scholarly journals Left Ventricular Dilatation and Posterior Papillary Muscle Displacement in an Ex Vivo Pulsatile Model of Functional Mitral Regurgitation

2018 ◽  
Vol 21 (4) ◽  
pp. E275-E280
Author(s):  
Krishaporn Kradangnga ◽  
Eric Monnet
Keyword(s):  
Mitral Regurgitation ◽  
Ex Vivo ◽  
Surgical Techniques ◽  
Left Ventricular ◽  
Ventricular Dilatation ◽  
Functional Mitral Regurgitation ◽  
Heart Model ◽  
Large Patch ◽  
Left Ventricular Dilatation ◽  
Patch Placement

Background: Surgical method of choice for functional mitral regurgitation (FMR) is debatable, since recurrence of FMR post-annuloplasty has been reported in a significant number of cases. Developing a pulsatile FMR heart model by left ventricular dilatation can be a favorable option for usage in the primary stages of developing new surgical techniques that adjunctively targets the posterior papillary muscle (PPM) geometry.Methods: PPM of ex vivo ovine hearts (N = 22) was displaced by three different sizes of patches to induce left ventricular dilatation and FMR. Mitral regurgitation (MR) flow, left ventricular and annular geometry were measured from the dynamic pulsatile flow system before and after patch placement.Results: Outward displacement of PPM was significantly increased in all patch sizes compared to baseline (P = .016, P = .031, and P = .008 from small to large patch, respectively). Left ventricular volume (LVV) significantly increased from 18.53 (15.01-26.03) mL at baseline to 27.5 (19.45-42.46) mL after large patch placement (P = .031). However, the small and medium patch groups did not show significant changes in the LVV after patch placement. MR significantly increased 554 (185-1,919.3) mL/min after applying the large patch compared to baseline (P = .016). There were no significant changes from baseline in MR flow after applying the small and medium patch. Application of the large patch produced the highest proportion of FMR heart models (87.5%, P = .031).Conclusion: The large patch ex vivo pulsatile heart model demonstrated outward displacement of the PPM and significantly produced MR flow. This ex vivo pulsatile heart model can be used to facilitate surgical techniques that targets the PPM displacement in FMR patients.

Atrial functional mitral regurgitation: mechanisms and surgical implications

2020 ◽  
Vol 28 (7) ◽  
pp. 421-426
Author(s):  
Yiting Fan ◽  
Song Wan ◽  
Randolph Hung-Leung Wong ◽  
Alex Pui-Wai Lee
Keyword(s):  
Mitral Regurgitation ◽  
Left Ventricular ◽  
Ventricular Dilatation ◽  
Functional Mitral Regurgitation ◽  
Current Evidence ◽  
Disease Entity ◽  
Risk Of Death ◽  
Left Ventricular Dilatation ◽  
Annular Dilatation ◽  
Increased Risk

The term atrial functional mitral regurgitation refers to a newly recognized disease entity in which mitral regurgitation occurs secondary to left atrial disease, without left ventricular dilatation and intrinsic mitral valve disease, typically in the setting of long-standing atrial fibrillation. Recent evidence suggests that atrial functional mitral regurgitation is associated with increased risk of death and heart failure re-hospitalization. The etiology, pathophysiology, and mechanism of atrial functional mitral regurgitation is not completely understood but they should not be regarded as the same as for the conventional type of functional mitral regurgitation secondary to left ventricular dilatation and dysfunction. Mitral annular dilatation, atriogenic leaflet distortion, insufficient leaflet remodeling, and subtle left ventricular dysfunction may play a role in the pathogenesis of atrial functional mitral regurgitation. The therapeutic and surgical considerations of atrial functional mitral regurgitation are different from those of ventricular functional mitral regurgitation. In this review, we assess current evidence regarding this new disease entity and propose a new surgical approach based on up-to-date understanding and experience of this condition.

