Ross Procedure in Adults for Cardiologists and Cardiac Surgeons

Management of bicuspid aortic valve disease in the transcatheter aortic valve implantation era

In an era of rapidly expanding use of transcatheter aortic valve implantation (TAVI), the management of patients with bicuspid aortic valve (BAV) disease is far less well established than in those with trileaflet anatomy. Results of isolated surgical aortic valve replacement are excellent in suitable patients, and surgery also allows treatment of concomitant pathology of the aortic root and ascending aorta that is frequently encountered in this cohort. Conversely, TAVI provides an excellent alternative in older patients who may be unsuitable for surgery, although outcomes in BAV disease have only been reported in relatively small non-randomised series. Here, we discuss the pertinent literature on this topic and outline contemporary interventional treatment options in this challenging setting.

Sex Differences in Aortic Stenosis: From the Pathophysiology to the Intervention, Current Challenges, and Future Perspectives

Calcific aortic stenosis (AS) is a major cause of morbidity and mortality in high-income countries. AS presents sex-specific features impacting pathophysiology, outcomes, and management strategies. In women, AS often manifests with a high valvular fibrotic burden, small valvular annuli, concentric left ventricular (LV) remodeling/hypertrophy, and, frequently, supernormal LV ejection fraction coupled with diastolic dysfunction. Paradoxical low-flow low-gradient AS epitomizes these traits, posing significant challenges post-aortic valve replacement due to limited positive remodeling and significant risk of patient-prosthesis mismatch. Conversely, men present more commonly with LV dilatation and dysfunction, indicating the phenotype of classical low-flow low-gradient AS, i.e., with decreased LV ejection fraction. However, these distinctions have not been fully incorporated into guidelines for AS management. The only treatment for AS is aortic valve replacement; women are frequently referred late, leading to increased heart damage caused by AS. Therefore, it is important to reassess surgical planning and timing to minimize irreversible cardiac damage in women. The integrity and the consideration of sex differences in the management of AS is critical. Further research, including sufficient representation of women, is needed to investigate these differences and to develop individualized, sex-specific management strategies.

Long-term outcome after the Ross procedure in 173 adults with up to 25 years of follow-up

OBJECTIVES

The potential risk of autograft dilatation and homograft stenosis after the Ross procedure mandates lifelong follow-up. This retrospective cohort study aimed to determine long-term outcome of the Ross procedure, investigating autograft and homograft failure patterns leading to reintervention.

METHODS

All adults who underwent the Ross procedure between 1991 and 2018 at the University Hospitals Leuven were included, with follow-up data collected retrospectively. Autograft implantation was performed using the full root replacement technique. The primary end-point was long-term survival. Secondary end-points were survival free from any reintervention, autograft or homograft reintervention-free survival, and evolution of autograft diameter, homograft gradient and aortic regurgitation grade over time.

RESULTS

A total of 173 adult patients (66% male) with a median age of 32 years (range 18-58 years) were included. External support at both the annulus and sinotubular junction was used in 38.7% (67/173). Median follow-up duration was 11.1 years (IQR, 6.4-15.9; 2065 patient-years) with 95% follow-up completeness. There was one (0.6%) perioperative death. Kaplan-Meier estimate for 15-year survival was 91.1% and Ross-related reintervention-free survival was 75.7% (autograft: 83.5%, homograft: 85%). Regression analyses demonstrated progressive neoaortic root dilatation (0.56 mm/year) and increase in homograft gradient (0.72 mmHg/year).

CONCLUSIONS

The Ross procedure has the potential to offer excellent long-term survival and reintervention-free survival. These long-term data further confirm that the Ross procedure is a suitable option in young adults with aortic valve disease which should be considered on an individual basis.

Mechanical Valves: Past, Present, and Future-A Review

The mechanical valve was first invented in the 1950s, and since then, a wide variety of prostheses have been developed. Although mechanical valves have outstanding durability, their use necessitates life-long treatment with anticoagulants, which increases the risk of bleeding and thromboembolic events. The current guidelines recommend a mechanical prosthetic valve in patients under 50-60 years; however, for patients aged 50-70 years, the data are conflicting and there is not a clear-cut recommendation. In recent decades, progress has been made in several areas. First, the On-X mechanical valve was introduced; this valve has a lower anticoagulant requirement in the aortic position. Second, a potential alternative to vitamin K-antagonist treatment, rivaroxaban, has shown encouraging results in small-scale trials and is currently being tested in a large randomized clinical trial. Lastly, an innovative mechanical valve that eliminates the need for anticoagulant therapy is under development. We attempted to review the current literature on the subject with special emphasis on the role of mechanical valves in the current era and discuss alternatives and future innovations.

Transcatheter aortic valve replacement in low-risk young population: A double edge sword?

Since the advent of transcatheter aortic valve replacement (TAVR) in 2002, it has now become the default interventional strategy for symptomatic patients presenting with severe aortic stenosis, particularly in intermediate to high-surgical risk patients. In 2019, the United States Food and Drug Administration approved TAVR in low-risk patients based on two randomized trials. However, these breakthrough trials excluded patients with certain unfavorable anatomies and odd profiles. While currently there is no randomized study of TAVR in young patients, it may be preferred by the young population given the benefits of early discharge, shorter hospital stay, and expedite recovery. Nonetheless, it is important to ruminate various factors including lifetime expectancy, risk of pacemaker implantation, and the need for future valve or coronary interventions in young cohorts before considering TAVR in these patients. Furthermore, the data on long-term durability (> 10 years) of TAVR is still unknown given most of the procedures were initially performed in the high or prohibitive surgical risk population. Thus, this editorial aims to highlight the importance of considering an individualized approach in young patients with consideration of various factors including lifetime expectancy while choosing TAVR against surgical aortic valve replacement.

Our 7-year experience supporting the Ross autograft with the novel technique of Personalized External Aortic Root Support

Objective

The Ross operation is a widely accepted option for aortic valve replacement in children, and evidence shows its excellent results in terms of hemodynamics and durability. However, indications are still limited due to the fact that it is a technically demanding procedure, only performed by specialized surgeons. On top of that, and despite numerous techniques being applied, autograft dilatation remains a key disadvantage, which can lead to graft failure. In recent years, the ExoVasc Personalized External Aortic Root Support (PEARS) has proven to be a safe and effective option to prevent aortic root dilatation in various aortopathies and is a technique that lends itself to support the pulmonary autograft in the Ross operation.

Methods

During the past 7 years, we have used the ExoVasc PEARS graft, manufactured from the patients' pulmonary artery measurements from computed tomography scan data, to support the pulmonary autograft in the Ross operation. This graft (manufactured by Exstent Ltd, UK) is implanted at the same time as the autograft. We have reviewed all the patients who underwent this surgery, including demographic data, aorta measurements, operative data, and follow-up assessment consisting of periodic echocardiograms and magnetic resonance imaging scans.

