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Mitral Valve Surgery in Patients With Severe Mitral Annular Calcification
Mitral Valve Surgery in Patients With Severe Mitral Annular Calcification Tomoya Uchimuro, MD, Toshihiro Fukui, MD, Atsushi Shimizu, MD, and Shuichirou Takanashi, MD Department of Cardiovascular Surgery, Sakakibara Heart Institute, Tokyo, Japan
Background. Mitral valve surgery in patients with severe mitral annular calcification can be challenging. We investigated surgical outcomes of mitral valve surgery with complete annular decalcification and reconstruction. Methods. Between January 2004 and December 2013, 2,104 patients underwent mitral valve surgery at our institution. Of these, 61 patients (mean age 70 years) with severe mitral annular calcification were reviewed. Valve lesions were stenosis in 20 patients (32.8%), regurgitation in 16 (26.2%), mixed in 19 (31.1%), and prosthetic valve dehiscence in 6 (9.8%). Calcified annulus was resected completely and reconstructed with equine pericardium in 48 patients (78.7%), autologous pericardium in 10 (16.4%), and polytetrafluoroethylene felt pledgets in 3 (4.9%). Mitral valve repair was attempted in 4 patients (6.6%) and mitral valve replacement in 57 (93.4%). One patient (1.6%) had conversion from repair to replacement due to cardiac rupture. Concomitant procedures included aortic valve
replacement in 36 patients (56.3%), tricuspid valve surgery in 28 (43.8%), and coronary artery bypass graft surgery in 18 (28.1%). Mean follow-up was 3.5 ± 2.5 years. Results. There was no 30-day hospital death. Early complications were left ventricular pseudoaneurysm in 1 patient, pericardial patch dehiscence in 1, severe arrhythmia in 6, and stroke in 2. At 5 years, rates of survival and freedom from cardiac death and major adverse valverelated events were 75.6%, 79.7%, and 72.7%, respectively. Multivariate analysis indicated coronary artery disease as an independent predictor of cardiac death. Conclusions. In patients with severe mitral annular calcification undergoing mitral valve surgery, complete annular decalcification and reconstruction yields favorable outcomes.
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replacements (MVR)—at our institution. Of these, 61 patients (2.9%) with severe MAC who underwent decalcification and reconstruction of the mitral annulus were enrolled in this study. Table 1 presents the clinical profile of the patients. Our Institutional Review Board approved this retrospective study and waived the need for written informed consent.
itral annular calcification (MAC) is a chronic degenerative noninflammatory condition characterized by calcification of the fibrous support surrounding the mitral valve (MV). The calcification usually extends along the posterior annulus and may also extend into the left ventricular (LV) muscles. Mitral valve surgery in the presence of MAC is associated with relatively high mortality and morbidity because it may result in cardiac rupture or prosthetic valve dehiscence [1–3]. Although various procedures have been described, no surgical strategy of choice has been established. We adopted the strategy of performing MV surgery after complete decalcification and reconstruction of the annulus; this enables the prosthesis to be safely secured into the newly reconstructed annulus [4]. The present study presents early and midterm outcomes of MV surgery with extensive annular decalcification and reconstruction in patients with MAC at our institution.
Patients and Methods Patient Characteristics Between January 2004 and December 2013, 2,104 patients underwent MV surgery—1,313 MV repairs and 791 MV Accepted for publication Aug 28, 2015. Address correspondence to Dr Uchimuro, Department of Cardiovascular Surgery, Sakakibara Heart Institute, 3-16-1, Asahi-cho, Fuchu, Tokyo 183-0003, Japan; e-mail: [email protected].
Ó 2015 by The Society of Thoracic Surgeons Published by Elsevier
(Ann Thorac Surg 2015;-:-–-) Ó 2015 by The Society of Thoracic Surgeons
Operative Procedures After sternotomy and establishment of cardiopulmonary bypass, the MV was exposed through a transseptal superior approach. Mitral valve repair is indicated for patients with nonrheumatic primary mitral regurgitation due to anterior leaflet prolapse, posterior prolapse, bileaflet prolapse, commissural prolapse, or combined lesions without extension of the MAC to the MV leaflet. However, MVR should be preferred for patients with mitral stenosis, rheumatic disease, extensive degenerative alteration of the valve, or extensive MAC involving valve leaflet or subvalvular apparatus. In 4 patients, the MV was considered to be repairable. The prolapsed section of the posterior leaflet was resected or prolapse of the anterior leaflet was corrected by artificial chordal reconstruction with expanded polytetrafluoroethylene sutures. The mural leaflet whose base had MAC was detached at the edge of the calcification, giving access to the ventricular aspect of the calcium formation. The annulus was carefully decalcified using scissors, 0003-4975/$36.00 http://dx.doi.org/10.1016/j.athoracsur.2015.08.071
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Table 1. Clinical Profile of Patients Clinical Profile
MVR (n ¼ 57)
Male 17 (29.8) Age, years 69.4 10.1 Diabetes mellitus 13 (22.8) Hemodialysis 14 (24.6) EuroSCORE II 6.6 6.7 Cardiac rhythm Sinus 36 (63.2) Atrial fibrillation 15 (26.3) Heart block (pacemaker rhythm) 6 (10.5) NYHA class III or IV 20 (35.1) Left ventricular ejection fraction, % 58.5 11.2 Mitral valve disease Mitral stenosis 20 (35.1) Mitral regurgitation 12 (21.1) Mitral stenosis and regurgitation 19 (33.3) Prosthetic valve dehiscence 6 (10.5) Infective endocarditis 3 (5.3) Coronary artery disease 16 (28.1) Tricuspid regurgitation II 27 (47.4) Previous cardiac operation 13 (22.4) Mitral valve replacement 6 (10.5) Commissurotomy 3 (5.3) Aortic valve replacement 0 (0) MVRþAVR 1 (1.8) Bentall 1 (1.8) Atrioventricular septal defect repair 2 (3.5)
MV Repair (n ¼ 4) 1 (25.0) 78.0 11.2 0 0 8.4 7.9 4 (100) 0 (0) 0 (0) 0 (0) 72.0 8.2 0 4 0 0 0 2 1 1 0 0 1 0 0 0
(0) (100.0) (0) (0) (0) (50.0) (25.0) (16.7) (0) (0) (25.0) (0) (0) (0)
Values are n (%) or mean SD. AVR ¼ aortic valve replacement; MV ¼ mitral valve; MVR ¼ mitral valve replacement; EuroSCORE ¼ European System for Cardiac Operative Risk Evaluation; NYHA ¼ New York Heart Association.
rongeurs, and a Cavitron ultrasonic surgical aspirator (CUSA EXcel; Integra LifeSciences, Plainsboro, NJ [Fig 1A and B]). This decalcification was performed until the all calcium was removed and circumscribing atrioventricular fat or ventricular myocardium could be identified. One of the margins of a pericardial patch was sutured to the posterior left atrial wall, and the other was sutured to the smooth endocardium of the healthy LV myocardium with a continuous 4-0 polypropylene suture to cover the entire debrided area (Fig 1C). The annulus was reconstructed using autologous pericardium in 2 patients and equine pericardium in 2 patients. Next, the posterior leaflet was reattached to the pericardial patch at the level of the original annulus (Fig 1D). Lastly, a prosthetic ring was placed at the reconstructed annulus in 3 cases with annular dilatation (Fig 1E). In 57 patients whose MV was thought to be nonrepairable, the native or prosthetic valve was removed. Debridement and patch reconstruction of the annulus was performed in the same way as described above (Fig 2A through C). However, the area of annulus requiring reconstruction was more extensive in patients requiring MVR. More than two thirds of the posterior annulus was
reconstructed in 40 (70.2%) of those patients. Of the 4 patients who underwent MV repair, 2 (50%) had reconstruction of more than two thirds of the posterior annulus. In 3 patients whose MAC was limited to the annulus, the annular defect was reinforced with several mattress sutures buttressed with polytetrafluoroethylene felt pledgets. In the other 55 patients whose MAC extended into the LV myocardium, the annulus was reconstructed using autologous pericardium in 8 and equine pericardium in 47. The prosthetic valve was secured at the supraannular position with noneverted horizontal mattress sutures (Fig 2D and E). Table 2 summarizes the operative data. Postoperative transthoracic echocardiography was performed before discharge and at 1 year after surgery. Midterm follow-up was obtained through outpatient chart review and telephone interviews. Mean follow-up was 42 30 months (range, 1 to 107), and no patient was lost to follow-up. Cardiac death and major adverse valve-related events (MAVRE) were defined according to published guidelines for reporting mortality and morbidity after valve operations [5].
