Aortic valve repair in the pediatric population: emerging role of aortic valve neocuspidization (AVNeo procedure)

Management of aortic valve diseases in children is challenging owing to the quality and quantity of the native tissue for repair, limitations in the currently available biological materials to supplement the repair and to achieve a long-lasting durable repair in an annulus where there is still growth potential. The aortic valve neocuspidization (AVNeo) procedure has emerged as a versatile alternative strategy in the armamentarium of pediatric aortic valve reconstructions that are currently available. In this review article, the focus of the discussion will be on the various aortic valve repair procedures in the pediatric population, with a special emphasis on the emerging role of AVNeo procedure in pediatrics and its outcomes.

Surgical Management of Complex Aortic Valve Disease in Young Adults: Repair, Replacement, and Future Alternatives

The ideal aortic valve substitute in young adults remains unknown. Prosthetic valves are associated with a suboptimal survival and carry a significant risk of valve-related complications in young patients, mainly reinterventions with tissue valves and, thromboembolic events and major bleeding with mechanical prostheses. The Ross procedure is the only substitute that restores a survival curve similar to that of a matched general population, and permits a normal life without functional limitations. Though the risk of reintervention is the Achilles' heel of this procedure, it is very low in patients with aortic stenosis and can be mitigated in patients with aortic regurgitation by tailored surgical techniques. Finally, the Ozaki procedure and the transcatheter aortic valve implantation are seen by many as future alternatives but lack evidence and long-term follow-up in this specific patient population.

Templates of flat pericardial patterns for precise aortic cusp extension

Background Aortic cusp extension is a subjective and operator-dependent technique. In order to facilitate surgical correction of aortic cusp retraction and reestablishment of adequate cusp coaptation, we sought to develop new templates that can be used to cut flat pericardial sheets into precise cusp extension patches. Methods Each template was designed as a two-dimensional unwrap of the natural geometry of a complete aortic cusp, and a series of templates were made available to correspond with all potential aortic cusp sizes. Based on these templates, aortic cusp extension was performed in 2 patients (aged 54 and 43 years) with significant retraction of the noncoronary aortic cusps and severe aortic valve insufficiency. In each patient, extension of the retracted native noncoronary cusp was undertaken using a bovine pericardial patch that matched the size of adjacent nondiseased native aortic cusps. Results Achieving geometrically perfect aortic cusp extensions was uncomplicated, and intraoperative transesophageal echocardiography confirmed satisfactory aortic valve repairs (aortic insufficiency < 1+ and low transvalvular gradients). Early follow-up transthoracic echocardiography confirmed that all valve cusps met at similar heights in the aortic root, and that their excursions were virtually identical. Conclusions The newly designed templates can be used to cut flat pericardial sheets into exact cusp extension patches, and initial clinical experience indicates that they are useful in performing precise aortic cusp extension procedures and restoring adequate aortic valve competence.

Current surgical strategies and techniques of aortic valve diseases in children

While the long-term outcome of surgical aortic valvotomy (SAV) appears to be better than that of balloon aortic valvuloplasty (BAV) as the primary procedure of aortic valve stenosis, the surgical strategies and techniques of treating aortic valve disease in children in other situations remain controversial. Valve repair should be first considered while replacement is still unavoidable in some cases, and new repair techniques developed by innovative surgeons are gradually becoming adopted. Some complex repair procedures such as cusp extension, leaflet replacement/reconstruction have provided satisfactory outcomes. The Ozaki technique replaces aortic valve leaflets with glutaraldehyde-treated autologous pericardium instead of replacing the valve entirely. Special instruments have been developed to make the Ozaki technique more reproducible and standardized. Neonates and infants undergoing aortic valve replacement (AVR) are a high-risk group, where repair should be the primary consideration rather than replacement. Several systematic reviews reveal that all currently available aortic valve substitutes such as pulmonary autograft, mechanical prosthesis, homograft and bioprosthesis are associated with suboptimal results in children, but pulmonary autograft appeared to be superior with high freedom from reintervention and better hemodynamic performance. The strategy for treatment of aortic valve disease should be specifically analyzed based on the brief of being beneficial for children.

