1
|
Cameli M, Aboumarie HS, Pastore MC, Caliskan K, Cikes M, Garbi M, Lim HS, Muraru D, Mandoli GE, Pergola V, Plein S, Pontone G, Soliman OI, Maurovich-Horvat P, Donal E, Cosyns B, Petersen SE. Multimodality imaging for the evaluation and management of patients with long-term (durable) left ventricular assist devices. Eur Heart J Cardiovasc Imaging 2024; 25:e217-e240. [PMID: 38965039 DOI: 10.1093/ehjci/jeae165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/12/2024] [Accepted: 06/12/2024] [Indexed: 07/06/2024] Open
Abstract
Left ventricular assist devices (LVADs) are gaining increasing importance as therapeutic strategy in advanced heart failure (HF), not only as bridge to recovery or to transplant but also as destination therapy. Even though long-term LVADs are considered a precious resource to expand the treatment options and improve clinical outcome of these patients, these are limited by peri-operative and post-operative complications, such as device-related infections, haemocompatibility-related events, device mis-positioning, and right ventricular failure. For this reason, a precise pre-operative, peri-operative, and post-operative evaluation of these patients is crucial for the selection of LVAD candidates and the management LVAD recipients. The use of different imaging modalities offers important information to complete the study of patients with LVADs in each phase of their assessment, with peculiar advantages/disadvantages, ideal application, and reference parameters for each modality. This clinical consensus statement sought to guide the use of multimodality imaging for the evaluation of patients with advanced HF undergoing LVAD implantation.
Collapse
Affiliation(s)
- Matteo Cameli
- Department of Medical Biotechnologies, Division of Cardiology, University of Siena, Viale Bracci 16, 53100 Siena, Italy
| | - Hatem Soliman Aboumarie
- Department of Anaesthetics, Critical Care and Mechanical Circulatory Support, Harefield Hospital, Royal Brompton and Harefield Hospitals, London, UK
- School of Cardiovascular, Metabolic Sciences and Medicine, King's College, WC2R 2LS London, UK
| | - Maria Concetta Pastore
- Department of Medical Biotechnologies, Division of Cardiology, University of Siena, Viale Bracci 16, 53100 Siena, Italy
| | - Kadir Caliskan
- Department of Cardiology, Erasmus MC University Medical Center, Rotterdam, The Netherlands
| | - Maja Cikes
- Department of Cardiovascular Diseases, University Hospital Centre, Zagreb, Croatia
| | | | - Hoong Sern Lim
- Institute of Cardiovascular Sciences, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
| | - Denisa Muraru
- Department of Cardiology, Istituto Auxologico Italiano IRCCS, Milan, Italy
- Department of Medicine and Surgery, University Milano-Bicocca, Milan, Italy
| | - Giulia Elena Mandoli
- Department of Medical Biotechnologies, Division of Cardiology, University of Siena, Viale Bracci 16, 53100 Siena, Italy
| | - Valeria Pergola
- Department of Cardiology, Padua University Hospital, Padua 35128, Italy
| | - Sven Plein
- Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK
| | - Gianluca Pontone
- Department of Perioperative Cardiology and Cardiovascular Imaging, Centro Cardiologico Monzino, IRCCS, Milan, Italy
| | - Osama I Soliman
- Department of Cardiology, College of Medicine, Nursing and Health Sciences, National University of Galway, Galway, Ireland
| | | | - Erwan Donal
- University of Rennes, CHU Rennes, INSERM, LTSI-UMR 1099, Rennes F-35000, France
| | - Bernard Cosyns