Statistical Analysis The software IBM SPSS Statistics for Windows, version 19 (IBM Corp, Armonk, NY), was used for all statistical analyses. Descriptive data were reported as mean SD for continuous variables and as proportions for categoric variables. The Kaplan-Meier method was used to estimate long-term survival and freedom from morbid events. All variables were analyzed by univariate analyses to identify risk factors for morbid events. Independent risk factors for late clinical adverse events were determined using the Cox proportional hazards regression model. Variables with a p value of less than 0.2 in univariate analysis were examined using multivariate analysis (Table 4). A p value of less than 0.05 was considered statistically significant.
Results Early Outcomes Early clinical results are presented in Table 3. There was no 30-day hospital mortality. Four patients died during hospitalization (inhospital mortality rate of 6.6%): 1 of pneumonia on postoperative day 133, 1 of rupture of LV pseudoaneurysm on postoperative day 80, 1 of mediastinitis on postoperative day 39, and 1 of cholecystitis on postoperative day 48. Postoperative complications included LV pseudoaneurysm in 1 patient, pericardial patch dehiscence in 1, stroke in 2, ventricular tachycardia in 1, permanent heart block requiring pacemaker insertion in 5, and mediastinitis in 3. A 93-year-old woman who underwent attempted MV repair and concomitant coronary artery bypass grafting had conversion to MVR because of intraoperative LV rupture; the MAC extended along the entire posterior annulus and into the LV myocardium. Complete decalcification, annulus reconstruction using equine pericardium, and prosthetic ring annuloplasty were performed. The LV
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Fig 1. Schematic diagram of the mitral valve repair. (A) Mitral valve with posterior leaflet prolapse and severe annular calcification. (B) Prolapsed leaflet was resected, and annular calcification was removed. (C) The annulus was reconstructed using the pericardium. (D) The posterior leaflet was reattached. (E) A prosthetic ring was placed at the annulus.
rupture was found after releasing the aortic clamp. Repair of the LV posterior wall using equine pericardium and MVR were performed but she had LV pseudoaneurysm postoperatively and died of rupture of the pseudoaneurysm. One patient with pericardial patch dehiscence underwent reoperation on postoperative day
6. In this patient, the pericardial patch used for reconstruction of the annulus had come off at residual calcification in the ventricular septal wall. We completely removed the residual calcification and performed reconstruction using a new equine pericardial patch. The postoperative course was uneventful. Fig 2. Schematic diagram of the mitral valve replacement. (A) Mitral valve with severe annular calcification. (B) Valve leaflets and annular calcification were removed completely. (C) The annulus was reconstructed using the pericardium. (D) Noneverted horizontal mattress sutures were placed at the annulus. (E) The prosthetic valve was secured at the supraannular position.
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Table 2. Operative Data Variables Extension of annular reconstruction Anterior annulus One third of posterior annulus Two thirds of posterior annulus Entire posterior annulus Whole annulus Material used for annular reconstruction Teflon felt Autologous pericardium Equine pericardium Mitral prostheses None Autologous pericardial band Flexible ring Semirigid ring Biologic valve CEP Mechanical valve SJM CarboMedics ATS ON-X Valve size, mm 21–23 25–27 29–31 Concomitant procedure Aortic valve replacement Tricuspid valve repair Coronary artery bypass graft Aortic graft Conversion from MV repair to MVR Operative time, minutes Cardiopulmonary bypass time, minutes Crossclamp time, minutes
Table 3. Early Clinical Results MVR MV Repair (n ¼ 57) (n ¼ 4) 2 15 21 18 1
(3.5) (26.3) (36.8) (31.6) (1.8)
3 (5.3) 8 (14.0) 46 (80.7)
0 2 1 1 0
0 (0) 2 (50.0) 2 (50.0) 1 1 1 1
9 48 21 15 9 3
(0) (50.0) (25.0) (25.0) (0)
(25.0) (25.0) (25.0) (25.0)
(15.8) (84.2) (36.8) (26.3) (15.8) (5.3)
5 (8.8) 47 (82.5) 5 (8.8) 36 27 16 2
(63.2) (47.4) (28.1) (3.5)
0 (0) 1 (25.0) 2 (50.0) 0 (0) 1 (25.0) 338 87 313 110 221 59 188 97 178 47 152 86
Values are n (%) or mean SD. ATS ¼ ATS Medical (Minneapolis, MN); CEP ¼ Carpentier-Edwards Perimount (Edwards Lifesciences, Irvine, CA); CM ¼ CarboMedics (Sorin Group, Milan, Italy); MV ¼ mitral valve; MVR ¼ mitral valve replacement; On-X ¼ On-X Life Technologies (Austin, TX); SJM ¼ St. Jude Medical (St. Paul, MN).
Early Results Thirty-day death Hospital death Perioperative complication Left ventricular rupture Stroke Reoperation Severe arrhythmia Mediastinitis New dialysis Respiratory failure (tracheotomy)
MVR (n ¼ 57)
MV Repair (n ¼ 4)
0 (0) 3 (5.3)
0 (0) 1 (25.0)
0 2 1 6 3 3 1
1 0 0 0 0 0 0
(0) (3.5) (1.8) (10.5) (5.3) (5.3) (1.8)
(25.0) (0) (0) (0) (0) (0) (0)
Values are n (%). MV ¼ mitral valve;
MVR ¼ mitral valve replacement.
patient who underwent MVR had moderate paravalvular leakage at the midposterior annulus on transthoracic echocardiography at 7 years 6 months postoperatively. The patient was followed without any intervention. No patients who completed MV repair had moderate or severe mitral regurgitation and required any reoperation during the follow-up period.
Risk Factors for Outcomes Univariate analyses showed that hemodialysis and coronary artery disease were associated with all-cause death (p < 0.2). Multivariate analysis identified coronary artery disease (hazard ratio [HR] 4.80, 95% confidence interval [CI]: 1.61 to 14.32, p < 0.01) as an independent predictor of all-cause death (Table 4). Similarly, univariate analyses showed that hemodialysis, MV repair, and coronary artery disease were also associated with cardiac death (p < 0.2). Multivariate analysis identified coronary artery disease (HR 11.1, 95% CI: 2.81 to 43.95, p < 0.01) as an independent predictor. Univariate analyses showed that the following variables were associated with MAVRE, with a p value of less than 0.2: coronary artery disease, tricuspid regurgitation greater than grade 2, and previous cardiac operation. Multivariate analysis identified coronary artery disease (HR 5.60, 95% CI: 1.86 to 16.86, p < 0.01) and tricuspid regurgitation greater than grade 2 (HR 3.12; 95% CI: 1.02 to 9.12, p ¼ 0.04) as independent predictors.
