Impacto de prótesis valvular pulmonar en la función ventricular derecha y eventos cardiacos en pacientes con tetralogía de Fallot: análisis retrospectivo / Impact of pulmonary valve replacement on ventricular function and cardiac events in patients with tetralogy of Fallot. A retrospective cohort study

Introducción y objetivos: Evaluar el impacto del recambio valvular pulmonar (RVP) en pacientes con tetralogía de Fallot reparada (TFr) en la evolución de los volúmenes y función b-ventricular, y en los eventos adversos.MétodosSe identificó adultos con TFr del registro SACHER. Se evaluó los datos seriados de cardiorresonancia magnética, ecocardiografía, capacidad de ejercicio y fracción aminoterminal del propéptido natriurético cerebral (tipo B) (NT-proBNP). El objetivo primario fue la fracción de eyección del ventrículo derecho (FEVD) medida por cardiorresonancia. Los objetivos secundarios fueron volúmenes biventriculares, capacidad de ejercicio, valores de NT-proBNP y tiempo hasta eventos adversos (arritmia auricular o ventricular, endocarditis). Se analizó las asociaciones entre el RVP previo y las trayectorias longitudinales de los resultados funcionales, y el tiempo hasta los eventos cardiacos adversos con modelos lineales de efectos mixtos y modelos de riesgos proporcionales de Cox, respectivamente.ResultadosSe analizó a 308 pacientes (153 con y 155 sin RVP) con 887 visitas de estudio. No se asoció el RVP de manera significativa con la trayectoria de la FEVD (CE=-1,33; IC95%, –5,87-3,21; p=0,566). Se asoció el RVP previo con menor volumen telediastólico del ventrículo derecho, pero no tuvo efecto significativo en la fracción de eyección del ventrículo izquierdo, capacidad de ejercicio o valores de NT-proBNP. Se asoció el RVP previo con un riesgo incrementado de arritmias auriculares (HR=2,09; IC95%, 1,17-3,72; p=0,012) y endocarditis infecciosa (HR=12,72; IC95%, 4,69-34,49; p<0,0001), pero no con un riesgo aumentado de arritmias ventriculares sostenidas (HR=0,64; IC95%, 0,18-2,27; p=0,490).ConclusionesNo se asoció el RVP previo de manera significativa con la trayectoria de la FEVD, pero sí con un riesgo aumentado de arritmias auriculares y endocarditis infecciosa. (AU)

Introduction and objectives: Our aim was to assess the impact of prosthetic pulmonary valve replacement (PVR) in patients with repaired tetralogy of Fallot (rTOF) on changes in biventricular volumes and function and on adverse cardiac events.MethodsAdults with rTOF were identified from the SACHER-registry. Data from serial cardiac magnetic resonance imaging, echocardiography, exercise capacity and n-terminal pro b-type natriuretic peptide (NT-proBNP) were collected. The primary endpoint was right ventricular ejection fraction (RVEF) as measured by cardiac magnetic resonance. Secondary endpoints were biventricular volumes, left ventricular ejection fraction, exercise capacity and NT-proBNP levels, and time to adverse cardiac outcomes (atrial and ventricular arrhythmia, endocarditis). Associations between previous PVR and longitudinal changes in functional outcomes and time to adverse cardiac outcomes were analyzed using linear mixed-effects models and Cox proportional hazards models, respectively.ResultsA total of 308 patients (153 with and 155 without PVR) with 887 study visits were analyzed. Previous PVR was not significantly associated with changes in RVEF (CE, -1.33; 95%CI, -5.87 to 3.21; P=.566). Previous PVR was associated with lower right ventricular end-diastolic volume but had no significant effect on left ventricular ejection fraction, exercise capacity, or NT-proBNP-levels. Previous PVR was associated with an increased hazard of atrial arrhythmias (HR, 2.09; 95%CI, 1.17-3.72; P=.012) and infective endocarditis (HR, 12.72; 95%CI, 4.69-34.49; P<.0001) but not with an increased hazard of sustained ventricular arrhythmias (HR, 0.64; 95%CI, 0.18-2.27; P=.490).ConclusionsPrevious PVR was not significantly associated with changes in RVEF but was associated with an increased risk of atrial arrhythmias and infective endocarditis. (AU)

Transcatheter-Based Interventions for Tetralogy of Fallot Across All Age Groups.

