Comparison Of Outcomes Of Tricuspid Annuloplasty With 3D-Rigid Versus Flexible Prosthetic Ring For Functional Tricuspid Regurgitation Secondary To Rheumatic Mitral Valve Disease

Background Functional tricuspid regurgitation(FTR)is common in patients with rheumatic mitral valve disease.The primary causes of FTR are annular dilation and right ventricular enlargement which may lead to tricuspid anatomical and functional abnormalities.FTR is often secondary to left heart failure from myocardial or valvular causes,right ventricular volume and pressure overload,and dilation of cardiac chambers.Secondary(functional)tricuspid regurgitation(TR)is associated with poor outcome and predicts poor survival,heart failure,and reduced functional capacity.However,the optimal surgical technique such as repair vs.replacement,access,type of prosthesis to rectify TR remains challenging.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.Objective 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).Method: We retrospectively collected the clinical data of those who underwent mitral valve replacement(MVR)in concomitant with tricuspid ring annuloplasty from September 2009 to December 2013.The flexible band was used in 46 patients(flexible group),and the three-dimension(3D)rigid ring was used in 60 patients(rigid group).Echocardiographic evaluation of tricuspid function was performed preoperatively and postoperatively.The indications for tricuspid ring annuloplasty were moderate and above FTR.Patients with tricuspid insufficiency caused by congenital tricuspid valve abnormalities or primary lesion such as trauma,infective endocarditis and autoimmune disease were excluded from this study.Patients who were treated with simultaneous aortic valve replacement,coronary artery bypass surgery,radiofrequency ablation of atrial fibrillation,and surgical correction of congenital heart disease were also excluded.All patients were assessed preoperatively by transthoracic two-dimensional and color Doppler echocardiography.The severity of TR were evaluated using the apical four chamber view and was graded as 0 for no regurgitation,1+ for mild regurgitation,2+ for moderate regurgitation,3+ for moderately severe regurgitation,and 4+ for severe regurgitation.All surgeries were performed through median sternotomies with bicaval and aortic cannulation and standard hypothermic cardiopulmonary bypass(CPB)by the same surgeon.After clamping the ascending aorta,the right atrium and interatrial septum were dissected.Thereafter,tricuspid valve repair was performed with flexible band or with rigid ring annuloplasty following concomitant MVR and closure of atrial septal incision.In this study,two kinds of tricuspid annuloplasty devices were used: Cosgrove-Edwards flexible band and Edwards MC3 rigid ring.For patients receiving flexible band,tricuspid ring annuloplasty was done with the use of the Cosgrove-Edwards annuloplasty system.Seven to ten 2–0 Ethibond Excel sutures(Ethicon Endo-Surgery,LLC,USA)were placed on the annulus along the anterior and posterior leaflets.A Cosgrove-Edwards flexible band was tied down with the sutures and placed on the annulus under cardiac arrest.For patients receiving rigid ring,tricuspid ring annuloplasty were done with the use of the Edwards MC3 tricuspid annuloplasty system.Nine to eleven 2–0 Ethibond Excel sutures were placed on the annulus,running from the anteroseptal commissure to the middle of the septal leaflet along the anterior and posterior leaflets.A MC3 rigid ring was tied down with the sutures and placed on the annulus under cardiac arrest.In both conditions,the ring size was determined by the length between the commissures along the septal leaflet under cardiac arrest.The prosthetic valves used during MVR were all On-X Mitral Prothetic Heart Valve(On-X Life Technologies,Inc.,USA).After surgery,patients were followed up on postoperative day seven and regularly every three to six months.The patients were followed at outpatient clinic in our hospital.During the follow up period,patient’s clinical status and echocardiographic results were obtained by the cardiologists.All data analyses were performed by using the Statistical Package,version 17.0(SPSS Inc.,Chicago,IL,USA).Categorical variables were expressed as numbers and/or percentage and compared using the χ2 test or Fisher’s exact test as appropriate.Continuous variables are expressed as mean ± standard deviation(SD)and compared by Mann-Whitney U test.Survival probabilities were constructed using Kaplan–Meier survival estimates.Comparisons between survival curves were performed by using the log-rank test.The differences were considered statistically significant at a P<0.05.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.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.