An Ex Vivo Model of Left Ventricular Dilation and Functional Mitral Regurgitation to Facilitate the Development of Surgical Techniques

2013 ◽  
Vol 16 (6) ◽  
pp. 329
Author(s):  
Eric Monnet ◽  
Kristal Pouching
Keyword(s):  
Mitral Regurgitation ◽  
Papillary Muscle ◽  
Ex Vivo ◽  
Surgical Techniques ◽  
Left Ventricular ◽  
Functional Mitral Regurgitation ◽  
Ex Vivo Model ◽  
Ischemic Disease ◽  
Posterior Papillary Muscle ◽  
Annular Dilation

<p><b>Objective:</b> Functional mitral regurgitation (FMR) is a common sequelae of myocardial ischemic disease. It results from annular dilation and outward rotation of the posterior papillary muscle. Different surgical techniques are under investigation for the treatment of FMR. However, an ex vivo model of FMR would be valuable to develop and compare the effect of techniques on the geometry of the left ventricle and the correction of FMR.</p><p><b>Methods:</b> FMR was induced in explanted ovine hearts (n = 12) by manual dilation of the mitral annulus or by posterior papillary muscle repositioning with a patch. Left ventricular dimensions were measured. Mitral regurgitant volume (MRV) was measured in a continuous flow system.</p><p><b>Results:</b> Annular dilation significantly increased MRV from 93.0 � 110.4 to 472.2 � 211.8 mL/min (<i>P</i> = 0.031), and the patch increased it from 37.8 � 55.2 to 365 � 189.6 mL/min (<i>P</i> = 0.031), with no significant differences between the 2 groups. When both techniques were applied, MRV significantly increased to 1383.5 � 567.0 mL/min (<i>P</i> = 0.0005). The left ventricular sphericity index decreased from 3.25 � 0.7 to 2.34 � 0.6 (<i>P</i> = 0.0025) after application of the patch. The posterior papillary muscle was displaced after patch placement, following an outward rotation.</p><p><b>Conclusion:</b> This ex vivo model reproduces annular dilation and outward rotation of the posterior papillary muscle, which are both present during FMR after ischemic myocardial disease. This model could be used to evaluate and compare interventions to treat FMR.</p>

scholarly journals Ex Vivo Model of Functional Mitral Regurgitation Using Deer Hearts

2020 ◽  
Author(s):  
Michal Jaworek ◽  
Andrea Mangini ◽  
Edoardo Maroncelli ◽  
Federico Lucherini ◽  
Rubina Rosa ◽  
...  
Keyword(s):  
Mitral Regurgitation ◽  
Ex Vivo ◽  
Mitral Annulus ◽  
Left Ventricular ◽  
Functional Mitral Regurgitation ◽  
Pathological State ◽  
Preclinical Research ◽  
Ex Vivo Model ◽  
Mitral Valves ◽  
Feasibility Assessment

Abstract Transcatheter therapies are emerging for functional mitral regurgitation (FMR) treatment, however there is lack of pathological models for their preclinical assessment. We investigated the applicability of deer hearts for this purpose. 8 whole deer hearts were housed in a pulsatile flow bench. At baseline, all mitral valves featured normal coaptation. The pathological state was induced by 60-minutes intraventricular constant pressurization. It caused mitral annulus dilation (antero-posterior diameter increase from 31.8 ± 5.6 mm to 39.5 ± 4.9 mm, p = 0.001), leaflets tethering (maximal tenting height increase from 7.3 ± 2.5 mm to 12.7 ± 3.4 mm, p < 0.001) and left ventricular diameter increase (from 67.8 ± 7.5 mm to 79.4 ± 6.5 mm, p = 0.004). These geometrical reconfigurations led to restricted mitral valve leaflets motion and leaflet coaptation loss. Preliminary feasibility assessment of two FMR treatments was performed in the developed model. Deer hearts showed ability to dilate under constant pressurization and have potential to be used for realistic preclinical research of novel FMR therapies.