Tetralogy of Fallot (TOF) is the most common form of cyanotic congenital heart disease. Palliative procedures, either surgical or transcatheter, aim to improve oxygen saturation, affording definitive procedures at a later stage. Transcatheter interventions have been used before and after surgical palliative or definitive repair in children and adults. This review aims to provide an overview of the different catheter-based interventions for TOF across all age groups, with an emphasis on palliative interventions, such as patent arterial duct stenting, right ventricular outflow tract stenting, or balloon pulmonary valvuloplasty in infants and children and transcatheter pulmonary valve replacement in adults with repaired TOF, including the available options for a large, dilated native right ventricular outflow tract.

Pulmonary artery sarcoma affecting the pulmonary valve mistaken as pulmonary vasculitis: a case report and comparative literature review.

Pulmonary arterial sarcomas (PAS) are rare aggressive tumours occurring mainly in the pulmonary trunk. We report a case of PAS involving the pulmonary trunk wall and valve, with uniform wall thickening which represents an atypical imaging manifestation of this tumour. A 63-year-old male presented with vague respiratory symptoms with rapid progression. CTPA showed low density filling defects in both pulmonary arteries and PET scan showed increased uptake in the pulmonary trunk, which along with raised ESR suggested Pulmonary Vasculitis. Echo imaging showed Right ventricular hypertrophy and pulmonary stenosis. Response to steroid therapy was minimal and his symptoms worsened. A referral for second opinion was made and he was diagnosed with PAS. He underwent Pulmonary thromboendarterectomy with Pulmonary valve replacement. Post-operative histopathology confirmed the diagnosis. PAS is rare and frequently misdiagnosed. Surgical resection is not curative, but together with chemotherapy can prolong survival.

Transcatheter Pulmonary Valve Replacement With the Harmony Valve in Patients Who Do Not Meet Recommended Oversizing Criteria on the Screening Perimeter Plot.

BACKGROUND: Anatomic selection for Harmony valve implant is determined with the aid of a screening report and perimeter plot (PP) that depicts the perimeter-derived radius along the right ventricular outflow tract (RVOT) and projects device oversizing. The PP provides an estimation of suitability for implant, but its sensitivity as a screening method is unknown. This study was performed to describe anatomic features and outcomes in patients who underwent Harmony TPV25 implant despite a PP that predicted inadequate oversizing. METHODS: We reviewed RVOT anatomic features and measurements in patients who underwent transcatheter pulmonary valve replacement with the Harmony TPV25 device despite a PP that predicted inadequate oversizing. RESULTS: This study included 22 patients. There were no unsuccessful implants or adverse valve-related events. Anatomic features varied, but all patients fit into 1 of 3 anatomic types characterized by differences in RVOT dimensions. Type 1 patients (n=9) had a long RVOT with a choke point and a wide main pulmonary artery. Type 2 patients (n=6) had a short RVOT that was pyramidal in shape, with no choke point, and extensive main pulmonary artery lengthening/expansion during systole. Type 3 patients (n=7) had a short, bulbous main pulmonary artery with a choke point and an open pulmonary artery bifurcation. CONCLUSIONS: Transcatheter pulmonary valve replacement with the Harmony valve is feasible in some patients whose PP fit analysis predicts inadequate oversizing. All cases in this series fit into 1 of 3 anatomic patterns, which are not identified in the screening report. Implanters must review cases individually to assess the feasibility of the implant.

Semilunar valve growth and function 10 years after infant heart transplantation: Predicting long-term outcomes of partial heart transplants.

