Aortic Position Research Articles

Percutaneous treatment of multi-valvular paraprosthetic leaks in a “fragile” heart

A 38-year-old male with osteogenesis imperfecta, had a history of mitral and aortic dysplasia with severe regurgitation requiring surgical valve replacement followed by two further reoperations due to the development of recurrent paravalvular leaks. Two months after his last intervention he presented with clinical signs of acute decompensated heart failure. Echocardiography showed multiple para-valvular leaks with both severe mitral and aortic periprosthetic regurgitation (Fig. 1). As the patient was deemed too high risk for further multiple valve surgery, a transcatheter percutaneous leak closure was performed with implantation of 3 Amplatzer Vascular Plug (St. Jude Medical Corp, St. Paul, MN, USA) 10 mm devices in the aortic leaks and 2 Amplatzer Vascular Plug II devices, 20 mm and 16 mm in the perimitral defect. After two years of clinical stability, he was readmitted for increasing dyspnoea (NYHA Class IV) and ankle swelling. Echocardiogram showed good function of both prosthetic valves with well-positioned plugs, but significant residual paravalvular leaks were still present (Fig. 2, Video 1). Fig. 2Panel A: At three-dimensional transesophageal echocardiography the two peri-mitral plugs (asterisks), with significant residual regurgitation, are imaged. Panel B: Transthoracic echocardiogram showing the periprosthetic plugs in aortic position with residual moderate regurgitation. View Large Image Figure Viewer Download Hi-res image

The effect of the aortic valve orientation on cavitation.

When implanting a mechanical aortic valve the annulus orientation is important with respect to turbulence. However, the effect on cavitation has not yet been investigated. The aim of this study was to investigate how cavitation is influenced hereof in vivo. Three pigs were included in the study. An Omnicarbon 21mm valve equipped with a rotating mechanism enabling controlled rotation of the valve was implanted in aortic position. Under stable hemodynamic conditions, measurements were performed using a hydrophone positioned at the aortic root. The valve was rotated from 0-360° in increments of 30°. From the pressure fluctuations recorded by the hydrophone the root mean square of the 50 kHz high pass filtered signal as well as the non-deterministic signal energy was calculated as indirect measures of cavitation. Various degrees of cavitation were measured but no relationship was found between either of the two cavitation measures and the valve orientation. Hemodynamics varied during the experiments for all pigs (3.9-5.7 l/min; 5.0-7.2 l/min; 3.1-7.5 l/min). Changes in cavitation quantities seemed to be caused by changes in hemodynamics rather than valve angular position. In conclusion, these results do not favor any position over another in terms of cavitation potential.

Biomechanics drive histological wall remodeling of neoaortic root: A mathematical model to study the expression levels of ki 67, metalloprotease, and apoptosis transition.

The pulmonary artery autograft (PA) is the ideal substitute for aortic valve disease in children and young adult. However, it is harnessed by the issue of long-term dilation and regurgitation, often requiring surgery. PA implanted in aortic position during the growth phase in children undergoes a process of mechanical remodeling. We previously developed a semiresorbable armored prosthesis able to mechanically sustain the neoaorta preventing dilation and to gradually integrate with the PA wall inducing a progressive arterial-like tissue positive remodeling. We also described the mechanisms of growth, remodeling and stress shielding of the reinforced PA through a mathematical model. We sought to demonstrate the biological counterpart and the potential molecular mechanisms underlying this histological and mechanical remodeling. A specific mathematical model was developed to describe mechanical behavior of the PA. Mallory trichrome red staining and immunohistochemistry for MMP-9 were performed to elucidate extracellular matrix remodeling phenomena. Apoptosis and cell proliferation were determined by TUNEL assay and immunohistochemistry for Ki67, respectively. An histological remodeling phenomenon sustained by increased level of MMP-9, augmented cell proliferation and reduced apoptosis in the reinforced PA was demonstrated. The mathematical model predicted the biomechanical behavior subtended by the histological changes of the PA in these settings. Changes in metalloproteinases (MMP-9), cell proliferation and apoptosis are the main actors in the remodeling process occurring after transposition of the PA into systemic regimens. Use of semiresorbable reinforcements might induce a positive remodeling of the PA in the context of Ross operation. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2785-2793, 2016.

Tissue-Engineered Fibrin-Based Heart Valve with Bio-Inspired Textile Reinforcement.

