The Ross procedure in children: a systematic review

Lifetime Management of Adolescents and Young Adults with Congenital Aortic Valve Disease

In this invited expert review, we focus on evolving lifetime management strategies for adolescents and young adults with congenital aortic valve disease, acknowledging that these patients often require multiple interventions during their lifetime. Our goal is to preserve the native aortic valve when feasible. Leveraging advanced multimodality imaging, a detailed assessment of the aortic valve and root complex can be obtained, and a surgically approach tailored to an individual patient's anatomy and pathology can be used. In turn, aortic valve repair and reconstruction can be offered to a greater number of patients, either as a definitive strategy or as a component of a staged strategy to delay the need for aortic valve replacement until later in life when more options are available.

The Ross Procedure in Children and Infants: A Systematic Review With Pooled Analyses

Background

The Ross procedure is a surgical option for congenital aortic stenosis that involves replacing the diseased aortic valve with a pulmonary autograft. Little is known about outcomes in children, particularly those younger than 1 year.

Methods

A systematic review with pooled analyses was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria. Inferred individual patient data were extracted from life tables. The primary end points were early (≤30 days) and late (>30 days) mortality rates following the Ross procedure in children. Secondary end points were freedom from reintervention for the right ventricular outflow tract and pulmonary autograft. These end points were assessed in the overall population of children. Sensitivity analyses were performed in subgroups younger than 1 year of age (infants) and in noninfant children.

Results

A total of 25 studies on 2737 patients met inclusion criteria. The pooled early survival rate was 96.0% (95% confidence interval [CI]: 95.1%-96.8%) overall and 86.8% (95% CI: 82.1%-90.3%) among infants. Pooled overall 10-year survival, freedom from pulmonary autograft reintervention, and freedom from right ventricular outflow tract reintervention rates were 91.1%, 90.2%, and 79.7%, respectively. Corresponding pooled rates in infants were 79.3%, 87.1%, and 51.2%. Mortality was significantly higher among infants compared with noninfant children (hazard ratio: 3.38, 95% CI: 2.44-4.68; P < 0.001). In metaregression analyses, younger age was strongly associated with poorer survival and higher reintervention rates.

Conclusions

Modest survival and autograft reoperation rates were observed following the Ross procedure in children. Surgery in infancy was strongly associated with poorer survival and higher reintervention rates.

Late Pulmonary Autograft Dilation: Can We Make a Good Operation Great? The Tailored Approach

While it is the main viable option in the growing child and young adult, the Ross procedure has expanded its applicability to older patients, for whom long-term results are equivalent, if not superior, to prosthetic aortic valve replacement. Strategies aiming at mitigating long-term autograft failure from root enlargement and valve regurgitation have led some to advocate for root reinforcement with prosthetic graft material. On the contrary, we will discuss herein the rationale for a tailored approach to the Ross procedure; this strategy is aimed at maintaining the natural physiology and interplay between the various autograft components. Several technical maneuvers, including careful matching of aortic and autograft annuli and sino-tubular junction as well as external support by autologous aortic tissue maintain these physiologic relationships and the viability of the autograft, and could translate in a lower need for late reintervention because of dilation and/or valve regurgitation.

The Ross Procedure in a Case of Baraitser-Winter Syndrome: A Case Report

Baraitser-Winter syndrome (BRWS) is a rare genetic disorder caused by mutations in the ACTB and ACTG1 genes. It is characterized by intellectual disability, physical malformations, and dysmorphic craniofacial features. Additionally, cardiovascular abnormalities may also be present. We present a case of a 15-year-old boy with BRWS associated with congenital bicuspid aortic valve and severe aortic insufficiency which was managed successfully with Ross procedure.