Late Outcomes Late deaths occurred in 15 patients. There were 12 cardiac deaths (sudden death in 6 patients, heart failure in 2, bleeding event in 2, prosthetic valve endocarditis in 1, and rupture of LV pseudoaneurysm in 1) and 3 noncardiac deaths (pneumonia in 1 patient, cholecystitis in 1, and mediastinitis in 1). At 5 years, survival from all-cause death and cardiac death was 75.6% 6.0% and 79.7% 5.9%, respectively (Fig 3A and B). There were 16 MAVRE (valve-related death in 9 patients, stroke in 3, cerebral hemorrhage in 3, and reoperation in 1). At 5 years, freedom from MAVRE and reoperation was 72.7% 6.5% and 98.3% 1.7%, respectively (Fig 3C and D). One
Comment Mitral valve surgery can be challenging for patients with MAC, which usually extends along the posterior annulus and spreads to the chordae tendineae and LV myocardium [6]. In this setting, MV surgery may cause serious complications such as cardiac rupture, left circumflex coronary artery injury, or thromboembolic events. The dangers of MAC in MV surgery were first described by Roberts and Morrow in 1967 [1], who noted LV perforation in 2 patients undergoing MVR in the presence of MAC. In 1985, Spencer and colleagues [2]
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Table 4. Predictors for Clinical Adverse Events
Outcome
Variable
All-cause CAD death Hemodialysis Cardiac CAD death MV repair Hemodialysis MAVRE CAD TR II Prev cardiac operation
Univariate Analysis p Value
Multivariate Analysis HR (95% CI)
p Value
<0.01
4.80 (1.61–14.32) <0.01
0.18 <0.01
1.30 (0.42–4.07) 0.65 11.1 (2.81–43.95) <0.01
0.15 0.18 <0.01 0.09 0.12
3.26 1.35 5.60 3.12 1.37
(0.64–16.69) 0.16 (0.36–5.11) 0.66 (1.86–16.86) <0.01 (1.07–9.12) 0.04 (0.79–2.37) 0.27
CAD ¼ coronary artery disease; CI ¼ confidence interval; HR ¼ hazard ratio; MAVRE ¼ major adverse valve-related events; MV ¼ mitral valve; Prev ¼ previous; TR ¼ tricuspid regurgitation.
reported severe MAC in 4 of the 14 patients with LV rupture after MVR. Cammack and colleagues [7] analyzed 72 septuagenarians undergoing MV surgery; MAC was present at the posterior annulus in 11
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patients, 3 of whom (27.3%) died postoperatively because of complications resulting from MAC. The early mortality of patients without MAC was 6.6%, significantly lower than that of patients with MAC. The investigators identified MAC at the posterior annulus as an independent risk factor for early death with MV surgery for elderly patients. Several surgical procedures have been proposed to avoid such complications associated with MAC [3, 4, 6–25]. They are divided into two groups: those with MAC debridement and annulus reconstruction, and those without it. In MVR, the first group includes prosthesis insertion techniques without decalcification of MAC [7–16]: direct placement of the prosthesis with sutures through or around the MAC [7, 10], placement at the mitral leaflets [8, 9], placement at the left atrial wall [11–14], and use of a collar patch attached to the sewing cuff [15, 16]. However, such techniques do not lower the risks of paravalvular leak, valve dehiscence, embolism of friable calcium, LV rupture, circumflex coronary artery injury, and a smallersized prosthesis than desired. Hospital mortality associated with these approaches has been reported to be 20% to 28%, higher than that reported for MVR overall (2.5% to 8.5%) [26–28].
Fig 3. Kaplan–Meier survival curves. (A) Survival from all-cause death. (B) Survival from cardiac death. (C) Freedom from major adverse valverelated events. (D) Freedom from reoperation.
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In MV repair, few researchers have reported repair techniques without resection of the MAC: edge-to-edge mitral repair without annuloplasty [17], simple leaflet repair, or artificial chordal reconstruction without annuloplasty [18, 19]. Maisano and colleagues [17] reported low hospital mortality of 3.7% and a high reoperation rate (freedom from reoperation at 4 years was 77% with MAC versus 95% without MAC). MAC was correlated with higher incidence of postoperative residual mitral regurgitation because the isolated leaflet repair could not correct annular dilatation and deformation. Although these techniques may lower the risks of LV rupture and circumflex coronary artery injury, a high risk of late failure should be expected. Maisano and colleagues [17] insisted that in a case of complete calcification of the annulus, or of high age, MVR might be the best solution. Simple leaflet repair, chordal reconstruction, or edge-toedge repair without manipulating MAC as a rescue procedure should be restricted to elderly patients at extremely high risk. The second group includes several procedures with decalcification of MAC [4, 6, 10, 18, 20–25]. Carpentier and associates [6] described sliding atrioplasty for annulus reconstruction using a freed left atrial flap, and some have followed this technique [10, 20]. Hospital mortality was reported to be 0% to 8.2% and 5-year survival, 84% to 100%. Carpentier and associates [6] reported good longterm results of 87% freedom from reoperation at 7 years. However, it is often difficult to mobilize and bring the left atrium over the debrided area in cases of pervasive MAC extending to the surrounding left atrial or LV wall [22]. Several investigators [4, 18, 20, 24, 25] described annulus reconstruction with Dacron or a pericardial patch. This technique is useful when extensive repair of the annulus is necessary after complete decalcification. Feindel and colleagues [24] reported the clinical outcomes of 54 patients undergoing 12 MV repairs and 42 MVR, with an operative mortality of 9.3%, a rate comparable with that of MVR overall (2.5% to 8.5%) and lower than that of the approaches without MAC debridement (20% to 28%). Therefore, we have also applied the patch reconstruction technique as a feasible and reliable management approach for MAC in MV surgery. The greatest concerns are that extensive debridement increases the risk of LV rupture and circumflex coronary artery injury. The pericardial patch increases the integrity of the atrioventricular groove and prevents fatal complications. In our series, 1 patient required reoperation for patch dehiscence because of residual calcification. Therefore, we believe that complete decalcification is important in the prevention of patch dehiscence. Carpentier and associates [6] also reported better long-term results with complete decalcification. The choice of material for the annulus reconstruction is also important because the prosthesis is sutured to the annulus made of the chosen material. Casselman and colleagues [21] described the use of an in situ anterior mitral leaflet. This technique is limited to patients in whom the anterior leaflet can be preserved. Vander Salm
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[22, 23] described reconstruction with Teflon felt pledgetreinforced sutures [22, 23]. David and colleagues [4] and Feindel and colleagues [24] reported the use of glutaraldehyde-fixed bovine pericardium or Dacron for the anterior annulus, and fresh autologous pericardium for the posterior annulus. Posterior annulus reconstruction alone could be achieved using the fresh autologous pericardium because the posterior annulus was subtended by the posterior LV wall, but in unsupported areas such as the fibrous tissue between the aortic and mitral annuli the use of glutaraldehyde-fixed bovine pericardium was recommended because of its apparent greater strength. Mihaljevic and colleagues [25] used autologous pericardium using the technique of the Toronto group [4, 24]. We initially used polytetrafluoroethylene felt pledget-reinforced sutures, especially when the area requiring reconstruction was limited to the annulus alone. As we gained experience, however, we began to use mainly pericardium. We prefer glutaraldehyde-fixed equine pericardium to fresh autologous pericardium because it is firm and strong, and applicable even in redo surgery, and because glutaraldehyde-preserved xenogenic pericardium available in Japan is equine rather than bovine. Few studies have examined long-term outcomes after MV surgery in patients with MAC; of these, the patient sample of Feindel and colleagues [24] was the largest, and the follow-up period the longest. They reported 5-year survival of 73% and freedom from reoperation at 5 years of 89%, with a mean follow-up of 4.1 years. Four patients required reoperation, including 1 for patch dehiscence and 1 for prosthetic valve dehiscence. There were no instances of LV rupture or aneurysm formation. In our series, 5-year survival and freedom from reoperation were 75.6% and 98.3%, respectively, over a followup period of 3.5 years. One patient had rupture of LV pseudoaneurysm. For MVR overall, 5-year survival and freedom from reoperation have been reported to be 64.7% to 90.0% and 95.3% to 97.7%, respectively [26–28]. The midterm results of the patch technique for patients with MAC were comparable to those of MVR overall. Our data suggest that complete removal of calcification leads to improved long-term results in patients with MAC. In our study, multivariate analysis identified coronary artery disease as an independent risk factor for cardiac death, and coronary artery disease and tricuspid regurgitation greater than grade 2 as independent risk factors for MAVRE. It seemed that preoperative ischemic cardiomyopathy or congestive heart failure might affect late mortality and morbidity. Therefore, if patients with MAC requiring MV surgery have coronary artery disease or tricuspid regurgitation greater than grade 2, careful follow-up over the long term is necessary. The present study has some limitations. This was a retrospective observational study at a single institution. The number of patients with MAC undergoing MV repair was small, and the follow-up period was short. In conclusion, in our experience of patients with severe MAC requiring MV surgery, extensive debridement of the annulus with reconstruction using pericardium is a feasible and effective procedure. This technique provides
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acceptable operative mortality and morbidity, and yields good midterm results.
