Atrial baffle problems following the Mustard operation in children and young adults with dextro-transposition of the great arteries: the need for improved clinical detection in the current era.

Objective: Intraatrial Mustard baffle repair of dextro-transposition of the great arteries (d-TGA) is vulnerable to complications, typically obstruction and leaks. Because patients often require pacemakers or intracardiac electrophysiology studies (EPS)/ablation for arrhythmias, narrowed or obstructed baffles restrict cardiac access hindering intracardiac procedures. Current guidelines recommend clinical as well as comprehensive transthoracic echocardiographic/Doppler (TTE) studies to identify baffle problems. This study reviews the effectiveness of these guidelines in detection of baffle issues pre-EPS catheterization and need for ancillary vascular interventions.

Design: Data from all patients with repaired d-TGA referred for hemodynamic catheterization or EPS between 1995 and 2009 at our institution were reviewed, including symptoms and TTE findings. Obstruction was defined as either a disturbed color Doppler flow or mean velocity >1 m/s above the mitral valve or directly measured pressure gradient >4 mm Hg or more than 50% baffle diameter narrowing by venography.

Results: Of 59 patients (34 pacemaker, 9 ablation, 16 routine hemodynamic) ages 8-39 years (mean 22.8), only three (5%) had symptoms of obstruction. However, baffle complications were found in 33 patients (56%), some with more than one problem: superior vena cava (SVC) obstruction in 32, inferior VC in two and leak in four. Baffle stenting was required in 24 patients and leak closure in two. Precatheterization TTE was available in 51 patients and showed 34% sensitivity, 61% specificity, 63% negative predictive value, and only 37% positive predictive value in recognizing baffle complications when compared with the actual catheterization findings.

Conclusion: This study reports that baffle complications in patients with d-TGA following Mustard operation are more common than previously reported. However, comprehensive TTE and clinical symptoms are not effective enough to recognize these complications. Suspicion of and better noninvasive imaging prior to catheterization is required.