Image-based ring size prediction for mitral valve repair

OBJECTIVES

Annuloplasty rings are routinely used in mitral valve repair (MVr). However, accurate annuloplasty ring size selection is essential to obtain a favorable outcome. Moreover, ring sizing can be challenging in some patients and is highly influenced by surgeons' experience. This study investigated the utility of three-dimensional mitral valve (3D-MV) reconstruction models to predict annuloplasty ring size for MVr.

METHODS

A total of 150 patients undergoing minimally invasive MVr with annuloplasty ring due to Carpentier type II pathology and who were discharged with none/trace residual MR were included. 3D-MV reconstruction models were created with a semi-automated software package (4D MV Analysis; Tomtec Imaging Systems, Munich, Germany) to quantitate MV geometry. To predict the ring size, univariable and multivariable linear regression analyses were performed.

RESULTS

Between 3D-MV reconstruction values and implanted ring sizes, the highest correlation coefficients were provided by commissural width (CW) (0.839; p < 0.001), intertrigonal distance (ITD) (0.796; p < 0.001), annulus area (0.782; p < 0.001), anterior mitral leaflet area (0.767; p < 0.001), Anterior-posterior diameter (0.679; p < 0.001) and AML length (0.515; p < 0.001). In multivariable regression analysis, only CW and ITD were found to be independent predictors of annuloplasty ring size (R2=0.743; p < 0.001). The highest level of agreement was achieved with CW and ITD, and 76.6% of patients received a ring with no greater than one ring size difference from the predicted ring sizes.

CONCLUSIONS

3D-MV reconstruction models can support surgeons in the decision-making process for annuloplasty ring sizing. The present study may be a first step towards accurate annuloplasty ring size prediction using multimodal Machine Learning decision support.

Case report: A novel surgical technique for rapid valve-in-ring implantation into the native aortic annulus during left ventricular assist device implantation

The implantation of a left ventricular assist device (LVAD) has become an essential requirement for managing patients with end-stage heart failure. However, aortic valve insufficiency is a contraindication for LVAD implantation in patients with end-stage heart failure, partly because of the decreasing efficiency of mechanical circulatory support and the eventual development of right ventricular failure. Herein, we present the first case of performing transcatheter aortic valve replacement in valve-in-ring along with LVAD implantation for the treatment of a 60-year-old male suffering from refractory heart failure due to dilated cardiomyopathy and pure aortic insufficiency in need of a new aortic bioprosthesis. A balloon-expandable bioprosthetic transcatheter heart valve was implanted into a previously sewn annulus ring into the aortic root via transaortic access. Subsequently, a centrifugal-flow LVAD was implanted. Postoperatively, the patient was in New York Heart Association Functional Class (NYHA) II with 6-min walk test of 310 m. The patient has completed 6 months of follow-up with no events. This novel and feasible surgical technique reduced the cardiopulmonary bypass time and duration of surgery. Furthermore, it avoids the risk of redo sternotomy and decreases the chances of paravalvular leakage and worsening of aortic regurgitation.

[Surgical repair of secondary tricuspid regurgitation]

Optimal surgical strategy for secondary tricuspid regurgitation is still under discussion. First of all, this is due to rare organic disease of tricuspid valve and tricuspid regurgitation is almost always classified as secondary insufficiency. Fibrous annulus enlargement of tricuspid valve is the most common cause of tricuspid regurgitation. Annular dilatation may by the result of left ventricular failure due to myocardial or valvular diseases, right ventricular enlargement, pressure or volume overload. No surgical correction of tricuspid insufficiency during cardiac surgery for other leading disease aggravates short- and long-term results. Considering the wide interest and disputes around optimal surgical strategy for tricuspid regurgitation, this review is devoted to modern methods of surgical treatment of secondary tricuspid insufficiency.

Bicuspid aortic valve repair adapted to aortic phenotype

The bicuspid aortic valve (BAV) is the most common congenital cardiovascular anomaly and may present with differing phenotypes including almost constant annular dilation. We have developed a standardized approach to BAV repair with a systematic adjunct of aortic annuloplasty according to the three phenotypes of the proximal aorta, which include a dilated aortic root, dilated ascending aorta and normal root and ascending aorta. In our cohort of 191 patients, freedom from AV-related re-intervention was 98% for remodeling with annuloplasty (n=100) and 100% for tubular aortic replacement with annuloplasty (n=31) at 8 years. In an isolated aortic insufficiency (AI) group, freedom from AV-related re-intervention varied from 72.4% with a single subvalvular annuloplasty ring (n=31) compared to 100% at 6 years when a double sub- and supra-valvular (STJ) annuloplasty ring was performed (n=29). Restoration of the annulus: sinotubular junction (STJ) ratio is a key factor to ensure longevity of the bicuspid valve repair and freedom from re-intervention.