References 1. Roberts WC, Morrow AG. Causes of early postoperative death following cardiac valve replacement: clinicopathologic correlations in 64 patients studied at necropsy. J Thorac Cardiovasc Surg 1967;54:422–37. 2. Spencer FC, Galloway AC, Colvin SB. A clinical evaluation of the hypothesis that rupture of the left ventricle following mitral valve replacement can be prevented by preservation of the chordae of the mural leaflet. Ann Surg 1985;202:673–80. 3. Okada Y. Surgical management of mitral annular calcification. Gen Thorac Cardiovasc Surg 2013;61:619–25. 4. David TE, Feindel CM, Armstrong S, Sun Z. Reconstruction of the mitral annulus. A ten-year experience. J Thorac Cardiovasc Surg 1995;110:1323–32. 5. Akins CW, Miller DC, Turina MI, et al. Guidelines for reporting mortality and morbidity after cardiac valve interventions. Eur J Cardiothorac Surg 2008;33:523–8. 6. Carpentier AF, Pellerin M, Fuzellier JF, Relland JY. Extensive calcification of the mitral valve annulus: pathology and surgical management. J Thorac Cardiovasc Surg 1996;111:718–29. 7. Cammack PL, Edie RN, Edmunds LH. Bar calcification of the mitral annulus. A risk factor in mitral valve operations. J Thorac Cardiovasc Surg 1987;94:399–404. 8. Coselli JS, Crawford ES. Calcified mitral valve annulus: prosthesis insertion. Ann Thorac Surg 1988;46:584–6. 9. Kurazumi H, Mikamo A, Suzuki R, Hamano K. Mitral-valve replacement for a severely calcified mitral annulus: a simple and novel technique. Eur J Cardiothorac Surg 2011;39:407–9. 10. d’Alessandro C, Vistarini N, Aubert S, Acar C, Pavie A, Gandjbakhch I. Mitral annulus calcification: determinants of repair feasibility, early and late surgical outcome. Eur J Cardiothorac Surg 2007;32:596–603. 11. Ruvolo G, Speziale G, Voci P, Marino B. “Patch-glue” annular reconstruction for mitral valve replacement in severely calcified mitral annulus. Ann Thorac Surg 1997;63:570–1. 12. Atoui R, Lash V, Mohammadi S, Cecere R. Intra-atrial implantation of a mitral valve prosthesis in a heavily calcified mitral annulus. Eur J Cardiothorac Surg 2009;36:776–8. 13. Di Stefano S, Lopez J, Florez S, Rey J, Arevalo A, San Roman A. Building a new annulus: a technique for mitral valve replacement in heavily calcified annulus. Ann Thorac Surg 2009;87:1625–7. 14. Kato Y, Hattori K, Bito Y, Kotani S, Inoue K, Shibata T. Simple supra-annular prosthesis insertion for dialysis patients with extensive mitral annular calcification. J Heart Valve Dis 2011;20:180–3.
UCHIMURO ET AL MANAGEMENT OF ANNULAR CALCIFICATION
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15. Nataf P, Pavie A, Jault F, Bors V, Cabrol C, Gandjbakhch I. Intraatrial insertion of a mitral prosthesis in a destroyed or calcified mitral annulus. Ann Thorac Surg 1994;58:163–7. 16. Okita Y, Miki S, Ueda Y, Tahata T, Sakai T, Matsuyama K. Mitral valve replacement with a collar-reinforced prosthetic valve for disrupted mitral annulus. Ann Thorac Surg 1995;59: 187–9. 17. Maisano F, Caldarola A, Blasio A, De Bonis M, La Canna G, Alfieri O. Midterm results of edge-to-edge mitral valve repair without annuloplasty. J Thorac Cardiovasc Surg 2003;126: 1987–97. 18. Chan V, Ruel M, Hynes M, Chaudry S, Mesana TG. Impact of mitral annular calcification on early and late outcomes following mitral valve repair of myxomatous degeneration. Interact Cardiovasc Thorac Surg 2013;17:120–5. 19. Morisaki A, Kato Y, Takahashi Y, Shibata T. Mitral valve repair without mitral annuloplasty with extensive mitral annular calcification. Interact Cardiovasc Thorac Surg 2014;19:1080–2. 20. Ng CK, Punzengruber C, Pachinger O, et al. Valve repair in mitral regurgitation complicated by severe annulus calcification. Ann Thorac Surg 2000;70:53–8. 21. Casselman FP, Gillinov AM, McDonald ML, Cosgrove DM. Use of the anterior mitral leaflet to reinforce the posterior mitral annulus after debridement of calcium. Ann Thorac Surg 1999;68:261–2. 22. Vander Salm TJ. Mitral annular calcification: a new technique for valve replacement. Ann Thorac Surg 1989;48: 437–9. 23. Vander Salm TJ. Mitral annular calcification: a new technique for valve replacement. Ann Thorac Surg 1997;63: 1819–20. 24. Feindel CM, Tufail Z, David TE, Ivanov J, Armstrong S. Mitral valve surgery in patients with extensive calcification of the mitral annulus. J Thorac Cardiovasc Surg 2003;126: 777–82. 25. Mihaljevic T, Koprivanac M, Kelava M, Smedira NG, Lytle BW, Blackstone EH. Mitral valve replacement in patients with severely calcified mitral valve annulus: surgical technique. J Thorac Cardiovasc Surg 2013;146:233–5. 26. Tominaga R, Kurisu K, Ochiai Y, et al. A 10-year experience with the Carbomedics cardiac prosthesis. Ann Thorac Surg 2005;79:784–9. 27. Chan V, Jamieson WR, Lam BK, Ling H, Fradet G, Mesana TG. Influence of the On-X mechanical prosthesis on intermediate-term major thromboembolism and hemorrhage: a prospective multicenter study. J Thorac Cardiovasc Surg 2010;140:1053–8. 28. Kaneko T, Aranki S, Javed Q, et al. Mechanical versus bioprosthetic mitral valve replacement in patients <65 years old. J Thorac Cardiovasc Surg 2014;147:117–26.