INTRODUCTION: Partial heart transplants are a new type of pediatric transplant that replace defective heart valves with the parts of matched donor hearts containing the necessary valves. Short-term outcomes of partial heart transplants are excellent, but long-term outcomes are unknown. In order to predict the long-term outcomes of partial heart transplants, we evaluated long-term growth and function of semilunar heart valves transplanted in infancy as part of a heart transplant. METHODS: All children who underwent infant heart transplantation at a single center from 1997 to 2014 were included in this study. Children in whom echocardiograms after heart transplantation and after 10 years were not available for review were excluded. The echocardiograms were reviewed by two authors to analyze semilunar valve annulus diameters, Z-scores, peak valve gradients, and valve regurgitation. Statistical difference was determined using two-tailed, paired sample t-tests with Bonferroni correction for multiple comparisons. RESULTS: Data from 15 patients were analyzed. The aortic valve annulus averaged 1.3 cm (range 0.7-1.8 cm) immediately after transplantation and grew to an average of 1.7 cm (range 1.4-2.3 cm) after 10 years (p < .001). After 10 years, the aortic valve peak gradient avereraged 5.1 mmHg (range 2.1-15.5 mmHg) and none of the valves had more than trivial regurgitation. The pulmonary valve annulus averaged 1.5 cm (range 1.1-2.5 cm) immediately after transplantation and grew to an average of 2.1 cm (range 1.0-2.9 cm) after 10 years (p < .001). After 10 years, the pulmonary valve peak gradient averaged 4.3 mmHg (range 1.1-13.8 mmHg), and 7% of valves had moderate regurgitation. DISCUSSION: Semilunar heart valves transplanted in infancy as part of a heart transplant demonstrate statistically significant growth and excellent function after 10 years. This predicts excellent long-term outcomes of partial heart transplants.

Early Outcomes From a Multicenter Transcatheter Self-Expanding Pulmonary Valve Replacement Registry.

BACKGROUND: Transcatheter pulmonary valve replacement (TPVR) with the self-expanding Harmony valve (Medtronic) is an emerging treatment for patients with native or surgically repaired right ventricular outflow tract (RVOT) pulmonary regurgitation (PR). Limited data are available since U.S. Food and Drug Administration approval in 2021. OBJECTIVES: In this study, the authors sought to evaluate the safety and short-term effectiveness of self-expanding TPVR in a real-world experience. METHODS: This was a multicenter registry study of consecutive patients with native RVOT PR who underwent TPVR through April 30, 2022, at 11 U.S. CENTERS: The primary outcome was a composite of hemodynamic dysfunction (PR greater than mild and RVOT mean gradient >30 mm Hg) and RVOT reintervention. RESULTS: A total of 243 patients underwent TPVR at a median age of 31 years (Q1-Q3: 19-45 years). Cardiac diagnoses were tetralogy of Fallot (71%), valvular pulmonary stenosis (21%), and other (8%). Acute technical success was achieved in all but 1 case. Procedural serious adverse events occurred in 4% of cases, with no device embolization or death. Hospital length of stay was 1 day in 86% of patients. Ventricular arrhythmia prompting treatment occurred in 19% of cases. At a median follow-up of 13 months (Q1-Q3: 8-19 months), 98% of patients had acceptable hemodynamic function. Estimated freedom from the composite clinical outcome was 99% at 1 year and 96% at 2 years. Freedom from TPVR-related endocarditis was 98% at 1 year. Five patients died from COVID-19 (n = 1), unknown causes (n = 2), and bloodstream infection (n = 2). CONCLUSIONS: In this large multicenter real-world experience, short-term clinical and hemodynamic outcomes of self-expanding TPVR therapy were excellent. Ongoing follow-up of this cohort will provide important insights into long-term outcomes.

Finite element modeling with patient-specific geometry to assess clinical risks of percutaneous pulmonary valve implantation.

