Optimal prevention and treatment of subaortic stenosis (SAS) in the univentricular heart (UH) and high pulmonary blood flow remains controversial, especially when complicated by aortic arch obstruction. Several surgical techniques have been used in infancy to palliate this group of patients.
From January 1980 to December 2004, 43 children with UH and systemic ventricular outflow obstruction underwent relief of SAS subsequent to pulmonary artery banding (PAB;n=34) and modified Norwood procedure (MNP;n=9). Median age at operation was 20 days (range; 2 to 298 days; 79% were less than 1 month) and the average preoperative pressure gradient across the ascending aorta and systemic ventricle was 72±17 mmHg (range 31 to 135 mmHg). Three techniques to relief SAS were performed: (1) the Damus-Kaye-Stansel (DKS) procedure (including MNP patients;n=32); (2) subaortic resection or ventricular septal defect enlargement (n=7); and (3) apical aortic conduit (AAC;n=4).
Four patients (9%) died in the early postoperative period: three infants after DNP (33%), and one after PAB (3%;p<0.001). The overall survival at 1 and 10 years was 79% and 70%, respectively. Complete heart block requiring insertion of a pacemaker occurred in five patients (12%). Completion Fontan, hemi-Fontan and heart transplantation have been performed in 25, 21 and 1 patient, respectively. Follow-up was complete in all survivors at a mean time of 7.2±6.6 years (range; 3 months to 23 years). Outcome was significantly worse in patients with associated aortic arch obstruction (p=0.002), and with the presence of AAC (p=0.006) or DNP (p=0.02).
Surgical relief of subaortic obstruction in patients with UH and high pulmonary blood flow can be effectively palliated with PAB or DNP. DKS construction and ventricular septal defect enlargement provide good long-term relief of SAS in select patients. SAS surgery should precede completion Fontan in most patients.
Surgical relief of subaortic obstruction in patients with UH and high pulmonary blood flow can be effectively palliated with PAB or DNP. DKS construction and VSD enlargement provide good long-term relief of SAS in select patients.
Mark Ruzmetov, None.