Background. Mitral valve surgery in patients with severe mitral annular calcification can be challenging. We investigated surgical outcomes of mitral valve surgery with complete annular decalcification and reconstruction. Methods. Between January 2004 and December 2013, 2,104 patients underwent mitral valve surgery at our institution. Of these, 61 patients (mean age 70 years) with severe mitral annular calcification were reviewed. Valve lesions were stenosis in 20 patients (32.8%), regurgitation in 16 (26.2%), mixed in 19 (31.1%), and prosthetic valve dehiscence in 6 (9.8%). Calcified annulus was resected completely and reconstructed with equine pericardium in 48 patients (78.7%), autologous pericardium in 10 (16.4%), and polytetrafluoroethylene felt pledgets in 3 (4.9%). Mitral valve repair was attempted in 4 patients (6.6%) and mitral valve replacement in 57 (93.4%). One patient (1.6%) had conversion from repair to replacement due to cardiac rupture. Concomitant procedures included aortic valve
replacement in 36 patients (56.3%), tricuspid valve surgery in 28 (43.8%), and coronary artery bypass graft surgery in 18 (28.1%). Mean follow-up was 3.5 ± 2.5 years. Results. There was no 30-day hospital death. Early complications were left ventricular pseudoaneurysm in 1 patient, pericardial patch dehiscence in 1, severe arrhythmia in 6, and stroke in 2. At 5 years, rates of survival and freedom from cardiac death and major adverse valverelated events were 75.6%, 79.7%, and 72.7%, respectively. Multivariate analysis indicated coronary artery disease as an independent predictor of cardiac death. Conclusions. In patients with severe mitral annular calcification undergoing mitral valve surgery, complete annular decalcification and reconstruction yields favorable outcomes.
M
replacements (MVR)—at our institution. Of these, 61 patients (2.9%) with severe MAC who underwent decalcification and reconstruction of the mitral annulus were enrolled in this study. Table 1 presents the clinical profile of the patients. Our Institutional Review Board approved this retrospective study and waived the need for written informed consent.
itral annular calcification (MAC) is a chronic degenerative noninflammatory condition characterized by calcification of the fibrous support surrounding the mitral valve (MV). The calcification usually extends along the posterior annulus and may also extend into the left ventricular (LV) muscles. Mitral valve surgery in the presence of MAC is associated with relatively high mortality and morbidity because it may result in cardiac rupture or prosthetic valve dehiscence [1–3]. Although various procedures have been described, no surgical strategy of choice has been established. We adopted the strategy of performing MV surgery after complete decalcification and reconstruction of the annulus; this enables the prosthesis to be safely secured into the newly reconstructed annulus [4]. The present study presents early and midterm outcomes of MV surgery with extensive annular decalcification and reconstruction in patients with MAC at our institution.
Patients and Methods Patient Characteristics Between January 2004 and December 2013, 2,104 patients underwent MV surgery—1,313 MV repairs and 791 MV Accepted for publication Aug 28, 2015. Address correspondence to Dr Uchimuro, Department of Cardiovascular Surgery, Sakakibara Heart Institute, 3-16-1, Asahi-cho, Fuchu, Tokyo 183-0003, Japan; e-mail: [email protected].
Ó 2015 by The Society of Thoracic Surgeons Published by Elsevier
(Ann Thorac Surg 2015;-:-–-) Ó 2015 by The Society of Thoracic Surgeons
Operative Procedures After sternotomy and establishment of cardiopulmonary bypass, the MV was exposed through a transseptal superior approach. Mitral valve repair is indicated for patients with nonrheumatic primary mitral regurgitation due to anterior leaflet prolapse, posterior prolapse, bileaflet prolapse, commissural prolapse, or combined lesions without extension of the MAC to the MV leaflet. However, MVR should be preferred for patients with mitral stenosis, rheumatic disease, extensive degenerative alteration of the valve, or extensive MAC involving valve leaflet or subvalvular apparatus. In 4 patients, the MV was considered to be repairable. The prolapsed section of the posterior leaflet was resected or prolapse of the anterior leaflet was corrected by artificial chordal reconstruction with expanded polytetrafluoroethylene sutures. The mural leaflet whose base had MAC was detached at the edge of the calcification, giving access to the ventricular aspect of the calcium formation. The annulus was carefully decalcified using scissors, 0003-4975/$36.00 http://dx.doi.org/10.1016/j.athoracsur.2015.08.071
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Table 1. Clinical Profile of Patients Clinical Profile
MVR (n ¼ 57)
Male 17 (29.8) Age, years 69.4 10.1 Diabetes mellitus 13 (22.8) Hemodialysis 14 (24.6) EuroSCORE II 6.6 6.7 Cardiac rhythm Sinus 36 (63.2) Atrial fibrillation 15 (26.3) Heart block (pacemaker rhythm) 6 (10.5) NYHA class III or IV 20 (35.1) Left ventricular ejection fraction, % 58.5 11.2 Mitral valve disease Mitral stenosis 20 (35.1) Mitral regurgitation 12 (21.1) Mitral stenosis and regurgitation 19 (33.3) Prosthetic valve dehiscence 6 (10.5) Infective endocarditis 3 (5.3) Coronary artery disease 16 (28.1) Tricuspid regurgitation II 27 (47.4) Previous cardiac operation 13 (22.4) Mitral valve replacement 6 (10.5) Commissurotomy 3 (5.3) Aortic valve replacement 0 (0) MVRþAVR 1 (1.8) Bentall 1 (1.8) Atrioventricular septal defect repair 2 (3.5)
MV Repair (n ¼ 4) 1 (25.0) 78.0 11.2 0 0 8.4 7.9 4 (100) 0 (0) 0 (0) 0 (0) 72.0 8.2 0 4 0 0 0 2 1 1 0 0 1 0 0 0
(0) (100.0) (0) (0) (0) (50.0) (25.0) (16.7) (0) (0) (25.0) (0) (0) (0)
Values are n (%) or mean SD. AVR ¼ aortic valve replacement; MV ¼ mitral valve; MVR ¼ mitral valve replacement; EuroSCORE ¼ European System for Cardiac Operative Risk Evaluation; NYHA ¼ New York Heart Association.