Computational virtual evaluation of the effect of annuloplasty ring shape

Mitral regurgitation (MR) is a result of mitral valve (MV) pathology. Its etiology can be categorized as degenerative or functional MR. Ring annuloplasty aims to reconfigure a dilated mitral annulus to its normal size and shape. We investigated the effect of annuloplasty ring shape on MR outcome using our established 3-dimensional (3-D) echocardiography-based computational MV evaluation protocols. Virtual patient MV models were created from 3-D transesophageal echocardiographic data in patients with MR because of mitral annular dilation. Two distinct annuloplasty rings (Physio II and GeoForm) were designed and virtually implanted to the patient MVs. Dynamic finite element simulations of MV function were performed for each MV after virtual ring annuloplasty of either ring, and physiologic and biomechanical characteristics of MV function were compared. Excessive stress values appeared primarily in the midanterior and midposterior regions, and lack of leaflet coaptation was found in pre-annuloplasty patient MVs. Both rings demonstrated marked reduction of stresses and efficient leaflet coaptation. The Physio II ring demonstrated more evenly distributed stress reduction across the leaflets and annulus compared with the GeoForm ring. Conversely, the highly nonplanar curvature of the GeoForm ring more effectively increased leaflet coaptation compared with the Physio II ring. This indicates that the shape of annuloplasty ring affects post-annuloplasty physiologic and biomechanical conditions, which can lead to tissue alteration over a longer period after ring annuloplasty. This virtual ring annuloplasty simulation strategy provides detailed physiologic and biomechanical information and may help better plan the optimal ring selection and improved patient-specific MV repairs.

Comparison of outcomes of tricuspid annuloplasty with 3D-rigid versus flexible prosthetic ring for functional tricuspid regurgitation secondary to rheumatic mitral valve disease

BACKGROUND

Annuloplasty bands and rings are widely used for repairing functional tricuspid regurgitation (FTR). However, the question regarding which is the ideal annuloplasty device remains unclear. The aim of this study was to compare the efficacy and mid-term durability of tricuspid ring annuloplasty for FTR secondary to rheumatic mitral valve disease using flexible Cosgrove-Edwards band and the rigid Edwards MC3 ring (Edwards Lifesciences, LLC, Irvine, CA, USA).

METHODS

We retrospectively collected the clinical data of those who underwent mitral valve replacement (MVR) in concomitant with tricuspid ring annuloplasty from 2009 to 2013. The flexible band was used in 46 patients (flexible group), and the 3D rigid ring was used in 60 patients (rigid group). Echocardiographic evaluation of tricuspid function was performed preoperatively and postoperatively.

RESULTS

The grade of TR was significantly improved compared to preoperative values in two groups. There was no significant difference regarding postoperative TR grade between the two groups at 1 week and 2-3 months but there was statistical significant difference at postoperative 6-12 months, and 2-3 years. During the follow up period, 25 of 46 patients (54.3%) in flexible group and 22 of 60 patients (30.3%) in rigid group developed recurrent TR. Freedom from recurrent TR in flexible group is significant lower than rigid group in each postoperative follow up period.

CONCLUSIONS

These findings suggest that 3D rigid ring annuloplasty might be more effective for tricuspid ring annuloplasty in FTR in mid-term postoperative periods when compared to flexible band.

Novel Echocardiographic Indices as Predictors of Immediate Recurrence after Undersized Ring Annuloplasty for Ischemic Mitral Regurgitation

BACKGROUND AND AIM

Ischemic mitral regurgitation (IMR) is among the most serious complications of myocardial infarction which doubles the late mortality; mainly treated by undersizing ring annuloplasty. To find some preoperative echocardiographic indices that predict immediate failure of mitral valve annuloplasty (MVA), we designed the present study with more focusing on some novel parameters.

METHOD

Transthoracic echocardiography (TTE) indices of consecutive patients referred with 3+ or 4+ IMR were registered 24 hours before surgery. Thirty days later, a second TTE was performed. According to the results, the patients were categorized as the "successful" group (with 1+ or less mitral regurgitation) and the "unsuccessful" group (with 2+ or higher MR). Preoperative TTE indices were compared among the two groups using suitable statistical tests.

RESULTS

Of the total of 126 cases, 68 had successful and 58 had unsuccessful MVA. Statistically significant differences were found between the two groups for left ventricular ejection fraction (LVEF) (P = 0.007), left ventricular end systolic volume (LVESV) (P = 0.044), and basal-interpapillary muscle distance (IPMD) diastolic-to-systolic ratio (DSR) (P = 0.008). Receiver Operating Characteristic analysis demonstrated 37.5%, 3.85 cm(3) , and 1.25, as the best cutoff points for LVEF (P = 0.03, sensitivity: 81%, specificity: 69%), LVESV (P = 0.023, sensitivity: 83%, specificity: 57%), and basal-IPMD DSR (P = 0.001, sensitivity: 100%, specificity: 95%), respectively.

CONCLUSION

Among all TTE indices, LVEF, LVESV, and basal-IPMD DSR were helpful to differentiate between the successful and unsuccessful MVA results. We believe the basal-IPMD DSR as a novel index could be targeted in the future studies.