Results

Fifty patients were included in the study. Mean age at the time of the operation was 29.84 years, the youngest patient was 9 years-old. Nineteen patients (38%) had previous sternotomies; 11 of them having had a previous aortic valve replacement. Seventy-two percent of patients had initially a bicuspid aortic valve. Mean diameter of the ascending aorta was 3.83 cm. Forty-four percent of patients required a concomitant reduction aortoplasty due to mismatch sizes between the ascending aorta and the autograft. Mean bypass and crossclamp times were 200.66 and 151.14 minutes, respectively. Median length of stay was 6 days. Mean follow-up was 16.88 months. Two patients required subsequent aortic valve replacement (1 had rheumatic valve disease and the other had iatrogenic damage in his autograft valve leaflet). Ascending aorta dimensions remain stable when compared with immediate postoperative studies. There were no deaths.

Conclusions

The ExoVasc PEARS graft has proven to be an excellent support in the Ross operation to prevent the autograft failure related to autograft dilatation that can offer several advantages compared with other existing techniques. With this type of support, we believe the Ross indications can be expanded to multiple clinical scenarios, given the good long-term results this operation offers in terms of durability, life expectancy, and hemodynamics.

Role of Transesophageal Echocardiography in the Diagnosis of Coronary Ischemia in a Patient with History of Ross Procedure

•Multidisciplinary management is essential for complications post–Ross procedure. •Symptomatic coronary ischemia may occur late in Ross procedure patients. •Coronary ostium narrowing is a differential for ischemia post–Ross procedure. •TEE can aid in diagnosing coronary stenosis in a Ross procedure patient. •TTE may miss eccentric AR post–Ross surgery; high suspicion justifies TEE.

Midterm follow-up of composite graft replacement of the aortic root (30-year experience)-remarkably safe, effective, and durable

Objectives

Contemporary operative choices for aortic root disease include aortic root replacement (ARR) and a variety of valve-sparing and aortic root-repair procedures. We evaluate ultra-long-term outcomes of ARR, focusing on survival, freedom from late reoperation, and adverse events.

Methods

Prospectively kept records were used to accomplish long-term follow-up of patients who underwent ARR (4-pronged Yale survival assessment paradigm).

Results

Between 1990 and 2020, 564 patients underwent ARR (mean 56 years, 84% male). A modified Cabrol procedure (Dacron coronary graft) was employed in 9.0% (51/564) and concomitant coronary artery bypass grafting in 9.4% (53/564). There were 12.8% (72/564) urgent/emergent and 7.4% (42/564) redo procedures. Operative mortality occurred in 12 patients (2.1%) overall, or 1.4% (8/554) of nondissection and 1.3% (6/468) of elective first-time operations. Six of the 12 deaths presented with acute type A dissection, urgent operation, or reoperative states. Operative mortality dropped to 0.6% during the past 10 years. In total, 11 patients developed endocarditis. Stroke occurred in 11 of 564 patients (2.0%), 4 of whom had presented with type A dissection. Late events included bleeding in 2.8% (16/564), thromboembolism in 1.4% (8/564), and reoperation of the root in 5 of 564 (0.9%) at 15 years and more distal aortic segments in 16/564 (2.8%). Survival was no different from age/sex-matched controls.

Conclusions

This ultra-long-term experience finds ARR to be extraordinarily safe, effective, and durable, with minimal long-term bleeding, thromboembolism, or graft failure. This experience provides a standard of durability for ARR against which ultra-long-term outcomes with alternate procedures (valve-sparing, Ross, other) may be compared.

Unique Aspects of Women's Valvular Heart Diseases: Impact for Diagnosis and Treatment

Valvular heart diseases (VHDs) are a major cause of cardiovascular morbidity and mortality worldwide. As degenerative and functional mechanisms represent the main etiologies in high-income countries are degenerative and functional, while in low income countries etiologie is mostly rheumatic. Although therapeutic options have evolved considerably in recent years, women are consistently diagnosed at later stages of their disease, are delayed in receiving surgical referrals, and exhibit worse postoperative outcomes, compared to men. This difference is a result of the historical underrepresentation of women in studies from which current guidelines were developed. However, in recent years, important research, including more female patients, has been conducted and has highlighted substantial sex-specific differences in the etiology, diagnosis, and treatment of VHDs. Systematic consideration of these sex-specific differences in VHD patients is crucial for providing equitable healthcare and optimizing clinical outcomes in both female and male patients. Hence, this review aims to explore implications of sex-specific particularities for diagnosis, treatment options, and outcomes in women with VHDs.

Lifetime Management of Patients With Severe Aortic Stenosis in the Era of Transcatheter Aortic Valve Replacement

Aortic stenosis is the most common valvular disease. Surgical aortic valve replacement (SAVR) using mechanical valves has been the preferred treatment for younger patients, but bioprosthetic valves are gaining favour to avoid anticoagulation with warfarin. Transcatheter aortic valve replacement (TAVR) was approved in recent years for the treatment of severe aortic stenosis in intermediate- and low-risk patients as an alternative to SAVR. The longer life expectancy of these groups of patients might exceed the durability of the TAVR or SAVR bioprosthetic valves. Therefore, many patients need 2 or even 3 interventions during their lifetime. Because it has important implications on the feasibility of subsequent procedures, the decision between opting for SAVR or TAVR as the primary procedure requires thorough consideration by the heart team, incorporating patient preferences, clinical indicators, and anatomic aspects. If TAVR is favoured initially, selecting the valve type and determining the implantation level should be conducted, aiming for positive outcomes in the index intervention and keeping in mind the potential for subsequent TAVR-in-TAVR procedures. When SAVR is selected as the primary procedure, the operator must make choices regarding the valve type and the potential need for aortic root enlargement, with the intention of facilitating future valve-in-valve interventions. This narrative review examines the existing evidence concerning the lifelong management of severe aortic stenosis, delving into available treatment strategies, particularly emphasising the initial procedure's selection and its impact on subsequent interventions.

Aortic Valve Embryology, Mechanobiology, and Second Messenger Pathways: Implications for Clinical Practice

During the Renaissance, Leonardo Da Vinci was the first person to successfully detail the anatomy of the aortic root and its adjacent structures. Ever since, novel insights into morphology, function, and their interplay have accumulated, resulting in advanced knowledge on the complex functional characteristics of the aortic valve (AV) and root. This has shifted our vision from the AV as being a static structure towards that of a dynamic interconnected apparatus within the aortic root as a functional unit, exhibiting a complex interplay with adjacent structures via both humoral and mechanical stimuli. This paradigm shift has stimulated surgical treatment strategies of valvular disease that seek to recapitulate healthy AV function, whereby AV disease can no longer be seen as an isolated morphological pathology which needs to be replaced. As prostheses still cannot reproduce the complexity of human nature, treatment of diseased AVs, whether stenotic or insufficient, has tremendously evolved, with a similar shift towards treatments options that are more hemodynamically centered, such as the Ross procedure and valve-conserving surgery. Native AV and root components allow for an efficient Venturi effect over the valve to allow for optimal opening during the cardiac cycle, while also alleviating the left ventricle. Next to that, several receptors are present on native AV leaflets, enabling messenger pathways based on their interaction with blood and other shear-stress-related stimuli. Many of these physiological and hemodynamical processes are under-acknowledged but may hold important clues for innovative treatment strategies, or as potential novel targets for therapeutic agents that halt or reverse the process of valve degeneration. A structured overview of these pathways and their implications for cardiothoracic surgeons and cardiologists is lacking. As such, we provide an overview on embryology, hemodynamics, and messenger pathways of the healthy and diseased AV and its implications for clinical practice, by relating this knowledge to current treatment alternatives and clinical decision making.