rongeurs, and a Cavitron ultrasonic surgical aspirator (CUSA EXcel; Integra LifeSciences, Plainsboro, NJ [Fig 1A and B]). This decalcification was performed until the all calcium was removed and circumscribing atrioventricular fat or ventricular myocardium could be identified. One of the margins of a pericardial patch was sutured to the posterior left atrial wall, and the other was sutured to the smooth endocardium of the healthy LV myocardium with a continuous 4-0 polypropylene suture to cover the entire debrided area (Fig 1C). The annulus was reconstructed using autologous pericardium in 2 patients and equine pericardium in 2 patients. Next, the posterior leaflet was reattached to the pericardial patch at the level of the original annulus (Fig 1D). Lastly, a prosthetic ring was placed at the reconstructed annulus in 3 cases with annular dilatation (Fig 1E). In 57 patients whose MV was thought to be nonrepairable, the native or prosthetic valve was removed. Debridement and patch reconstruction of the annulus was performed in the same way as described above (Fig 2A through C). However, the area of annulus requiring reconstruction was more extensive in patients requiring MVR. More than two thirds of the posterior annulus was
reconstructed in 40 (70.2%) of those patients. Of the 4 patients who underwent MV repair, 2 (50%) had reconstruction of more than two thirds of the posterior annulus. In 3 patients whose MAC was limited to the annulus, the annular defect was reinforced with several mattress sutures buttressed with polytetrafluoroethylene felt pledgets. In the other 55 patients whose MAC extended into the LV myocardium, the annulus was reconstructed using autologous pericardium in 8 and equine pericardium in 47. The prosthetic valve was secured at the supraannular position with noneverted horizontal mattress sutures (Fig 2D and E). Table 2 summarizes the operative data. Postoperative transthoracic echocardiography was performed before discharge and at 1 year after surgery. Midterm follow-up was obtained through outpatient chart review and telephone interviews. Mean follow-up was 42 30 months (range, 1 to 107), and no patient was lost to follow-up. Cardiac death and major adverse valve-related events (MAVRE) were defined according to published guidelines for reporting mortality and morbidity after valve operations [5].
Statistical Analysis The software IBM SPSS Statistics for Windows, version 19 (IBM Corp, Armonk, NY), was used for all statistical analyses. Descriptive data were reported as mean SD for continuous variables and as proportions for categoric variables. The Kaplan-Meier method was used to estimate long-term survival and freedom from morbid events. All variables were analyzed by univariate analyses to identify risk factors for morbid events. Independent risk factors for late clinical adverse events were determined using the Cox proportional hazards regression model. Variables with a p value of less than 0.2 in univariate analysis were examined using multivariate analysis (Table 4). A p value of less than 0.05 was considered statistically significant.
Results Early Outcomes Early clinical results are presented in Table 3. There was no 30-day hospital mortality. Four patients died during hospitalization (inhospital mortality rate of 6.6%): 1 of pneumonia on postoperative day 133, 1 of rupture of LV pseudoaneurysm on postoperative day 80, 1 of mediastinitis on postoperative day 39, and 1 of cholecystitis on postoperative day 48. Postoperative complications included LV pseudoaneurysm in 1 patient, pericardial patch dehiscence in 1, stroke in 2, ventricular tachycardia in 1, permanent heart block requiring pacemaker insertion in 5, and mediastinitis in 3. A 93-year-old woman who underwent attempted MV repair and concomitant coronary artery bypass grafting had conversion to MVR because of intraoperative LV rupture; the MAC extended along the entire posterior annulus and into the LV myocardium. Complete decalcification, annulus reconstruction using equine pericardium, and prosthetic ring annuloplasty were performed. The LV
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Fig 1. Schematic diagram of the mitral valve repair. (A) Mitral valve with posterior leaflet prolapse and severe annular calcification. (B) Prolapsed leaflet was resected, and annular calcification was removed. (C) The annulus was reconstructed using the pericardium. (D) The posterior leaflet was reattached. (E) A prosthetic ring was placed at the annulus.
rupture was found after releasing the aortic clamp. Repair of the LV posterior wall using equine pericardium and MVR were performed but she had LV pseudoaneurysm postoperatively and died of rupture of the pseudoaneurysm. One patient with pericardial patch dehiscence underwent reoperation on postoperative day
6. In this patient, the pericardial patch used for reconstruction of the annulus had come off at residual calcification in the ventricular septal wall. We completely removed the residual calcification and performed reconstruction using a new equine pericardial patch. The postoperative course was uneventful. Fig 2. Schematic diagram of the mitral valve replacement. (A) Mitral valve with severe annular calcification. (B) Valve leaflets and annular calcification were removed completely. (C) The annulus was reconstructed using the pericardium. (D) Noneverted horizontal mattress sutures were placed at the annulus. (E) The prosthetic valve was secured at the supraannular position.
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Table 2. Operative Data Variables Extension of annular reconstruction Anterior annulus One third of posterior annulus Two thirds of posterior annulus Entire posterior annulus Whole annulus Material used for annular reconstruction Teflon felt Autologous pericardium Equine pericardium Mitral prostheses None Autologous pericardial band Flexible ring Semirigid ring Biologic valve CEP Mechanical valve SJM CarboMedics ATS ON-X Valve size, mm 21–23 25–27 29–31 Concomitant procedure Aortic valve replacement Tricuspid valve repair Coronary artery bypass graft Aortic graft Conversion from MV repair to MVR Operative time, minutes Cardiopulmonary bypass time, minutes Crossclamp time, minutes
Table 3. Early Clinical Results MVR MV Repair (n ¼ 57) (n ¼ 4) 2 15 21 18 1
(3.5) (26.3) (36.8) (31.6) (1.8)
3 (5.3) 8 (14.0) 46 (80.7)
0 2 1 1 0
0 (0) 2 (50.0) 2 (50.0) 1 1 1 1
9 48 21 15 9 3
(0) (50.0) (25.0) (25.0) (0)
(25.0) (25.0) (25.0) (25.0)
(15.8) (84.2) (36.8) (26.3) (15.8) (5.3)
5 (8.8) 47 (82.5) 5 (8.8) 36 27 16 2
(63.2) (47.4) (28.1) (3.5)
0 (0) 1 (25.0) 2 (50.0) 0 (0) 1 (25.0) 338 87 313 110 221 59 188 97 178 47 152 86
Values are n (%) or mean SD. ATS ¼ ATS Medical (Minneapolis, MN); CEP ¼ Carpentier-Edwards Perimount (Edwards Lifesciences, Irvine, CA); CM ¼ CarboMedics (Sorin Group, Milan, Italy); MV ¼ mitral valve; MVR ¼ mitral valve replacement; On-X ¼ On-X Life Technologies (Austin, TX); SJM ¼ St. Jude Medical (St. Paul, MN).
Early Results Thirty-day death Hospital death Perioperative complication Left ventricular rupture Stroke Reoperation Severe arrhythmia Mediastinitis New dialysis Respiratory failure (tracheotomy)
MVR (n ¼ 57)
MV Repair (n ¼ 4)
0 (0) 3 (5.3)
0 (0) 1 (25.0)
0 2 1 6 3 3 1
1 0 0 0 0 0 0
(0) (3.5) (1.8) (10.5) (5.3) (5.3) (1.8)
(25.0) (0) (0) (0) (0) (0) (0)
Values are n (%). MV ¼ mitral valve;
MVR ¼ mitral valve replacement.
patient who underwent MVR had moderate paravalvular leakage at the midposterior annulus on transthoracic echocardiography at 7 years 6 months postoperatively. The patient was followed without any intervention. No patients who completed MV repair had moderate or severe mitral regurgitation and required any reoperation during the follow-up period.
Risk Factors for Outcomes Univariate analyses showed that hemodialysis and coronary artery disease were associated with all-cause death (p < 0.2). Multivariate analysis identified coronary artery disease (hazard ratio [HR] 4.80, 95% confidence interval [CI]: 1.61 to 14.32, p < 0.01) as an independent predictor of all-cause death (Table 4). Similarly, univariate analyses showed that hemodialysis, MV repair, and coronary artery disease were also associated with cardiac death (p < 0.2). Multivariate analysis identified coronary artery disease (HR 11.1, 95% CI: 2.81 to 43.95, p < 0.01) as an independent predictor. Univariate analyses showed that the following variables were associated with MAVRE, with a p value of less than 0.2: coronary artery disease, tricuspid regurgitation greater than grade 2, and previous cardiac operation. Multivariate analysis identified coronary artery disease (HR 5.60, 95% CI: 1.86 to 16.86, p < 0.01) and tricuspid regurgitation greater than grade 2 (HR 3.12; 95% CI: 1.02 to 9.12, p ¼ 0.04) as independent predictors.
