Subvalvular Apparatus Research Articles

EARLY MORTALITY & MORBIDITY IN MITRAL VALVE REPLACEMENT WITH TOTAL SUB-VALVULAR APPARATUS PRESERVATION, PARTIAL PRESERVATION AND NO PRESERVATION - A COMPARATIVE STUDY

Objective: To compare the early morbidity & mortality of total sub-valvular apparatus preservation technique vs partial preservation technique and no preservation technique in mitral valve replacement.
 Study Design: Cross-sectional comparative study.
 Place and Duration of Study: Department of Cardiac Surgery, Armed Forces Institute of Cardiology Rawalpindi, from Jan 2017 to Dec 2018.
 Methodology: One hundred fifty seven patients who underwent Mitral valve replacement were included in study. These patients were divided into three groups; group “A” comprised of those patients with total subvalvular apparatus preservation (n1=46), group “B” comprised of those patients with partial sub-valvular apparatus preservation (n2=70), group “C” comprised of those patients with no sub-valvular apparatus preservation(n3=41).
 Results: There were no statistical difference in the pre-operative data of the patients. No statistical difference noted in cross clamp & bypass time (p>0.05). The early morbidity in terms of ICU stay, Ventilation time, Inotropic supports, post-operative bleeding, Blood transfusion, postoperative rhythm abnormality & Re-exploration were statically significant (p<0.05). The mortality rate of patients with total sub-valvular apparatus preservation was 2.17% which is significantly less than those with partial preservation (2.85%) & no preservation (9.75%).
 Conclusions: Mitral valve replacement with total subvalvular apparatus preservation had low postoperative morbidity & mortality in comparison with partial and no preservation techniques.

The unfinished saga of invasive procedures for secondary mitral regurgitation.

Secondary mitral regurgitation (MR) is a common valvular heart disease. Its prognostic burden in patients suffering from idiopathic or ischemic cardiomyopathy (ICM) with left ventricular (LV) dysfunction/dilation has been clearly demonstrated. Severe secondary MR is associated with an increased mortality and frequent heart failure hospitalizations. Although guideline-directed medical therapy (GDMT) is the cornerstone of the management of secondary MR, a certain proportion of patients remain symptomatic. For these patients, several surgical techniques have been progressively developed during the last few decades (replacement, repair, sub-valvular apparatus interventions and other ventricular approaches). In the absence of evidence-based medicine, the benefits of these surgical procedures remains controversial, leading to a low level of recommendation in the guidelines. One way to anticipate the future is to look to the past. Recent prospective randomized trials evaluated surgical and percutaneous techniques and led to a better understanding of how best to treat this disease. In this article, we aim to describe the saga of the surgical and percutaneous treatments for secondary MR throughout the previous decades.

IMPACT OF THE PRESERVATION OF THE SUBVALVULAR APPARATUS OF THE ANTERIOR MITRAL LEAFLET ON THE LEFT VENTRICULAR FUNCTION AFTER MITRAL VALVE REPLACEMENT IN EARLY POST-OPERATIVE PERIOD

Background:Long-term morbidity and mortality appear to be associated with mitral valve replacement for mitral valve disease. The morbidity rate has not decreased dramatically over the years, despite enhancements in myocardial safety and prosthetic valves. Cardiac failure is the most common cause of death following MVR. Subvalvular apparatus preservation preserves LV function and thus improves survival. Repair, particularly with rheumatic valve disease in young patients and extremely disorganised valves, is not always feasible or effective. The use of smaller valve prothesis was not only the argument of preserving the anterior leaflet, but also that it could cause LVOT obstruction. Methods:A prospective controlled randomized study will include(sixty patients aged from 25 to 55 years of both sexes) They will be divided into two groups of patients: Group I: thirty patients who underwent MVR without preservation of The chordae tendinae of the anterior mitral leaflet and only preserving the posterior mitral leaflet. Group II: thirty patients who underwent MVR with complete or partial Preservation of the chordae tendinaeof the anterior mitral leaflet. Results:The sixty patients were divided into two groups where 30 of them underwent preservation of AML, These patients had a better LV function in the early and the short term postoperative period. Conclusion:Results of this study concluded that preservation of the AML leads to better postoperative outcome. We recommend its application on a greater scale of cases of MVR.

