The three patients with occlusion of one coronary artery had perioperative ischaemic complications, with associated electrocardiogram evidence of ischaemia and left ventricular dysfunction with mitral valve insufficiency. Both patients with stenosis of the left main coronary artery trunk did not have any evidence of an anomaly before catheterisation.

CONCLUSIONS

The prevalence of the late coronary artery complications after an arterial switch operation was low in this series. This accords with the view that the arterial switch operation remains the preferred treatment for such patients. Screening for late coronary artery patency should be done by using selective coronary artery angiography, because even patients who remain symptom free can have coronary artery anomalies.

Right ventricular systolic function in adolescents and young adults after Mustard operation for transposition of the great arteries

This study evaluates long-term ( > 10 years since surgery) right ventricular (RV) systolic function in patients who had previously undergone intraatrial baffle surgery for transposition of the great arteries. Studies suggest these patients are clinically stable and lead satisfactory lifestyles, but long-term ventricular performance is not known. Radionuclide angiocardiography was used to estimate RV ejection fraction in 58 patients a mean of 14 years after the Mustard operation. Repeat studies were performed in 32 patients. The absolute RV ejection fraction of 0.53 +/- 0.10 in our patients did not differ from normal values. Nine patients had a value < 0.42, placing them > 2 SDs below normal. Repeat RV ejection fraction decreased from 0.54 +/- 0.11 to 0.51 +/- 0.11 (p < 0.1) in 32 patients, and > 0.10 in 6. Thus, RV ejection fraction was abnormal in 9 of 58 patients (16%) evaluated > 10 years after a Mustard operation. Repeat studies demonstrate worsening in at least 6 of 32 patients (19%). These postoperative Mustard patients require continued evaluation, even in the absence of overt symptomatology.

Coronary angioplasty for coronary stenosis after the arterial switch procedure

Coronary balloon angioplasty seems to be an adequate therapy for proximal coronary stenoses developing after the arterial switch operation, with adequate medium-term results. Overexpansion of the lesion seems to be necessary.

Coronary artery abnormalities detected at cardiac catheterization following the arterial switch operation for transposition of the great arteries

Because the arterial switch operation has become the routine surgical approach for transposition of the great arteries, there is increasing awareness of adverse sequelae in some survivors. For the arterial switch to be considered the procedure of choice for transposition of the great arteries, long-term patency and normal function of the translocated coronary arteries must be achieved. We reviewed the cineangiograms and hemodynamic data in 366 patients who underwent postoperative catheterization after arterial switch operation. Of these, 13 patients (3%) had previously unsuspected coronary abnormalities diagnosed angiographically. No patient had noninvasive evidence of resting systolic dysfunction. Findings included left main coronary artery stenosis (n = 3) or occlusion (n = 2), anterior descending coronary artery stenosis (n = 1) or occlusion (n = 2), right coronary artery stenosis (n = 1) or occlusion (n = 1), and small coronary artery fistulas (n = 3). One patient died suddenly 3.3 years after surgery, 1 patient is lost to follow-up, and the remaining 10 patients are alive and asymptomatic up to 11 years after surgery.