BACKGROUND: Percutaneous pulmonary valve implantation (PPVI) is a non-surgical treatment for right ventricular outflow tract (RVOT) dysfunction. During PPVI, a stented valve, delivered via catheter, replaces the dysfunctional pulmonary valve. Stent oversizing allows valve anchoring within the RVOT, but overexpansion can intrude on the surrounding structures. Potentially dangerous outcomes include aortic valve insufficiency (AVI) from aortic root (AR) distortion and myocardial ischemia from coronary artery (CA) compression. Currently, risks are evaluated via balloon angioplasty/sizing before stent deployment. Patient-specific finite element (FE) analysis frameworks can improve pre-procedural risk assessment, but current methods require hundreds of hours of high-performance computation. METHODS: We created a simplified method to simulate the procedure using patient-specific FE models for accurate, efficient pre-procedural PPVI (using balloon expandable valves) risk assessment. The methodology was tested by retrospectively evaluating the clinical outcome of 12 PPVI candidates. RESULTS: Of 12 patients (median age 14.5 years) with dysfunctional RVOT, 7 had native RVOT and 5 had RV-PA conduits. Seven patients had undergone successful RVOT stent/valve placement, three had significant AVI on balloon testing, one had left CA compression, and one had both AVI and left CA compression. A model-calculated change of more than 20% in lumen diameter of the AR or coronary arteries correctly predicted aortic valve sufficiency and/or CA compression in all the patients. CONCLUSION: Agreement between FE results and clinical outcomes is excellent. Additionally, these models run in 2-6 min on a desktop computer, demonstrating potential use of FE analysis for pre-procedural risk assessment of PPVI in a clinically relevant timeframe.

Technical considerations and sizing of external annuloplasty in the Ross procedure.

Pure aortic regurgitation and dilation of aortic annulus are the most significant risk factors for the failure of pulmonary autograft after the Ross procedure. Aortic annuloplasty has a positive effect on the durability of the autograft. Previously, we described a technique for external annuloplasty with dedicated CORONEO ring. In the present manuscript, we suggest the sizing of annuloplasty based on the diameter of pulmonary autograft annulus.

Patient Screening for Self-Expanding Percutaneous Pulmonary Valves Using Virtual Reality.

BACKGROUND: In recent years, self-expanding technology to treat pulmonary regurgitation in the native right ventricular outflow tract became Food and Drug Administration approved in the United States and is now routinely used. The current practice for selection of patients who are candidates for these devices includes screening for "anatomic fit," performed by each of the manufacturing companies. Our study aims to validate the use of virtual reality (VR) as a tool for local physician-led screening of patients. METHODS AND RESULTS: This retrospective study from Children's Hospital Colorado included patients who underwent pulmonary valve replacement and had screening for a Harmony TPV or Alterra Prestent performed between September 2020 and January 2022. The data from the commercial companies' dedicated analysis for self-expanding transcatheter pulmonary valve frames evaluation with perimeter analysis were collected. VR simulation was performed blinded by 2 congenital interventional cardiologists using Elucis VR software and an Oculus Quest 2 headset. Among the 27 evaluated cases, the use of a self-expandable valve was recommended by companies' dedicated analysis in 23 cases (85.2%), by VR assessment in 26 cases (96.3), and finally implanted in 25 cases (92.6%). Regarding the level of agreement, both modalities (manufacturer and VR) were good at screening-in patients who received a self-expanding valve (100% versus 96.1%). When it came to screening-out the patients, VR presented good capacity to accurately classify nonsuitable patients (50% versus 100%). CONCLUSIONS: Our institutional experience with VR transcatheter pulmonary valve implantation planning accurately predicted clinical outcomes. This paves the way for routine use of VR in patient selection for self-expanding valve technologies.

Long-term function of a novel autologous transcatheter pulmonary heart valve implant in an adult animal model.

BACKGROUND: Current heart valve implants entail major disadvantages in the treatment for younger patients or those with congenital heart defects. AIM: Evaluation of novel transcatheter pulmonary valve implant made from autologous pericardium with natural crosslinking agent in an in vitro setup and in vivo animal model METHODS: Valves were tested in a pulse duplicator according to ISO-standard 5840. For in vivo studies computer tomography was performed to measure sheep's native pulmonary valve dimensions. Pericardium was harvested by thoracotomy, personalized implants were manufactured and deployed in pulmonary valve position of the same sheep. Every 3 months implant functionality was evaluated by intracardiac echocardiography, intracardiac pressure measurements and cardiac magnetic resonance imaging (cMRI). Implants were explanted for macroscopic and histological examination. RESULTS: In vitro experiments showed compliance with regulatory requirements in terms of valve opening and insufficiency. Five sheep successfully received an autologous valve implant. Two animals had to be euthanized due to trauma sustained in the stable. Long-term valve function was excellent in three out of four animals with median implant cMRI regurgitation fraction of 9% (n = 4) at 3 months, 8% (n = 3) at 6, 8% (n = 3) at 9, 12% (n = 3) at 13, 8% (n = 2) at 17% and 8% (n = 2) at 20.5 months after implantation. Despite good adherence to neighboring tissue and endothelization, histological assessment revealed some signs of degeneration. CONCLUSION: Transcatheter pulmonary valve implants showed promising function for up to 20.5 months encouraging research to further improve this approach.