The mechanical properties of tissue-engineered heart valves still need to be improved to enable their implantation in the systemic circulation. The aim of this study is to develop a tissue-engineered valve for the aortic position - the BioTexValve - by exploiting a bio-inspired composite textile scaffold to confer native-like mechanical strength and anisotropy to the leaflets. This is achieved by multifilament fibers arranged similarly to the collagen bundles in the native aortic leaflet, fixed by a thin electrospun layer directly deposited on the pattern. The textile-based leaflets are positioned into a 3D mould where the components to form a fibrin gel containing human vascular smooth muscle cells are introduced. Upon fibrin polymerization, a complete valve is obtained. After 21 d of maturation by static and dynamic stimulation in a custom-made bioreactor, the valve shows excellent functionality under aortic pressure and flow conditions, as demonstrated by hydrodynamic tests performed according to ISO standards in a mock circulation system. The leaflets possess remarkable burst strength (1086 mmHg) while remaining pliable; pronounced extracellular matrix production is revealed by immunohistochemistry and biochemical assay. This study demonstrates the potential of bio-inspired textile-reinforcement for the fabrication of functional tissue-engineered heart valves for the aortic position.

Invited Commentary

Patient–prosthesis mismatch after mitral valve replacement is still of uncertain relevance because the long-term outcome and underlying potential pathomechanisms are not identified. The evidence is conflicting that patient–prosthesis mismatch is a clinically relevant phenomenon and affects long-term prognosis. The hemodynamic mechanisms of compensation in patient–prosthesis mismatch in the mitral position are different from those of patient–prosthesis mismatch in the aortic position. As nicely shown by Ho Young and colleagues [1Hwang H.Y. Kim Y.H. Kim K.H. et al.Patient–prosthesis mismatch after mitral valve replacement: a propensity score analysis.Ann Thorac Surg. 2016; 101: 1796-1803Abstract Full Text Full Text PDF Scopus (23) Google Scholar], there is a shift from a cardiac type toward a respiratory type of clinical presentation, inasmuch as pulmonary congestion and residual hypertension were more frequent in patients with mitral patient–prosthesis mismatch. This indicates congestion in the pulmonary vascular system with a negative impact on pulmonary recovery. Unfortunately, the authors could not provide information about the incidence of new-onset atrial fibrillation after surgery, which may have an impact on the postoperative clinical course. As in the aortic position, patient–prosthesis mismatch in the mitral valves seems to relate to the presence of bioprostheses rather than mechanical prostheses; however, the data failed to prove this statistically. The most striking new information in this study is the negative impact of patient–prosthesis mismatch in the mitral position on long-term survival. In the past, this clinical issue has been underestimated in the long-term follow-up after mitral valve replacement, and we will now be forced to rethink the concepts of intraoperative decision making. Patient-Prosthesis Mismatch After Mitral Valve Replacement: A Propensity Score AnalysisThe Annals of Thoracic SurgeryVol. 101Issue 5PreviewWe evaluated the impact of patient-prosthesis mismatch (PPM) after mitral valve replacement on the clinical outcomes using propensity score models. Full-Text PDF

Comparison of mid-term haemodynamic performance between the BioValsalva and the BioIntegral valved conduits after aortic root replacement

We retrospectively compared the haemodynamic performance of the BioValsalva (BV) and BioIntegral (BI) biological aortic-valved conduits in the aortic root position. Between July 2008 and June 2014, a total of 55 patients underwent aortic root replacement using the BV conduit (n = 27) or the BI conduit (n = 28). The primary study endpoints were haemodynamic performance during follow-up, including mean pressure gradients (MPGs) and effective orifice areas (EOAs). Secondary study endpoints were early postoperative outcomes within 30 days and survival. Both groups did not differ in regard to demographics (BV: median age 71 years, 70.4% female; BI: median age 66 years, 85.7% female, P = 0.15 and P = 0.17) and risk profile (median EuroSCORE-II BV: 3.8 vs 5.3% for BI, P = 0.38). A total of 20% of the total patients (BV 5/27, 18.5% vs BI 6/28, 21.4%) presented with acute type-A aortic dissection. During follow-up, both groups showed no difference in MPGs for all valve sizes [BV, 11.0 mmHg (8.3-14.8 mmHg) vs BI, 11.5 mmHg (9.0-13.0), P = 0.82]. Similar results were achieved for EOAs for all valve sizes [BV, 1.85 cm(2) (1.55-2.21) vs BI, 1.80 cm(2) (1.64-1.83), P = 0.24]. Moreover, there was no statistically significant difference in aortic regurgitation (AR) with none/trace AR in (21/23) 91.3% in BV patients versus (16/21) 76.2% in BI patients (P = 0.23) at follow-up. Both groups showed a high rate of concomitant procedures (BV: 59.3% vs BI: 71.4%, P = 0.40) and emergency indication (BV: 18.5% vs BI: 21.4%, P = 0.79), resulting in an overall 30-day mortality rate of 7.3% (4/55 patients). The present small single-centre study is one of the first to evaluate and compare the BioValsalva and BioIntegral biological aortic-valved conduit in the aortic root position. Both conduits showed optimal haemodynamic results with a low incidence of aortic regurgitation.