Abstract 16979: Hemodynamic Comparison of Tricuspid Ring Annuloplasty vs. Hetzer Annuloplasty Technique to Repair Functional Tricuspid Regurgitation

Introduction: Surgical repair of functional tricuspid regurgitation (FTR) is increasingly performed, and the techniques are evolving. Annuloplasty is currently the technique of choice, with different techniques yielding varied results, and thus require optimization. Objective: In this study, we sought to compare tricuspid valve function and kinematics after ring annuloplasty and Hetzer’s double orifice repair in an ex vivo model of FTR. Methods: Ten pig hearts were mounted into a right heart simulator, and studied at 70 bpm while maintaining the total volume of working fluid. FTR was created by increasing afterload, which caused acute right ventricular dilation and TV tethering. Tricuspid valve annuloplasty (TVA) was performed with a 26mm MC 3 ring. Hetzer procedure was performed with pledgeted sutures that approximated the anteroposterior and septal annular segments. Flow probes were used to measure FTR, and leaflet kinematics with echocardiography. Results: FTR of 17.7±9.2mL(p<0.0001) after RV dilation. Repair with TVA and Hetzer reduced FTR to 8.8±6.8ml(p=0.7142) and 7.8±6.9ml(p=0.0919), respectively, but did not eliminate it. Septal leaflet excursion angle decreased by 48.1% with FTR (p=0.04 vs. baseline ) . Repair with TVA and Hetzer increased the angle to 17.3±6.7°(p=0.0312) and 21.5±8.3°(vs FTR, p=0.0034), respectively. The Hetzer improved septal leaflet mobility better than TVA (p=0.0145). The posterior leaflet excursion angle decreased by 49.2% compared to baseline to 18.4±10.5° (p=0.0060) and both TVA and Hetzer significantly improved mobility to 33.6±8.4° (p=0.0081) and 31.6±15.6° (p=0.0256), respectively. Anterior leaflet mobility decreased after FTR by 60.7% to 18.1±8.2°. The effect of these repairs on the sub-valvular apparatus was negligible. Conclusion: TVA and Hetzer both reduced regurgitation but did not eliminate it. Septal and posterior leaflet mobility was improved, while the anterior leaflet remained tethered.

Early bioprosthesis failure in mitral valve replacement.

The causes of early bioprosthesis failure include infective endocarditis, pannus formation, and structural valve deterioration. We reported a patient who suffered from early mitral bioprosthesis failure due to leaflets restricted by the subvalvular apparatus and early pannus formation. In patients with symptoms relapse and mitral regurgitation recurrence early after mitral valve replacement, early pannus formation needs to be anticipated, and surgical intervention should be performed if symptoms persist after medical treatment.

Surgery for Anomalous Papillary Muscle Directly Into the Anterior Mitral Leaflet

The anomalous insertion of papillary muscle directly into the anterior mitral leaflet is a rare congenital anomaly concomitant with hypertrophic cardiomyopathy. We herein report our surgical technique, which is designed to relieve left ventricular obstruction and preserve the mitral valve and subvalvular apparatus. Among 38 patients who underwent septal myectomy from 2007 to 2020, 4 had an anomalous mitral subvalvular apparatus with papillary muscle with direct insertion into the anterior mitral leaflets. In all cases, mitral valve repair was accomplished with excision and reconstruction of all anomalous papillary muscles, concomitant with septal myectomy. In another 34 patients, 20 cases needed mitral valve repair with regard to systolic anterior motion by hypertrophic cardiomyopathy. The comparison study was conducted between the anomalous papillary muscle group (group A) and the others (group B). There was no early or late death in group A, and there were 3 early deaths and 2 late deaths in group B. The mean peak gradient in the left ventricle was significantly decreased in both groups. Mitral valve regurgitation grade was also significantly decreased from 3 to 0.5 without valve replacement in group A, and from 2 to 0.6 in group B. Six patients needed mitral valve replacement because of the thickness of anterior mitral leaflet in group B. Hypertrophic obstructive cardiomyopathy associated with the anomalous insertion of papillary muscle can be successfully treated without mitral valve replacement. Excision and reconstruction with the anomalous papillary muscle seems to be a feasible operation to reduce mitral regurgitation and relieve outflow tract obstruction.

