Ann Thorac Surg 2000;70:1073-1076
© 2000 The Society of Thoracic Surgeons
Supplement: cardiothoracic techniques & technologies
Mitral valvuloplasty with sutures used for aortic prosthesis implantation
Wojciech Sarnowski, MDa,
Aleksy Ponizy
ski, MDa,
Andrzej Szyszka, MDa,
Zofia Oko-Sarnowska, MDa,
Mariusz Laciski, MDa,
Piotr Buczkowski, MDa,
Wojciech Dyszkiewicz, MD, PhDa
a Institute of Cardiology, Karol Marcinkowski University of Medical Sciences in Pozna, Pozna, Poland
Address reprint requests to Dr Sarnowski, ul. Dluga 1/2, 61-848 Pozna, Poland
e-mail: mlacinsk{at}sequoia.usoms.poznan.pl
Presented at the Sixth Annual Cardiothoracic Techniques and Technologies Meeting 2000, Ft Lauderdale, FL, Jan 27–29, 2000.
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Abstract
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Background. The purpose of this study was to analyze surgical treatment for aortic valve lesions with coexisting mitral regurgitation (MR).
Methods. Seventy-five patients were divided into two groups according to intensity of MR (group 1, MR less than or equal to II; group 2, MR greater than or equal to II/III). There were two control groups (control 1, only patients with implantation of aortic valve; control 2, patients with implantation of both aortic and mitral prostheses). During implantation of a mechanical aortic prosthesis, the same suture for fixation of a mechanical prosthesis and for suspension of mitral commissural regions and lifting the base of anterior mitral cusp was used.
Results. In all patients, no early death occurred. There were two late deaths, one due to endocarditis, and the other to heart failure. All patients from both groups had decreased MR. Selected echocardiographic parameters improved: end diastolic and end systolic diameter and ejection fraction in group 2 improved in proportion to patients in whom mitral valves were implanted (control 2).
Conclusions. Simultaneous suspension of the mitral commissure area during mechanical aortic prosthesis implantation reduces associated MR. This technique seems to be efficient during implantation of aortic prostheses in patients with coexisting MR.
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Introduction
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In natural history of acquired aortic valve lesion, dilatation of the left ventricle (LV) may be seen. Due to this dilatation, mitral regurgitation (MR) can occur, which is secondary to the dilatation of mitral annulus [1–3]. Implantation of aortic prosthesis decreases end-diastolic and end-systolic left ventricular diameter (EDD and ESD) usually and restores normal geometry of LV [2–4]. Consequently, dilatation of mitral annulus is decreased and MR disappears. During implantation of aortic prosthesis many surgeons do not modify coexisting MR [1].
During implantation of the mechanical aortic prosthesis in patients with organically changed mitral valve some kind of mitral valvuloplasty ought to be considered instead of mitral valve replacement [1, 4–6].
Physiologically, the base of the mitral annulus is strongly anchored to the aortic valve ring. Dilatation of the LV and the left atrium weakens lateral annulus and the base of the posterior cusp, which becomes dilated and displaced downwards. This downward displacement was well described by Grant in 1953 (as cited in Wooler and associates [7]). In 1962, Wooler and coworkers [7] showed that surgical correction of MR is connected with elevation and plication of anterior and posterior mitral commissural region. In 1977 the same results were presented by Kay and coworkers [8] who repaired MR with mattress sutures placed in the commissural area to obliterate the MR by stretching and lifting the posterior part of the mitral annulus. After placing the sutures, the posterior part of the dilated mitral annulus decreased considerably [7, 8].
According to the results of Wooler and Kay and their colleagues we aimed to decrease coexisting MR during implantation of mechanical aortic prosthesis, using the same suture for fixation of mechanical prosthesis and suspension of mitral commissural regions. Likewise, the lifting of the base of anterior mitral cusp was carried out.
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Material and methods
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A total of 75 patients were operated on with aortic valve disease and coexisting MR. Due to the size of the MR we divided them into two groups. Group 1 (n = 32, 5 women, 27 men, aged 54.6 ± 12.3 years) MR was less than or equal to II and group 2 (n = 43, 12 women, 31 men, aged 54.5 ± 8.9) MR was greater than or equal to II/III. In all patients, implantation of mechanical aortic prosthesis and suspension of commissural mitral areas with lifting of anterior mitral leaflet were performed. For group 1 there was a control group, control 1, which consisted of 23 patients (8 women, 15 men, aged 56.8 ± 10.6) with aortic valve disease and coexisting MR. In that group only implantation of aortic prosthesis was done. For group 2, there was another control group, control 2 (n = 10, 4 women, 6 men, aged 53.3 ± 8.6 years) in which mitral prostheses were implanted as well.