Noteworthy Literature in Cardiac Surgery 2015.

In 2015, the cardiac literature has pushed for change in cardiac practice. The areas are evolving quickly based on new technology, ranging from percutaneous valves in the aortic position to mechanical support. The new devices in both these fields are changing the way patients are cared for very quickly. Another topic evolving is temperature management in aortic arch cases. This field is being pushed more by the threat of endovascular technology creeping into the arch than technology directly causing change in care. But that threat is real and inevitable. Finally, the discussion about optimal conduits is unending in coronary bypass grafting. A new algorithm has been proposed for utilization of more arterial grafts; however, there remains trepidation in changing from more vein grafts. Furthermore, those pushing for more arterial grafting seem to be black and white about these approaches rather than using what is best for the patient. These topics, among others, have made the literature from cardiac surgery in 2015 worth reading.

Degeneration of Pericardial Aortic Valve Biological Prostheses in Correlation with Age Decades and Different Types of Prostheses - Long Term Follow-up Results

Objectives: Currently trends are moving toward the use of bioprosthetic valves in the aortic position in younger patients to avoid lifelong anticoagulation therapy. This study examines the long-term durability associated with structural valve degeneration (SVD) of three pericardial bioprostheses in the aortic position considering patients' age and preoperative characteristics. Methods: From 2004 to 2014, 1506 consecutive patients underwent aortic valve replacement (AVR) with either a Sorin Mitroflow (n = 815; 54,1%; M-group), Edwards Lifesciences Perimount (n = 614; 40.8%; P-group) or Sorin Freedom Solo (n = 77; 5.1%; S-group) pericardial bioprosthesis at our institution. Freedom from SVD and reoperation were studied according to the 3 different bioprosthesis and age group. Mean age at time of surgery was 73.7 ± 7.7 years for Mitroflow, 64.1 ± 11.8 years for Perimount, and 69.5 ± 11.3 years for Solo bioprosthesis, respectively. Mean follow-up was 4.7 ± 5.3 years (range 0–10.3 years) and was 100% complete. Results: Overall survival was 86.8% (at 5-year/10-year follow-up 84.9%/83.8% in the M-group, 94.5%/91.7% in the P-group and 80.5%/79.2% for the S-group). A total of 199 (13.2%) patients died during follow-up, 132 (16.2%) patients in the M-group, 51(8.3%) patients in the P-group, and 16 (20.8%) patients in the S-group (p< 0.001). The overall number of valve-related deaths was 16 (8.04%) - 8 patients (6.06%) were from the M-group, 3(5.088%) from the P-group and 5 (31.25%) patients from the S-group (p< 0.001). Overall, 77 patients underwent reoperation, with 55 (71.4%) cases related to SVD and 19 (24.7%) cases related to endocarditis. Freedom from re-operation after 5/10 years was 93.1%/92.6% in the M-group, 98.7%/98.4% in the P-group and 93.5%/90.9% in the S-group, respectively. 81.7% of all Mitroflow re-operations were due to SVD, 40% of all Perimount and 28.6% of all Solo, respectively (p< 0.001). Endocarditis occurred in 18.3% of all re-operations in the M-group, 40% in the P-group, and 57% in the S-group, respectively (p< 0.001). Conclusions: Long-term survival was significantly different among groups with higher rate of survival for Mitroflow and Perimount prostheses. Long-term freedom from re-operation was significantly different among groups with a higher rate of re-operation in Mitroflow and Solo prostheses. The significant majority of re-operation in Mitroflow prostheses was due to SVD, in Solo prostheses due to endocarditis.

Effect of heart rate on the hemodynamics of bileaflet mechanical heart valves' prostheses (St. Jude Medical) in the aortic position and in the opening phase: A computational study.

