VSD formation in corrected TGA. Management of a previously undescribed complication after tricuspid valve replacement

Disruption of the membranous ventricular septum following replacement of the tricuspid systemic atrioventricular valve in corrected TGA has not, to our knowledge, been reported in the literature. Our experience with this uncommon complication, which we observed and treated in two patients, is therefore presented. In the first case the native value anulus was large in relation to the largest available prosthetic valve. VSD formation occurred on the fifth postoperative day, probably due to "push and pull" forces acting on the membranous ventricular septum during the cardiac cycle. Fixation of the prosthetic sewing ring to the atrial tissue well above the adjacent membranous ventricular septum may invalidate the push and pull forces and thus be a preventive measure. In the second case the membranous ventricular septum remained intact following the primary valve replacement. When the outgrown prosthesis was excised 11 1/2 years later, disruption of the membranous septum resulted from attempts to widen the native valve anulus. This complication may be avoided if part of the sewing ring is cut away from the prosthetic valve and left in situ along the adjacent membranous ventricular septum. Sutures can be placed through the remnant of the sewing ring with minor or no risk of ventricular septal disruption.