Aortic valve repair and Ross operation in children: the importance of patient selection and surgical technique

Wilder et al. [ 1 ] have reported an important series of 90 children operated for significant aortic regurgitation in recent years in a single institution. The children received either aortic valve repair (51%), the Ross procedure (23%) or valve replacement with a prosthesis [aortic valve replacement (AVR), 26%]. The series was quite heterogeneous and included children with root dilatation and valve insufficiency (AI), or with congenital malformation or iatrogenic lesions following balloon dilatation. Furthermore, up to 52% of the kids had some degree of aortic stenosis. During a mean follow-up of 6 years, the authors found that aortic valve repair procedures were associated with a higher rate of recurrent AI, a higher left ventricle outflow tract peak pressure and a greater annular dilatation. Moreover, the rate of freedom from reoperation was only 51% for AVR and 64% for aortic valve (AV) repair compared with 100% with the pulmonary autograft (the Ross procedure) at 6 years. Further analysis revealed AVR to be a significant risk factor for reoperation. Nevertheless, when excluding the cases of bioprosthesis degeneration, AV repair became a significant predictor of reoperation over time. However, when transcathether procedures were also taken into consideration, the authors found no difference in the rate of reintervention between the three groups. The authors concluded that, in their experience, AV repair might not offer any advantage over valve replacement with the pulmonary autograft for older children with significant AI. Despite the limitations of a retrospective analysis of a limited number of cases with a broad spectrum of lesions and most likely a significant selection bias that makes the comparison between the three groups difficult, the study highlights some important points that deserve consideration. From our 20 years of experience with aortic valve repair in adults and children [ 2 ], we have learned that the two most important determinants of repair durability are: (i) the quality and quantity of the leaflet tissue the surgeon has to deal with during the procedure and (ii) the quality of the immediate result in terms of leaflet coaptation, motion, coaptation height and residual AI, as assessed by intraoperative transoesophageal echocardiography (TOE) after weaning from cardiopulmonary bypass. Moreover, similar to mitral valve repair, annular stabilization improves the long-term result, preventing further dilatation and recurrence of AI. We have seen in adults that a detailed identification of the mechanism of aortic regurgitation by means of preoperative TOE is of paramount importance to predict valve reparability and to choose the most appropriate repair technique [ 3 ]. In children, the congenital lesions of the aortic valve may be classified from a surgical point of view in lesions with enough or an excess of leaflet tissue (or in any case with good quality of leaflets; such as dilatation of the ascending aorta or root, bicuspid valves without restrictive raphe), and lesions with a lack of tissue (such as unicuspid, rheumatic and post-balloon valvotomy valves). In the first instance, the excess of leaflet tissue usually allows a successful repair by means of free margin shortening (with either plication or resuspension) without the need of exogenous material such as the pericardial patch. In these cases, excellent and durable results are expected. It is noteworthy that, in this series by Wilder et al. , 43% of the children who underwent AV repair showed some degree of valve stenosis and up to 85% of them needed pericardial leaflet extension. Although some children received commissuroplasty with the Trusler stitch, a central plication of the free margin or triangular resection was not applied in any case. This reveals that the quality of these valves was probably quite poor from the beginning and hence the suboptimal results with repair. Nevertheless, if the pericardial patch was overused, these results demonstrate that one should avoid its use as much as possible. The authors have also shown through an impressive number of follow-up echoes that the children in the repair group presented with a significant dilatation of the annulus over time with a mean size of 2.4–2.5 cm at 5–7 years after surgery. We have also learned that annular stabilization with either subcommissural or circumferential annuloplasty is an important determinant of repair durability over time [ 4 ]. This study further reveals that progressive annular dilatation is possible in children and is associated with recurrence of AI. Therefore, annular stabilization should be considered also in children to increase repair durability. Although AV repair may have a certain risk of failure over time, as the authors have correctly pointed out, repair techniques may delay a further valve replacement regardless of a prosthesis or a pulmonary autograft was used. This time gain is very valuable in children, allowing, on the one hand, one to avoid the oral anticoagulation associated with a mechanical prosthesis for some years and, on the other hand, some annular growth and potentially a better anatomical condition for the Ross procedure or AVR at a later time. Even though the authors have also shown excellent results with the Ross procedure up to 7 years after surgery, considering the ease of valve repair versus the Ross procedure, the complexity of a reoperation following repair versus a reoperation following Ross and for the reasons seen above, we believe that valve repair should still be considered the option of choice for the initial procedure whenever possible. In conclusion, we believe that if careful patient selection is applied together with the fundamental principles of aortic valve repair widely accepted for adults, including restoring of leaflet motion, proper coaptation and annular stabilization, we may expect excellent long-term results following aortic valve repair in children as well as in adults.