Gaetano Burriesci
@ucl.ac.uk
Professor of Bioengineerin, Dept of Mechanical Engineering, Faculty of Engineering Science
University College London
Scopus Publications
Scopus Publications
Giulio Musotto, Alessandra Monteleone, Danila Vella, Bernardo Zuccarello, Ruggero Cannova, Andrew Cook, Giorgia Maria Bosi, and Gaetano Burriesci
Elsevier BV
Alessandra Monteleone, Sofia Di Leonardo, Enrico Napoli, and Gaetano Burriesci
Elsevier BV
Danila Vella, Giulio Musotto, Andrew Cook, Giorgia Maria Bosi, and Gaetano Burriesci
Elsevier BV
Sofia Di Leonardo, Alessandra Monteleone, Patrizia Caruso, Hugo Meecham-Garcia, Giuseppe Pitarresi, and Gaetano Burriesci
Elsevier BV
Junke Yao, Jacob Salmonsmith, Giorgia Maria Bosi, Gaetano Burriesci, and Helge Wurdemann
Institute of Electrical and Electronics Engineers (IEEE)
Magdi H. Yacoub, Yuan-Tsan Tseng, Jolanda Kluin, Annemijn Vis, Ulrich Stock, Hassiba Smail, Padmini Sarathchandra, Elena Aikawa, Hussam El-Nashar, Adrian H. Chester,et al.
Springer Science and Business Media LLC
AbstractHeart valve disease is a major cause of mortality and morbidity worldwide with no effective medical therapy and no ideal valve substitute emulating the extremely sophisticated functions of a living heart valve. These functions influence survival and quality of life. This has stimulated extensive attempts at tissue engineering “living” heart valves. These attempts utilised combinations of allogeneic/ autologous cells and biological scaffolds with practical, regulatory, and ethical issues. In situ regeneration depends on scaffolds that attract, house and instruct cells and promote connective tissue formation. We describe a surgical, tissue-engineered, anatomically precise, novel off-the-shelf, acellular, synthetic scaffold inducing a rapid process of morphogenesis involving relevant cell types, extracellular matrix, regulatory elements including nerves and humoral components. This process relies on specific material characteristics, design and “morphodynamism”.
Junke Yao, Giorgia Maria Bosi, Andrea Palombi, Gaetano Burriesci, and Helge Wurdemann
Institute of Electrical and Electronics Engineers (IEEE)
OBJECTIVE
Aortic stenos (AS) is a heart valve disease that commonly affects the elderly. Transcatheter aortic valve implantation is a minimally invasive treatment that allows to replace the function of the diseased native valve with a prosthetic device, relying on catheters for device implantation. According to the current clinical guidelines, the choice of the implanted device is based on preoperative sizing determined by image-based technology. However, this assessment faces inherent limitations that can lead to sub-optimal sizing of the prosthesis; in turn, this can cause major post-operative complications like aortic regurgitation or cardiac electrical signal disruption.
METHOD
By utilizing balloon pressure and volume data, this paper proposes an intra-operative method for determining the dimension of the aortic annulus which takes into account its compliance and geometric irregularity. The intra-balloon pressure-volume curves were obtained using an Automated Balloon Inflation Device operating a commercially available valvuloplasty balloon catheter. A sizing algorithm to estimate the dimensions of the annulus was integrated via a validated analytical model and a numerical model for balloon free-inflation. Tests were performed on circular and elliptical idealised aortic phantoms.
RESULTS
Experimental results confirm that the pressure-volume data processed with the sizing algorithm can be used to determine the circular annular diameter for all tissue rigidities.
CONCLUSION
The measurement of stiffer elliptical annulus phantoms shows good accuracy and high repeatability.
SIGNIFICANCE
This work represents substantial progress toward improving the selection of TAVI devices by using balloon catheters to improve the sizing of compliant aortic annuli with complex geometry.
Sofia Di Leonardo, Danila Vella, Carmelo Savio Grillo, Carla Martorana, Salvatore Torre, Vincenzo Argano, and Gaetano Burriesci
Oxford University Press (OUP)
Abstract OBJECTIVES Valve-sparing procedures are surgical techniques allowing to restore adequate function of the native aortic valve by replacing the dysfunctional ascending aorta with a prosthetic conduit. A number of techniques are currently used, such as Yacoub’s remodelling and David’s reimplantation, based on a regular straight conduit. More recently, the De Paulis proposed the use of bulging conduits to reconstruct the shape of the Valsalva sinuses. This work investigates the impact of the valve-sparing technique on the aortic valve function. METHODS The performance of 3 porcine aortic roots (Medtronic Freestyle™) was assessed in a cardiovascular pulse duplicator before and after performing 3 alternative valve-sparing procedures: David’s reimplantation, Yacoub’s remodelling and De Paulis’ reimplantation. RESULTS The porcine aortic roots, representative of the healthy native configuration, were characterized by the highest efficiency, with a mean energetic dissipation under normal operating conditions of 26 mJ. David’s and Yacoub’s techniques resulted in significantly lower performance (with mean energetic loss of about 70 mJ for both cases). The De Paulis’ procedure exhibited intermediate behaviour, with superior systolic performance and valve dynamics similar to the native case, and a mean energetic loss of 38 mJ. CONCLUSIONS The dynamics and performance after valve-sparing strongly depend on the adopted technique, with the use of conduits replicating the presence of Valsalva sinuses restoring more physiological conditions.