To date, to the best of the authors' knowledge, in almost all of the studies performed around the hemodynamics of bileaflet mechanical heart valves, a heart rate of 70-72 beats/min has been considered. In fact, the heart rate of ~72 beats/min does not represent the entire normal physiological conditions under which the aortic or prosthetic valves function. The heart rates of 120 or 50 beats/min may lead to hemodynamic complications, such as plaque formation and/or thromboembolism in patients. In this study, the hemodynamic performance of the bileaflet mechanical heart valves in a wide range of normal and physiological heart rates, that is, 60-150 beats/min, was studied in the opening phase. The model considered in this study was a St. Jude Medical bileaflet mechanical heart valve with the inner diameter of 27 mm in the aortic position. The hemodynamics of the native valve and the St. Jude Medical valve were studied in a variety of heart rates in the opening phase and the results were carefully compared. The results indicate that peak values of the velocity profile downstream of the valve increase as heart rate increases, as well as the location of the maximum velocity changes with heart rate in the St. Jude Medical valve model. Also, the maximum values of shear stress and wall shear stresses downstream of the valve are proportional to heart rate in both models. Interestingly, the maximum shear stress and wall shear stress values in both models are in the same range when heart rate is <90 beats/min; however, these values significantly increase in the St. Jude Medical valve model when heart rate is >90 beats/min (up to ~40% growth compared to that of the native valve). The findings of this study may be of importance in the hemodynamic performance of bileaflet mechanical heart valves. They may also play an important role in design improvement of conventional prosthetic heart valves and the design of the next generation of prosthetic valves, such as percutaneous valves.

Perioperative outcomes with sutureless versus stented biological aortic valves in elderly persons

ObjectivesSutureless aortic valves are deemed suitable for patients considered at high risk for surgery. The objective of this study is to evaluate the perioperative results of implanting a sutureless valve in elderly persons, compared with a stented biological valve in the aortic position. MethodsBetween 2011 and 2015, 76 patients underwent aortic valve replacement with the Perceval prosthesis (Sorin Group, Saluggia, Italy). The group was compared with 319 consecutive patients who received aortic valve replacement with the stented valve in that same period. ResultsThe mean age of patients was 83 ± 2 years in the Perceval group and 83 ± 3 years in the stented valve group (P = .3). Preoperative demographics were similar in both groups. Median cardiopulmonary bypass and crossclamp times were lower in the Perceval group than in the stented valve group (P < .001). Mortality was 5% in the Perceval group and 6% in the stented valve group (P = .8). There were more pacemaker implantations in the Perceval group than in the stented valve group (17% vs 8%; P = .02). A subgroup analysis of patients who underwent aortic valve replacement and concomitant procedures showed the same results as the entire cohort. ConclusionsAortic valve replacement with a sutureless prosthesis resulted in shorter aortic crossclamp and bypass times compared with a stented biological prosthesis. The reduced cardiopulmonary bypass and aortic crossclamp times obtained using the Perceval prosthesis did not translate into perioperative gains in our population of elderly patients.

EA-valve: development of a tissue-engineered elastin-based heart valve prosthesis

