Transaortic and Right Atrial Approach for Pediatric Tunnel-Type Left Ventricular Outflow Tract Obstruction: An Alternative to Modified Konno.

BACKGROUND

Tunnel-type left ventricular outflow tract obstruction (LVOTO) in children requires extensive resection of long-segment fibromuscular narrowing and is traditionally treated with Konno or modified Konno procedures, which involve right ventriculotomy and may risk right ventricular dysfunction and conduction injury.

METHODS

Between 2012 and 2023, 26 children (mean ± SD age, 5.4 ± 1.3 years; 34.6% with prior septal myectomy) underwent repair of tunnel-type LVOTO using a combined transaortic and right atrial approach at 3 tertiary centers. The operation consisted of transaortic exposure, controlled creation of an iatrogenic membranous ventricular septal defect to access deep obstructive tissue, bidirectional resection via the aortic root and right atrium, and patch closure of the septal defect from the right atrium.

RESULTS

There was no early or late mortality. The mean ± SD left ventricular-aortic gradient decreased from 67.6 ± 11.9 mm Hg preoperatively to 15.8 ± 5.0 mm Hg at last follow-up (P < .0001). Freedom from reoperation at 5 years was 96.2%, with 1 patient (3.8%) reoperated for aortic insufficiency. Right bundle branch block occurred in 23.1% of patients, but no complete heart block was observed. Right ventricular systolic function showed only modest reductions from baseline.

CONCLUSIONS

A transaortic and right atrial, right ventricle-sparing approach can achieve durable relief of tunnel-type LVOTO in children while preserving right ventricular function and avoiding right ventriculotomy, and may represent a useful alternative to modified Konno repair.