Management of right ventricular outflow tract with percutaneous Melody valve implantation in pediatric patients: experience in a high complexity center in Colombia.

BACKGROUND: Congenital heart disease poses a therapeutic challenge, specifically pulmonary valve stenosis. This has been treated for many years with invasive procedures and bioprostheses, which over time, become dysfunctional due to the accumulation of fibrous tissue and calcification. OBJECTIVE: The aim of this study is to describe the use of endovascular management in the right ventricular outflow tract, as the beginning of an ongoing effot to improve pediatric outcomes in developing countries. METHODS: Seven pediatric patients with endovascular management of the right outflow tract are presented. Three of them underwent surgical valvuloplasty with persistent pulmonary stenosis. They decided to insert a percutaneous transcatheter pulmonary valve (PPVI) with a Melody valve using the valve-in-valve technique, with 100% stenosis and no complications associated with the procedure. RESULTS: Four patients with successful percutaneous valve implantation had different congenital heart diseases. In addition, the case of a patient in whom an intentional pulmonary valve fracture was performed, an innovative procedure in pediatric endovascular management in the country, is highlighted. CONCLUSIONS: The procedure was minimally invasive, safe, and effective. The IVPP technique could be a viable option in our country for managing failed primary valve implantations or even in native tracts.

ANTECEDENTES: Las cardiopatías congénitas plantean un desafío terapéutico, específicamente la estenosis de la válvula pulmonar. Esta ha sido tratada durante muchos años con procedimientos invasivos e inserción de bioprótesis, que con el tiempo se vuelven disfuncionales y pueden reestenosarse por acumulación de tejido fibroso y calcificación. Debido a las complicaciones generadas por la injuria quirúrgica, se han descrito medidas menos invasivas para el manejo de la estenosis residual e inicial por medios endovasculares en adultos y más recientemente en población pediátrica. OBJETIVO: El objetivo de este reporte es describir la misma en el manejo endovascular del tracto de salida del ventrículo derecho, como el inicio de un trabajo continuo para la mejoría de los resultados pediátricos en países en vía de desarrollo. MÉTODOS: Se presentan siete casos pediátricos de manejo endovascular del tracto de salida derecho; tres de ellos sometidos a valvuloplastia quirúrgica con persistencia de la estenosis pulmonar, por lo cual se decidió inserción percutánea de una válvula pulmonar (IVPP) transcatéter con válvula Melody utilizando la técnica valve-in-valve, con lo que se consiguió una resolución del 100% de la estenosis y no se presentó ningún tipo de complicación asociada al procedimiento. RESULTADOS: En cuatro pacientes se logró una implantación exitosa de la válvula por vía percutánea en diferentes cardiopatías congénitas, siendo uno de ellos en tracto nativo; además, destaca el caso de un paciente en quien se realizó fractura intencional de la válvula pulmonar, procedimiento innovador en el manejo endovascular pediátrico en Colombia. CONCLUSIONES: En estos pacientes el procedimiento resultó ser poco invasivo, seguro y efectivo. La técnica IVPP podría ser considerada una opción viable en Colombia (y en otros países en desarrollo) para el manejo de implantes valvulares primarios fallidos o incluso en tractos nativos.

Surgical Heritage: You Had to Be There, Ross: The Comeback Kid.

Half a century after the first pulmonary autograft operation (Ross operation), performed in 1967 by Donald Ross in central London, there is a very strong conviction that the Ross operation is the best available valve substitute today, not only for children, but also for younger and older adults. The Ross operation has stimulated a lot of science to do with tissue-engineering and biology of heart valves, which is a promising avenue for the future. For one of us (M.Y.), it has certainly been a privilege to be associated with the comeback of the Ross operation.

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.

Late Pulmonary Autograft Dilation: Can We Make a Good Operation Great? The Supported Ross.