Mitral Regurgitation After Percutaneous Mitral Valvuloplasty: Insights Into Mechanisms and Impact on Clinical Outcomes

ObjectivesThe aim of this study was to assess the incidence, mechanisms, and outcomes of mitral regurgitation (MR) after percutaneous mitral valvuloplasty (PMV). BackgroundSignificant MR continues to be a major complication of PMV, with a wide range in clinical presentation and prognosis. MethodsConsecutive patients with mitral stenosis undergoing PMV were prospectively enrolled. MR severity was evaluated by using quantitative echocardiographic criteria, and its mechanism was characterized by 3-dimensional transesophageal echocardiography, divided broadly into 4 categories based on the features contributing to the valve damage. B-type natriuretic peptide levels were obtained before and 24 h after the procedure. Endpoints estimated cardiovascular death or mitral valve (MV) replacement due to predominant MR. ResultsA total of 344 patients, ages 45.1 ± 12.1 years, of whom 293 (85%) were women, were enrolled. Significant MR after PMV was found in 64 patients (18.6%). The most frequent mechanism of MR was commissural, which occurred in 22 (34.4%) patients, followed by commissural with posterior leaflet in 16 (25.0%), leaflets at central scallop or subvalvular damage in 15 (23.4%), and central MR in 11 (17.2%). During the mean follow-up period of 3 years (range 1 day to 10.6 years), 60 patients reached the endpoint. The event-free survival rates were similar among patients with mild or commissural MR, whereas patients with damaged central leaflet scallop or subvalvular apparatus had the worst outcome, with an event-free survival rate at 1 year of only 7%. Long-term outcome was predicted by net atrioventricular compliance (Cn) at baseline and post-procedural variables, including valve area, mean gradient, and magnitude of decrease in B-type natriuretic peptide levels, adjusted for the mechanism of MR. ConclusionsSignificant MR following PMV is a frequent event, mainly related to commissural splitting, with favorable clinical outcome. Parameters that express the relief of valve obstruction and the mechanism by which MR develops were predictors of long-term outcomes.

Acute Severe Functional Mitral Regurgitation After Non-Mitral Valve Cardiac Surgery—Left Ventricular Dyssynchrony as a Potential Mechanism

Functional mitral regurgitation (MR) describes valve leakage in the absence of disease or damage to the mitral leaflets or subvalvular apparatus. Significant, new functional MR after cardiopulmonary bypass (CPB) may result from a number of intraoperative processes, including left ventricular (LV) ischemia and enlargement, left atrial enlargement secondary to increased filling pressure, and systolic anterior motion of the mitral valve after mitral repair. Assessment of new MR after CPB is important because it may direct hemodynamic maneuvers or prompt reinitiation of CPB if surgical intervention is deemed necessary. Described extensively in the electrophysiology literature but underreported as a cause of MR after CPB, LV dyssynchrony represents another possible mechanism of functional MR, in which resynchronization of conduction via pacing maneuvers may prove beneficial. Herein, a series of 4 patients in whom new MR was found after non-mitral valve cardiac surgery in the setting of normal LV systolic function is presented, and LV dyssynchrony is proposed as a major contributing factor. The findings suggested that the concomitant observation of new or worsened functional MR, together with normal global and regional LV systolic function, should lead the clinician to consider ventricular dyssynchrony as a possible cause. Attempts to improve or alter ventricular conduction should be considered before contemplating a return to CPB for mitral valve intervention.

Health-related quality of life following minimally invasive totally endoscopic mitral valve surgery

