Predictors of Left Ventricular Outflow Tract Obstruction After Primary Interrupted Aortic Arch Repair

Left ventricular outflow tract obstruction is an important complication after interrupted aortic arch repair and subsequent interventions may adversely affect survival. Identification of patients at risk for obstruction is important to facilitate clinical decision-making and monitoring during follow-up. The aim of this review is to summarize reported risk factors for left ventricular outflow tract obstruction after corrective surgery for interrupted aortic arch. A systematic search of the literature was performed across the PubMed and EMBASE databases. Studies that reported echocardiographic and/or clinical predictors for left ventricular outflow tract obstruction in infants that underwent biventricular repair of interrupted aortic arch were included. From the 44 potentially relevant studies, eight studies met the inclusion criteria. Postoperative left ventricular outflow tract obstruction requiring an intervention was common, with an incidence ranging between 14 and 38%. Manifestation of postoperative left ventricular outflow tract obstruction was associated with a smaller pre-operative size of the aortic root (sinus of Valsalva), sinotubular junction, and aortic annulus. Anatomic and surgical risk factors for left ventricular outflow tract obstruction were the presence of an aberrant right subclavian artery, use of a pulmonary homograft or polytetrafluoroethylene interposition graft for aortic arch repair, and the presence of a small- or medium-sized ventricular septal defect. In patients with a borderline left ventricular outflow tract that undergo a primary repair, these (pre-) operative predictors can provide guidance for optimal surgical decision-making and for close monitoring during follow-up of patients at increased risk for developing left ventricular outflow tract obstruction after corrective surgery.