scholarly journals Epicardial Posterior Papillary Muscle Repositioning with Mitral Annular Reduction for FIMR Treatment: Initial Ex Vivo Heart Model Study

2020 ◽  
Vol 23 (1) ◽  
pp. E010-E017
Author(s):  
Krishaporn Kradangnga ◽  
Eric Monnet
Keyword(s):  
Mitral Regurgitation ◽  
Ex Vivo ◽  
Frontal Plane ◽  
Left Ventricular ◽  
Percentage Increase ◽  
Percentage Decrease ◽  
Model Study ◽  
Annular Dilatation ◽  
Α Angle ◽  
Leaflet Coaptation

Background: High recurrent functional ischemic mitral regurgitation (FIMR) has been observed after annuloplasty. Since annuloplasty alone could not prevent late recurrent FIMR or improve the survival rate after CABG, adjunctive subvalvular opt for better treatment tailored for each individual patient. Methods: Ex vivo ovine heart models with annular dilatation and PPM displacement were used for analysis of mitral regurgitation (MR) flow, left ventricular and annular geometry after treatment by mitral annular reduction alone (MA, nMA = 12) or combined with epicardial PPM repositioning (MA+PPM, nMA+PPM=13). Results: MR significantly was reduced from baseline in both the MA (P = .03) and MA+PPM (P = .02) groups, but was not significantly different between the groups. The septo-lateral mitral annular distance decreased after applying both methods (MA group P = .005; MA+PPM group P = .05). The tethering α angle of the APM in the frontal plane significantly increased from baseline in the MA+PPM group (P = .027). Furthermore, the MA+PPM group had a larger APM and PPM α angle in the frontal plane compared with the MA group after reducing the MR (P = .04). There were no statistically significant changes in tethering angles found in the MA group compared with baseline. MR reduction correlated with percentage decrease of septo-lateral mitral annular distance (rs = 0.51, P = .01), the percentage decrease of fibrosa-PPM distance (rs = 0.43, P = .03), and the percentage increase of the PPM anterior displacement (rs = -0.41, P = .04). Conclusion: The decreased tethered angle of the PPM referred to the annulus, and the decreased interpapillary muscles distance suggested the PPM was repositioned inward and toward the septal annulus by the epicardial pushing pad. Epicardial repositioning of the PPM adjunct with mitral annular reduction facilitated leaflet coaptation without the risk of overlying restriction of the mitral annular orifice.

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.

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.

scholarly journals Adult Obstructive Cor Triatriatum with Severe Mitral Regurgitation: A Case Report

2021 ◽  
Vol 24 (3) ◽  
pp. E578-E579
Author(s):  
Tomomi Nakajima ◽  
Dung Van Hung ◽  
Yuji Hiramatsu
Keyword(s):  
Mitral Regurgitation ◽  
Mitral Annulus ◽  
Left Ventricular ◽  
Cor Triatriatum ◽  
Severe Mitral Regurgitation ◽  
Mitral Annuloplasty ◽  
Progressive Heart Failure ◽  
Left Ventricular Dilatation ◽  
Annular Dilatation ◽  
Cor Triatriatum Sinister

Adult cor triatriatum sinister associated with severe mitral regurgitation is extremely rare. As these obstructive cor triatriatum feature hemodynamics that mimic mitral stenosis, a pressure load is theoretically generated only on the left atrial proximal chamber, and therefore the left ventricle is less likely to suffer volume loading. Here, we report a surgical case with such rare hemodynamics. A 22-year-old man with obstructive cor triatriatum and severe mitral regurgitation received an anomalous membrane excision and mitral annuloplasty. An abnormal membrane with an orifice 7 mm in size was completely resected while a grossly dilated mitral annulus was repaired via annuloplasty ring. Mitral regurgitation was controlled well, and the postoperative course was uneventful. Even with obstructive cor triatriatum, severe mitral annular dilatation and subsequent left ventricular dilatation may occur, causing the progressive heart failure encountered in this case.