- Centrum Voor Harten Vaatziekten (CHVZ), Vrije Universiteit Brussel (VUB), Universitair Ziekenhuis Brussel (UZ Brussel), Brussels, Belgium
- In Vivo Cellular and Molecular Imaging (ICMI) Center, Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Steffen E Petersen
- William Harvey Research Institute, National Institute for Health and Care Research Barts Biomedical Research Centre, Queen Mary University London, London, UK
- Barts Heart Centre, St Bartholomew's Hospital, Barts Health National Health Service Trust, London, UK
| |
Collapse
|
2
|
Estep JD, Nicoara A, Cavalcante J, Chang SM, Cole SP, Cowger J, Daneshmand MA, Hoit BD, Kapur NK, Kruse E, Mackensen GB, Murthy VL, Stainback RF, Xu B. Recommendations for Multimodality Imaging of Patients With Left Ventricular Assist Devices and Temporary Mechanical Support: Updated Recommendations from the American Society of Echocardiography. J Am Soc Echocardiogr 2024; 37:820-871. [PMID: 39237244 DOI: 10.1016/j.echo.2024.06.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 09/07/2024]
Affiliation(s)
| | | | - Joao Cavalcante
- Minneapolis Heart Institute, Abbott Northwestern Hospital, Minneapolis, Minnesota
| | | | | | | | | | - Brian D Hoit
- Case Western Reserve University, Cleveland, Ohio
| | | | - Eric Kruse
- University of Chicago, Chicago, Illinois
| | | | | | | | - Bo Xu
- Cleveland Clinic, Cleveland, Ohio
| |
Collapse
|
3
|
Lilja D, Schalit I, Espinoza A, Hoel TN, Larsen G, Pettersen FJ, Halvorsen PS. Extracorporeal driveline vibrations to detect left ventricular assist device thrombosis - A porcine model study. J Heart Lung Transplant 2024; 43:111-119. [PMID: 37673384 DOI: 10.1016/j.healun.2023.08.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 08/10/2023] [Accepted: 08/31/2023] [Indexed: 09/08/2023] Open
Abstract
BACKGROUND Pump thrombosis (PT) and related adverse complications contributed to the HeartWare Ventricular Assist Device (HVAD) market withdrawal. Many patients still receive lifelong support, with deficient PT surveillance based on pump power trends. Analysis of pump vibrations is better for detecting PT. Here, we investigated the feasibility of an extracorporeal accelerometer to detect PT from pump vibrations propagated out on the driveline. METHODS In a porcine HVAD model (n = 6), an accelerometer was attached to the pump as a reference and another to the driveline for comparisons of signals. In total, 59 thrombi were injected into the heart to induce PT, followed by intermittent thrombus washout maneuvers. Signals were compared visually in spectrograms and quantitatively in third harmonic saliences (S3H) by correlation analysis. Receiver operating characteristic curves expressed the method's outcome in sensitivity vs specificity, with the overall diagnostic performance in the area under the curve (AUC) score. RESULTS Five experiments had good driveline signal strength, with clear spectrographic relationships between the 2 accelerometers. Third harmonic driveline vibrations were visible 20 vs 30 times in the reference. The comparison in S3H showed a strong correlation and yielded an AUC of 0.85. Notably, S3H proved robust regarding noise and false PT detections. CONCLUSIONS An extracorporeal accelerometer on the driveline can be a readily available method for accurate HVAD PT detection before an accelerometer integration with left ventricular assist device is feasible.
Collapse
Affiliation(s)
- Didrik Lilja
- The Intervention Centre, Division of Technology and Innovation, Oslo University Hospital, Oslo, Norway; Institute of Clinical Medicine, University of Oslo, Oslo, Norway.