An Echocardiographic and Doppler Study of the Mechanisms of Mitral Regurgitation in Left Ventricular Dilatation

1988 ◽  
Vol 2 (6) ◽  
pp. 313-317 ◽  
Author(s):  
Seymour S. Maze ◽  
Morris N. Kotler ◽  
Wayne R. Parry ◽  
Anthony P. Goldman ◽  
Melvin H. Schwartz
Keyword(s):  
Mitral Regurgitation ◽  
Left Ventricular ◽  
Ventricular Dilatation ◽  
Left Ventricular Dilatation ◽  
Doppler Study

Effect of Progressive Left Ventricular Dilatation on Degree of Mitral Regurgitation Secondary to Mitral Valve Prolapse

2019 ◽  
Vol 123 (11) ◽  
pp. 1887-1888
Author(s):  
William C. Roberts ◽  
Paul A. Grayburn ◽  
Stuart R. Lander ◽  
Dan M. Meyer ◽  
Shelley A. Hall
Keyword(s):  
Mitral Valve ◽  
Mitral Regurgitation ◽  
Mitral Valve Prolapse ◽  
Left Ventricular ◽  
Ventricular Dilatation ◽  
Left Ventricular Dilatation

scholarly journals Left Ventricular Thinning and Distension in Pig Hearts as a Reproducible Ex Vivo Model of Functional Mitral Regurgitation

ASAIO Journal ◽  
2020 ◽  
Vol 66 (9) ◽  
pp. 1016-1024 ◽  
Author(s):  
Elorm J. Agra ◽  
Kirthana Sreerangathama Suresh ◽  
Qi He ◽  
Daisuke Onohara ◽  
Robert A. Guyton ◽  
...  
Keyword(s):  
Mitral Regurgitation ◽  
Ex Vivo ◽  
Left Ventricular ◽  
Functional Mitral Regurgitation ◽  
Ex Vivo Model

scholarly journals Midterm results of mitral valve repair for atrial functional mitral regurgitation: a retrospective study

2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Daisuke Kaneyuki ◽  
Hiroyuki Nakajima ◽  
Toshihisa Asakura ◽  
Akihiro Yoshitake ◽  
Chiho Tokunaga ◽  
...  
Keyword(s):  
Mitral Valve ◽  
Mitral Regurgitation ◽  
Mitral Valve Repair ◽  
Left Ventricular ◽  
Maze Procedure ◽  
Functional Mitral Regurgitation ◽  
Valve Repair ◽  
Left Ventricular Dilatation ◽  
Ring Annuloplasty

Abstract Background Annular dilation by left atrial remodeling is considered the main cause of atrial function mitral regurgitation. Although acceptable outcomes have been obtained using mitral ring annuloplasty alone for atrial functional mitral regurgitation, data assessing outcomes of this procedure are limited. Therefore, we aimed to assess midterm outcomes of mitral valve repair in patients with atrial functional mitral regurgitation. Methods We retrospectively studied 40 patients (mean age: 69 ± 9 years) who had atrial fibrillation that persisted for > 1 year, preserved left ventricular ejection fraction of > 40%, and mitral valve repair for atrial functional mitral regurgitation. The mean clinical follow-up duration was 42 ± 24 months. Results Mitral ring annuloplasty was performed for all patients. Additional repair including anterior mitral leaflet neochordoplasty was performed for 22 patients. Concomitant procedures included maze procedure in 20 patients and tricuspid ring annuloplasty in 31 patients. Follow-up echocardiography showed significant decreases in left atrial dimensions and left ventricular end-diastolic dimensions. Recurrent mitral regurgitation due to ring detachment or leaflet tethering was observed in five patients and was seen more frequently among those with preoperative left ventricular dilatation. Three patients without tricuspid ring annuloplasty or sinus rhythm recovery by maze procedure developed significant tricuspid regurgitation. Five patients who underwent the maze procedure showed sinus rhythm recovery. Rates of freedom from re-admission for heart failure at 1 and 5 years after surgery were 95 and 86%, respectively. Conclusions Mitral valve repair is not sufficient to prevent recurrent atrial functional mitral regurgitation in patients with preoperative left ventricular dilatation. Tricuspid ring annuloplasty may be required for long-term prevention of significant tricuspid regurgitation.

