Mechanics of Healthy and Functionally Diseased Mitral Valves: A Critical Review

2013 ◽  
Vol 135 (2) ◽  
Author(s):  
Jean-Pierre M. Rabbah ◽  
Neelakantan Saikrishnan ◽  
Andrew W. Siefert ◽  
Arvind Santhanakrishnan ◽  
Ajit P. Yoganathan
Keyword(s):  
Mitral Valve ◽  
Left Atrium ◽  
Surgical Planning ◽  
Patient Specific ◽  
Mitral Valves ◽  
Medical Device Design ◽  
Unidirectional Flow ◽  
Patient Health

The mitral valve is a complex apparatus with multiple constituents that work cohesively to ensure unidirectional flow between the left atrium and ventricle. Disruption to any or all of the components—the annulus, leaflets, chordae, and papillary muscles—can lead to backflow of blood, or regurgitation, into the left atrium, which deleteriously effects patient health. Through the years, a myriad of surgical repairs have been proposed; however, a careful appreciation for the underlying structural mechanics can help optimize long-term repair durability and inform medical device design. In this review, we aim to present the experimental methods and significant results that have shaped the current understanding of mitral valve mechanics. Data will be presented for all components of the mitral valve apparatus in control, pathological, and repaired conditions from human, animal, and in vitro studies. Finally, current strategies of patient specific and noninvasive surgical planning will be critically outlined.

Custom Patient-Specific Three-Dimensional Printed Mitral Valve Models for Pre-Operative Patient Education Enhance Patient Satisfaction and Understanding

2019 ◽  
Vol 13 (3) ◽  
Author(s):  
Kay S. Hung ◽  
Michael J. Paulsen ◽  
Hanjay Wang ◽  
Camille Hironaka ◽  
Y. Joseph Woo
Keyword(s):  
Patient Education ◽  
Mitral Valve ◽  
Three Dimensional ◽  
3D Models ◽  
Patient Specific ◽  
Imaging Data ◽  
Anatomical Models ◽  
Mitral Valves ◽  
Flexible Polymer ◽  
3D Printed

In recent years, advances in medical imaging and three-dimensional (3D) additive manufacturing techniques have increased the use of 3D-printed anatomical models for surgical planning, device design and testing, customization of prostheses, and medical education. Using 3D-printing technology, we generated patient-specific models of mitral valves from their pre-operative cardiac imaging data and utilized these custom models to educate patients about their anatomy, disease, and treatment. Clinical 3D transthoracic and transesophageal echocardiography images were acquired from patients referred for mitral valve repair surgery and segmented using 3D modeling software. Patient-specific mitral valves were 3D-printed using a flexible polymer material to mimic the precise geometry and tissue texture of the relevant anatomy. 3D models were presented to patients at their pre-operative clinic visit and patient education was performed using either the 3D model or the standard anatomic illustrations. Afterward, patients completed questionnaires assessing knowledge and satisfaction. Responses were calculated based on a 1–5 Likert scale and analyzed using a nonparametric Mann–Whitney test. Twelve patients were presented with a patient-specific 3D-printed mitral valve model in addition to standard education materials and twelve patients were presented with only standard educational materials. The mean survey scores were 64.2 (±1.7) and 60.1 (±5.9), respectively (p = 0.008). The use of patient-specific anatomical models positively impacts patient education and satisfaction, and is a feasible method to open new opportunities in precision medicine.

Stereoscopic Particle Image Velocimetry of Native Ovine Mitral Valves in a Pulsatile Left Heart Simulator

2012 ◽  
Author(s):  
Jean-Pierre Rabbah ◽  
Neelakantan Saikrishnan ◽  
Ajit P. Yoganathan
Keyword(s):  
Particle Image Velocimetry ◽  
Mitral Valve ◽  
Computational Models ◽  
Particle Image ◽  
Numerical Models ◽  
Stereoscopic Particle Image Velocimetry ◽  
Patient Specific ◽  
Flow Loop ◽  
Mitral Valves ◽  
Image Velocimetry

Patient specific mitral valve computational models are being actively developed to facilitate surgical planning. These numerical models increasingly employ more realistic geometries, kinematics, and mechanical properties, which in turn requires rigorous experimental validation [1]. However, to date, native mitral flow dynamics have not been accurately and comprehensively characterized. In this study, we used Stereoscopic Particle Image Velocimetry (SPIV) to characterize the ventricular flow field proximal to a native mitral valve in a pulsatile experimental flow loop.