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.

Long-term autograft dilation and durability after the Ross procedure are similar in infants, children, and adolescents with primary aortic stenosis

BACKGROUND

Autograft durability and remodeling are thought to be superior in younger pediatric patients after the Ross operation. We sought to delineate the fate of autografts across the pediatric age spectrum in patients with primary aortic stenosis (AS).

METHODS

We retrospectively reviewed patients age ≤18 years with primary AS who underwent the Ross operation between 1993 and 2020. Patients were categorized by age. The primary endpoint was autograft dimensional change, and secondary endpoints were severe neo-aortic insufficiency (AI) and autograft reintervention.

RESULTS

A total of 119 patients underwent the Ross operation, including 37 (31.1%) in group I (age <18 months), 24 (20.2%) in group II (age 18 months-8 years), and 58 (48.7%) in group III (age 8-18 years). All groups exhibited similar annular growth rates within the first 5 postoperative years, followed by a collective decrease in annulus growth rates from year 5 to year 10. Group III experienced rapid sinus dilation in the first 5 years, followed by stabilization of the sinus z-score from year 5 to year 10, whereas groups I and II demonstrated stable sinus z-scores over 10 years. There were 4 early deaths (3.4%) and 2 late deaths (1.7%) at a median follow-up of 8.1 years (range, 0.01-26.3 years). At 15 years, the incidences of severe neo-AI (0.0 ± 0.0% vs 0.0 ± 0.0% vs 3.9 ± 3.9%; P = .52) and autograft reintervention (8.4 ± 6.0% vs 0.0 ± 0.0% vs 2.4 ± 2.4%; P = .47) were similar in the 3 groups.

CONCLUSIONS

Age at the time of Ross operation for primary AS does not influence long-term autograft remodeling or durability. Other physiologic or technical factors are likely greater determinants of autograft fate.

Considering alternatives to transcatheter heart valves for managing patients with severe aortic valve stenosis

INTRODUCTION

Transcatheter aortic valve implantation (TAVI) is becoming the standard of care for severe symptomatic aortic stenosis (AS). Yet, some patients with AS are not indicated/eligible for TAVI. Several noninvasive, catheter-based or surgical alternatives exist, and other therapeutic options are emerging.

AREAS COVERED

This review provides an overview of non-TAVI options for severe AS. Non-invasive, transcatheter, and alternative surgical strategies are discussed, emphasizing their backgrounds, techniques, and outcomes.

EXPERT OPINION

Alternative therapies to TAVI, whether device-based or non-device-based, continue to evolve or emerge and provide either alternative treatments or a bridge to TAVI, for patients not meeting indications for, or having contraindications to TAVI.Although TAVI and SAVR are the current dominant therapies, there are still some patients that could benefit in the future from other alternatives.Data on alternative options for such patients are scarce. Many advantages and disadvantages arise when selecting a specific treatment strategy for individual patients.Head-to-head comparison studies could guide physicians toward better patient selection and procedural planning. Awareness of therapeutic options, indications, techniques, and outcomes should enable heart teams to achieve optimized patient selection. Furthermore, it can increase the use of these alternatives to optimize the management of AS among different patient populations.

Long-Term Clinical and Echocardiographic Outcomes Following the Ross Procedure: A Post Hoc Analysis of a Randomized Clinical Trial

Importance

The Ross procedure as treatment for adults with aortic valve disease (AVD) has been the subject of renewed interest.

Objective

To evaluate the long-term clinical and echocardiographic outcomes following the Ross procedure for the treatment of adults with AVD.

Design, Setting, and Participants

This post hoc analysis of a randomized clinical trial included adult patients (age <69 years) who underwent a Ross procedure for the treatment of AVD, including those with active endocarditis, rheumatic AVD, decreased ejection fraction, and previous cardiac surgery. The trial, conducted from September 1, 1994, to May 31, 2001, compared homograft root replacement with the Ross procedure at a single center. Data after 2010 were collected retrospectively in November and December 2022.

Exposure

Ross procedure.

Main Outcomes and Measures

The primary end point was long-term survival among patients who underwent the Ross procedure compared with that in the age-, country of origin- and sex-matched general population. Secondary end points were freedom from any reintervention, autograft reintervention, or homograft reintervention and time-related valve function, autograft diameter, and functional status.

Results

This study included 108 adults (92 [85%] male) with a median age of 38 years (range, 19-66 years). Median duration of clinical follow-up was 24.1 years (IQR, 22.6-26.1 years; 2488 patient-years), with 98% follow-up completeness. Of these patients, 9 (8%) had active endocarditis and 45 (42%) underwent reoperations. The main hemodynamic lesion was stenosis in 30 (28%) and regurgitation in 49 (45%). There was 1 perioperative death (0.9%). Twenty-five year survival was 83.0% (95% CI, 75.5%-91.2%), representing a relative survival of 99.1% (95% CI, 91.8%-100%) compared with the general population (83.7%). At 25 years, freedom from any reintervention was 71.1% (95% CI, 61.6%-82.0%); from autograft reintervention, 80.3% (95% CI, 71.9%-89.6%); and from homograft reintervention, 86.3% (95% CI, 79.0%-94.3%). Thirty-day mortality after the first Ross-related reintervention was 0% and after all Ross-related reinterventions was 3.8% (n = 1); 10-year survival after reoperation was 96.2% (95% CI, 89.0%-100%).

Conclusions and Relevance

This study found that the Ross procedure provided excellent survival into the third decade postoperatively that was comparable to that in the general population. Long-term freedom from reintervention demonstrated that the Ross procedure may be a durable substitute into late adulthood, showing a delayed but progressive functional decline.

Trial Registration

isrctn.org Identifier: ISRCTN03530985.

Bicuspid Aortic Valve Disease: Classifications, Treatments, and Emerging Transcatheter Paradigms

Bicuspid aortic valve (BAV) is a common congenital valvular malformation, which may lead to early aortic valve disease and bicuspid-associated aortopathy. A novel BAV classification system was recently proposed to coincide with transcatheter aortic valve replacement being increasingly considered in younger patients with symptomatic BAV, with good clinical results, yet without randomized trial evidence. Procedural technique, along with clinical outcomes, have considerably improved in BAV patients compared with tricuspid aortic stenosis patients undergoing transcatheter aortic valve replacement. The present review summarizes the novel BAV classification systems and examines contemporary surgical and transcatheter approaches.