BackgroundTo compare the impact of two different types of mitral valve surgery on health-related quality of life, we conducted a retrospective study comparing modified totally endoscopic mitral valve surgery with median sternotomy mitral valve surgery.MethodsA total of 163 patients who underwent mitral valve surgery at our institution between January 1, 2019 and December 31, 2019 were enrolled. For these 163 patients, mitral valve surgery was performed using either a modified totally endoscopic approach or median sternotomy approach. We used the numerical rating scale and the Scar Cosmesis Assessment and Rating Scale to measure pain intensity and the aesthetic appearance of the surgical incision and used the MOS 36-item Short-Form Health Survey to assess health-related quality of life.ResultsSeventy-eight patients underwent the modified totally endoscopic mitral valve surgery, and eighty-five patients underwent the median sternotomy mitral valve surgery. The two groups of patients were similar in terms of demographics and echocardiography findings. The number of bioprosthetic valve replacements performed was significantly higher in the totally endoscopic group than in the median sternotomy group (p = 0.04), whereas the subvalvular apparatus was less preserved in only 33 cases in the totally endoscopic group (p = 0.01). The rate of postoperative adverse events was similar between the two groups. The pain was mild and aesthetic appearance was significantly better in the totally endoscopic approach group than in the sternotomy approach group. Significant differences in the scores for the bodily pain and mental health subscales of the MOS 36-item Short-Form Health Survey were found between the two groups.ConclusionsCompared with median sternotomy mitral valve surgery, totally endoscopic mitral valve surgery has an equally good treatment effect, improving patient’s health-related quality of life with a better cosmetic appearance and a lower pain intensity. Our study suggested that the totally endoscopic approach is superior to the median sternotomy approach in terms of pain intensity, aesthetic appearance and health-related quality of life.

The Tricuspid Valve in Single-Ventricle Patients: Forgotten, Unforgivable, and Indispensable

The Tricuspid Valve in Single-Ventricle Patients: Forgotten, Unforgivable, and Indispensable

Tricuspid valve Swan-Ganz catheter entrapment before cardiac surgery.

A Swan-Ganz catheter during cardiac surgery offers peri-operative haemodynamic monitoring, although insertion of these catheters is not without risk. We report a case of Swan-Ganz catheter entrapment within the tricuspid valve during elective off-pump coronary artery bypass surgery. The diagnosis was made immediately by transoesophageal echocardiography, thus preventing forced withdrawal of the catheter. Intra-operatively, the echocardiographically detected findings of complex entrapment was confirmed. The Swan-Ganz catheter was tightly wrapped around the subvalvular apparatus, requiring on-pump open surgical removal. This case illustrates the anatomical complexity of such a catheter entrapment around the tricuspid valve apparatus and the importance of rapid echocardiographic diagnosis to prevent iatrogenic damage.

Mitral Valve Posterior Leaflet Reconstruction Using Extracellular Matrix: In Vitro Evaluation.

To investigate the anatomical and functional effects of complete surgical reconstruction of the posterior mitral leaflet and associated chordae tendineae with a patch made of 2-ply small intestinal submucosal extracellular matrix in vitro. Seven explanted mitral valves with intact subvalvular apparatus from 80-kg pigs were evaluated in a left heart simulator and served as their own controls. After testing the native valve, the mitral posterior leaflet and associated chordae tendineae were excised and reconstructed by using the 2-ply small intestinal submucosa extracellular matrix patch. The characterization of the reconstruction was based on geometric data from digital images, papillary muscle force, annular tethering force and leaflet pressure force. The reconstructed valves were fully functional without regurgitation, tearing or rupture during incrementally increased pressure from 0 to 120 mmHg. The leaflet areas were preserved after reconstruction, with a normal configuration of the coaptation line. However, the coaptation midpoint moved posteriorly after reconstruction (A2: 15.8 ± 1.4 vs. 18.9 ± 1.5 mm, p = 0.002, diff = 3.1 mm, 95% CI 1.3 to 4.8 mm). The anterior papillary muscle force increased significantly (3.9 vs. 4.6 N, p = 0.029, diff = 0.7 N, 95% CI 0.1 to 1.4 N at 120mmHg) after reconstruction. The posterior papillary muscle force, leaflet pressure force and annular pressure force did not change significantly. In this in vitro model, mitral valve anatomy and function were comparable between the native mitral valve and our new surgical technique for complete reconstruction of the posterior mitral leaflet and associated chordae tendineae. These promising results warrant further in vivo evaluation.