| | - Itai Schalit
- The Intervention Centre, Division of Technology and Innovation, Oslo University Hospital, Oslo, Norway
| | - Andreas Espinoza
- The Intervention Centre, Division of Technology and Innovation, Oslo University Hospital, Oslo, Norway
| | - Tom Nilsen Hoel
- Department of Cardiothoracic Surgery, Oslo University Hospital, Oslo, Norway
| | - Guttorm Larsen
- The Intervention Centre, Division of Technology and Innovation, Oslo University Hospital, Oslo, Norway
| | - Fred-Johan Pettersen
- Department of Clinical and Biomedical Engineering, Oslo University Hospital, Oslo, Norway; Department of Physics, University of Oslo, Oslo, Norway
| | - Per Steinar Halvorsen
- The Intervention Centre, Division of Technology and Innovation, Oslo University Hospital, Oslo, Norway; Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| |
Collapse
|
4
|
Khamooshi M, Azimi M, Gregory SD. Computational analysis of thrombosis risk with variations in left ventricular assist device inflow cannula design in a multi-patient model. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2023; 240:107730. [PMID: 37531687 DOI: 10.1016/j.cmpb.2023.107730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 07/03/2023] [Accepted: 07/21/2023] [Indexed: 08/04/2023]
Abstract
BACKGROUND AND OBJECTIVES Left ventricular assist devices (LVADs) are mechanical pumps used to support patients with end-stage heart failure. The inflow cannula is a critical component of the LVAD as it connects the pump to the left ventricle, allowing blood to be drawn from the heart. However, the design of the cannula can significantly impact LV hemodynamics and cause complications, including thrombosis. Therefore, this study aimed to analyze the numerical effects of left ventricle (LV) size on cannula design in order to enhance hemodynamic performance using post-operative left ventricular assist device (LVAD) models. METHODS A parametric design evaluation of two different inflow cannulas were carried out on left ventricles (LV) of varying sizes (ranging from 154 to 430 ml) constructed from computerized tomography (CT) data from VAD patients using computational fluid dynamics (CFD) simulations. The study analyzed three key factors contributing to thrombosis formation: blood residence time, blood stagnation ratio, and wall shear stress. RESULTS Results showed higher blood residence time and stagnation ratio for larger left ventricular sizes. In addition, increasing the insertion length of the cannula reduced the average wall shear stress. CONCLUSION Overall, the study's findings suggest that the optimal cannula shape for LVADs varies with left ventricular size.
Collapse
Affiliation(s)
- Mehrdad Khamooshi
- Cardio-Respiratory Engineering and Technology Laboratory (CREATElab), Department of Mechanical and Aerospace Engineering, Monash University, Melbourne, VIC, Australia.
| | - Marjan Azimi
- Cardio-Respiratory Engineering and Technology Laboratory (CREATElab), Department of Mechanical and Aerospace Engineering, Monash University, Melbourne, VIC, Australia
| | - Shaun D Gregory
- Cardio-Respiratory Engineering and Technology Laboratory (CREATElab), Department of Mechanical and Aerospace Engineering, Monash University, Melbourne, VIC, Australia
| |
Collapse
|
5
|
Lilja D, Schalit I, Espinoza A, Fiane AE, Dahle G, Littorin-Sandbu H, Pettersen FJ, Russell KE, Thiara APS, Elle OJ, Halvorsen PS. Detection of inflow obstruction in left ventricular assist devices by accelerometer: A porcine model study. J Heart Lung Transplant 2023; 42:1005-1014. [PMID: 37023840 DOI: 10.1016/j.healun.2023.03.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2022] [Revised: 03/10/2023] [Accepted: 03/27/2023] [Indexed: 04/08/2023] Open
Abstract
BACKGROUND Left ventricular assist devices (LVAD) provide circulatory blood pump support for severe heart failure patients. Pump inflow obstructions may lead to stroke and pump malfunction. We aimed to verify in vivo that gradual inflow obstructions, representing prepump thrombosis, are detectable by a pump-attached accelerometer, where the routine use of pump power (PLVAD) is deficient. METHOD In a porcine model (n = 8), balloon-tipped catheters obstructed HVAD inflow conduits by 34% to 94% in 5 levels. Afterload increases and speed alterations were conducted as controls. We computed nonharmonic amplitudes (NHA) of pump vibrations captured by the accelerometer for the analysis. Changes in NHA and PLVAD were tested by a pairwise nonparametric statistical test. Detection sensitivities and specificities were investigated by receiver operating characteristics with areas under the curves (AUC). RESULTS NHA remained marginally affected during control interventions, unlike PLVAD. NHA elevated during obstructions within 52-83%, while mass pendulation was most pronounced. Meanwhile, PLVAD changed far less. Increased pump speeds tended to amplify the NHA elevations. The corresponding AUC was 0.85-1.00 for NHA and 0.35-0.73 for PLVAD. CONCLUSION Elevated NHA provides a reliable indication of subclinical gradual inflow obstructions. The accelerometer can potentially supplement PLVAD for earlier warnings and localization of pump.