Dissemination and implementation analysis of the Ross procedure in adults: time to update the guidelines?

Background

The science of dissemination and implementation (D&I) aims to improve the quality and effectiveness of care by addressing the challenges of incorporating research and evidence-based practice into routine clinical practice. This lens of D&I has challenged the interpretation and incorporation of data, noting that failure of a given therapy may not reflect lack of efficacy, but instead reflect an imperfect implementation. The aim of this manuscript is to review the influence of the Ross procedure's historical context on its D&I.

Methods

A contextual baseline of the Ross procedure was defined from the procedure's original description in the literature to major publications since the 2017 valvular heart disease guidelines. D&I evaluation was conducted using the Consolidated Framework for Implementation Research (CFIR), using constructs from each of the five respective domains to define the main determinants.

Results

Each of the five CFIR domains appears to be correlated with a factor influencing the Ross procedure's varied history of enthusiasm and acceptance. The complex nature of Ross required adaptation for optimization, with a strong correlation of center volume on outcomes that were not considered in non-contemporary studies. Outcomes later published from those studies influenced social and cultural contexts within the aortic surgery community, and led to further organizational uncertainty, resulting in slow guideline incorporation.

Conclusions

The D&I of the Ross procedure was a result of inadequate appreciation of technical complexity, effect of patient selection, and complex aortic surgery experience, resulting in dismissal of an efficacious procedure due to a misunderstanding of effectiveness.

Drivers of vascular growth and remodeling: A computational framework to promote benign adaptation in the Ross procedure

In the sixties, Dr Donald Ross designed a surgical solution for young patients with aortic valve disease by using the patients' own pulmonary valve. The Ross procedure is the only aortic valve replacement technique that can restore long-term survival and preserve quality of life. The main failure mode of the Ross procedure is wall dilatation, potentially leading to valve regurgitation and leakage. Dilatation occurs due to the inability of the pulmonary autograft to adapt to the sudden increase in loading when exposing to aortic pressures. Previous experimental data has shown that a permanent external support wrapped around the artery can prevent the acute dilatation of the arterial wall. However, the textile support leads to stress-shielding phenomena due to the loss of mechanical wall compliance. We present a pragmatic and modular computational framework of arterial growth and remodeling predicting the long-term outcomes of cardiovascular tissue adaptation, with and without textile wrapping. The model integrates mean, systolic and diastolic pressures and assumes the resulting wall stresses to drive the biological remodeling rules. Rather than a single mean pressure or stress deviation from the homeostatic state, we demonstrate that only pulsatile stresses can predict available experimental results. Therefore, we suggest that a biodegradable external support could induce benign remodeling in the Ross procedure. Indeed, a biodegradable textile wrapped around the autograft fulfills the trade-off between prevention of acute dilatation on the one hand and recovery of arterial wall compliance on the other hand. After further validation, the computational framework can set the basis for the development of an actual biodegradable external support for the Ross procedure with optimized polymer mechanical properties and degradation behavior.

Strategies for Development of Synthetic Heart Valve Tissue Engineering Scaffolds

The current clinical solutions, including mechanical and bioprosthetic valves for valvular heart diseases, are plagued by coagulation, calcification, nondurability, and the inability to grow with patients. The tissue engineering approach attempts to resolve these shortcomings by producing heart valve scaffolds that may deliver patients a life-long solution. Heart valve scaffolds serve as a three-dimensional support structure made of biocompatible materials that provide adequate porosity for cell infiltration, and nutrient and waste transport, sponsor cell adhesion, proliferation, and differentiation, and allow for extracellular matrix production that together contributes to the generation of functional neotissue. The foundation of successful heart valve tissue engineering is replicating native heart valve architecture, mechanics, and cellular attributes through appropriate biomaterials and scaffold designs. This article reviews biomaterials, the fabrication of heart valve scaffolds, and their in-vitro and in-vivo evaluations applied for heart valve tissue engineering.

A Literature Review on the Use of Aortic Allografts in Modern Cardiac Surgery for the Treatment of Infective Endocarditis: Is There Clear Evidence or Is It Merely a Perception?

Infective valve endocarditis is caused by different pathogens and 60% of those involve the aortic valve with valve failure. Although S. aureus is recognized as the most frequently isolated causative bacterium associated with IE in high-income countries, Gram-positive cocci nevertheless play a crucial role in promoting infection in relation to their adhesive matrix molecules. The presence of pili on the surface of Gram-positive bacteria such as in different strains of Enterococcus faecalis and Streptococcus spp., grants these causative pathogens a great offensive capacity due to the formation of biofilms and resistance to antibiotics. The indications and timing of surgery in endocarditis are debated as well as the choice of the ideal valve substitute to replace the diseased valve(s) when repair is not possible. We reviewed the literature and elaborated a systematic approach to endocarditis management based on clinical, microbiological, and anatomopathological variables known to affect postoperative outcomes with the aim to stratify the patients and orient decision making. From this review emerges significant findings on the risk of infection in the allograft used in patients with endocarditis and no endocarditis etiology suggesting that the use of allografts has proved safety and effectiveness in patients with both pathologies.

Mortality trends of aortic stenosis in high-income countries from 2000 to 2020

OBJECTIVE

The purpose of this study is to describe recent mortality trends from aortic stenosis (AS) among eight high-income countries.

METHODS

We analysed the WHO mortality database to determine trends in mortality from AS in the UK, Germany, France, Italy, Japan, Australia, the USA and Canada from 2000 to 2020. Crude and age-standardised mortality rates per 100 000 persons were calculated. We calculated age-specific mortality rates in three groups (<64, 65-79 and ≥80 years). Annual percentage change was analysed using joinpoint regression.

RESULTS

During the observation period, the crude mortality rates per 100 000 persons increased in all the eight countries (from 3.47 to 5.87 in the UK, from 2.98 to 8.93 in Germany, from 3.84 to 5.52 in France, from 1.97 to 4.33 in Italy, from 1.12 to 5.49 in Japan, from 2.14 to 3.38 in Australia, from 3.58 to 4.22 in the USA and from 2.12 to 5.00 in Canada). In joinpoint regression of age-standardised mortality rates, trend changes towards a decrease were observed in Germany after 2012 (-1.2%, p=0.015), Australia after 2011 (-1.9%, p=0.005) and the USA after 2014 (-3.1%, p<0.001). Age-specific mortality rates in age group ≥80 years had shifts towards decreasing trends in all the eight countries in contrast to other younger age groups.

CONCLUSIONS

While crude mortality rates increased in the eight countries, shifts towards decreasing trends were identified in age-standardised mortality rates in three countries and in the elderly aged ≥80 years in the eight countries. Further multidimensional observation is warranted to clarify the mortality trends.