Device profile of the AltaValve system for transcatheter mitral valve replacement: overview of its safety and efficacy

ABSTRACT Introduction In patients with severe mitral regurgitation (MR), transcatheter mitral valve replacement (TMVR) has recently emerged as an alternative to surgery. However, compared with transcatheter aortic valve replacement, TMVR faces several technical challenges and a high screening failure rate, mainly due to a more complex mitral annulus geometry and the potential interaction with the sub-valvular apparatus and the left ventricular outflow tract (LVOT). The AltaValve system is a device intended for TMVR with unique design features that may overcome most anatomical limitations for this therapy. Areas covered A summary of the current evidence regarding TMVR is presented, followed by a review of the main technical challenges. The main features, differential characteristics, and potential advantages of the AltaValve system are discussed. Finally, we describe the first-in-human procedures with AltaValve and the main details of the upcoming feasibility trial. Expert opinion A high number of high-risk surgical patients with MR remain undertreated. TMVR is continuously evolving, and AltaValve constitutes another step forward in this field. Its unique design avoiding annular and LVOT engagement represents a clear potential benefit, along with its recently incorporated trans-septal approach system. However, more evidence is warranted regarding its feasibility in different clinical settings and mid-term performance.

Mitral Valve Replacement Using Subvalvular Apparatus: A Systematic Review and Meta-Analysis.

To assess clinical outcomes among participants undergoing mitral valve replacement with preservation of subvalvular apparatus. Electronic databases, including PubMed, Embase, Science Direct, World of Science, Scopus, Biosis, SciElo and Cochrane library, were probed using an extensive search strategy. Studies that reported at least one clinical outcome, such as morbidity, mortality, early 30-day mortality, myocardial failure, survival, late cerebrovascular events, length of stay, or major operative complications (stroke, prolonged ventilation, and reoperation for bleeding, renal failure, and sternal infection) were considered for inclusion. Data was extracted and pooled into a meta-analysis in RevMan (version 5.3) using a random-effects model. A total of 21 studies with 5,106 participants (age range: 27.3-69.2 years) were included in this meta-analysis. Preservation of the subvalvular apparatus during MVR significantly reduces the risk of long-term mortality (OR: 0.46; 95% CI: 0.33-0.64), but not early mortality (OR: 0.76; 95% CI: 0.12-4.93). No significant difference ejection fraction was observed (SMD: 0.10; 95% CI: -0.44-0.64). Similarly, there was no significant difference in the risk of stroke, renal failure, and pneumonia between C-MVR and in the control group. MVR with the preservation of subvalvular apparatus improves clinical outcomes, such as long-term mortality, hospital length of stay, pneumonia, and bleeding. There is no significant difference in the risk of stroke, renal failure, or ICU length of stay. However, there is very limited data available with respect to bleeding, sepsis, and nosocomial infections.

Fluid-Structure Interaction Analysis of Subject-Specific Mitral Valve Regurgitation Treatment with an Intra-Valvular Spacer

Mitral regurgitation imposes a significant symptomatic burden on patients who are not candidates for conventional surgery. For these patients, transcatheter repair and replacement devices are emerging as alternative options. One such device is an intravalvular balloon or spacer that is inserted between the mitral valve leaflets to fill the gap that gives rise to mitral regurgitation. In this study, we apply a large-deformation fluid-structure interaction analysis to a fully 3D subject-specific mitral valve model to assess the efficacy of the intra-valvular spacer for reducing mitral regurgitation severity. The model includes a topologically 3D subvalvular apparatus with unprecedented detail. Results show that device fixation and anchoring at the location of the subject’s regurgitant orifice is imperative for optimal reduction of mitral regurgitation.

The tricuspid valve in review: anatomy, pathophysiology and echocardiographic assessment with focus on functional tricuspid regurgitation.

The tricuspid valve (TV) is a complex anatomical structure that incorporates a saddle-shaped annulus, asymmetric leaflets, the subvalvular apparatus and the right ventricle and its loading conditions. In this paper, an appreciation of the normal anatomy and physiology of the TV is reviewed before discussing functional tricuspid regurgitation (TR), a disease that has garnered renewed interest due to increased awareness of adverse outcomes and novel transcatheter therapeutic options. Two and three-dimensional echocardiographic imaging of the TV using transthoracic and transesophageal windows are subsequently discussed. The future of cardiovascular medicine will have more to offer the “forgotten” right-sided chambers and valves, and this review aims to refresh knowledge and enthusiasm around the forgotten but crucially important TV.

Mitral regurgitation: lessons learned from COAPT and MITRA-Fr.