Event Abstract Back to Event EA-valve: development of a tissue-engineered elastin-based heart valve prosthesis Israel González De Torre1, 2*, Ricardo Moreira3*, Matilde Alonso1*, Stefan Jockenhoevel3, 4, José-Carlos Rodríguez Cabello1* and Petra Mela4* 1 Universidad de Valladolid, BIOFORGE, CIBER-BBN, Spain 2 Technical Proteins NanoBioTechnology S.L., TPNBT, Spain 3 AME-Institute of Applied Medical Engineering, Helmholtz Institute, RWTH Aachen University, Tissue Engineering and Textile Implants, Germany 4 RWTH Aachen University, Institut für Textiltechnik, Germany Introduction: Aortic stenosis and regurgitation are the most common aortic diseases leading to valve failure in Europe and North America. The aim of this study was to develop a TEHV based on elastin-like recombinamers (ELRs). ELRs are bioengineered polymers based on the natural elastin, produced by recombinant techniques[1] and positioned midway between natural products and synthetic polymers, due to they keep the biological origin and nature in addition to the advantages of an engineered material[2], for instance, the exhaustive control over their composition, functionality and tunable mechanical properties. They possess an extremely low polydispersity, thermosensitive behavior, a very low thombogenicity[2] and the possibility to include different bioactive sequences for cell adhesion and proliferation or sequences sensitive to enzymes[1]. Materials and Methods: The ELRs used in this work were obtained by using standard genetic engineering techniques. Their purification was based on the intrinsic thermal behavior of these compounds[3]. ELRs were chemically modified by transformation of the α-amine group in the lateral lysine chain to bear cyclooctine and azide groups. Valves were formed by catalyst free click reactions between an azide group and an activated cyclooctine group[4]. Solutions of ELRs-cyclooctine and ELRs-azide (90 mg/mL) were prepared in PBS at the desired concentration and kept at 4°C for at least 24h. 30 million cells were suspended in 500 µL of PBS and mixed with the HRGD6-N3 solution previously prepared. 1.5 mL of each polymer solution, total volume of 3 ml) (VKVx24-cyclo and HRGD6-N3 (final concentration 75 mg/mL) containing the cells were co-injected inside a 15 mm diameter aortic shape mould and kept 45 minutes at room temperature. Then the valves (n=3) were cultivated under static conditions for 7 days following dynamic conditioning for 14 days at 37 °C, 5% CO2 and 21% O2 in a custom-made bioreactor[5]. Results and Discussion: The valves were fully functional with an unobstructed opening (systolic phase) and complete closure (diastolic phase), as verified by frames extracted from high-speed movies and ultrasound. Figure 1. Valve`s functionality and macroscopic appearance after 21 days of cultivation. Frames showing the closed (A) and open (B) positions of the valve, (B and D) ultrasound echography pictures of the EA-valves in the closed and open position respectively (dashed line was added to clarify the ultrasound images), and macroscopic appearance of the valve from the vascular side (E) and ventricular side including the wall (F). Immunohistochemistry revealed a pronounced deposition of collagens type I and III and alpha-SMA active cells aligned within the longitudinal direction of both wall and leaflets. Figure 2. Tissue analysis of the EA-valves after 21 days of in vitro culture. Immunohistochemical staining against alpha-smooth muscle actin (A, B), collagen I (C, D), collagen III (E, F) and elastin (G, H). DAPI was used for nuclei staining in all samples studied. Scale bars 50 mm. The applied conditioning protocol resulted in an increase of the mechanical properties as determined by burst strength measurements. After conditioning, wall and leaflet tissues burst at 579.5 ± 145.8 mmHg and 642.8 ± 135.5 mmHg respectively. Collagen content of the walls and leaflets reached 22.6 ± 3.3 % and 30.7 ± 2.4 % respectively, relative to the native human aortic valve. Conclussions: The previous results show the first TEHV made exclusively of ELRs as scaffold. These valves exhibited an excellent mechanical properties, good cell proliferation and development of new extracellular matrix, as immunochemistry and burst strength test reveals. These results highlight the potential of these functional TEHVs to be implanted in the aortic position. European regional development fund (ERDF), from the MINECO (MAT-2010-15982, MAT2010-15310, PRI-PIBAR-2011-1403 and MAT2012-38043), the JCyL (projects VA049A11, VA152A12 and VA155A12), the CIBER-BBN, and the JCyL and the Instituto de Salud Carlos III under the “Network Center of Regenerative Medicine and Cellular Therapy of Castilla and Leon”; People Programme (Marie Curie Actions) of the European Union´s Seventh Framework Programme FP7/2007-2013/ under REA grant agreement n°317512; Funding was also provided by the People Programme (Marie Curie Actions) of the European Union´s Seventh Framework Programme FP7/2007-2013/ under REA grant agreement n°317512, by the Integrated Interdisciplinary Institute of Technology for Medicine (I³TM) of RWTH Aachen University [Seed-Fund SF_14-4-08] and by the the START-Program of the Medical Faculty of RWTH Aachen University [Innenfond 691348].; “The THEGRAIL project is funded by the European Union’s ‘Seventh Framework’ Programme for research, technological development and demonstration under Grant Agreement n° HEALTH.2011.1.4-2- 278557 From 2012-01-01 to 2016-12-31″

Successful thrombolysis of a thrombosed mechanical aortic valve prosthesis using a slow intravenous Tenecteplase infusion

Prosthetic valve thrombosis is defined as any obstruction of prosthesis by non-infective thrombotic material. It has an estimated incidence of 0.03%-4.3% per year and is reported to occur in 0.5%-8% of the left-sided prosthetic valves and in up to 20% of tricuspid prosthesis. We describe a successful treatment of a young man presented with a thrombosed prosthetic aortic valve using a slow intravenous infusion of Tenecteplase without any bolus dose in a newly described dose regimen for aortic valve position and with a complete resolution of the thrombus and regaining the full mobility of both valve leaflets within 48 hours.