Pulmonary homograft failure presents as abdominal ascites

Ascites is a condition typically attributed to liver disease but can be cardiac in aetiology as well. We report of an atypical case of pulmonary homograft failure status-post the Ross-Yacoub procedure as an underlying cause of anasarca. A man in his mid-30s with a history of congenital heart disease presented with abdominal distension and exercise intolerance. His prior history was relevant for congenital bicuspid aortic valve with critical aortic stenosis. Abdomen and pelvis CT revealed a grossly dilated inferior vena cava while transthoracic echocardiogram showed severe homograft pulmonary stenosis and regurgitation. Further investigation with cardiac MRI demonstrated severe pulmonary valve stenosis and regurgitation with significant tricuspid regurgitation and right ventricular dilatation. The transcatheter stent in the right ventricular to pulmonary artery conduit followed by transcatheter valve replacement, which resulted in full resolution of his presenting symptoms.

Characterization of a Decellularized Sheep Pulmonary Heart Valves and Analysis of Their Capability as a Xenograft Initial Matrix Material in Heart Valve Tissue Engineering

In order to overcome the disadvantages of existing treatments in heart valve tissue engineering, decellularization studies are carried out. The main purpose of decellularization is to eliminate the immunogenicity of biologically derived grafts and to obtain a scaffold that allows recellularization while preserving the natural tissue architecture. SD and SDS are detergent derivatives frequently used in decellularization studies. The aim of our study is to decellularize the pulmonary heart valves of young Merino sheep by using low-density SDS and SD detergents together, and then to perform their detailed characterization to determine whether they are suitable for clinical studies. Pulmonary heart valves of 4-6-month-old sheep were decellularized in detergent solution for 24 h. The amount of residual DNA was measured to determine the efficiency of decellularization. Then, the effect of decellularization on the ECM by histological staining was examined. In addition, the samples were visualized by SEM to determine the surface morphologies of the scaffolds. A uniaxial tensile test was performed to examine the effect of decellularization on biomechanical properties. In vitro stability of scaffolds decellularized by collagenase treatment was determined. In addition, the cytotoxic effect of scaffolds on 3T3 cells was examined by MTT assay. The results showed DNA removal of 94% and 98% from the decellularized leaflet and pulmonary wall portions after decellularization relative to the control group. No cell nuclei were found in histological staining and it was observed that the three-layer leaflet structure was preserved. As a result of the tensile test, it was determined that there was no statistically significant difference between the control and decellularized groups in the UTS and elasticity modulus, and the biomechanical properties did not change. It was also observed that decellularized sheep pulmonary heart valves had no cytotoxic effect. In conclusion, we suggest that the pulmonary valves of decellularized young Merino sheep can be used as an initial matrix in heart valve tissue engineering studies.

Ross procedure versus pulmonary homograft versus mechanical valve versus bioprosthetic valve versus Ozaki procedure for surgical aortic valve replacement: a frequentist network meta-analysis

BACKGROUND

There has been a resurgence in interest regarding the Ross procedure due to recent publications detailing positive long-term outcomes. Conversely, surgical aortic valve replacement (SAVR) with a pulmonary homograft (PH), mechanical (MV), bioprosthetic (BV), or the Ozaki procedure each has its own technical advantages and disadvantages. Therefore, we performed a network meta-analysis (NMA) comparing other alternatives to Ross procedure.

METHODS

Medical databases were comprehensively searched for studies comparing the Ross procedure with AVR using a PH, MV, BV, or the Ozaki procedure. Outcomes were pooled as risk ratios (RR) with their 95% confidence intervals (95% CI).

RESULTS

A total of 7816 patients were pooled for our NMA from 24 studies. Compared to Ross procedure, both BV and MV were associated with significantly higher rates of 30-day mortality of RR (2.37, 95% CI 1.20-4.67) and (1.88 95% CI 1.04-3.40), respectively, with no significant difference regarding PH or Ozaki. However, only MV was associated with a higher risk of 30-day stroke (RR 8.42, 95% CI 1.57-45.23) with no significant difference in the other alternatives, as well as 30-day MI which showed no significant differences between any of the aortic conduits compared to the Ross procedure. Regarding 30-day major bleeding, MV was associated with a higher when compared to the Ross procedure RR (4.58, 95% CI 1.94-10.85), PH was associated with a lower risk of major bleeding with RR (0.35, 95% CI 0.17-0.71), and BV showed no significant difference. With a mean follow-up duration of 8.5 years compared to the Ross procedure, BV, PH, and MV were associated with a higher risk of long-term mortality with RR (1.89, 95% CI 1.38-2.58), (1.38, 95% CI 1.0-1.87), and (1.94, 95% CI 1.52-2.47), respectively, with the Ozaki procedure showed no significant difference. Regarding long-term stroke-with a mean of 6.3-year follow-up duration-there were no significant differences between any of the aortic conduits compared to the Ross procedure. Nevertheless, long-term need for reintervention-with a mean follow-up duration of 17.5 years-was significant of higher risk with both BV and PH with RR (3.28, 95% CI 1.21-8.84) and (2.42, 95% CI 1.05-5.58), respectively, compared to Ross procedure with MV and Ozaki having no significant difference.

CONCLUSIONS

The Ross procedure is a viable treatment option for patients undergoing SAVR, showing promising outcomes at short- and long-term follow-ups.

Aortic Regurgitation and Heart Failure: Advances in Diagnosis, Management, and Interventions

This review discusses the contemporary clinical evaluation and management of patients with comorbid aortic regurgitation (AR) and heart failure (HF) (AR-HF). Importantly, as clinical HF exists along the spectrum of AR severity, the present review also details novel strategies to detect early signs of HF before the clinical syndrome ensues. Indeed, there may be a vulnerable cohort of AR patients who benefit from early detection and management of HF. Additionally, while the mainstay of operative management for AR has historically been surgical aortic valve replacement, this review discusses alternate procedures that may be beneficial in high-risk cohorts.

Pediatric pulmonary valve replacements: Clinical challenges and emerging technologies

Congenital heart diseases (CHDs) frequently impact the right ventricular outflow tract, resulting in a significant incidence of pulmonary valve replacement in the pediatric population. While contemporary pediatric pulmonary valve replacements (PPVRs) allow satisfactory patient survival, their biocompatibility and durability remain suboptimal and repeat operations are commonplace, especially for very young patients. This places enormous physical, financial, and psychological burdens on patients and their parents, highlighting an urgent clinical need for better PPVRs. An important reason for the clinical failure of PPVRs is biofouling, which instigates various adverse biological responses such as thrombosis and infection, promoting research into various antifouling chemistries that may find utility in PPVR materials. Another significant contributor is the inevitability of somatic growth in pediatric patients, causing structural discrepancies between the patient and PPVR, stimulating the development of various growth-accommodating heart valve prototypes. This review offers an interdisciplinary perspective on these challenges by exploring clinical experiences, physiological understandings, and bioengineering technologies that may contribute to device development. It thus aims to provide an insight into the design requirements of next-generation PPVRs to advance clinical outcomes and promote patient quality of life.