Recent studies about percutaneous treatment of secondary mitral regurgitation (MR) underlined the importance of left ventricular geometry and features of mitral valve as determinants of procedural and long-term success. Guideline-directed medical therapy (GDMT), transcatheter mitral valve treatment (TMVT) and surgical procedures (mitral valve replacement, mitral valve repair at level of the annulus or subvalvular apparatus) have been extensively evaluated but not adequately compared in current clinical studies. A detailed analysis of the results of the study about transcatheter mitral valve repair would allow to evaluate the safety and effectiveness of such procedure and would provide potential indications for improving the quality of percutaneous and surgical repair in patients with moderate-to-severe secondary MR. Patients with proportionate MR (i.e., MR severity is proportional to the amount of left ventricular dilatation) are prone to respond to the optimization of medical therapy, while patients with disproportionate MR (i.e., MR severity is disproportionately higher than predicted by left ventricular dilatation, with high EROA and small left ventricle) are likely to benefit from additional repair. The identification of specific subpopulation of "high responders", based on the anatomic characteristics of the mitral valve and the relative dimensions of the annulus, the regurgitation and the left ventricle, can also apply to medical therapy. However, some pivotal component of MR (such as the symmetry of tethering and the differences in biomechanical features of leaflets) are not adequately investigated in current studies and warrant further evaluation.

Antegrade transseptal transcatheter aortic valve replacement: Back to the future?

Antegrade transseptal approach was utilized in the first human case of transcatheter aortic valve replacement (TAVR) and in the early phase of TAVR. Various challenges with the antegrade transseptal approach including procedural complexity, need for atrial septal crossing, and potential for injury to the mitral valve apparatus led it to being supplanted by other approaches. These challenges have now largely been mitigated as structural interventionalists routinely perform left atrial procedures. We report a case of antegrade transseptal TAVR using a large bore sheath placed in the mid left ventricle across the mitral orifice to protect the mitral valve apparatus and facilitate valve deployment. An 84-year-old man with heart failure symptoms was seen for severe aortic stenosis. The severity of peripheral arterial disease precluded femoral, axillary, carotid, or transcaval routes. After transseptal puncture and creation of an arteriovenous rail, a long 26-Fr sheath was advanced from the right femoral vein transseptally over the arteriovenous rail, past the mitral valve inflow to the mid left ventricular cavity. The sheath provided a stable platform with stable intraprocedure hemodynamics. Balloon valvuloplasty was performed in an antegrade manner, after which a 29-mm SAPIEN S3 prosthesis was advanced into the aortic valve position and deployed under rapid pacing. We observed no injury to the mitral leaflets or subvalvular apparatus after the procedure. The antegrade transseptal approach should be revisited as an option for patients at high surgical risk with no other suitable access site. The use of a large bore sheath facilitates this approach.

Reparación de una disección de aurícula izquierda. Presentación de un caso.

Introducción: La disección de la aurícula izquierda es una complicación infrecuente pero potencialmente fatal de la cirugía cardíaca. Es frecuentemente asociada a cirugías de la válvula mitral, tanto su reparación el reemplazo, con una incidencia de 0,16%. Sin embargo, otros procedimientos como intervenciones percutaneas también presentan este riesgo.Objetivos: Presentar la resolución quirúrgica de un caso de disección de aurícula izquierda y aportar a la casuística nacional.Materiales y métodos: Registro clínico, imagenológico y fotográfico del episodio clínico.Resultados: Una paciente que fue sometida a ablación por radiofrecuencia por vía retrógrada, y cursa durante el periodo post-intervencional con insuficiencia cardíaca y su estudio identifíca una disección auricular.Se realiza reparación del anillo mitral, plastía del aparato subvalvular y parche de pericardio, la paciente presenta evolución clínica y ecográfica favorable.Discusión: El tratamiento de esta entidad debe analizarse caso a caso, ya que la etiología relacionada a procedimientos percutáneos es diferente a la causada por cirugía valvular mitral.Conclusión: La reparación de una disección auricular con parche es una buena alternativa de tratamiento en estos casos.

Right Ventricular Device HeartWare Implant to the Right Atrium with Fixation to the Chest Wall in Patient with Biventricular Support.

Right Ventricular Device HeartWare Implant to the Right Atrium with Fixation to the Chest Wall in Patient with Biventricular Support.