STENTED BIOPROSTHESIS IN AORTIC POSITION: ANALYSIS OF THE EARLY RESULTS BASED ON A RETROSPECTIVE STUDY

Purpose. Retrospective analysis of the immediate results of the treatment of these patients will form an idea of the need for a prospective randomized study. Materials and methods. Are analyzed the results of 411 operations performed in patients with aortic stenosis. The first group – 227 patients with implanted bioprosthesis in the aortic position UniLine, the second group – 184 patients with implanted stented bioprosthesis Biolab. Results. Postoperative mortality in group I was 1.8 % (4 patients), in group II – 2.7 % (5 patients) (p=0.8). To determine the factors that have a connection to the pressure gradient in the aortic prosthesis, regression analysis was performed. In group I, the relationship between the peak pressure gradient and body mass index (p = 0.001). In group II, the relationship peak pressure gradient and stroke volume of the left ventricle, body mass index and diameter of the prosthesis. In group I in the perioperative period required reimplantation valve 1 (0.4 %) patient. Reason dysfunction – iatrogenic damage to the prosthesis. In group II all recorded 3 (1.6 %) early prosthetic dysfunction, including 1 (0.5 %) – iatrogenic and 2 (1 %) – due to the prosthesis itself. Conclusion . A prospective randomized controlled study conducted over a long period of time, a few clinics at the same time, allow more objectively assess the advantages and disadvantages of dentures and to define prospects of development of this direction in Russia.

Mid- to long-term outcome comparison of the Medtronic Hancock II and bi-leaflet mechanical aortic valve replacement in patients younger than 60 years of age: a propensity-matched analysis.

This study aims to compare mid-long-term clinical outcomes between patients younger than 60 years of age undergoing bioprosthetic and mechanical aortic valve replacement. From January 2002 to December 2009, patients younger than 60 years of age who received Medtronic Hancock II porcine bioprostheses were selected and compared with those who received mechanical bi-leaflet valves in the aortic position. A stepwise logistic regression propensity score identified a subset of 112 evenly matched patient-pairs. Mid-long-term outcomes of survival, valve-related reoperations, thromboembolic events and bleeding events were assessed. The follow-up was only 95.1% complete. Fourteen measurable variables were statistically similar for the matched cohort. Postoperative in-hospital mortality was 3.6% (bioprosthetic valves) and 2.7% (mechanical valves) (P = 0.700). Survival at 5 and 10 years was 96.3 and 88.7% for patients receiving bioprosthetic valve replacement versus 96.3 and 87.9% for patients receiving mechanical valve replacement (P = 0.860), respectively. At 5 and 10 years after operations, freedom from valve-related reoperation was 97.2 and 94.8% for patients receiving mechanical valve replacement, and 96.3 and 90.2% for patients receiving bioprosthetic valve replacement (P = 0.296), respectively. There was no difference between freedom from thromboembolic events (P = 0.528) and bleeding events (P = 0.128) between the matched groups during the postoperative 10 years. In patients younger than 60 years of age undergoing aortic valve replacement, mid-long-term survival rate was similar for patients receiving bioprosthetic versus mechanical valve replacement. Bioprosthetic valves were associated with a trend for a lower risk of anticoagulation treatment and did not have significantly greater likelihood of a reoperation. These findings suggest that a bioprosthetic valve may be a reasonable choice for AVR in patients younger than 60 years of age.

Long-term results after surgical treatment of paravalvular leak in the aortic and mitral position

ObjectivesThe aim of this study was to determine immediate results and long-term outcomes after surgical management of paravalvular leak (PVL). MethodsBetween 1995 and 2012, a total of 190 patients underwent primary surgical repair (n = 142) or valve replacement (n = 48) for a PVL at our institution. The PVL was mild in 6 (3%) patients, moderate in 85 (45%), moderate to severe in 84 (44%), and severe in 15 (8%). Among these, 120 (63%) had PVL in the mitral position, 63 (33%) had PVL in the aortic position, and 7 (4%) had PVL in both valves. Mean follow-up was 5.3 ± 4.6 years. ResultsMean age at surgery was 63 ± 12 years (64% men). Operative mortality occurred in 13 (7%) patients (10 [8%] in mitral; 2 [3%] in aortic; and 1 [14%] in double valve procedures). Survival at 1, 5, and 10 years was 85% ± 3%, 73% ± 4%, and 56% ± 5%, respectively. The cumulative incidence of PVL recurrence was 3% ± 1%, 14% ± 3%, and 32% ± 6%, at 1, 5, and 10 years, respectively. The number of previous surgeries was a predictor of survival and PVL recurrence. Freedom from New York Heart Association class ≥III was 96% ± 2%, 82% ± 4%, and 58% ± 6%, at 1, 5, and 10 years, respectively. The freedom from rehospitalization for heart failure was 92% ± 2%, 83% ± 4%, and 67% ± 6%, at 1, 5, and 10 years. ConclusionsSurgical treatment of PVL resulted in acceptable outcomes. Nevertheless, the continued risk of PVL recurrence is higher in patients who have had multiple previous surgeries. More studies are needed to compare these results with the transcatheter PVL reduction technique.