Collapse
Affiliation(s)
- Didrik Lilja
- The Intervention Centre, Division of Technology and Innovation, Oslo University Hospital, Oslo, Norway; Institute of Clinical Medicine, University of Oslo, Oslo, Norway.
| | - Itai Schalit
- The Intervention Centre, Division of Technology and Innovation, Oslo University Hospital, Oslo, Norway
| | - Andreas Espinoza
- The Intervention Centre, Division of Technology and Innovation, Oslo University Hospital, Oslo, Norway
| | - Arnt Eltvedt Fiane
- Institute of Clinical Medicine, University of Oslo, Oslo, Norway; Department of Cardiothoracic Surgery, Oslo University Hospital, Oslo, Norway
| | - Gry Dahle
- Department of Cardiothoracic Surgery, Oslo University Hospital, Oslo, Norway
| | - Helen Littorin-Sandbu
- The Intervention Centre, Division of Technology and Innovation, Oslo University Hospital, Oslo, Norway
| | - Fred-Johan Pettersen
- Department of Clinical and Biomedical Engineering, Oslo University Hospital, Oslo, Norway; Department of Physics, University of Oslo, Oslo, Norway
| | | | - Amrit P S Thiara
- Department of Cardiothoracic Surgery, Oslo University Hospital, Oslo, Norway
| | - Ole Jakob Elle
- The Intervention Centre, Division of Technology and Innovation, Oslo University Hospital, Oslo, Norway; Department of Informatics, University of Oslo, Norway
| | - Per Steinar Halvorsen
- The Intervention Centre, Division of Technology and Innovation, Oslo University Hospital, Oslo, Norway; Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| |
Collapse
|
6
|
Pearman M, Emmanuel S, Jansz P, Watson A, Connellan M, Iyer A, Barua S, Hayward CS. Comparing left ventricular assist device inflow cannula angle between median sternotomy and thoracotomy using 3D reconstructions. Artif Organs 2022. [PMID: 36582131 DOI: 10.1111/aor.14492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Revised: 12/06/2022] [Accepted: 12/16/2022] [Indexed: 12/31/2022]
Abstract
BACKGROUND Left ventricular assist device (LVAD) implantation via thoracotomy has many potential advantages compared to conventional sternotomy, including improved inflow cannula (IFC) positioning. We compared the difference in IFC angles, postoperative, and long-term outcomes for patients with LVADs implanted via thoracotomy and sternotomy. METHODS A single-center, retrospective analysis of 14 patients who underwent thoracotomy implantation was performed and matched with 28 patients who underwent sternotomy LVAD implantations for a total of 42 patients. Inclusion required a minimum LVAD support duration of 30 days and excluded concomitant procedures. A postoperative CT-chest was used to measure the angle the between the IFC and mitral valve in two-dimensions and results were compared with three-dimensional reconstruction using the same CT chest. Outcome data were extracted from medical records. RESULTS There was no significant difference in gender, INTERMACS score, BMI, or age between the two groups. Median cardiopulmonary bypass time was longer in the thoracotomy group compared to the sternotomy group, 107 min (86-122) versus 76 min (56-93), p < 0.01. 3D reconstructions revealed less deviation of the IFC away from the mitral valve in devices implanted via thoracotomy compared to sternotomy, median (IQR) angle 16.3° (13.9°-21.0°) versus 23.2° (17.9°-26.4°), p < 0.01. Rates of pump thrombosis, stroke, and gastrointestinal bleeding were not significantly different. CONCLUSIONS Devices implanted via thoracotomy demonstrated less deviation away from mitral valve. However, there was no difference in morbidity between the two approaches. 3D reconstruction of the heart is an innovative technique to measure angulation and is clinically advantageous when compared to 2D imaging.
