Mitral Annular Forces and Their Potential Impact on Annuloplasty Ring Selection

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.

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

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.

Transcatheter mitral valve repair using the Cardioband® system: Histopathological insights in device ingrowth and biocompatibility

Surgical implantation of a complete or incomplete ring to reduce the valve annulus and improve leaflet coaptation is the mainstay of mitral valve surgery. The Cardioband® system (Edwards Lifesciences, Irvine, CA, USA) was designed to address the pathophysiological mechanism of annular dilatation through a catheter-based approach. We present the histopathological workup of a Cardioband® device, which had been implanted 21 months earlier in a 34-year-old male with ischemic cardiomyopathy. Device examination demonstrate a well-positioned and securely anchored device. The described tissue reactions may have an impact on choice of device and timing in case of re-do surgery.

Bail-out edge-to-edge mitral repair for an acute single leaflet device attachment: a case report

Background An acute single leaflet device attachment (SLDA) may occur during transcatheter mitral valve edge-to-edge repair (TMVr), if an inadequate grasping of the target leaflet and/or a leaflet injury are concomitant. The bail-out TMVr often fails due to the complex pathophysiology. Case summary We report a case of an acute SLDA after TMVr with the PASCAL Repair System for severe mitral regurgitation (MR) with mixed aetiology, i.e., a thin-appeared posterior leaflet and pseudo-prolapse of the anterior mitral leaflet due to mitral annular dilatation. An acute SLDA occurred 2 min after the deployment, with device detachment of the posterior leaflet. A bail-out TMVr with the MitraClip XTR system led to an optimal MR reduction with the PASCAL stabilized. Despite an adequate leaflet insertion of the 1st device achieved, the posterior leaflet was tear due to its fragile tissue characteristics. At discharge, echocardiography confirmed an optimal MR reduction to mild grade with both devices stabilized. Discussion The pathology of the mitral valve leaflet is essential to achieve successful TMVr procedure using edge-to-edge repair device. Since the mechanical stress to the target leaflet appears to vary according to the edge-to-edge repair devices, the leaflet tissue characteristics should be respected during device selection.

Leaflet Dimensions as a Guide to Remodeling Annuloplasty During Aortic Valve Repair

Objective In chronic aortic insufficiency (AI), the method and degree of annular downsizing required to achieve durable coaptation in aortic valve repair (AVr) remains poorly defined. This study evaluated the relationship between leaflet size and annular diameter to predict adequate annular sizing in remodeling AVr. Methods Under regulatory supervision, 74 patients with chronic tri-leaflet AI underwent AVr using ring annuloplasty and leaflet reconstruction. Fifty-four (73%) had ascending aortic ( n = 25) and/or root ( n = 29) aneurysms, and aortic grafts were sized 5 to 7 mm larger than the rings. Intraoperatively, leaflet free-edge length (FEL) was measured with special ball sizers positioned in the coronary sinus, and “normal” annular diameter was predicted from the validated formula: Required “normal” diameter = FEL/1.5. “Normal” annular diameters predicted from FEL were compared with pathologic diameters measured intraoperatively with Hegar dilators, and both were correlated with gender, age, and BSA. Results Average age was 62.1 ± 13.3 years (mean ± SD), 73% (54/74) were male, and 96% (71/74) had moderate-to-severe AI. All patients had annular dilatation, with a pathologic diameter 26.6 ± 2.3 mm before repair, and a predicted “normal” diameter of 21.7 ± 1.7 mm ( P < 0.001). Both predicted and pathologic annular diameters were larger in men ( P < 0.001), but no relationship existed with age. BSA correlated with both predicted and pathologic diameters, although variability was large. Conclusions Based on a simple validated method to predict “normal” annular diameter, all patients with chronic AI have some degree of annular dilatation. This finding implies that most AVr should include annuloplasty, with adequate and precise annular reduction based on leaflet size.

Incremental prognostic value of tricuspid annular dilatation over the STS score

Background Transcatheter aortic valve replacement (TAVR) is the treatment of choice in most patients with severe aortic stenosis. The Society of Thoracic Surgeons (STS) score is a well established risk score to estimate morbidity, mortality and procedural risk of patients undergoing TAVR. However, tricuspid annular Dilatation (TAD), which is an increasingly recognized pathology associated with increased mortality, is not implemented in the STS Score. Purpose The purpose of this analysis was to investigate the incremental prognoctic value of TAD over the STS score. Methods Maximal septo-lateral diameter of the tricuspid annulus was measured in 923 patients on 3-dimensional MDCT datasets. A cut-off of 23 mm/m2 body-surface area was revealed by receiver-operating curve statistics and used to define TAD. Incremental prognostic Information was tested with c-index statistics and continuous net reclassification improvement (NRI). Patients were followed for 2 years and all-cause mortality was defined as study endpoint. Results Of 923 patients included in this analyis, TAD was found in 370 patients (40%). Patients with TAD had a significantly higher mortality (hazard ratio 2.18 with 95% CI 1.71 and 2.78, p&lt;0.001). The mean STS score in the investigated patient cohort was 5.6±5.0. TAD provided incremental prognostic Information over the STS score when assessed with c-index statistics (rise from 0.63 to 0.66, p&lt;0.01) or continuous NRI (0.209 with 95% CI 0.127 and 0.292, p&lt;0.001). Estimated survival rates at 2 years were 88.2% (95% CI 84.5 and 92.1) in patients with a low STS score (&lt;4) and no TAD and 57.5% (95% CI 51.1 and 64.7) in patients with a high STS score (&gt;4) and TAD. Estimated survival rates in patients with a low STS score and TAD and patients with a high STS score and no TAD were similiar (75.8% with 95% CI 68.9 and 83.5 and 74.8% with 95% CI 69.2 and 80.7, respectively). Kaplan-Meier curves are shown in Figure 1. Conclusion TAD is a common entity in patients undergoing TAVR for severe aortic stenosis. It is associated with significantly higher mortality and provides incremental prognostic Information over the STS score. Funding Acknowledgement Type of funding source: None

Atrial functional mitral regurgitation: mechanisms and surgical implications

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.