Late Outcomes Late deaths occurred in 15 patients. There were 12 cardiac deaths (sudden death in 6 patients, heart failure in 2, bleeding event in 2, prosthetic valve endocarditis in 1, and rupture of LV pseudoaneurysm in 1) and 3 noncardiac deaths (pneumonia in 1 patient, cholecystitis in 1, and mediastinitis in 1). At 5 years, survival from all-cause death and cardiac death was 75.6% 6.0% and 79.7% 5.9%, respectively (Fig 3A and B). There were 16 MAVRE (valve-related death in 9 patients, stroke in 3, cerebral hemorrhage in 3, and reoperation in 1). At 5 years, freedom from MAVRE and reoperation was 72.7% 6.5% and 98.3% 1.7%, respectively (Fig 3C and D). One
Comment Mitral valve surgery can be challenging for patients with MAC, which usually extends along the posterior annulus and spreads to the chordae tendineae and LV myocardium [6]. In this setting, MV surgery may cause serious complications such as cardiac rupture, left circumflex coronary artery injury, or thromboembolic events. The dangers of MAC in MV surgery were first described by Roberts and Morrow in 1967 [1], who noted LV perforation in 2 patients undergoing MVR in the presence of MAC. In 1985, Spencer and colleagues [2]
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Table 4. Predictors for Clinical Adverse Events
Outcome
Variable
All-cause CAD death Hemodialysis Cardiac CAD death MV repair Hemodialysis MAVRE CAD TR II Prev cardiac operation
Univariate Analysis p Value
Multivariate Analysis HR (95% CI)
p Value
<0.01
4.80 (1.61–14.32) <0.01
0.18 <0.01
1.30 (0.42–4.07) 0.65 11.1 (2.81–43.95) <0.01
0.15 0.18 <0.01 0.09 0.12
3.26 1.35 5.60 3.12 1.37
(0.64–16.69) 0.16 (0.36–5.11) 0.66 (1.86–16.86) <0.01 (1.07–9.12) 0.04 (0.79–2.37) 0.27
CAD ¼ coronary artery disease; CI ¼ confidence interval; HR ¼ hazard ratio; MAVRE ¼ major adverse valve-related events; MV ¼ mitral valve; Prev ¼ previous; TR ¼ tricuspid regurgitation.
reported severe MAC in 4 of the 14 patients with LV rupture after MVR. Cammack and colleagues [7] analyzed 72 septuagenarians undergoing MV surgery; MAC was present at the posterior annulus in 11
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patients, 3 of whom (27.3%) died postoperatively because of complications resulting from MAC. The early mortality of patients without MAC was 6.6%, significantly lower than that of patients with MAC. The investigators identified MAC at the posterior annulus as an independent risk factor for early death with MV surgery for elderly patients. Several surgical procedures have been proposed to avoid such complications associated with MAC [3, 4, 6–25]. They are divided into two groups: those with MAC debridement and annulus reconstruction, and those without it. In MVR, the first group includes prosthesis insertion techniques without decalcification of MAC [7–16]: direct placement of the prosthesis with sutures through or around the MAC [7, 10], placement at the mitral leaflets [8, 9], placement at the left atrial wall [11–14], and use of a collar patch attached to the sewing cuff [15, 16]. However, such techniques do not lower the risks of paravalvular leak, valve dehiscence, embolism of friable calcium, LV rupture, circumflex coronary artery injury, and a smallersized prosthesis than desired. Hospital mortality associated with these approaches has been reported to be 20% to 28%, higher than that reported for MVR overall (2.5% to 8.5%) [26–28].
Fig 3. Kaplan–Meier survival curves. (A) Survival from all-cause death. (B) Survival from cardiac death. (C) Freedom from major adverse valverelated events. (D) Freedom from reoperation.
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In MV repair, few researchers have reported repair techniques without resection of the MAC: edge-to-edge mitral repair without annuloplasty [17], simple leaflet repair, or artificial chordal reconstruction without annuloplasty [18, 19]. Maisano and colleagues [17] reported low hospital mortality of 3.7% and a high reoperation rate (freedom from reoperation at 4 years was 77% with MAC versus 95% without MAC). MAC was correlated with higher incidence of postoperative residual mitral regurgitation because the isolated leaflet repair could not correct annular dilatation and deformation. Although these techniques may lower the risks of LV rupture and circumflex coronary artery injury, a high risk of late failure should be expected. Maisano and colleagues [17] insisted that in a case of complete calcification of the annulus, or of high age, MVR might be the best solution. Simple leaflet repair, chordal reconstruction, or edge-toedge repair without manipulating MAC as a rescue procedure should be restricted to elderly patients at extremely high risk. The second group includes several procedures with decalcification of MAC [4, 6, 10, 18, 20–25]. Carpentier and associates [6] described sliding atrioplasty for annulus reconstruction using a freed left atrial flap, and some have followed this technique [10, 20]. Hospital mortality was reported to be 0% to 8.2% and 5-year survival, 84% to 100%. Carpentier and associates [6] reported good longterm results of 87% freedom from reoperation at 7 years. However, it is often difficult to mobilize and bring the left atrium over the debrided area in cases of pervasive MAC extending to the surrounding left atrial or LV wall [22]. Several investigators [4, 18, 20, 24, 25] described annulus reconstruction with Dacron or a pericardial patch. This technique is useful when extensive repair of the annulus is necessary after complete decalcification. Feindel and colleagues [24] reported the clinical outcomes of 54 patients undergoing 12 MV repairs and 42 MVR, with an operative mortality of 9.3%, a rate comparable with that of MVR overall (2.5% to 8.5%) and lower than that of the approaches without MAC debridement (20% to 28%). Therefore, we have also applied the patch reconstruction technique as a feasible and reliable management approach for MAC in MV surgery. The greatest concerns are that extensive debridement increases the risk of LV rupture and circumflex coronary artery injury. The pericardial patch increases the integrity of the atrioventricular groove and prevents fatal complications. In our series, 1 patient required reoperation for patch dehiscence because of residual calcification. Therefore, we believe that complete decalcification is important in the prevention of patch dehiscence. Carpentier and associates [6] also reported better long-term results with complete decalcification. The choice of material for the annulus reconstruction is also important because the prosthesis is sutured to the annulus made of the chosen material. Casselman and colleagues [21] described the use of an in situ anterior mitral leaflet. This technique is limited to patients in whom the anterior leaflet can be preserved. Vander Salm
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[22, 23] described reconstruction with Teflon felt pledgetreinforced sutures [22, 23]. David and colleagues [4] and Feindel and colleagues [24] reported the use of glutaraldehyde-fixed bovine pericardium or Dacron for the anterior annulus, and fresh autologous pericardium for the posterior annulus. Posterior annulus reconstruction alone could be achieved using the fresh autologous pericardium because the posterior annulus was subtended by the posterior LV wall, but in unsupported areas such as the fibrous tissue between the aortic and mitral annuli the use of glutaraldehyde-fixed bovine pericardium was recommended because of its apparent greater strength. Mihaljevic and colleagues [25] used autologous pericardium using the technique of the Toronto group [4, 24]. We initially used polytetrafluoroethylene felt pledget-reinforced sutures, especially when the area requiring reconstruction was limited to the annulus alone. As we gained experience, however, we began to use mainly pericardium. We prefer glutaraldehyde-fixed equine pericardium to fresh autologous pericardium because it is firm and strong, and applicable even in redo surgery, and because glutaraldehyde-preserved xenogenic pericardium available in Japan is equine rather than bovine. Few studies have examined long-term outcomes after MV surgery in patients with MAC; of these, the patient sample of Feindel and colleagues [24] was the largest, and the follow-up period the longest. They reported 5-year survival of 73% and freedom from reoperation at 5 years of 89%, with a mean follow-up of 4.1 years. Four patients required reoperation, including 1 for patch dehiscence and 1 for prosthetic valve dehiscence. There were no instances of LV rupture or aneurysm formation. In our series, 5-year survival and freedom from reoperation were 75.6% and 98.3%, respectively, over a followup period of 3.5 years. One patient had rupture of LV pseudoaneurysm. For MVR overall, 5-year survival and freedom from reoperation have been reported to be 64.7% to 90.0% and 95.3% to 97.7%, respectively [26–28]. The midterm results of the patch technique for patients with MAC were comparable to those of MVR overall. Our data suggest that complete removal of calcification leads to improved long-term results in patients with MAC. In our study, multivariate analysis identified coronary artery disease as an independent risk factor for cardiac death, and coronary artery disease and tricuspid regurgitation greater than grade 2 as independent risk factors for MAVRE. It seemed that preoperative ischemic cardiomyopathy or congestive heart failure might affect late mortality and morbidity. Therefore, if patients with MAC requiring MV surgery have coronary artery disease or tricuspid regurgitation greater than grade 2, careful follow-up over the long term is necessary. The present study has some limitations. This was a retrospective observational study at a single institution. The number of patients with MAC undergoing MV repair was small, and the follow-up period was short. In conclusion, in our experience of patients with severe MAC requiring MV surgery, extensive debridement of the annulus with reconstruction using pericardium is a feasible and effective procedure. This technique provides
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acceptable operative mortality and morbidity, and yields good midterm results.