Alessandra Monteleone, Alessia Viola, Enrico Napoli, and Gaetano Burriesci
Public Library of Science (PLoS)
In this paper a novel model, based on the smoothed particle hydrodynamics (SPH) method, is proposed to simulate thrombus formation. This describes the main phases of the coagulative cascade through the balance of four biochemical species and three type of platelets. SPH particles can switch from fluid to solid phase when specific biochemical and physical conditions are satisfied. The interaction between blood and the forming blood clot is easily handled by an innovative monolithic FSI approach. Fluid-solid coupling is modelled by introducing elastic binds between solid particles, without requiring detention and management of the interface between the two media. The proposed model is able to realistically reproduce the thromboembolic process, as confirmed by the comparison of numerical results with experimental data available in the literature.
Ebba Montgomery-Liljeroth, Silvia Schievano, and Gaetano Burriesci
Elsevier BV
Danila Vella, Parnaz Boodagh, Laura Modica de Mohac, Federica Cosentino, Federica Scaglione, William Wagner, Antonio D’Amore, and Gaetano Burriesci
Avestia Publishing
Alessandra Monteleone, Gaetano Burriesci, and Enrico Napoli
Elsevier BV
Giulio Musotto, Alessandra Monteleone, Danila Vella, Sofia Di Leonardo, Alessia Viola, Giuseppe Pitarresi, Bernardo Zuccarello, Antonio Pantano, Andrew Cook, Giorgia M. Bosi,et al.
Frontiers Media SA
BackgroundA large majority of thrombi causing ischemic complications under atrial fibrillation (AF) originate in the left atrial appendage (LAA), an anatomical structure departing from the left atrium, characterized by a large morphological variability between individuals. This work analyses the hemodynamics simulated for different patient-specific models of LAA by means of computational fluid–structure interaction studies, modeling the effect of the changes in contractility and shape resulting from AF.MethodsThree operating conditions were analyzed: sinus rhythm, acute atrial fibrillation, and chronic atrial fibrillation. These were simulated on four patient-specific LAA morphologies, each associated with one of the main morphological variants identified from the common classification: chicken wing, cactus, windsock, and cauliflower. Active contractility of the wall muscle was calibrated on the basis of clinical evaluations of the filling and emptying volumes, and boundary conditions were imposed on the fluid to replicate physiological and pathological atrial pressures, typical of the various operating conditions.ResultsThe LAA volume and shear strain rates were analyzed over time and space for the different models. Globally, under AF conditions, all models were well aligned in terms of shear strain rate values and predicted levels of risk. Regions of low shear rate, typically associated with a higher risk of a clot, appeared to be promoted by sudden bends and focused at the trabecule and the lobes. These become substantially more pronounced and extended with AF, especially under acute conditions.ConclusionThis work clarifies the role of active and passive contraction on the healthy hemodynamics in the LAA, analyzing the hemodynamic effect of AF that promotes clot formation. The study indicates that local LAA topological features are more directly associated with a thromboembolic risk than the global shape of the appendage, suggesting that more effective classification criteria should be identified.