The Ross procedure is an excellent option for aortic valve replacement resulting in outstanding hemodynamic performance and the ability to avoid systemic anticoagulation. The long-term durability of the autograft is generally good but concerns for later aortic root dilation with ensuing neoaortic insufficiency have prompted efforts to stabilize the autograft, root, sinuses and Sino-tubular junction in order to delay or entirely avoid late reinterventions on the neoaortic root. We have employed an inclusion technique, supporting the Auto-graft in a Terumo Gelweave™ Valsalva graft. We performed a retrospective study of all 129 patients undergoing the Ross procedure from 1992 to 2019 at Children's Wisconsin. Fifty-one underwent the supported Ross (SR) and 78 underwent unsupported Ross (UR). Structured clinical data was collected and echocardiograms were reviewed. Median follow-up was 4.9 years (up to 22.6 years) for UR patients and 3.6 years (up to 11.4 years) for SR patients. In order to provide a fair comparison, we sub -analyzed patients aged 10 to 18 years who underwent the Ross procedure, 16 who underwent the UR and 18 patients who underwent the SR. Change in aortic annulus diameter (P = 0.002), aortic sinus diameter (P = 0.001) change in left ventricular function (P = 0.039) and change in aortic insufficiency (P = 0.008) were all worse in UR. The SR is simple, reproducible, and predictable. It seems to prevent change in annulus diameter, sinus diameter and to reduce late neoaortic insufficiency. Longer follow-up with a larger group of patients is required to draw definitive conclusions.

Automated isochronal late activation mapping for substrate characterization in patients with repaired tetralogy of Fallot.

AIMS: Slow conduction (SC) anatomical isthmuses (AIs) are the dominant substrate for monomorphic ventricular tachycardia (VT) in patients with repaired tetralogy of Fallot (rTF). This study aimed to evaluate the utility of automated propagational analysis for the identification of SC-AI in patients with rTF. METHODS AND RESULTS: Consecutive rTF patients undergoing VT substrate characterization were included. Automated isochronal late activation maps (ILAM) were obtained with multielectrode HD Grid Catheter. Identified deceleration zones (DZs) were compared with both SC-AI defined by conduction velocity (CV) (<0.5 m/s) and isthmuses of induced VT for mechanistic correlation. Fourteen patients were included (age 48; p25-75 35-52 years; 57% male), 2 with spontaneous VT and 12 for risk stratification. Nine VTs were inducible in seven patients. Procedure time was 140 (p25-75 133-180) min and mapping time 29.5 (p25-75 20-37.7) min, using a median of 2167 points. All the patients had at least one AI by substrate mapping, identifying a total of 27 (11 SC-AIs). Isochronal late activation maps detected 10 DZs mostly in the AI between ventricular septal defect and pulmonary valve (80%). Five patients had no DZs. A significant negative correlation between number of isochrones/cm and CV was observed (rho -0.87; P < 0.001). Deceleration zones correctly identified SC-AI (90% sensitivity; 100% specificity; 0.94 accuracy) and was related to VT inducibility (P = 0.006). Deceleration zones co-localized to the critical isthmus of induced VTs in 88% of cases. No complications were observed. CONCLUSION: Deceleration zones displayed by ILAM during sinus rhythm accurately identify SC-AIs in rTF patients allowing a safe and short-time VT substrate characterization procedure.

Letter to the Editor Ross procedure valve function, clinical outcomes and predictors after 25 years follow up.

The following letter presents an answer of a comment of our work titled "Ross procedure: valve function, clinical outcomes and predictors after 25 years' follow-up," recently published in your journal by Rangwala et al.1 As our colleagues point out, the Ross procedure has excellent survival rates but a significant risk of valve dysfunction and therefore reintervention at follow-up. Although the survival advantage with the Ross procedure appears to be consistent compared with mechanical valve substitutes, this benefit is not as clear compared with biological valve substitutes. However, biological valve substitutes also have significant reintervention rates during follow-up. The different surgical modifications of the Ross procedure have not clearly demonstrated better results in follow-up in terms of autograft reintervention. This procedure can be performed in a medium-volume center with good results as long as adequate patient selection and adequate surgical training are carried out.