Progression of Aortic Regurgitation After Different Repair Techniques for Congenital Aortic Valve Stenosis

We sought to characterize the incidence of AR progression and determine risk factors for AR progression in a consecutive series of infants and children after surgical correction of congenital aortic valvular and supravalvular stenosis. N = 30 patients underwent repair of the aortic valve for isolated congenital aortic valve stenosis (n = 14, 47 %) or combined with aortic regurgitation (AR, n = 16, 53%). N = 27 (90%) had a valvular and n = 3 patients (10%) presented with supravalvular pathology of their aortic valve. In n = 16 patients (53%) a bicuspid and in n = 2 (6%) patients, a unicuspid valve was present. Comparative survival was analyzed using the Cox model and log-rank calculations. Log-rank calculations were performed for variables reaching statistical significance in order to identify differences in survival between groups. Commissurotomy was performed in n = 20 patients, patch implantation in n = 4, cusp shaving in n = 8, cusp prolapse correction in n = 3, and cusp augmentation in n = 4 patients. In patients with combined dysfunction and preoperative AR, AR was successfully reduced by the initial procedure, and postoperatively the overall median AR grade was 1+ (range 0-2.5+, p = 0.001, for AR reduction among patients with any grade of preoperative AR). By the time of follow-up echocardiography, the median AR grade had significantly progressed toward 1.5+ (p = 0.004). At the time of mid-term follow-up at 3.2 years, none of the patients had moderate or severe AR grades >2.5+. Patients with a monocuspid aortic valve and patients who had some kind of patch implantation into their cusps or commissures or shaving of thickened cusps were more likely to present with progression of aortic regurgitation. Monocuspid aortic valve and patch implantation, as well as cusp shaving, are probably linked to AR progression. The standard procedure of commissurotomy results in an absolute rate of AR progression of 40 % over a medium-term follow-up period.

A review of outcome following valve surgery for rheumatic heart disease in Australia

Background

Globally, rheumatic heart disease (RHD) remains an important cause of heart disease. In Australia it particularly affects younger Indigenous and older non-Indigenous Australians. Despite its impact there is limited understanding of the factors influencing outcome following surgery for RHD.

Methods

The Australian and New Zealand Society of Cardiac and Thoracic Surgeons Cardiac Surgery Database was analysed to assess outcomes following surgical procedures for RHD and non-RHD valvular disease. The association with demographics, co-morbidities, pre-operative status, valve(s) affected and operative procedure was evaluated.

Results

Outcome of 1384 RHD and 15843 non-RHD valve procedures was analysed. RHD patients had longer ventilation, experienced fewer strokes and had more readmissions to hospital and anticoagulant complications. Mortality following RHD surgery at 30 days was 3.1 % (95 % CI 2.2 – 4.3), 5 years 15.3 % (11.7 – 19.5) and 10 years 25.0 % (10.7 – 44.9). Mortality following non-RHD surgery at 30 days was 4.3 % (95 % CI 3.9 - 4.6), 5 years 17.6 % (16.4 - 18.9) and 10 years 39.4 % (33.0 - 46.1). Factors independently associated with poorer longer term survival following RHD surgery included older age (OR1.03/additional year, 95 % CI 1.01 – 1.05), concomitant diabetes (OR 1.7, 95 % CI 1.1 – 2.5) and chronic kidney disease (1.9, 1.2 – 2.9), longer invasive ventilation time (OR 1.7 if greater than median value, 1.1– 2.9) and prolonged stay in hospital (1.02/additional day, 1.01 – 1.03). Survival in Indigenous Australians was comparable to that seen in non-Indigenous Australians.

Conclusion

In a large prospective cohort study we have demonstrated survival following RHD valve surgery in Australia is comparable to earlier studies. Patients with diabetes and chronic kidney disease, were at particular risk of poorer long-term survival. Unlike earlier studies we did not find pre-existing atrial fibrillation, being an Indigenous Australian or the nature of the underlying valve lesion were independent predictors of survival.