Congenital Heart Surgery

Unicuspid aortic valve repair with bicuspidization in the paediatric population.   Matsushima S, Heß A, Lämmerzahl JR, Karliova I, Abdul-Khaliq H, Schäfers HJ.   Eur J Cardiothorac Surg. 2020 Oct 1:ezaa285. doi: 10.1093/ejcts/ezaa285. Online ahead of print.   Take Home Points:   Unicuspid aortic valve repair in pediatric patients remains a significant challenge. Bicuspidization is a technique used for repair of unicuspid aortic valves, involving the creation of a second functional commissure using patch material. The technique of bicuspidization appear safe and reproducible in experienced hands, with excellent survival and good freedom from re-intervention.     Commentary from Dr. Luis Quinonez (Boston MA. USA), congenital heart surgery section editor of Journal Watch: This is a review of 60 consecutive patients, ages 1 through 18 years (median 13), with unicuspid aortic valves who underwent aortic valve repair for stenosis, regurgitation, or a combination. Half the patients had undergone a previous valvuloplasties. The repair technique is bicuspidization. The technique involves creation of a second functional commissure opposite the best developed commissure using a combination of detached autologous valve tissue and patch material. The new commissure is created at the same height as the existing one. The concepts of geometric height and effective height are described, where the effective height should be approximately 50% of the geometric height. The geometric height is curved the length of the leaflet from base to free edge and the effective height is the vertical distance between the annulus and free edge. The study spans between 2003-2018 and uses various patch materials and an external suture annuloplasty. Overall survival was 96% at 10 years. Freedom from aortic valve reoperation was 73% at 5 years and 50% at 10 years. The time to reoperation was 0.2 to 13 years (median 5.2).   Significance: Durable repair of unicuspid aortic valves remains a significant challenge in the pediatric population. Replacement options may be limited in younger age groups.   Comment: This reports presents a sizable experience with repair of unicuspid aortic valves in the pediatric population. The technique of bicuspidization has been used by Dr. Schafer’s group in Germany since 2003. It is certain it has gone through several modifications over time. The technique is not described in sufficient detail to apply. Although the age range of the patient's is wide it is notable that half the patients were under 13 years of age and that 12 of the 60 patients were between 1 and 5 years of age, suggesting the technique can be applied early on even in small annuli. The authors mention that the technique can be applied to an aortic root size is down to 10 mm. Survival for the overall cohort was excellent. The freedom from aortic valve reoperation is very acceptable. Although there were some early failures, the median time of re-intervention was just over 5 years, which would allow enough growth to expand the options for re-repair or replacement. When looking at the patch material used, Gore-Tex performed the worst. Interestingly, fixed autologous pericardium did not perform as well as the other decellularized patches, although the follow-up for the latter is less than 5 years. The results of this study support the notion that in experienced hands unicuspid aortic valve repair can be effectively used "as a bridge to more definitive AVR". The question remains whether the technique is sufficiently standardized to make it reproducible in less experienced hands.      

Age over 35 years is associated with increased mortality after pulmonary valve replacement in repaired tetralogy of Fallot: results from the UK National Congenital Heart Disease Audit database.   Dorobantu DM, Sharabiani MTA, Taliotis D, Parry AJ, Tulloh RMR, Bentham JR, Caputo M, van Doorn C, Stoica SC.Eur J Cardiothorac Surg. 2020 Oct 1;58(4):825-831. doi: 10.1093/ejcts/ezaa069.PMID: 32187367   Corrigendum to 'Age over 35 years is associated with increased mortality after pulmonary valve replacement in repaired tetralogy of Fallot: results from the UK National Congenital Heart Disease Audit database' [Eur J Cardiothorac Surg 2020;58:825-31].   Dorobantu DM, Sharabiani MTA, Taliotis D, Parry AJ, Tulloh RMR, Bentham JR, Caputo M, van Doorn C, Stoica SC.Eur J Cardiothorac Surg. 2020 Oct 1;58(4):873. doi: 10.1093/ejcts/ezaa190.PMID: 32688385 No abstract available.     Commentary from Dr. Frederic Jacques (Quebec City, Quebec, Canada), congenital heart surgery section editor of Journal Watch: Dorobantu et al. published a study in the European Journal of Cardiothoracic Surgery trying to answer the question: Does age at the time of the first pulmonary valve replacement (PVR) among repaired tetralogy of Fallot (ToF) patients impact the long-term outcomes?[1] More specifically, it addresses survival. In this national registry-based multicentric retrospective study, the authors included all (707) ToF patients aged 15 or older who had to have PVR in the UK. They set to determine an age at which patients were more likely to survive both the procedure and in the long-term. They used a Cox regression model as well as CART (classification and regression tree analysis) to identify the optimal cut-off age. Both methods identified 35 years old as their cut-off, with older patients experiencing a 5.6-fold increased risk of dying at 10 years after PVR compared to the younger patients. Said differently, patients under 35 years of age at first PVR had a 10-year mortality of 1.3% compared to 10.4% for those between 35 and 50 years. Older patients required more tricuspid repair or replacement (15% vs. 6%) and arrhythmia surgery (18% vs. 6%) compared to the younger patients. The association of tricuspid valve surgery was linked to a worse survival in those between 35 and 50 years old, but not for the younger patients. Both age groups had worse survival than the general UK population, but the mortality excess was less for those with PVR under 35 (0.9%) compared to the 35-50 age group (7.7%).   Significance: Current guidelines for PVR among ToF patients do not take age into account in setting the surgical indication and timing but they likely should include guidance on this point. This study raises the question: Should we operate on patients earlier to achieve better long-term outcome?   Comment: With this type of registry, surgical indication criteria are not strongly defined, but one can reasonably assume most patients were treated with current Western standards. The most important strength of this study is that it is based on the mandatory inclusion of all the congenital patients from one country: no patient is missed. This likely results in catching subclinical right-sided damage that have not reach clinical significance. The reader is well aware that both residual regurgitation and stenosis are linked to myocardial damage, impact on exercise tolerance and even survival. Current guidelines recommend PVR when either volume or pressure overload had resulted in clinical signs and symptoms. So far, the literature has shown repercussion of PVR on RV volume and symptoms, but clear survival benefit is still to be demonstrated. Recent findings suggest that most of the hemodynamic recovery is seen immediately after surgery. This supports the idea that once right ventricular damage has been severe enough and long-standing, it might not be reversible. This also favors earlier intervention, since relieving the burden on the right ventricle earlier may prevent other comorbidities from developing. This study shows that older patients had more tricuspid regurgitation and arrhythmias. Obviously, a spectrum of subclinical myocardial damage occurs in the background before reaching to other clinically significant lesions. It is not known what portion of this damage is reversible. The authors suggest that current guidelines should be revisited not only based on hemodynamic parameters and symptoms, but that age should be accounted for in order to achieve a survival that approaches the general population as closely as possible. Will the paradigm shift from reacting to hemodynamic complications to preventing them?