The Use of the Cryopreserved Aortic Homograft for Aortic Valve Replacement: Is It Still an Option?

The indications for cryopreserved allografts in aortic valve replacement are still debatable. We aim to identify factors influencing early and long-term durability of the aortic homograft and to define subgroups of patients with an improved long-term quality of life, survival, and freedom from structural valve degeneration (SVD). We evaluated our series of 210 patients who underwent allograft implantation with a retrospective cohort study design over a period of 20 years. Endpoints were overall mortality, cardiac mortality related to SVD, the incidence of SVD, reoperation, and a composite endpoint comprising major adverse cardiac and cerebrovascular events (MACCEs), which includes cardiac death both related and not related to SVD, subsequent aortic valve surgery, new or recurrent infection of implanted allograft, recurrent aortic regurgitation, rehospitalization for heart failure, an increase in New York Heart Association (NYHA) class of ≥1, or cerebrovascular events. The primary indication for surgery was endocarditis (48%), which was also a predisposing factor for increased cardiac mortality. Overall mortality was 32.4% with a 27% incidence of SVD and mortality associated with SVD of 13.8%. Reoperation occurred in 33.8% and MACCEs in 54.8%. Long-term NYHA functional class and echocardiographic parameters improved over time. Statistical analysis demonstrated that root replacement technique and adult age were protective factors for SVD. We found no statistically significant difference in the clinical outcomes analyzed between women of childbearing age who had children after surgery and the rest of the women. The cryopreserved allograft is still a valid option in aortic valve replacement, providing acceptable durability and clinical outcomes with optimal hemodynamic performance. SVD is influenced by the implantation technique. Women of childbearing age might have additional benefits from this procedure.

Autograft reoperations after the Ross procedure

OBJECTIVES

After a Ross procedure, autograft failure can occur. At reoperation, repair of the autograft preserves the advantages of the Ross procedure. The aim of this retrospective study was to assess mid-term results after reoperation of a failed autograft.

METHODS

Between 1997 and 2022, 30 consecutive patients (83% male; age 41 ± 11 years) underwent autograft reintervention between 60 days and 24 years (median 10 years) after a Ross procedure. The initial technique varied, full-root replacement (n = 25) being the most frequent. The indication for reoperation was isolated autograft regurgitation (n = 7), root dilatation (>43 mm) with (n = 17) or without (n = 2) autograft regurgitation, mixed dysfunction (n = 2) and endocarditis (n = 2). In 4 instances, the valve was replaced by valve (n = 1) or combined valve and root replacement (n = 3). Valve-sparing procedures consisted of isolated valve repair (n = 7) or root replacement (n = 19), and tubular aortic replacement. Cusp repair was performed in all but 2. Mean follow-up was 5.4 ± 6 years (35 days to 24 years).

RESULTS

Mean cross-clamp and perfusion times were 74 ± 26 and 132 ± 64 min. There were 2 perioperative deaths (7%; both valve replacement) and 2 patients died late (32 days to 1.2 years postoperatively). Freedom from cardiac death at 10 years was 96% after valve repair and 50% after replacement. Two patients required reoperation (1.68 and 16 years) following repair. One underwent valve replacement for cusp perforation, the other, root remodelling for dilatation. Freedom from autograft reintervention at 15 years was 95%.

CONCLUSIONS

Autograft reoperations after the Ross procedure can be performed as valve-sparing operations in the majority of cases. With valve-sparing, long-term survival and freedom from reoperation are excellent.

The Ross Operation in Young Patients: A 15-Year Experience Focused on Right Ventricle to Pulmonary Artery Conduit Outcomes

Background

Data on long-term outcomes of the Ross operation in children and young adult patients are limited. The best pulmonary valve substitute for the right ventricular outflow tract reconstruction remains uncertain. This study aimed to assess the outcomes of right ventricular outflow tract reconstruction in the Ross operation in young patients using various pulmonary valve substitutes at a single institution. In addition, a comparison of reintervention rates between patients younger than 18 years and those older than 18 years was performed.

Methods

The study assessed all patients (N = 110) who underwent the Ross operation at the University Hospital of Bordeaux, France, between 2004 and 2020.

Results

The median follow-up time was 4.2 years, and the median age at operation was 15.9 years. There was no operative mortality and 1 late noncardiac death (0.8%). The overall survival rate at 10 years was 99.2%. The need for right ventricular outflow tract reoperation was lower with the pulmonary homograft compared with the Contegra conduit and Freestyle bioprosthesis: 94.3%, 93.8%, and 80% at 5 years, respectively, and 94.3%, 72.3%, and 34.3% at 10 years, respectively (P = 0.011). The probability of reintervention was not significantly different at 10 years among children vs adults (P = 0.22).

Conclusions

The Ross procedure in children and young adults was associated with a lower requirement for right ventricular outflow tract reoperation when pulmonary homografts were used instead of xenografts.

Structural dysregulation of the pulmonary autograft was associated with a greater density of p16INK4A-vascular smooth muscle cells

The present study tested the hypothesis that a senescent phenotype of vascular smooth muscle cells (VSMCs) may represent the seminal event linked to maladaptive pulmonary autograft remodeling of a small number of patients that underwent the Ross procedure. The diameter of the pulmonary autograft (47±4 mm) of three male patients was significantly greater compared to the pulmonary artery (26±1 mm) excised from bicuspid aortic valve (BAV) patients. The pulmonary autograft was associated with a neointimal region and the adjacent medial region was significantly thinner compared to the pulmonary artery of BAV patients. Structural dysregulation was evident as elastin content of the medial region was significantly reduced in the pulmonary autograft compared to the pulmonary artery of BAV patients. By contrast, collagen content of the medial region of the pulmonary autograft and the pulmonary artery of BAV patients was not significantly different. Reduced medial elastin content of the pulmonary autograft was associated with increased protein levels of matrix metalloproteinase-9. The latter phenotype was not attributed to a robust inflammatory response as the percentage of Mac-2⁽⁺⁾-infiltrating monocytes/macrophages was similar between groups. A senescent phenotype was identified as protein levels of the cell cycle inhibitor p27^kip1 were upregulated and the density of p16^INK4A/non-muscle myosin IIB⁽⁺⁾-VSMCs was significantly greater in the pulmonary autograft compared to the pulmonary artery of BAV patients. Thus, senescent VSMCs may represent the predominant cellular source of increased matrix metalloproteinase-9 protein expression translating to maladaptive pulmonary autograft remodeling characterized by elastin degradation, medial thinning and neointimal formation.