Christopher McGregor, Jacob Salmonsmith, Gaetano Burriesci, and Guerard Byrne
Springer Science and Business Media LLC
Abstract Objective There is growing interest in the application of genetically engineered reduced antigenicity animal tissue for manufacture of bioprosthetic heart valves (BHVs) to reduce antibody induced tissue calcification and accelerated structural valve degeneration (SVD). This study tested biological equivalence of valves made from Gal-knockout (GalKO) and standard porcine pericardium after 90-day mitral valve implantation in sheep. Methods GalKO (n = 5) and standard (n = 5) porcine pericardial BHVs were implanted in a randomized and blind fashion into sheep for 90-days. Valve haemodynamic function was measured at 30-day intervals. After explantation, valves were examined for pannus, vegetation, inflammation, thrombus, and tissue calcification. Results Nine of 10 recipients completed the study. There was no difference between study groups for haemodynamic performance and no adverse valve-related events. Explanted BHVs showed mild pannus integration and minimal thrombus, with no difference between the groups. Limited focal mineral deposits were detected by x-ray. Atomic spectroscopy analysis detected tissue calcium levels of 1.0 µg/mg ± 0.2 for GalKO BHVs and 1.9 µg/mg ± 0.9 for standard tissue BHVs (p = 0.4), considered to be both low and equivalent. Conclusions This is the first demonstration of biological equivalence between GalKO and standard pig pericardium. The GalKO mutation causes neither intrinsic detrimental biological nor functional impact on BHV performance. Commercial adaptation of GalKO tissue for surgical or transcatheter BHVs would remove the clinical disparity between patients producing anti-Gal antibody and BHVs containing the Gal antigen. GalKO BHVs may reduce accelerated tissue calcification and SVD, enhancing patient choices, especially for younger patients. Graphical Abstract
Sofia Di Leonardo, Giuseppe Pitarresi, and Gaetano Burriesci
Elsevier BV
Alessandra Monteleone, Guido Borino, Enrico Napoli, and Gaetano Burriesci
Elsevier BV
Junke Yao, Giorgia Maria Bosi, Gaetano Burriesci, and Helge Wurdemann
IEEE
Aortic valvuloplasty is a minimally invasive procedure for the dilatation of stenotic aortic valves. Rapid ventricular pacing is an established technique for balloon stabilization during this procedure. However, low cardiac output due to the pacing is one of the inherent risks, which is also associated with several potential complications. This paper proposes a numerical modelling approach to understand the effect of different inflation levels of a valvuloplasty balloon catheter on the positional instability caused by a pulsating blood flow. An unstretched balloon catheter model was crimped into a tri-folded configuration and inflated to several levels. Ten different inflation levels were then tested, and a Fluid-Structure Interaction model was built to solve interactions between the balloon and the blood flow modelled in an idealised aortic arch. Our computational results show that the maximum displacement of the balloon catheter increases with the inflation level, with a small step at around 50% inflation and a sharp increase after reaching 85% inflation. This work represents a substantial progress towards the use of simulations to solve the interactions between a balloon catheter and pulsating blood flow.
Sofia Di Leonardo, Riccardo Cappello, Gaetano Burriesci, and Giuseppe Pitarresi
MDPI AG
Nickel–Titanium (NiTi) shape memory alloys subjected to cyclic loading exhibit reversible temperature changes whose modulation is correlated with the applied load. This reveals the presence of reversible thermomechanical heat sources activated by the applied stresses. One such source is the elastocaloric effect, accounting for the latent heat of Austenite–Martensite phase transformation. It is, however, observed that when the amplitude of cyclic loads is not sufficient to activate or further propagate this phase transformation, the material still exhibits a strong cyclic temperature modulation. The present work investigates the thermomechanical behaviour of NiTi under such low-amplitude cyclic loading. This is carried out by analysing the frequency domain content of temperature sampled over a time window. The amplitude and phase of the most significant harmonics are obtained and compared with the theoretical predictions from the first and second-order theories of the Thermoelastic Effect, this being the typical reversible thermomechanical coupling prevailing under elastic straining. A thin strip of NiTi, exhibiting a fully superelastic behaviour at room temperature, was investigated under low-stress amplitude tensile fatigue cycling. Full-field strain and temperature distributions were obtained by means of Digital Image Correlation and IR Thermography. The work shows that the full field maps of amplitude and phase of the first three significant temperature harmonics carry out many qualitative information about the stress and structural state of the material. It is, though, found that the second-order theory of the Thermoelastic Effect is not fully capable of justifying some of the features of the harmonic response, and further work on the specific nature of thermomechanical heat sources is required for a more quantitative interpretation.
Giacomo Annio, Ryo Torii, Andrea Ducci, Vivek Muthurangu, Victor Tsang, and Gaetano Burriesci
Springer Science and Business Media LLC
Anna Maria Tango, Andrea Ducci, and Gaetano Burriesci
Elsevier BV
Danila Vella, Alessandra Monteleone, Giulio Musotto, Giorgia Maria Bosi, and Gaetano Burriesci
Frontiers Media SA
Atrial fibrillation (AF) is a common arrhythmia mainly affecting the elderly population, which can lead to serious complications such as stroke, ischaemic attack and vascular dementia. These problems are caused by thrombi which mostly originate in the left atrial appendage (LAA), a small muscular sac protruding from left atrium. The abnormal heart rhythm associated with AF results in alterations in the heart muscle contractions and in some reshaping of the cardiac chambers. This study aims to verify if and how these physiological changes can establish hemodynamic conditions in the LAA promoting thrombus formation, by means of computational fluid dynamic (CFD) analyses. In particular, sinus and fibrillation contractility was replicated by applying wall velocity/motion to models based on healthy and dilated idealized shapes of the left atrium with a common LAA morphology. The models were analyzed and compared in terms of shear strain rate (SSR) and vorticity, which are hemodynamic parameters directly associated with thrombogenicity. The study clearly indicates that the alterations in contractility and morphology associated with AF pathologies play a primary role in establishing hemodynamic conditions which promote higher incidence of ischaemic events, consistently with the clinical evidence. In particular, in the analyzed models, the impairment in contractility determined a decrease in SSR of about 50%, whilst the chamber pathological dilatation contributed to a 30% reduction, indicating increased risk of clot formation. The equivalent rigid wall model was characterized by SSR values about one order of magnitude smaller than in the contractile models, and substantially different vortical behavior, suggesting that analyses based on rigid chambers, although common in the literature, are inadequate to provide realistic results on the LAA hemodynamics.