Stress-shielding, growth and remodeling of pulmonary artery reinforced with copolymer scaffold and transposed into aortic position.

Ross operation, i.e., the use of autologous pulmonary artery to replace diseased aortic valve, has been recently at the center of a vivid debate regarding its unjust underuse in the surgical practice. Keystone of the procedure regards the use of an autologous biologically available graft which would preserve the anticoagulative and tissue homeostatic functions normally exerted by the native leaflets and would harmoniously integrate in the vascular system, allowing for progressive somatic growth of aortic structures. With this respect, recently, some of the authors have successfully pioneered a large animal model of transposition of pulmonary artery in systemic pressure load in order to reproduce the clinical scenario in which this procedure might be applied and allow for the development and testing of different devices or techniques to improve the pulmonary autograft (PA) performance, by testing a bioresorbable mesh for PA reinforcement. In the present work, to support and supplement the in vivo animal experimentation, a mathematical model is developed in order to simulate the biomechanical changes in pulmonary artery subjected to systemic pressure load and reinforced with a combination of resorbable and auxetic synthetic materials. The positive biological effects on vessel wall remodeling, the regional somatic growth phenomena and prevention of dilatative degeneration have been analyzed. The theoretical outcomes show that a virtuous biomechanical cooperation between biological and synthetic materials takes place, stress-shielding guiding the physiological arterialization of vessel walls, consequently determining the overall success of the autograft system.

Multidetector computed tomography sizing of bioprosthetic valves: guidelines for measurement and implications for valve-in-valve therapies

To describe a technique for bioprosthetic multidetector computed tomography (MDCT) sizing and to compare MDCT-derived values against manufacturer-provided sizing. Fourteen bioprosthetic stented valves commonly used in the aortic valve position were evaluated using a Philips 256 MDCT system. All valves were scanned using a dedicated cardiac CT protocol with a four-channel electrocardiography (ECG) simulator. Measurements were made of major and minor axes and the area and perimeter of the internal stent using varying reconstruction kernels and window settings. Measurements derived from MDCT (MDCT ID) were compared against the stent internal diameter (Stent ID) as provided by the valve manufacturer and the True ID (Stent ID + insertion of leaflets). All data were collected and analysed using SPSS for Mac (version 21). The mean difference between the MDCT ID and Stent ID was 0.6±1.9mm (r=0.649, p=0.012) and between MDCT ID and True ID 2.1±2mm (r=0.71, p=0.005). There was no difference in the major (p=0.90), minor (p=0.87), area (p=0.92), or perimeter (p=0.92) measurements when sharp, standard, and detailed stent kernels were used. Similarly, the measurements remained consistent across differing windowing levels. Bioprosthetic stented valves may be reliably sized using MDCT in patients requiring valve-in-valve (VIV) interventions where the valve type and size are unknown. In these cases, clinicians should be aware that MDCT has a tendency to overestimate the True ID size.

A New Transcatheter Aortic Valve Replacement System for Predominant Aortic Regurgitation Implantation of the J-Valve and Early Outcome.

This study introduces a newly designed transcatheter aortic valve system, the J-Valve system, and evaluates its application in patients with predominant aortic regurgitation without significant valve calcification. We also report the early results of one of the first series of transapical implantations of this device and aim to offer guidance on the technical aspects of the procedure. Transcatheter aortic valve replacement (TAVR) has been widely used in high-risk patients for surgical aortic valve replacement. However, the majority of the TAVR devices were designed for aortic valve stenosis with significant valve calcification. Six patients with native aortic regurgitation without significant valve calcification (age, 61 to 83 years; mean age, 75.50 ± 8.14 years) underwent transapical implantation of the J-Valve prosthesis (JieCheng Medical Technology Co., Ltd., Suzhou, China), a self-expandable porcine valve, in the aortic position at our institution. All patients were considered to be prohibitive or high risk for surgical valve replacement (logistic EuroSCORE [European System for Cardiac Operative Risk Evaluation], 22.15% to 44.44%; mean, 29.32 ± 7.70%) after evaluation by an interdisciplinary heart team. Procedural and clinical outcomes were analyzed. Implantations were successful in all patients. During the follow-up period (from 31 days to 186 days, mean follow-up was 110.00 ± 77.944 days), only 1 patient had trivial prosthetic valve regurgitation, and none of these patients had paravalvular leak of more than mild grade. There were no major post-operative complications or mortality during the follow-up. Our study demonstrated the feasibility of transapical implantation of the J-Valve system in high-risk patients with predominant aortic regurgitation.