Ross Operation in Pediatric Population: Impact of the Surgical Timing and the Native Pulmonary Diameter on the Outcome

Aortic valve replacement early in life may be inevitable. Ross operation, until present day, remains the favorite surgical option in pediatrics with irreparable aortic valve disease. Nonetheless, the necessity for re-operation was always its principal limitation due to aortic valve failure or homograft degeneration. We present our 25 years of experience in the pediatric population. From August 1994 until June 2018, 157 children below 18 years underwent the Ross operation. This retrospective review aims at assessing the long-term outcomes, as well as the risk factors for re-operation after Ross procedure. Median age was 10.9 years, of which seven patients were infants, 79 children, and 71 adolescents. The median follow-up time was 14 years. Hospital mortality was 0.6%. Freedom from autograft re-operation for children was 96.7% and 94.1% at 10 and 20 years, respectively; whereas for adolescents, it was 92.6% and 74.9% at 10 and 20 years. For children, freedom from homograft re-operation was 92.5%, 83.5%, and 56.2% at 10, 15, and 20 years; while for adolescents, it was 96.8%, 91.8%, and 86.7% at 10, 15, and 20 years. Homograft size (p = 0.008) and childhood (p = 0.05) were risk factors for homograft re-operation. Pulmonary valve diameter > 24 mm (p = 0.044) and adolescence (p = 0.032) were risk factors for autograft re-operation. Our experience demonstrated excellent early and late survival. While children have preferential outcomes concerning autograft re-operation, those who received a smaller homograft had a higher right-sided re-intervention incidence than adolescents. Pulmonary diameter > 24 mm at surgery was an indicator of future autograft failure.

The Ross Procedure in Adolescence and Beyond: Are There Still Contraindications?

The Ross procedure is an excellent operation to treat children and adults with aortic valve disease. Compared to prosthetic aortic valve replacement, it provides important clinical benefits in terms of survival, hemodynamics, freedom from valve-related complications, and durability, especially in women of childbearing age. However, the Ross procedure is a longer and technically more challenging operation. As a result, the choice of procedure should be driven by patient anatomy and clinical characteristics. This highlights the importance of concentrating care in Ross reference centers where surgical expertise and experience are present to ensure patient safety and long-term effectiveness of the operation. This manuscript reviews the major and relative contraindications to the Ross procedure.

TAVR in 2023: Who Should Not Get It?

Since the first transcatheter delivery of an aortic valve prosthesis was performed by Cribier et al in 2002, the picture of aortic stenosis (AS) therapeutics has changed dramatically. Initiated from an indication of inoperable to high surgical risk, extending to intermediate and low risk, transcatheter aortic valve replacement (TAVR) is now an approved treatment for patients with severe, symptomatic AS across all the risk categories. The current evidence supports TAVR as a frontline therapy for treating severe AS. The crucial question remains concerning the subset of patients who still are not ideal candidates for TAVR because of certain inherent anatomic, nonmodifiable, and procedure-specific factors. Therefore, in this study, we focus on these scenarios and reasons for referring selected patients for surgical aortic valve replacement in 2023.

Formal consensus study on surgery to replace the aortic valve in adults aged 18-60 years

OBJECTIVE

There is uncertainty about surgical procedures for adult patients aged 18-60 years undergoing aortic valve replacement (AVR). Options include conventional AVR (mechanical, mAVR; tissue, tAVR), the pulmonary autograft (Ross) and aortic valve neocuspidisation (Ozaki). Transcatheter treatment may be an option for selected patients. We used formal consensus methodology to make recommendations about the suitability of each procedure.

METHODS

A working group, supported by a patient advisory group, developed a list of clinical scenarios across seven domains (anatomy, presentation, cardiac/non-cardiac comorbidities, concurrent treatments, lifestyle, preferences). A consensus group of 12 clinicians rated the appropriateness of each surgical procedure for each scenario on a 9-point Likert scale on two separate occasions (before and after a 1-day meeting).

RESULTS

There was a consensus that each procedure was appropriate (A) or inappropriate (I) for all clinical scenarios as follows: mAVR: total 76% (57% A, 19% I); tAVR: total 68% (68% A, 0% I); Ross: total 66% (39% A, 27% I); Ozaki: total 31% (3% A, 28% I). The remainder of percentages to 100% reflects the degree of uncertainty. There was a consensus that transcatheter aortic valve implantation is appropriate for 5 of 68 (7%) of all clinical scenarios (including frailty, prohibitive surgical risk and very limited life span).

CONCLUSIONS

Evidence-based expert opinion emerging from a formal consensus process indicates that besides conventional AVR options, there is a high degree of certainty about the suitability of the Ross procedure in patients aged 18-60 years. Future clinical guidelines should include the option of the Ross procedure in aortic prosthetic valve selection.

Future prospects in the tissue engineering of heart valves: a focus on the role of stem cells

INTRODUCTION

Heart valve disease is a growing burden on the healthcare system. Current solutions are insufficient for young patients and do not offer relief from reintervention. Tissue engineered heart valves (TEHVs) offer a solution that grows and responds to the native environment in a similar way to a healthy valve. Stem cells hold potential to populate these valves as a malleable source that can adapt to environmental cues.

AREAS COVERED

This review covers current methods of recapitulating features of native heart valves with tissue engineering through use of stem cell populations with in situ and in vitro methods.

EXPERT OPINION

In the field of TEHVs, we see a variety of approaches in cell source, biomaterial, and maturation methods. Choosing appropriate cell populations may be very patient specific; consistency and predictability will be key to long-term success. In situ methods are closer to translation but struggle with consistent cellularization. In vitro culture requires specialized methods but may recapitulate native valve cell populations with higher fidelity. Understanding how cell populations react to valve conditions and immune response is vital for success. Detrimental valve pathologies have proven to be difficult to avoid in early translation attempts.

Outcomes of the Ross procedure in young adults with previous aortic valve interventions

OBJECTIVES

Contemporarily modified Ross procedure continues to deliver excellent outcomes and remains part of the treatment strategy for aortic valve disease in the young adult population. The aim of this study was to assess whether Ross procedure carried out as a second or subsequent intervention for aortic valve disease carries similar risk and long-term benefit, when compared to Ross procedure for the first-time aortic valve replacement.

METHODS

A total of 158 patients aged 16-60 years from a single congenital cardiac centre between 1997 and 2020 were included. The sample was split into 2 subgroups, based on the history of previous aortic valve interventions prior to the Ross procedure. Primary outcomes were defined as survival and pulmonary autograft failure. Coarsened exact matching was used to balance for covariates.

RESULTS

A total of 103 patients underwent primary Ross and 55 underwent secondary Ross with a mean follow-up of 7.8 years. Twenty-two patients underwent 28 reoperations during follow-up. Forty-nine well-matched pairs were obtained through matching. Freedom from pulmonary autograft failure at 10 years was 84.5% in the primary group vs 100% in the secondary group (P = 0.021). Five- and ten-year survival were identical, 97.5% in the primary group vs 95.6% in the secondary group (P = 0.53). Male sex and era were found to be predictors of neoaortic root dilatation.

CONCLUSIONS

The lower incidence of graft failure seen in secondary Ross could justify a stepwise approach to aortic valve intervention. Ross procedure delivers excellent outcomes in the adult population with no difference in survival for primary or secondary Ross.