A Novel Quantitative Ex Vivo Model of Functional Mitral Regurgitation

2020 ◽  
Vol 15 (4) ◽  
pp. 329-337
Author(s):  
Chetan Pasrija ◽  
Rachael Quinn ◽  
Mehrdad Ghoreishi ◽  
Thomas Eperjesi ◽  
Eric Lai ◽  
...  
Keyword(s):  
Mitral Regurgitation ◽  
Ex Vivo ◽  
3D Structure ◽  
Left Ventricular Pressure ◽  
Left Ventricular ◽  
Functional Mitral Regurgitation ◽  
Ex Vivo Model ◽  
3 Dimensional ◽  
Structured Light Scanner ◽  
Repair Techniques

Objective Durability of mitral valve (MV) repair for functional mitral regurgitation (FMR) remains suboptimal. We sought to create a highly reproducible, quantitative ex vivo model of FMR that functions as a platform to test novel repair techniques. Methods Fresh swine hearts ( n = 10) were pressurized with air to a left ventricular pressure of 120 mmHg. The left atrium was excised and the altered geometry of FMR was created by radially dilating the annulus and displacing the papillary muscle tips apically and radially in a calibrated fashion. This was continued in a graduated fashion until coaptation was exhausted. Imaging of the MV was performed with a 3-dimensional (3D) structured-light scanner, which records 3D structure, texture, and color. The model was validated using transesophageal echocardiography in patients with normal MVs and severe FMR. Results Compared to controls, the anteroposterior diameter in the FMR state increased 32% and the annular area increased 35% ( P < 0.001). While the anterior annular circumference remained fixed, the posterior circumference increased by 20% ( P = 0.026). The annulus became more planar and the tenting height increased 56% (9 to 14 mm, P < 0.001). The median coaptation depth significantly decreased (anterior leaflet: 5 vs 2 mm; posterior leaflet: 7 vs 3 mm, P < 0.001). The ex vivo normal and FMR models had similar characteristics as clinical controls and patients with severe FMR. Conclusions This novel quantitative ex vivo model provides a simple, reproducible, and inexpensive benchtop representation of FMR that mimics the systolic valvular changes of patients with FMR.

scholarly journals Midterm results of mitral valve repair for atrial functional mitral regurgitation: A retrospective study

2020 ◽  
Author(s):  
Daisuke Kaneyuki ◽  
Hiroyuki Nakajima ◽  
Toshihisa Asakura ◽  
Akihiro Yoshitake ◽  
Chiho Tokunaga ◽  
...  
Keyword(s):  
Mitral Valve ◽  
Mitral Regurgitation ◽  
Mitral Valve Repair ◽  
Left Ventricular ◽  
Maze Procedure ◽  
Functional Mitral Regurgitation ◽  
Valve Repair ◽  
Left Ventricular Dilatation ◽  
Ring Annuloplasty

Abstract Background: Annular dilation by left atrial remodeling is considered the main cause of atrial function mitral regurgitation. Although acceptable outcomes have been obtained using mitral ring annuloplasty alone for atrial functional mitral regurgitation, data assessing outcomes of this procedure are limited. Therefore, we aimed to assess midterm outcomes of mitral valve repair in patients with atrial functional mitral regurgitation.Methods: We retrospectively studied 40 patients (mean age: 69 ± 9 years) who had atrial fibrillation that persisted for >1 year, preserved left ventricular ejection fraction of >40%, and mitral valve repair for atrial functional mitral regurgitation. The mean clinical follow-up duration was 42 ± 24 months.Results: Mitral ring annuloplasty was performed for all patients. Additional repair including anterior mitral leaflet neochordoplasty was performed for 22 patients. Concomitant procedures included maze procedure in 20 patients and tricuspid ring annuloplasty in 31 patients. Follow-up echocardiography showed significant decreases in left atrial dimensions and left ventricular end-diastolic dimensions. Recurrent mitral regurgitation due to ring detachment or leaflet tethering was observed in five patients and was seen more frequently among those with preoperative left ventricular dilatation. Three patients without tricuspid ring annuloplasty or sinus rhythm recovery by maze procedure developed significant tricuspid regurgitation. Five patients who underwent the maze procedure showed sinus rhythm recovery. Rates of freedom from re-admission for heart failure at 1 and 5 years after surgery were 95% and 86%, respectively.Conclusions: Mitral valve repair is not sufficient to prevent recurrent atrial functional mitral regurgitation in patients with preoperative left ventricular dilatation. Tricuspid ring annuloplasty may be required for long-term prevention of significant tricuspid regurgitation.

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