The selected echocardiographic parameters of group 1 and group 2, control 1, and control 2 before operation are presented in Table 1.
Surgery
All operations were performed with the use of cardiopulmonary bypass, with membrane or capillary oxygenation. Moderate hypothermia (28°C) and topical cardiac cooling were applied. Cold cardioplegic solutions of St. Thomas Hospital II were used. After cross-clamping the aorta and incising the aortic wall, maximal excision of aortic valve was acquired. Later on, the anterior mitral leaflet and subvalvular apparatus was inspected. When the anterior mitral cusp was flexible without the calcium, the chordae tendineae were longer than normal and different in shape. Afterward the mitral commissural areas and the base of anterior mitral leaflet were suspended. Next, the mattress sutures were placed on aortic annulus from inside the LV and passed through a Dacron ring of mechanical prostheses. Two sutures with Teflon pledgets were placed in areas of mitral commissures. Other sutures between them, without pledgets, were placed in the bottom of anterior mitral leaflet (Fig 1).
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Fig 1. Suspending sutures in the mitral commissure area. (aml = anterior mitral leaflet; ar = aortic ring; lca = ostium of the left coronary artery; mr = mitral ring; ms = mattress sutures; PW = posterior wall; rca = ostium of the right coronary artery; tp = Teflon pledget.)
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Echocardiographic examination
All patients had a transthoracal echocardiographic examination with the use of a Hewlett-Packard Sonos 1000 device with a 3.5-MHz electronic transducer. Examinations performed before operation and 4 months to 5 years after were compared. Presence and magnitude of MR were assessed by comparison of the regurgitation volume (MRV) and the left atrium volume (LAV). We categorized the MR in 4 degrees according to the following formula: degree of MR (%) = MRV/LAV x 100%. Thus, 0 = no MR; 0/I less than 10% MR; I = 20% MR; I/II = 30% MR; II = 40% MR; II/III = 50% MR; III = 60% MR; III/IV = 70% MR; IV greater than or equal to 80% MR.
Statistical analysis
Results were presented as mean value ± standard deviation (SD). Differences between groups were evaluated with the use of Student’s t test for independent variables.
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Results
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No early death had occurred in both groups. After the second aortic valve implantation performed in the course of endocarditis 4 months after the first operation 1 patient from group 1 died. Due to progression of heart failure 1 patient from group 2 died.
In both groups early and later after operation showed no serious thromboembolic events. Early after operation, there was one dysfunction of the aortic prosthesis in group 1. In this case (a man aged 49 years), 4 days after the operation, echo examination revealed dysfunction of an aortic prosthesis. During reoperation dehiscence between the prosthetic ring and the aortic annulus ring in left coronary Valsalva sinus was observed. After that he underwent implantation of a new mechanical prosthesis one size smaller than previous. Without complication he was discharged from the hospital 12 days after operation.
In most patients in groups 1 and 2 improvement of physical capacity was observed postoperatively. Mean grade of New York Heart Association (NYHA) classification decreased from II/III to I/II in group 1 (p < 0.0001) and from III to II in group 2 (p < 0.0001). This improvement was observed in patients from the control groups too. In control 1 NYHA improved from II/III to I/II (p < 0.0001) and in control 2 NYHA improved from II/III to II (p < 0.01).
In proportion to the control 1 group, the degree of MR diminished significantly in all groups but there were more patients with less advanced MR after operation in group 1 (Fig 2). There was no MR higher than II in group 1. In control 1 (in which implantation of only a mechanical prosthesis was done) there were 3 patients who had III MR and 1 patient with IV MR after operation.
In patients from group 1 all analyzed parameters decreased significantly except ejection fraction (EF), which increased significantly (Table 1). In patients from group 2 (MR higher than II/III) EF increased significantly. Others parameters decreased significantly except diameter of the aorta (Table 1). In patients from control 1 all parameters decreased significantly except ESD, LA, and EF (Table 1).
In patients from control 2 there were no significant changes in the analyzed parameters (Table 1).
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Comment
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Hemodynamically significant MR in the course of aortic valve lesion in most cases is due to altered geometry of LV, predominantly its dilatation, altered spatial relationship of subvalvular structures, and distension of the mitral valve annulus [2–4, 9]. If MR accompanies pure aortic regurgitation, the two low impedance lesions cause accumulation of hemodynamic consequences. Coexistence of MR with complex aortic lesions with dominance of stenosis can be considered in the early stages of disease as a mechanism protecting LV from rapid elevation of systolic pressure in the chamber. However, in late stages compensating mechanisms begin to fail; in mixed left ventricular hypertrophy additional MR poses cumulative stress to a failing LV [2, 3, 5, 9]. Coexistence of organic pathology of both aortic and mitral valves produces disturbances of a mixed nature from the very beginning. The management of patients with combined lesions of mitral and aortic valves presents a difficult medical and surgical problem [1, 5, 6, 9].