Abstract 18729: Prosthetic Valve Positioning - Not a Static Question

A 65-year-old female with a history of bicuspid aortic valve s/p AVR with a Medtronic Hall mechanical valve presented with chest pain. Her recent history was notable for one week of intermittent substernal chest pain present when lying in the left lateral position. Initial ECG, obtained during an episode of chest pain, revealed 2 mm ST segment depression in the anterolateral leads and ST segment elevation in lead aVR. The ECG changes normalized with cessation of her chest pain. Laboratory evaluation showed an INR of 3.5 (on warfarin), and normal cardiac biomarkers. Chest imaging, including CT angiography, was unremarkable. Physical examination demonstrated a normal jugular venous pressure, a mechanical second heart sound, and a II/VI crescendo-decrescendo systolic murmur at the right upper sternal border. Transthoracic echocardiography (TTE) revealed normal biventricular systolic function and a mechanical valve in the aortic position, associated with mild aortic regurgitation. Valve fluoroscopy revealed an aortic monoleaflet mechanical prosthesis with normal opening and closing angles in the supine position, but with closing restriction when in the left lateral decubitus position (closing angle 46 degrees, associated with recurrent chest pain and ischemic ECG changes). Transesophageal echocardiography (TEE) showed moderate aortic stenosis, mild aortic regurgitation, and multiple linear echodensities on the aortic prosthesis. These echogenicities were felt to represent thrombi, and the patient was treated with 5 doses of tPA and intravenous heparin. Subsequent TEE and valve fluoroscopy revealed improved prosthetic leaflet motion in supine and lateral decubitus positions. This case describes an unusual presentation of mechanical aortic valve thrombosis. The contiguous association of the mechanical valve with the coronary ostia can contribute to ischemic complications, in this case positionally induced. It also highlights the value of timely valve fluoroscopy and the consideration of patient maneuvers to delineate valve function. Current guidelines support the use of thrombolytic therapy for small, left-sided thrombi, with recent literature suggesting that slowly infused low-dose tPA provides the optimal risk-benefit profile.

Abstract 15470: Long Term Durability and Haemodynamic Performance of Freedom Solo Stentless Valve for Aortic Valve Replacement: A European, Multicenter Experience

Introduction: Stentless aortic valves have been developed to overcome the obstructive limitations associated with stented bioprostheses. The Freedom Solo (FS) bovine pericardial valve is a third generation stentless bioprosthesis introduced in 2004 and FDA approved in 2014. Hypothesis: The aim of the current study is to report the multi-institutional experience by the three European centers that started implanting FS extensively as first from its introduction, providing the largest series with long-term follow-up. Methods: From 2004 to 2009, 478 patients (mean age 73±8.6 years, 199 [41.6%] females) underwent isolated (n=321) or combined (n=157) aortic valve replacement (AVR) with the FS. Follow-up, including clinical and strict echocardiographic evaluation, was 97.4% complete with an average follow-up time of 6.5±3.2 years (maximum 11.4 years) and cumulative follow up was 2612 patient/years. Primary end-point was freedom from structural valve deterioration (SVD) while secondary end-points were freedom from reoperation and overall survival. Results: Overall operative mortality was 2.9% (1.5% for isolated and 5.7% for combined AVR) and none was valve-related. Preoperative peak(mean) gradients were 76.1±30.6 mmHg (47.1±18.7 mmHg) decreased to 17.7±9.1 mmHg (9.9±5.4 mmHg), stable over the follow-up. Post-operative effective orifice area was 1.8±0.6 cm2, 1.98±0.5 cm2, 2.13±0.43 cm2 and 2.21±0.56 cm2 for valve size 21, 23, 25, and 27 respectively. There was no severe prostheses-patient mismatch (PPM) and moderate PPM occurred only in 1 patient(0.2%). Twenty-four patients (5.7%) underwent reoperation (16 surgical replacement, 8 TAVR) due to endocarditis(9), blunt trauma(1), and SVD(14). SVD was reported in 5 other patients alive at time of censor. Freedom from SVD and reoperation were 90.6% [88.2-93%] and 88.3% [85.8-90.8%] respectively at 10 years follow-up, while overall actuarial survival was 55.8% [52.5-59.1%]. Conclusions: The FS valve demonstrated excellent hemodynamic performance and long-term durability in this large, multi-institutional European experience. In particular, the FS proved to be a reliable bioprosthesis in aortic position given the low rate of structural valve deterioration along with a simple implantability.