Stenosis of the superior limb of the systemic venous baffle following a Mustard procedure: An under-recognized problem

BackgroundPatients with atrioventricular concordance and ventriculoarterial discordance (DTGA) and a Mustard procedure may develop stenosis of the superior limb of the systemic venous baffle (SLSVB). The frequency of this complication in an adult cohort was evaluated.MethodsPatients > 18 years with DTGA and a Mustard procedure with and without a pacemaker (PM)/implantable cardioverter defibrillator (ICD) were identified through an institutional database. Subjects were included following a cardiac imaging study (computed tomography, magnetic resonance imaging, venography or cardiac catheterization) and follow-up in the PM/ICD or congenital cardiac clinics from 2001 to 2007. The primary end-point was narrowing of the SLSVB (< 10 mm) on cardiac imaging. Hemodynamically significant narrowing was defined by: azygous vein dilatation with retrograde flow or superior vena cava syndrome or the need for dilatation ± stenting of the SLSVB.ResultsNarrowing of the SLSVB was observed in 49/112 patients (70 males) age 31 ± 6 years (range 18-49) and was hemodynamically significant in 15/49. Of 29 patients with a PM (23) or ICD (6) and cardiac imaging, 17 had narrowing of the SLSVB which was hemodynamically significant in 8. Non-echocardiographic imaging had a sensitivity of 88% at detecting narrowing of the SLSVB in contrast to pulse-wave Doppler, which yielded a sensitivity of 16% (61% negative predictive value, 88% positive predictive value).ConclusionsIn our adult cohort of Mustard patients, narrowing of the SLSVB had a prevalence of 44% and was more likely to be detected by non-echocardiographic imaging. Baffle patency should be evaluated before transvenous device implantation.