Collapse
Affiliation(s)
- Madeleine Pearman
- St Vincent's Hospital, Sydney, Darlinghurst, New South Wales, Australia.,School of Medicine, University of Notre Dame, Sydney, Chippendale, New South Wales, Australia
| | - Sam Emmanuel
- St Vincent's Hospital, Sydney, Darlinghurst, New South Wales, Australia.,School of Medicine, University of Notre Dame, Sydney, Chippendale, New South Wales, Australia.,School of Medicine, University of New South Wales, Sydney, Kensington, New South Wales, Australia.,Victor Chang Cardiac Research Institute, Sydney, New South Wales, Australia
| | - Paul Jansz
- St Vincent's Hospital, Sydney, Darlinghurst, New South Wales, Australia.,School of Medicine, University of Notre Dame, Sydney, Chippendale, New South Wales, Australia.,School of Medicine, University of New South Wales, Sydney, Kensington, New South Wales, Australia.,Victor Chang Cardiac Research Institute, Sydney, New South Wales, Australia
| | - Alasdair Watson
- St Vincent's Hospital, Sydney, Darlinghurst, New South Wales, Australia
| | - Mark Connellan
- St Vincent's Hospital, Sydney, Darlinghurst, New South Wales, Australia
| | - Arjun Iyer
- St Vincent's Hospital, Sydney, Darlinghurst, New South Wales, Australia
| | - Sumita Barua
- St Vincent's Hospital, Sydney, Darlinghurst, New South Wales, Australia.,School of Medicine, University of New South Wales, Sydney, Kensington, New South Wales, Australia.,Victor Chang Cardiac Research Institute, Sydney, New South Wales, Australia
| | - Christopher Simon Hayward
- St Vincent's Hospital, Sydney, Darlinghurst, New South Wales, Australia.,School of Medicine, University of New South Wales, Sydney, Kensington, New South Wales, Australia.,Victor Chang Cardiac Research Institute, Sydney, New South Wales, Australia
| |
Collapse
|
7
|
Huo Y, Gregory SD. Editorial: Computational biomechanics for ventricle-arterial dysfunction and remodeling in heart failure, Volume II. Front Physiol 2022; 13:1100037. [PMID: 36569756 PMCID: PMC9773985 DOI: 10.3389/fphys.2022.1100037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Accepted: 11/28/2022] [Indexed: 12/13/2022] Open
Affiliation(s)
- Yunlong Huo
- Institute of Mechanobiology and Medical Engineering, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China,PKU-HKUST Shenzhen-Hong Kong Institution, Shenzhen, Guangdong, China,*Correspondence: Yunlong Huo, ; Shaun D. Gregory,
| | - Shaun D. Gregory
- Cardio-Respiratory Engineering and Technology Laboratory, Department of Mechanical and Aerospace Engineering, Monash University, Melbourne, VIC, Australia,*Correspondence: Yunlong Huo, ; Shaun D. Gregory,
| |
Collapse
|
8
|
Lilja D, Schalit I, Espinoza A, Pettersen FJ, Elle OJ, Halvorsen PS. Detection of inflow obstruction in left ventricular assist devices by accelerometer: An in vitro study. Med Eng Phys 2022; 110:103917. [PMID: 36564132 DOI: 10.1016/j.medengphy.2022.103917] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2022] [Revised: 11/01/2022] [Accepted: 11/02/2022] [Indexed: 11/09/2022]
Abstract
Inflow obstruction in left ventricular assist devices (LVAD) may lead to embolic stroke and pump malfunction. We investigated if an accelerometer detected graded LVAD inflow obstructions. Detection performances were compared to the current continuous surveillance routine based on the pump power consumption (PLVAD). In ten mock circuit experiments, four different-sized pendulating balloons obstructed HVAD™ inflow conduits cross-section areas by 14%-75%. Nonharmonic amplitudes (NHA) of continuous signals from a triaxial accelerometer attached to the LVAD were compared against single-point PLVAD values, using load and speed alterations as control interventions. We analyzed the NHA band power with a pairwise nonparametric statistical test. The detection performances were analyzed by receiver operating characteristics with areas under the curves (AUC). The NHA remained unaffected during load alterations. In contrast, NHA increased significantly from the 27% obstruction level (AUC≥0.82), an effect amplified by increased pump speed. PLVAD did not change significantly below the maximal 75% obstruction level (AUC≤0.36). In conclusion, NHA detected the inflow obstructions much better than PLVAD. The technique may provide a future monitoring modality of any pendulating obstructive inflow pathology.