Graft rejection in paediatric congenital heart disease

Congenital heart disease (CHD) affects around 1.35 million neonates worldwide per annum, and surgical repair is necessary in approximately 25% of cases. Xenografts, usually of bovine or porcine origin, are often used for the surgical reconstruction. These xenografts elicit an immune response due to significant immunological incompatibilities between host and donor. Current techniques to dampen the initial hyperacute rejection response involve aldehyde fixation to crosslink xenoantigens, such as galactose-α1,3-galactose and N-glycolylneuraminic acid. While this temporarily masks the epitopes, aldehyde fixation is a suboptimal solution, degrading over time, resulting in cytotoxicity and rejection. The immune response to foreign tissue eventually leads to chronic inflammation and subsequent graft failure, necessitating reintervention to replace the defective bioprosthetic. Decellularisation to remove immunoincompatible material has been suggested as an alternative to fixation and may prove a superior solution. However, incomplete decellularisation poses a significant challenge, causing a substantial immune rejection response and subsequent graft rejection. This review discusses commercially available grafts used in surgical paediatric CHD intervention, looking specifically at bovine jugular vein conduits as a substitute to cryopreserved homografts, as well as decellularised alternatives to the aldehyde-fixed graft. Mechanisms of biological prosthesis rejection are explored, including the signalling cascades of the innate and adaptive immune response. Lastly, emerging strategies of intervention are examined, including the use of tissue from genetically modified pigs, enhanced crosslinking and decellularisation techniques, and augmentation of grafts through in vitro recellularisation or functionalisation with human surface proteins.

Urgent aortic valve neocuspidization using the Ozaki procedure in an infant with native aortic valve endocarditis

Native valve aortic endocarditis is rarely seen in the paediatric population. Although, the first-line of treatment is medical, surgical intervention may be indicated in patients with unrepairable valvular and subvalvular disease. Recently, the aortic valve neocuspidization (AVNeo) procedure has gained popularity both in adult and children in whom other repair techniques are not feasible. In this case report, we present an urgent aortic valve replacement using the AVNeo technique in a critically ill infant with a small annulus, severe left ventricular outflow tract stenosis, and severe aortic regurgitation.

Biological Scaffolds for Congenital Heart Disease

Congenital heart disease (CHD) is the most predominant birth defect and can require several invasive surgeries throughout childhood. The absence of materials with growth and remodelling potential is a limitation of currently used prosthetics in cardiovascular surgery, as well as their susceptibility to calcification. The field of tissue engineering has emerged as a regenerative medicine approach aiming to develop durable scaffolds possessing the ability to grow and remodel upon implantation into the defective hearts of babies and children with CHD. Though tissue engineering has produced several synthetic scaffolds, most of them failed to be successfully translated in this life-endangering clinical scenario, and currently, biological scaffolds are the most extensively used. This review aims to thoroughly summarise the existing biological scaffolds for the treatment of paediatric CHD, categorised as homografts and xenografts, and present the preclinical and clinical studies. Fixation as well as techniques of decellularisation will be reported, highlighting the importance of these approaches for the successful implantation of biological scaffolds that avoid prosthetic rejection. Additionally, cardiac scaffolds for paediatric CHD can be implanted as acellular prostheses, or recellularised before implantation, and cellularisation techniques will be extensively discussed.

Ross Procedure in the era of Handmade-Valved Conduits for Right Ventricular Outflow Tract Reconstruction in Children: Short-Term Surgical Outcomes

Objective

Ross procedure is considered as the “gold standard” for aortic valve replacement, but the conduits used for right ventricular outflow tract (RVOT) reconstruction, such as homografts and bovine jugular vein (BJV) conduits, are of limited availability in China. Handmade expanded polytetrafluoroethylene-valved conduits (HVCs) have been used recently as the alternative for RVOT reconstruction, but their specific experience in Ross procedure is limited in the literature.

Methods

This was a retrospective review of 27 children who underwent Ross procedure in our center from January 2018 to January 2022.

Results

Mean age at surgery was 8.0 ± 3.8 years. During the study period, BJV conduits were used for RVOT reconstruction in 6 patients (22%), and HVCs were used in 21 patients (78%). Median conduit size was 20 mm (range, 16–24 mm), and mean conduit Z-score was +0.8 ± 0.9. Median time for cardiopulmonary bypass was 158 min (range, 109–275 min), and mean time for aortic crossclamping was 110 ± 21 min. There was no early mortality. During a median follow-up time of 1.4 years (range, 0.1–3.7 years), 3 patients (11%) with BJV conduits had peak conduit velocity of &gt; 3.5 m/s; 3 patients (11%) with HVCs developed moderate conduit insufficiency; no patients had more than moderate conduit insufficiency. Three patients with BJV conduits had 5 reinterventions, and all received conduit replacement with HVCs.

Conclusion

HVC is an appealing alternative to BJV conduit for RVOT construction for children undergoing Ross procedure, with favorable short-term outcomes.