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 Ring annuloplasty prevents delayed leaflet coaptation and mitral regurgitation during acute left ventricular ischemia

2000 ◽  
Vol 119 (4) ◽  
pp. 774-783 ◽  
Author(s):  
Tomasz Timek ◽  
Julie R. Glasson ◽  
Paul Dagum ◽  
G.Randall Green ◽  
J.Francisco Nistal ◽  
...  
Keyword(s):  
Mitral Regurgitation ◽  
Left Ventricular ◽  
Ring Annuloplasty ◽  
Leaflet Coaptation

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 Mitral Annular Forces and Their Potential Impact on Annuloplasty Ring Selection

2022 ◽  
Vol 8 ◽  
Author(s):  
Johannes H. Jedrzejczyk ◽  
Lisa Carlson Hanse ◽  
Shadi Javadian ◽  
Søren N. Skov ◽  
J. Michael Hasenkam ◽  
...  
Keyword(s):  
Mitral Regurgitation ◽  
Mitral Annulus ◽  
Type I ◽  
Search Term ◽  
Annuloplasty Ring ◽  
Mitral Annuloplasty ◽  
Annular Dilatation ◽  
Specific Morphology ◽  
Leaflet Coaptation ◽  
Flexible Ring

Objectives: To provide an overview that describes the characteristics of a mitral annuloplasty device when treating patients with a specific type of mitral regurgitation according to Carpentier's classification of mitral regurgitation.Methods: Starting with the key search term “mitral valve annuloplasty,” a literature search was performed utilising PubMed, Google Scholar, and Web of Science to identify relevant studies. A systematic approach was used to assess all publications.Results: Mitral annuloplasty rings are traditionally categorised by their mechanical compliance in rigid-, semi-rigid-, and flexible rings. There is a direct correlation between remodelling capabilities and rigidity. Thus, a rigid annuloplasty ring will have the highest remodelling capability, while a flexible ring will have the lowest. Rigid- and semi-rigid rings can furthermore be divided into flat and saddled-shaped rings. Saddle-shaped rings are generally preferred over flat rings since they decrease annular and leaflet stress accumulation and provide superior leaflet coaptation. Finally, mitral annuloplasty rings can either be complete or partial.Conclusions: A downsized rigid- or semi-rigid ring is advantageous when higher remodelling capabilities are required to correct dilation of the mitral annulus, as seen in type I, type IIIa, and type IIIb mitral regurgitation. In type II mitral regurgitation, a normosized flexible ring might be sufficient and allow for a more physiological repair since there is no annular dilatation, which diminishes the need for remodelling capabilities. However, mitral annuloplasty ring selection should always be based on the specific morphology in each patient.

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.

Mitral Annular Dilatation and Papillary Muscle Dislocation Without Mitral Regurgitation in Sheep

Circulation ◽  
1999 ◽  
Vol 100 (suppl_2) ◽  
Author(s):  
G. Randall Green ◽  
Paul Dagum ◽  
Julie R. Glasson ◽  
George T. Daughters ◽  
Ann F. Bolger ◽  
...  
Keyword(s):  
Left Ventricle ◽  
Mitral Regurgitation ◽  
Papillary Muscle ◽  
Ex Vivo ◽  
Mitral Annulus ◽  
Functional Mitral Regurgitation ◽  
3 Dimensional ◽  
Annular Dilatation ◽  
Muscle Geometry ◽  
Anterior Papillary Muscle

Background —Asymmetrical mitral annular (MA) dilatation and papillary muscle dislocation are implicated in the pathogenesis of functional mitral regurgitation (MR). Methods and Results —To determine the mechanism by which annular and papillary muscle geometric alterations result in MR, we implanted radiopaque markers in the left ventricle, mitral annulus, anterior and posterior mitral leaflets, and papillary muscle tips and bases in 2 groups of sheep. One group served as controls (CTL, n=7); an experimental group (EXP, n=9) underwent topical phenol application to obliterate anterior annular and leaflet muscle (confirmed histologically ex vivo). After 1 week of recovery, markers were imaged with biplane videofluoroscopy, and hemodynamic data were recorded. MA area (computed from 3-dimensional marker coordinates) was 11% to 13% larger in the EXP group than in the CTL group ( P <0.05 by ANOVA). This area increase resulted exclusively from intercommissural axis increase except in 1 heart with large (>1 cm) increases in both the intercommissural and septolateral annular axes. The anterior papillary muscle tip in EXP was displaced from CTL by 2.9±0.23 mm toward the anterolateral left ventricle and 2.5±0.12 mm toward the mitral annulus at end systole; the posterior papillary muscle geometry was unchanged. Transthoracic echocardiography revealed MR only in the heart exhibiting biaxial annular enlargement. Conclusions —MA dilatation in the intercommissural dimension with anterior papillary muscle tip displacement toward the annulus is insufficient to produce MR in sheep. Functional MR may require MA dilatation in the septolateral axis, as observed with proximal circumflex coronary occlusion.

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