Nearly 35 years have passed since Tirone David described the replacement of the aortic root and ascending aorta with preservation (reimplantation) of the aortic valve. Today, this procedure, known as the David procedure, is the gold standard for adults with aneurysms of the aorta involving the sinuses of Valsalva. Due to its excellent surgical outcomes and the benefit of preserving the native aortic valve, the procedure was quickly extended to the pediatric population.

Initially, the surgical indication was aortic root aneurysm in children with Marfan or Loeys-Dietz syndrome. It gradually expanded to treat patients with cono-truncal congenital anomalies such as tetralogy of Fallot and transposition of the great arteries. However, the outcomes in this patient group have been inconsistent: some studies report discouraging results, while others describe survival and freedom from aortic valve reoperation comparable to that seen in adults.

In this article, the authors retrospectively reviewed 17 pediatric patients who underwent the David procedure at the Royal Children’s Hospital between April 2006 and April 2016. Clinical and imaging data were retrieved from electronic medical records. Echocardiographic evaluation included aortic root diameters (with Z-scores) and the degree of valvular regurgitation before and after surgery. Kaplan-Meier estimates were used for survival analysis.

Among the cases reviewed, the most common etiological diagnosis was transposition of the great arteries following an arterial switch operation, followed by Loeys-Dietz syndrome and Marfan syndrome. Eleven of the 17 patients had detailed surgical reports, showing that 63.6% required central plication to achieve adequate valvular coaptation. One patient underwent subcommissural annuloplasty, and two required cusp resection and extension. No mortality was reported during follow-up. However, five patients (29.4%) underwent reoperations, and four (23.5%) required aortic valve replacement. Freedom from reoperation for aortic valve replacement at 1, 5, and 10 years was 93.8%, 93.8%, and 68.2%, respectively. The indication for aortic valve reoperation was recurrent severe valvular regurgitation. One patient operated on at the age of 3 underwent reoperation 3 months later for proximal anastomosis dehiscence. A patient with Loeys-Dietz syndrome required ascending aorta and arch replacement a decade after the reparative surgery.

The authors concluded that while aortic valve-sparing surgery can be successfully performed in pediatric patients, it demands a highly skilled and experienced surgeon due to the frequently dysplastic nature of the aortic valves in this population.

COMMENTARY:

Not long ago, valve-sparing surgery revolutionized aortic root interventions, establishing itself as the optimal treatment for sinus aorta dilation with secondary valvular insufficiency. However, it is important to recognize that children represent a distinct subgroup of patients with unique considerations regarding indications, techniques, and surgical outcomes. As a reference, in the adult population, David et al. reported an accumulated reintervention rate of 2.1% at 10 years and 6% at 20 years of follow-up. Similarly, our group at the Puerta de Hierro Hospital reported freedom from aortic valve reoperation at 10 and 15 years of 96% and 87%, respectively. In contrast, this Australian team reports a 10-year freedom from valve replacement of 68.2% in children. What is different about children?

It is crucial to emphasize the peculiarities of pediatric aortic valves. While in adults the repaired leaflets are typically morphologically normal, pediatric valves are often markedly dysplastic, necessitating more extensive interventions, particularly in bicuspid valves and those following arterial switch operations, where the neo-aortic root is histologically and morphologically pulmonary.

Adolescents with bicuspid aortic valves form a noteworthy subgroup. The authors highlight a higher failure rate of repairs in these patients due to inadequate stabilization of the annulus. Given their experience and the increased frequency of leaflet abnormalities, a shift toward Ross procedures with the inclusion technique appears highly valid. This approach has shown greater valve longevity, minimal coronary distortion risk, and a right ventricle-to-pulmonary artery conduit lifespan exceeding initial expectations.

Another discussion point is surgical indication. While in adults the recommendation is based on an established aortic diameter linked to increased morbidity and mortality, pediatric teams interpret arterial dimensions using Z-scores, complicating a realistic estimation of aortic dilation severity. Since children are known to have a very low risk of aortic dissection and rupture, the authors emphasize delaying surgery until the aorto-ventricular junction measures at least 21 mm, allowing for the placement of a minimum 24-mm Dacron graft that can accommodate the patient into adulthood without requiring replacement.

Finally, at the technical level, beyond the challenge of valvular dysplasia, the left ventricular outflow tract is more deeply embedded within the right ventricle in tetralogy of Fallot, complicating the dissection of the aortic root. In these cases, it may be necessary to position the proximal suture line slightly higher within the subcommissural triangle between the cusps.

In conclusion, children and their pathologies are distinct, and surgical success parameters often differ significantly from adults. To ensure favorable outcomes from aortic valve-sparing surgery in the pediatric population, these interventions must be performed at specialized centers by surgeons with extensive valve repair experience, especially when addressing leaflet abnormalities.

REFERENCE:

d’Udekem Y, Kisamori E, Ishigami S, Konstantinov IE. Aortic valve-sparing procedure in the pediatric population. Ann Cardiothorac Surg. 2023 May 31;12(3):253-258. doi: 10.21037/acs-2023-avs1-0029.