Collapse
Affiliation(s)
- Didrik Lilja
- The Intervention Centre, Division of Technology and Innovation, Oslo University Hospital, Oslo Norway; Institute of Clinical Medicine, University of Oslo, Oslo, Norway.
| | - Itai Schalit
- The Intervention Centre, Division of Technology and Innovation, Oslo University Hospital, Oslo Norway; Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - Andreas Espinoza
- The Intervention Centre, Division of Technology and Innovation, Oslo University Hospital, Oslo Norway
| | - Fred-Johan Pettersen
- Department of Clinical and Biomedical Engineering, Oslo University Hospital, Oslo, Norway; Department of Physics, University of Oslo, Norway
| | - Ole Jakob Elle
- The Intervention Centre, Division of Technology and Innovation, Oslo University Hospital, Oslo Norway; Department of Informatics, The University of Oslo, Norway
| | - Per Steinar Halvorsen
- The Intervention Centre, Division of Technology and Innovation, Oslo University Hospital, Oslo Norway; Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| |
Collapse
|
9
|
Zijderhand CF, Knol WG, Budde RPJ, van der Heiden CW, Veen KM, Sjatskig J, Manintveld OC, Constantinescu AA, Birim O, Bekkers JA, Bogers AJJC, Caliskan K. Relapsing low-flow alarms due to suboptimal alignment of the left ventricular assist device inflow cannula. Eur J Cardiothorac Surg 2022; 62:ezac415. [PMID: 35993906 PMCID: PMC9789739 DOI: 10.1093/ejcts/ezac415] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 07/29/2022] [Indexed: 11/14/2022] Open
Abstract
OBJECTIVES This retrospective study investigated the correlation between the angular position of the left ventricular assist device (LVAD) inflow cannula and relapsing low-flow alarms. METHODS Medical charts were reviewed of all patients with HeartMate 3 LVAD support for relapsing low-flow alarms. A standardized protocol was created to measure the angular position with a contrast-enhanced computed tomography scan. Statistics were done using a gamma frailty model with a constant rate function. RESULTS For this analysis, 48 LVAD-supported patients were included. The majority of the patients were male (79%) with a median age of 57 years and a median follow-up of 30 months (interquartile range: 19-41). Low-flow alarm(s) were experienced in 30 (63%) patients. Angulation towards the septal-lateral plane showed a significant increase in low-flow alarms over time with a constant rate function of 0.031 increase in low-flow alarms per month of follow-up per increasing degree of angulation (P = 0.048). When dividing this group using an optimal cut-off point, a significant increase in low-flow alarms was observed when the septal-lateral angulation was 28° or more (P = 0.001). Anterior-posterior and maximal inflow cannula angulation did not show a significant difference. CONCLUSIONS This study showed an increasing number of low-flow alarms when the degrees of LVAD inflow cannula expand towards the septal-lateral plane. This emphasizes the importance of the LVAD inflow cannula angular position to prevent relapsing low-flow alarms with the risk of diminished quality of life and morbidity.
Collapse
Affiliation(s)
- Casper F Zijderhand
- Department of Cardiothoracic Surgery, Thoraxcenter, Erasmus MC, University Medical Center Rotterdam, Rotterdam, Netherlands
- Department of Cardiology, Thoraxcenter, Erasmus MC, University Medical Center Rotterdam, Rotterdam, Netherlands
| | - Wiebe G Knol
- Department of Cardiothoracic Surgery, Thoraxcenter, Erasmus MC, University Medical Center Rotterdam, Rotterdam, Netherlands
- Department of Radiology and Nuclear Medicine, Erasmus MC, University Medical Center Rotterdam, Rotterdam, Netherlands
| | - Ricardo P J Budde
- Department of Radiology and Nuclear Medicine, Erasmus MC, University Medical Center Rotterdam, Rotterdam, Netherlands
| | - Cornelis W van der Heiden
- Department of Cardiology, Thoraxcenter, Erasmus MC, University Medical Center Rotterdam, Rotterdam, Netherlands
| | - Kevin M Veen
- Department of Cardiothoracic Surgery, Thoraxcenter, Erasmus MC, University Medical Center Rotterdam, Rotterdam, Netherlands
| | - Jelena Sjatskig
- Department of Cardiothoracic Surgery, Thoraxcenter, Erasmus MC, University Medical Center Rotterdam, Rotterdam, Netherlands
| | - Olivier C Manintveld