Thus it seems obvious to consider surgical correction of both valves in cases of aortic valve lesions associated with MR. Some researchers have reported that in cases of coexistent MR with surgical aortic valve it is enough to implant only an aortic prosthesis, because after that the coexisting MR will disappear [1]. For example, the surgical relief of aortic stenosis may decrease the distending force in the left ventricular chamber and permit diminution in size of the cavity thus allowing closure of the valve leaflets. This chain of events might explain the postoperative disappearance of the MR that had been proved to exist preoperatively by clinical and hemodynamic studies [1, 4]. Controversy begins when aortic valve disease coexists with MR of more than II/III. Decision about implantation of a second mitral prosthesis usually depends on the anatomic state of the mitral valve estimated through the excised aortic valve at the time of operation [1, 3]. At that time the surgeon ought to decide whether to implant a mitral prosthesis or to perform a smaller operation, such as some kind of plasty of the mitral valve.
Terzaki and colleagues [1] found that during surgery of combined mitral and aortic valve diseases in the patients in whom two prostheses were implanted the mortality was worse than in patients in whom only an aortic prosthesis was implanted. Of course when mitral valve cusps are calcified and the subvalvular apparatus is shortened and seriously thickened because of fiber deposition, resection of valve and implantation of a prosthetic valve seems to be necessary. In cases when MR results from dilatation of mitral annulus we consider possibility of correction only with the sutures that we need for fixation of aortic prosthesis.
Wooler and Kay and colleagues [7, 8] introduced methods of plastic surgery of MR with suture placing in the region of the mitral commissure so after tying them the bottom of the mitral annulus was stretched and lifted up. This method was the basis of our study. In our technique two sutures with pledgets were placed in the commissural region and after tying them on the prosthetic ring the region was lifted up about 1 to 1.5 cm. Additional sutures were placed in the bottom of the anterior mitral cusp (Fig 1).
In all patients after operation we observed clinical and echocardiographic improvement (Table 1). Analysis of obtained results shows interesting differences between group 2 and control 2. In patients in whom mitral valves were preserved (group 2) EDD, ESD, and left ventricle mass were significantly greater at baseline in proportion to the patients in whom mitral valves were replaced (control 2). In spite of that performed procedures changed analysed echocardiographic parameters more effective in group 2 than was observed in patients after aortic and mitral replacement. We suggest that it may be better to suspend the mitral valve area than to implant a mitral prosthesis, probably due to preservation of the subvalvular apparatus of the mitral valve.
Aortic valve replacement with suspension of mitral commissure seems to be more effective than aortic valve replacement only in reduction of MR.
The results obtained demonstrate that aortic valve surgery in which the same sutures were used to implant the aortic prosthesis and to suspend the mitral commissure may be indicated for treatment of mitral regurgitation coexisting with aortic valve disease.
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References
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Terzaki A.K., Cokkinos D.V., Leachman R.D., Meade J.B., Hallman G.L., Cooley D.A. Combined mitral and aortic valve disease. Am J Cardiol 1970;25:588-601.[Medline]
-
Carabello B.A., Williams H., Gash A.K., et al. Hemodynamic predictors of outcome in patients undergoing valve replacement. Circulation 1986;6:1309-1316.
-
Ross J. Afterload mismatch in aortic and mitral valve disease. J Am Coll Cardiol 1985;5:811-826.[Medline]
-
Morris J.J., Schaff H.V., Mullany C.J., et al. Determinants of survival and recovery of left ventricular function after aortic valve replacement. Ann Thorac Surg 1993;56:22-30.[Abstract/Free Full Text]
-
Harpole D.H., Jr, Rankin J.S., Wolfe W.G., et al. Effects of standard mitral valve replacement on left ventricular function. Ann Thorac Surg 1990;49:866-874.[Abstract/Free Full Text]
-
Acar J., Michel P.L., Luxereau P., et al. How to manage patients with severe left ventricular dysfunction and valvular regurgitation. J Heart Valve Dis 1996;5:421-429.[Medline]
-
Wooler G.H., Nixon P.G.F., Grimshaw V.A., Watson D.A. Experiences with the repair of the mitral valve in mitral incompetence. Thorax 1962;17:49-57.
-
Kay J.H., Zubiate P., Mendez M.A., Vanstrom N., Yokoyama T. Mitral valve repair for significant mitral insufficiency. Am Heart J 1978;96:254-262.
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Hess O.M., Ritter M., Schneider J., Grimm J., Turina M., Krayenbuehl H. Diastolic stiffness and myocardial structure in aortic valve disease before and after valve replacement. Circulation 1984;69:855-865.[Abstract/Free Full Text]
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Abstract
Introduction