Developing an Experimental Database for Mitral Valve Computational Modeling, Surgical Repair, and Device Evaluation

2013 ◽  
Author(s):  
Jean-Pierre M. Rabbah ◽  
Neelakantan Saikrishnan ◽  
Andrew W. Siefert ◽  
Ajit P. Yoganathan
Keyword(s):  
Mitral Valve ◽  
Surgical Planning ◽  
Surgical Repair ◽  
Numerical Models ◽  
Three Dimensional ◽  
Model Accuracy ◽  
Experimental Database ◽  
Benchmark Data ◽  
Fully Coupled

Numerical models of the heart’s mitral valve are being used to study valve biomechanics, facilitate predictive surgical planning, and are used in the design and development of repair devices. These models have evolved from simple two-dimensional approximations to complex three-dimensional fully coupled fluid structure interaction models. However, to date these models lack direct one-to-one experimental validation. Moreover, as computational solvers vary considerably based on researcher implementation, experimental benchmark data are critically important to ensure model accuracy. To this end, a multi-modality in-vitro pulsatile left heart simulator was used to establish a database of geometric and hemodynamic boundary conditions coupled with resultant valvular and fluid mechanics.

scholarly journals CATHETER ABLATION OF ATRIAL FIBRILLATION IN LEFT ATRIUM IN PATIENT WITH MECHANICAL MITRAL VALVE: ACUTE AND LONG-TERM RESULTS

2011 ◽  
Vol 57 (14) ◽  
pp. E17
Author(s):  
Rong Bai ◽  
Luigi Di Biase ◽  
Prasant Mohanty ◽  
Douglas Gibson ◽  
Salwa Beheiry ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Catheter Ablation ◽  
Mitral Valve ◽  
Left Atrium ◽  
Long Term Results

scholarly journals Validation test on 3d heart phantom for mitral valve leaflet tracking

2021 ◽  
Vol 22 (2) ◽  
pp. 717
Author(s):  
Lina Farhana Mahadi ◽  
Nabilah Ibrahim ◽  
Shahnoor Shanta ◽  
Hideyuki Hasegawa
Keyword(s):  
Mitral Valve ◽  
Water Tank ◽  
Font Size ◽  
Mitral Valve Leaflet ◽  
Mitral Valves ◽  
True Value ◽  
Video Frames ◽  
Validation Experiment ◽  
Temporal Rate

<p><span style="font-family: 'Times New Roman',serif; font-size: 9pt; mso-bidi-font-size: 11.0pt; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;" lang="EN-US"><span style="font-family: 'Times New Roman',serif; font-size: 9pt; mso-bidi-font-size: 11.0pt; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;" lang="EN-US">Mitral valve movement is essential to be identified in order to monitor the abnormality of blood flow in right side of heart. The estimation and tracking of mitral valve has seldom been investigated since it required high temporal rate to scan the echocardiography images and it depends on the operator to capture the low-speckle and-noise images. This study presents the validation experiment performed on heart phantom made of t</span><span style="font-family: 'Times New Roman',serif; font-size: 9pt; mso-bidi-font-size: 10.0pt; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;" lang="EN-US">hermoplastic polyurethane (TPU) filament which the objective is to validate the previous </span><span style="font-family: 'Times New Roman',serif; font-size: 9pt; mso-bidi-font-size: 11.0pt; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;" lang="EN-US">features tracking technique implemented in mitral valve locating in video frames using Kanade-Lucas-Tomasi (KLT) algorithm. The outcome was able to automatically detect the edge of mitral valve and thus in future, it manages to predict the flowing of blood pattern. An in-vitro experiment was conducted which involved a valve phantom scanning in water tank that connected to water pump. It was found in this study that the technique capable to detect and visualize the mitral valve up to 59 frames in 2.36 secondsby tracking the features of minimum eigenvalue within the selected region. It was also produced a good agreement of valve distance between the true value and the measured one, which achieved the minimum of 88% similarity. This yielded the validation of the proposed technique to track and visualize the mitral valves. </span></span></p>

scholarly journals CONCOMITANT PROCEDURE OF ATRIAL FIBRILLATION ABLATION WITH AND WITHOUT LEFT ATRIOPLASTY DURING SURGICAL CORRECTION OF THE MITRAL VALVE DISEASE: PROSPECTIVE, RANDOMIZED TRIAL

2018 ◽  
Vol 33 (3) ◽  
pp. 63-70
Author(s):  
A. V. Bogachev-Prokophiev ◽  
S. I. Zheleznev ◽  
M. A. Ovcharov ◽  
A. V. Afanasyev ◽  
R. M. Sharifulin ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Mitral Valve ◽  
Left Atrium ◽  
Mitral Valve Disease ◽  
Left Atrial ◽  
Valve Disease ◽  
Atrial Ablation ◽  
Group I ◽  
Group Ii