- Department of Cardiology, Thoraxcenter, Erasmus MC, University Medical Center Rotterdam, Rotterdam, Netherlands
| | - Alina A Constantinescu
- Department of Cardiology, Thoraxcenter, Erasmus MC, University Medical Center Rotterdam, Rotterdam, Netherlands
| | - Ozcan Birim
- Department of Cardiothoracic Surgery, Thoraxcenter, Erasmus MC, University Medical Center Rotterdam, Rotterdam, Netherlands
| | - Jos A Bekkers
- Department of Cardiothoracic Surgery, Thoraxcenter, Erasmus MC, University Medical Center Rotterdam, Rotterdam, Netherlands
| | - Ad J J C Bogers
- Department of Cardiothoracic Surgery, Thoraxcenter, Erasmus MC, University Medical Center Rotterdam, Rotterdam, Netherlands
| | - Kadir Caliskan
- Department of Cardiology, Thoraxcenter, Erasmus MC, University Medical Center Rotterdam, Rotterdam, Netherlands
| |
Collapse
|
10
|
Santiago A, Butakoff C, Eguzkitza B, Gray RA, May-Newman K, Pathmanathan P, Vu V, Vázquez M. Design and execution of a verification, validation, and uncertainty quantification plan for a numerical model of left ventricular flow after LVAD implantation. PLoS Comput Biol 2022; 18:e1010141. [PMID: 35696442 PMCID: PMC9232142 DOI: 10.1371/journal.pcbi.1010141] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 06/24/2022] [Accepted: 04/26/2022] [Indexed: 11/18/2022] Open
Abstract
Background
Left ventricular assist devices (LVADs) are implantable pumps that act as a life support therapy for patients with severe heart failure. Despite improving the survival rate, LVAD therapy can carry major complications. Particularly, the flow distortion introduced by the LVAD in the left ventricle (LV) may induce thrombus formation. While previous works have used numerical models to study the impact of multiple variables in the intra-LV stagnation regions, a comprehensive validation analysis has never been executed. The main goal of this work is to present a model of the LV-LVAD system and to design and follow a verification, validation and uncertainty quantification (VVUQ) plan based on the ASME V&V40 and V&V20 standards to ensure credible predictions.
Methods
The experiment used to validate the simulation is the SDSU cardiac simulator, a bench mock-up of the cardiovascular system that allows mimicking multiple operation conditions for the heart-LVAD system. The numerical model is based on Alya, the BSC’s in-house platform for numerical modelling. Alya solves the Navier-Stokes equation with an Arbitrary Lagrangian-Eulerian (ALE) formulation in a deformable ventricle and includes pressure-driven valves, a 0D Windkessel model for the arterial output and a LVAD boundary condition modeled through a dynamic pressure-flow performance curve. The designed VVUQ plan involves: (a) a risk analysis and the associated credibility goals; (b) a verification stage to ensure correctness in the numerical solution procedure; (c) a sensitivity analysis to quantify the impact of the inputs on the four quantities of interest (QoIs) (average aortic root flow Q A o a v g, maximum aortic root flow Q A o m a x, average LVAD flow Q V A D a v g, and maximum LVAD flow Q V A D m a x); (d) an uncertainty quantification using six validation experiments that include extreme operating conditions.
Results
Numerical code verification tests ensured correctness of the solution procedure and numerical calculation verification showed a grid convergence index (GCI)95% <3.3%. The total Sobol indices obtained during the sensitivity analysis demonstrated that the ejection fraction, the heart rate, and the pump performance curve coefficients are the most impactful inputs for the analysed QoIs. The Minkowski norm is used as validation metric for the uncertainty quantification. It shows that the midpoint cases have more accurate results when compared to the extreme cases. The total computational cost of the simulations was above 100 [core-years] executed in around three weeks time span in Marenostrum IV supercomputer.
Conclusions
This work details a novel numerical model for the LV-LVAD system, that is supported by the design and execution of a VVUQ plan created following recognised international standards. We present a methodology demonstrating that stringent VVUQ according to ASME standards is feasible but computationally expensive.