Lifetime Management of Aortic Stenosis: Transcatheter Versus Surgical Treatment for Young and Low-Risk Patients

Transcatheter aortic valve replacement is now indicated across all risk categories of patients with symptomatic severe aortic stenosis and has been proposed as first line option for the majority of patients >74 years old. However, median age of patients enrolled in the transcatheter aortic valve replacement low-risk trials is 74 years and transcatheter aortic valve replacement has never been systematically investigated in young low risk patients. Although the long-term data in surgical aortic valve replacement in young patients (age <75) are well known, such data remain lacking in transcatheter aortic valve replacement. In the absence of clear guideline recommendations in patients with challenging anatomies (eg, hostile calcium, bicuspid), it is important to know the potential advantages and disadvantages of each treatment and to consider how they might integrate with each other in the lifetime management of such patients. In this review, we discuss current outstanding issues on the management of severe aortic stenosis from a lifetime management perspective, particularly in terms of initial intervention and future reinterventions.

Patients with Bicuspid Aortopathy and Aortic Dilatation

(1) Background: Bicuspid aortic valve (BAV) is the most frequent congenital cardiac disease. Alteration of ascending aorta diameter is a consequence of shear stress alterations due to haemodynamic abnormalities developed from inadequate valve cusp coaptation. (2) Objective: This narrative review aims to discuss anatomical, pathophysiological, genetical, ultrasound, and radiological aspects of BAV disease, focusing on BAV classification related to imaging patterns and flux models involved in the onset and developing vessel dilatation. (3) Methods: A comprehensive search strategy was implemented in PubMed from January to May 2022. English language articles were selected independently by two authors and screened according to the following criteria. (4) Key Contents and Findings: Ultrasound scan is the primary step in the diagnostic flowchart identifying structural and doppler patterns of the valve. Computed tomography determines aortic vessel dimensions according to the anatomo-pathology of the valve. Magnetic resonance identifies hemodynamic alterations. New classifications and surgical indications derive from these diagnostic features. Currently, indications correlate morphological results, dissection risk factors, and genetic alterations. Surgical options vary from aortic valve and aortic vessel substitution to aortic valve repair according to the morphology of the valve. In selected patients, transcatheter aortic valve replacement has an even more impact on the treatment choice. (5) Conclusions: Different imaging approaches are an essential part of BAV diagnosis. Morphological classifications influence the surgical outcome.

Redo aortic valve-sparing root replacement for failing autograft after the Ross procedure: A case report

Introduction and importance

Late pulmonary autograft dilatation is observed in 10–20 % of patients after the Ross procedure, more often during the second decade of follow-up. Composite aortic root replacement with a valved conduit is the most common redo procedure. An aortic valve-sparing root replacement does not require lifelong anticoagulation and may significantly decrease the risk of complications, associated with a valve prosthesis.

Presentation of the case

We report a case of late pulmonary autograft dilatation developed after the Ross procedure. The annual transthoracic echocardiography after 20 years revealed severe dilatation of the pulmonary autograft, measuring 60 mm in diameter. The patient underwent a successful elective redo valve-sparing aortic root replacement (David I procedure). The aortic cross-clamp time was 144 min, and the CPB time was 181 min. The patient had an uneventful midterm postoperative course.

Clinical discussion

Late pulmonary autograft failure after the Ross procedure is a relatively rare condition, leading to repeat operation. Late autograft failure can contribute to aortic regurgitation, heart failure, and death due to ascending aortic dissection and rupture. Several research groups reported good early and midterm results of redo valve-sparing root replacement in such cases. In a reoperative valve-sparing root replacement after the Ross procedure, the portion of the native aorta with the adjacent part of the autograft may complicate the aortic root proper sizing.

Conclusion

Redo valve-sparing root replacement (David I procedure) is a viable option in pulmonary autograft dilatation with unaffected valve leaflets.

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Late pulmonary autograft dilatation is a rare but potentially fatal condition.

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Failing autograft may lead to aortic regurgitation, heart failure, and rupture.

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Redo David procedure is a viable option in autograft failure with unaffected cusps.

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The native aorta with the part of the autograft may complicate the proper sizing.

Ross procedure for acute infective endocarditis

Surgical treatment of infective endocarditis remains a challenge, with concerns of optimal prosthesis selection and risks of recurrent infection remaining paramount. The pulmonary autograft has unique features which may make it the ideal aortic valve substitute, especially in infectious endocarditis. We describe strategic considerations and technical details in performing a Ross procedure in a young patient with acute aortic valve endocarditis.

Biomechanics of Pulmonary Autograft as Living Tissue: A Systematic Review

Introduction: The choice of valve substitute for aortic valve surgery is tailored to the patient with specific indications and contraindications to consider. The use of an autologous pulmonary artery (PA) with a simultaneous homograft in the pulmonary position is called a Ross procedure. It permits somatic growth and the avoidance of lifelong anticoagulation. Concerns remain on the functionality of a pulmonary autograft in the aortic position when exposed to systemic pressure. Methods: A literature review was performed incorporating the following databases: Pub Med (1996 to present), Ovid Medline (1958 to present), and Ovid Embase (1982 to present), which was run on 1 January 2022 with the following targeted words: biomechanics of pulmonary autograft, biomechanics of Ross operation, aortic valve replacement and pulmonary autograph, aortic valve replacement and Ross procedure. To address the issues with heterogeneity, studies involving the pediatric cohort were also analyzed separately. The outcomes measured were early- and late-graft failure alongside mortality. Results: a total of 8468 patients were included based on 40 studies (7796 in pediatric cohort and young adult series and 672 in pediatric series). There was considerable experience accumulated by various institutions around the world. Late rates of biomechanical failure and mortality were low and comparable to the general population. The biomechanical properties of the PA were superior to other valve substitutes. Mathematical and finite element analysis studies have shown the potential stress-shielding effects of the PA root. Conclusion: The Ross procedure has excellent durability and longevity in clinical and biomechanical studies. The use of external reinforcements such as semi-resorbable scaffolds may further extend their longevity.

Transcatheter Versus Surgical Aortic Valve Replacement in Young, Low-risk Patients with Severe Aortic Stenosis

Aortic stenosis is a common form of acquired degenerative valvular disease associated with poor survival after the onset of symptoms. Treatment options for patients with aortic stenosis in addition to medical therapy include surgical aortic valve replacement (SAVR) with either tissue or mechanical valves, or transcatheter aortic valve replacement (TAVR) with either balloon-expandable or self-expanding valves via either transfemoral or alternative access routes. In this review, the authors discuss the current evidence and special considerations regarding the use of TAVR versus SAVR in the management of severe aortic stenosis in young (<65 years of age), low-risk patients, highlighting the history of aortic stenosis treatment, the current guidelines and recommendations, and important issues that remain to be addressed. Ultimately, until ongoing clinical trials with long-term follow-up data shed light on whether interventions for aortic stenosis can be broadened to a low-risk population, TAVR in young, low-risk patients should be undertaken with caution and with guidance from a multidisciplinary heart team.