Objective. Main objective of this prospective randomized study was to assess safety and efficiency of the combined approach for the left atrial ablation in combination with and without reduction left atrioplasty in patients with mitral valve disease.Material and Methods. The study was performed from September, 2014 to February, 2017. A total of 120 patients with mitral valve disease, permanent atrial fibrillation (AF), and left atriomegaly were enrolled in the study. Patients were randomized to two groups: group I comprised patients who received correction of mitral valve disease in combination with AF ablation and without reduction atrioplasty of the left atrium (MV+MAZE); group II (n=60) comprised patients with correction of mitral valve disease in combination with AF ablation and with reduction atrioplasty of the left atrium (MV+MAZE+AP). Patient characteristics did not differ between groups.Results. There were no significant differences between groups in the early mortality rates (2 patients in group I versus 5 patients in group II, p=0.64); bleeding rates (total 5 cases including 2 patients in group I and 3 patients in group II, p=0.34), and the rates of AF recurrence in the early postoperative period. Permanent pacemakers were implanted in 8 patients (13.3%) of group I and in 4 patients (6.7%) of group II. Total long-term mortality was 4 patients including 1 and 3 patients in group I and II, respectively, which did not significantly differed. The rates of one-year freedom from AF were 84.8 and 86.2% in group I and II, respectively. No new onsets of atrial fibrillation were observed for 36 months in both groups. The rates of freedom from thromboembolic events during the time of observation were 88.6% in group I and 96.5% in group II. Conclusion. The left atrial reduction concomitant with the left atrial ablation and correction of mitral valve disease is safe and effective procedure. However, this procedure did not impact the rates of long-term freedom from AF.

scholarly journals Primary Extracellular Matrix Enables Long-Term Cultivation of Human Tumor Oral Mucosa Models

2020 ◽  
Vol 8 ◽  
Author(s):  
Leonie Gronbach ◽  
Philipp Jurmeister ◽  
Monika Schäfer-Korting ◽  
Ulrich Keilholz ◽  
Ingeborg Tinhofer ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Oral Mucosa ◽  
Hypoxia Inducible Factor ◽  
Human Tumor ◽  
Patient Specific ◽  
Long Term Effects ◽  
Tumor Models

3D tumor models clearly outperform 2D cell cultures in recapitulating tissue architecture and drug response. However, their potential in understanding treatment efficacy and resistance development should be better exploited if also long-term effects of treatment could be assessed in vitro. The main disadvantages of the matrices commonly used for in vitro culture are their limited cultivation time and the low comparability with patient-specific matrix properties. Extended cultivation periods are feasible when primary human cells produce the extracellular matrix in situ. Herein, we adapted the hyalograft-3D approach from reconstructed human skin to normal and tumor oral mucosa models and compared the results to bovine collagen-based models. The hyalograft models showed similar morphology and cell proliferation after 7 weeks compared to collagen-based models after 2 weeks of cultivation. Tumor thickness and VEGF expression increased in hyalograft-based tumor models, whereas expression of laminin-332, tenascin C, and hypoxia-inducible factor 1α was lower than in collagen-based models. Taken together, the in situ produced extracellular matrix better confined tumor invasion in the first part of the cultivation period, with continuous tumor proliferation and increasing invasion later on. This proof-of-concept study showed the successful transfer of the hyalograft approach to tumor oral mucosa models and lays the foundation for the assessment of long-term drug treatment effects. Moreover, the use of an animal-derived extracellular matrix is avoided.

Abstract 15648: Quantitative Evaluation of Mitral Valve Dynamics for Improved Planning of Mitral Valve Repairs

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Ahnryul Choi ◽  
Yonghoon Rim ◽  
Susan T Laing ◽  
David D McPherson ◽  
Hyunggun Kim
Keyword(s):  
Stress Concentration ◽  
Mitral Valve ◽  
Stress Reduction ◽  
Surgical Planning ◽  
Computational Simulation ◽  
Patient Specific ◽  
Stress Concentrations ◽  
Computational Evaluation ◽  
Ring Annuloplasty ◽  
Leaflet Coaptation

