Geometry and growth of the reconstructed aorta in patients with hypoplastic left heart syndrome and variants.

Objective: The interdigitating technique in aortic arch reconstruction in hypoplastic left heart syndrome and variants (HLHS) reduces the recoarctation rate. Little is known on aortic arch growth characteristics and resulting clinical impact.

Methods: A total of 139 patients with HLHS underwent staged palliation between 2007 and 2014; 73 patients underwent arch reconstruction. Dimensions of ascending aorta, transverse arch, interdigitating anastomosis, and descending aorta in pre-stage II and pre-Fontan angiograms were measured. Aortic arch dimensions were analyzed. Ventricular and atrioventricular valve function were assessed.

Results: Diameters increased in all segments between pre-stage II and pre-Fontan (P < .0005). The z scores remained unchanged in all segments but the descending aorta that was significantly larger pre-Fontan (P = .039). Dimensions and z scores between pre-stage II and pre-Fontan correlated in proximal segments, but not at and distal to the interdigitating anastomosis. Pronounced tapering occurred between the transverse arch and the interdigitating anastomosis. Arch intervention of any type was performed in 7 (9.6%), and intervention for recoarctation in 3 (4.1%) patients.

Conclusions: The aortic arch after reconstruction with the interdigitating technique differs from normal. Growth was proportional with no further geometrical distortion. Recoarctation and reintervention rate is low. Further improvement may be achieved by optimizing patch configuration and material.