Collapse
Affiliation(s)
- Alfonso Santiago
- Barcelona Supercomputing Center (BSC), Barcelona, Spain
- ELEM biotech, Barcelona, Spain
| | | | | | - Richard A. Gray
- US Food and Drug Administration (FDA), Silver Spring, Maryland, United States of America
| | - Karen May-Newman
- Department of Mechanical Engineering, San Diego State University (SDSU), San Diego, California, United States of America
| | - Pras Pathmanathan
- US Food and Drug Administration (FDA), Silver Spring, Maryland, United States of America
| | - Vi Vu
- Department of Mechanical Engineering, San Diego State University (SDSU), San Diego, California, United States of America
| | - Mariano Vázquez
- Barcelona Supercomputing Center (BSC), Barcelona, Spain
- ELEM biotech, Barcelona, Spain
- * E-mail:
| |
Collapse
|
11
|
Kaufmann F, Hoermandinger C, Knosalla C, Falk V, Potapov E. Thrombus formation at the inflow cannula of continuous-flow left ventricular assist devices - a systematic analysis. Artif Organs 2022; 46:1573-1584. [PMID: 35230721 DOI: 10.1111/aor.14222] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 01/13/2022] [Accepted: 02/21/2022] [Indexed: 11/27/2022]
Abstract
BACKGROUND Despite numerous design iterations, thrombus formation at the inflow cannula of continuous-flow left ventricular assist devices (CF-LVAD) remains an unsolved problem. We systematically investigated the impact of cannula surface on thrombus formation. METHODS Thrombus appearance was photographically documented in 177 explanted hearts with the polished (N=46) or sintered (N=131) inflow cannula of the HVAD. Thrombus load was compared for both inflow cannula types. Mean thrombus length was correlated with protruding cannula length. Support duration and the extent of thrombus growth were examined. The prevalence of thrombi at the left ventricular entry site and at the sintered-to-polished transition zone was correlated with left ventricular geometry and hemodynamic parameters. RESULTS Polished inflow cannulas showed a greater percentage and also a greater mean length of thrombus formation at the entry site than sintered cannulas (91.3% [Pol] vs. 36.7% [sTi]; p<0.0001; mean 7.6 mm vs. 1.9 mm; p<0.0001). A comparison of the early postoperative period (POD1-90) with long-term support (POD>90) showed an increase in thrombus length originating from the transition zone (1.96, ±3.41 mm vs. 3.03 ±2.91 mm; p=0.013). CONCLUSIONS A sintered titanium surface at the entry site is crucial to enable anchoring of myocardial tissue to the cannula. As thrombus growth progresses on polished surfaces, a greater sintered length seems to be beneficial. After an initial three-month healing period, thrombus load appears to decline during prolonged support duration at the sintered entry site but not at the transition zone.
Collapse
Affiliation(s)
- Friedrich Kaufmann
- Department of Cardiothoracic and Vascular Surgery, German Heart Center Berlin, Berlin, Germany
| | - Christoph Hoermandinger
- Department of Cardiothoracic and Vascular Surgery, German Heart Center Berlin, Berlin, Germany
| | - Christoph Knosalla
- Department of Cardiothoracic and Vascular Surgery, German Heart Center Berlin, Berlin, Germany.,DZHK (German Centre for Cardiovascular Research), Partner Site Berlin, Berlin, Germany
| | - Volkmar Falk
- Department of Cardiothoracic and Vascular Surgery, German Heart Center Berlin, Berlin, Germany.,DZHK (German Centre for Cardiovascular Research), Partner Site Berlin, Berlin, Germany.,Department of Cardiovascular Surgery, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany.,Department of Health Sciences and Technology, Eidgenössische Technische Hochschule Zürich, Translational Cardiovascular Technology, Zurich, Switzerland
| | - Evgenij Potapov
- Department of Cardiothoracic and Vascular Surgery, German Heart Center Berlin, Berlin, Germany.,DZHK (German Centre for Cardiovascular Research), Partner Site Berlin, Berlin, Germany
| |
Collapse
|