Introduction: Mitral valve (MV) repair with ring annuloplasty is the standard surgical technique for the treatment of mitral regurgitation (MR). Long-term studies report MR recurrence in up to 2-4% of repairs. We have developed a novel computational evaluation strategy to determine the biomechanical and physiologic characteristics of MV dynamics prior to and following virtual MV repair to help with optimal surgical planning. Methods: Virtual MV models from patients with large annular dilation and severe MR in the anterolateral region were created using 3D echocardiographic data sets. Two different types of annuloplasty rings were modeled in the simulation: Physio (flat) and Physio II (saddle-shaped). Proper ring size was determined using standard clinical guidelines. Computational simulations of MV function (pre- and post-repair) were performed using dynamic finite element methods. Coaptation ratio (CR) and structural stress distribution across the MVs were determined and compared. Results: Pathologic MVs demonstrated substantial anterolateral malcoaptation (CR=0.34, Fig. 1A). Following virtual ring annuloplasty, there was marked improvement in coaptation (CR=0.65 for Physio, CR=0.62 for Physio II). Pre-repair simulation revealed large stress concentrations over the posterior leaflet (Fig. 1B). Stress concentration decreased by 54% after virtual MV repair. The saddle-shaped Physio II ring demonstrated more evenly distributed stress reduction while the flat ring (Physio) more effectively increased leaflet coaptation. Conclusion: We have quantitatively evaluated patient-specific MV function before and after MV repair using a novel computational simulation protocol. Virtual ring annuloplasty simulation demonstrated sufficient restoration of leaflet coaptation and reduced stress concentration following repair. This simulation strategy has the potential for improved pre-surgical planning and intraoperative evaluation of MV repair.

Abstract 17214: Prediction of Mitral Valve Repair: Pre-Repair versus Virtual Repair versus Post-Repair

Circulation ◽  
2018 ◽  
Vol 138 (Suppl_1) ◽  
Author(s):  
MyungGu Yeo ◽  
Tom T Nguyen ◽  
David D McPherson ◽  
Hyunggun Kim
Keyword(s):  
Mitral Valve ◽  
Surgical Planning ◽  
Patient Specific ◽  
Valve Repair ◽  
Repair Strategy ◽  
Dynamic Finite Element ◽  
Ring Annuloplasty ◽  
Before And After ◽  
Leaflet Coaptation ◽  
Leaflet Prolapse

Introduction: Partial leaflet resection followed by ring annuloplasty is a reliable and reproducible mitral valve (MV) repair technique for the treatment of severe mitral regurgitation (MR) due to posterior chordal rupture. Hypothesis: We have developed a novel computational virtual MV repair strategy to predict the biomechanical and physiologic characteristics of post-repair MV dynamics to help with optimal surgical planning. Methods: Computational MV models were created using pre- and post-repair 3D echocardiographic data of a patient having posterior chordal rupture and severe MR. Virtual resection was designed by removing a pre-defined triangle-shaped leaflet portion in the P2 scallop and merging the excised leaflet edges. Virtual ring annuloplasty with the same ring size as the post-repair MV was performed following the triangular leaflet resection. Computational simulations of MV function (pre-repair, virtual repair, and post-repair) were performed using dynamic finite element methods. Leaflet coaptation across the MVs were quantitatively determined and compared. Results: The pre-repair MV with P2 chordal rupture showed severe P2 prolapse and leaflet malcoaptation. The post-repair MV demonstrated markedly reduced prolapse and sufficiently restored leaflet coaptation. The virtually repaired MV revealed a similar coaptation ratio as the post-repair MV indicating effective restoration of normal MV function. Both virtual repair and post-repair MVs showed improved coaptation not only in the P2 region but also in the A1-P1 and A3-P3 regions. Conclusions: We have quantitatively evaluated patient-specific MV function before and after potential MV repair using a novel virtual MV repair protocol. Both virtual repair and post-repair MVs decreased posterior leaflet prolapse and restored normal coaptation. This virtual MV repair strategy has the potential for improved pre-surgical planning to predict and optimize post-repair MV function.

3D modeling: a future of cardiovascular medicine

2019 ◽  
Vol 97 (4) ◽  
pp. 277-286 ◽  
Author(s):  
Kaley H. Garner ◽  
Dinender K. Singla
Keyword(s):  
3D Modeling ◽  
Surgical Planning ◽  
Surgical Techniques ◽  
3D Models ◽  
Health Concern ◽  
Patient Specific ◽  
Future Directions ◽  
Medical Device Design ◽  
Significant Interest ◽  
Operative Planning

Cardiovascular disease resulting from atypical cardiac structures continues to be a leading health concern despite advancements in diagnostic imaging and surgical techniques. However, the ability to visualize spatial relationships using current technologies remains a challenge. Therefore, 3D modeling has gained significant interest to understand complex and atypical cardiovascular disorders. Moreover, 3D modeling can be personalized and patient-specific. 3D models have been demonstrated to aid surgical planning and simulation, enhance communication among surgeons and patients, optimize medical device design, and can be used as a potential teaching tool in medical schools. In this review, we discuss the key components needed to generate cardiac 3D models. We highlight prevalent structural conditions that have utilized 3D modeling in pre-operative planning. Furthermore, we discuss the current limitations of routine use of 3D models in the clinic as well as future directions for utilization of this technology in the cardiovascular field.

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