Paolo Peruzzo, Gaetano Burriesci, Francesca Maria Susin, and Andrea Colli
Springer Science and Business Media LLC
Luigi Di Micco, Paolo Peruzzo, Andrea Colli, Gaetano Burriesci, Daniela Boso, Laura Besola, Gino Gerosa, and Francesca M. Susin
Elsevier BV
Jacob Andrew Salmonsmith, Andrea Ducci, and Gaetano Burriesci
BMJ
ObjectiveThis study investigates the effect of transcatheter aortic valve (TAV) angular alignment on the postprocedure haemodynamics. TAV implantation has emerged as an effective alternative to surgery when treating valve dysfunction. However, the benefit of avoiding surgery is paid back by the inability to remove the native diseased leaflets and accurately position the device in relation to the aortic root, and the literature has shown the root anatomy and substitute position can play an essential role on valve function.MethodsA commercial TAV was placed in a silicone mock aortic root in vitro, including mock native leaflets, and either aligned commissure-to-commissure or in maximum misalignment. Haemodynamic performance data at various stroke volumes were measured, and Particle Image Velocimetry analysis was performed at a typical stroke volume for rest conditions. The two configurations were also studied without mock native leaflets, for comparison with previous in vitro studies.ResultsHaemodynamic performance data were similar for all configurations. However, imaging analysis indicated that valve misalignment resulted in the central jet flow not extending to the root wall in the native commissures’ vicinity, replaced by a low shear flow, and a reduction of upper sinus flow of 40%, increasing flow stagnation in the sinus.ConclusionsTAV misalignment did not result in a significant change in valve hydrodynamic performance, but determined some change in the fluid flow patterns, which may promote pathological scenarios, such as increased thrombogenicity of blood flow within the sinuses of Valsalva, and plaque formation around the lumen of the sinotubular junction.
Fabrizio D’Ascenzo, Stefano Salizzoni, Andrea Saglietto, Martina Cortese, Azeem Latib, Anna Franzone, Marco Barbanti, Fabian Nietlispach, Erik W Holy, Gaetano Burriesci,et al.
Oxford University Press (OUP)
Abstract OBJECTIVES We examined the incidence, the impact of subsequent cerebrovascular events and the clinical or procedural predictors of leaflet thrombosis (LT) in patients undergoing transcatheter aortic valve implantation (TAVI). METHODS MEDLINE/PubMed was systematically screened for studies reporting on LT in TAVI patients. Incidence [both clinical and subclinical, i.e. detected with computed tomography (CT)] of LT was the primary end point of the study. Predictors of LT evaluated at multivariable analysis and impact of LT on stroke were the secondary ones. RESULTS Eighteen studies encompassing 11 124 patients evaluating incidence of LT were included. Pooled incidence of LT was 0.43% per month [5.16% per year, 95% confidence interval (CI) 0.21–0.72, I2 = 98%]. Pooled incidence of subclinical LT was 1.36% per month (16.32% per year, 95% CI 0.71–2.19, I2 = 94%). Clinical LT was less frequent (0.04% per month, 0.48% per year, 95% CI 0.00–0.19, I2 = 93%). LT increased the risk of stroke [odds ratio (OR) 4.21, 95% CI 1.27–13.98], and was more frequent in patients with a valve diameter of 28-mm (OR 2.89: 1.55–5.8), for balloon-expandable (OR 8: 2.1–9.7) or after valve-in-valve procedures (OR 17.1: 3.1–84.9). Oral anticoagulation therapy reduced the risk of LT (OR 0.43, 95% CI: 0.22–0.84, I2 = 64%), as well as the mean transvalvular gradient. CONCLUSIONS LT represents an infrequent event after TAVI, despite increasing risk of stroke. Given its full reversal with warfarin, in high-risk patients (those with valve-in-valve procedures, balloon expandable or large-sized devices), a protocol which includes a control CT appears reasonable.