References 1. Roberts WC, Morrow AG. Causes of early postoperative death following cardiac valve replacement: clinicopathologic correlations in 64 patients studied at necropsy. J Thorac Cardiovasc Surg 1967;54:422–37. 2. Spencer FC, Galloway AC, Colvin SB. A clinical evaluation of the hypothesis that rupture of the left ventricle following mitral valve replacement can be prevented by preservation of the chordae of the mural leaflet. Ann Surg 1985;202:673–80. 3. Okada Y. Surgical management of mitral annular calcification. Gen Thorac Cardiovasc Surg 2013;61:619–25. 4. David TE, Feindel CM, Armstrong S, Sun Z. Reconstruction of the mitral annulus. A ten-year experience. J Thorac Cardiovasc Surg 1995;110:1323–32. 5. Akins CW, Miller DC, Turina MI, et al. Guidelines for reporting mortality and morbidity after cardiac valve interventions. Eur J Cardiothorac Surg 2008;33:523–8. 6. Carpentier AF, Pellerin M, Fuzellier JF, Relland JY. Extensive calcification of the mitral valve annulus: pathology and surgical management. J Thorac Cardiovasc Surg 1996;111:718–29. 7. Cammack PL, Edie RN, Edmunds LH. Bar calcification of the mitral annulus. A risk factor in mitral valve operations. J Thorac Cardiovasc Surg 1987;94:399–404. 8. Coselli JS, Crawford ES. Calcified mitral valve annulus: prosthesis insertion. Ann Thorac Surg 1988;46:584–6. 9. Kurazumi H, Mikamo A, Suzuki R, Hamano K. Mitral-valve replacement for a severely calcified mitral annulus: a simple and novel technique. Eur J Cardiothorac Surg 2011;39:407–9. 10. d’Alessandro C, Vistarini N, Aubert S, Acar C, Pavie A, Gandjbakhch I. Mitral annulus calcification: determinants of repair feasibility, early and late surgical outcome. Eur J Cardiothorac Surg 2007;32:596–603. 11. Ruvolo G, Speziale G, Voci P, Marino B. “Patch-glue” annular reconstruction for mitral valve replacement in severely calcified mitral annulus. Ann Thorac Surg 1997;63:570–1. 12. Atoui R, Lash V, Mohammadi S, Cecere R. Intra-atrial implantation of a mitral valve prosthesis in a heavily calcified mitral annulus. Eur J Cardiothorac Surg 2009;36:776–8. 13. Di Stefano S, Lopez J, Florez S, Rey J, Arevalo A, San Roman A. Building a new annulus: a technique for mitral valve replacement in heavily calcified annulus. Ann Thorac Surg 2009;87:1625–7. 14. Kato Y, Hattori K, Bito Y, Kotani S, Inoue K, Shibata T. Simple supra-annular prosthesis insertion for dialysis patients with extensive mitral annular calcification. J Heart Valve Dis 2011;20:180–3.
UCHIMURO ET AL MANAGEMENT OF ANNULAR CALCIFICATION
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15. Nataf P, Pavie A, Jault F, Bors V, Cabrol C, Gandjbakhch I. Intraatrial insertion of a mitral prosthesis in a destroyed or calcified mitral annulus. Ann Thorac Surg 1994;58:163–7. 16. Okita Y, Miki S, Ueda Y, Tahata T, Sakai T, Matsuyama K. Mitral valve replacement with a collar-reinforced prosthetic valve for disrupted mitral annulus. Ann Thorac Surg 1995;59: 187–9. 17. Maisano F, Caldarola A, Blasio A, De Bonis M, La Canna G, Alfieri O. Midterm results of edge-to-edge mitral valve repair without annuloplasty. J Thorac Cardiovasc Surg 2003;126: 1987–97. 18. Chan V, Ruel M, Hynes M, Chaudry S, Mesana TG. Impact of mitral annular calcification on early and late outcomes following mitral valve repair of myxomatous degeneration. Interact Cardiovasc Thorac Surg 2013;17:120–5. 19. Morisaki A, Kato Y, Takahashi Y, Shibata T. Mitral valve repair without mitral annuloplasty with extensive mitral annular calcification. Interact Cardiovasc Thorac Surg 2014;19:1080–2. 20. Ng CK, Punzengruber C, Pachinger O, et al. Valve repair in mitral regurgitation complicated by severe annulus calcification. Ann Thorac Surg 2000;70:53–8. 21. Casselman FP, Gillinov AM, McDonald ML, Cosgrove DM. Use of the anterior mitral leaflet to reinforce the posterior mitral annulus after debridement of calcium. Ann Thorac Surg 1999;68:261–2. 22. Vander Salm TJ. Mitral annular calcification: a new technique for valve replacement. Ann Thorac Surg 1989;48: 437–9. 23. Vander Salm TJ. Mitral annular calcification: a new technique for valve replacement. Ann Thorac Surg 1997;63: 1819–20. 24. Feindel CM, Tufail Z, David TE, Ivanov J, Armstrong S. Mitral valve surgery in patients with extensive calcification of the mitral annulus. J Thorac Cardiovasc Surg 2003;126: 777–82. 25. Mihaljevic T, Koprivanac M, Kelava M, Smedira NG, Lytle BW, Blackstone EH. Mitral valve replacement in patients with severely calcified mitral valve annulus: surgical technique. J Thorac Cardiovasc Surg 2013;146:233–5. 26. Tominaga R, Kurisu K, Ochiai Y, et al. A 10-year experience with the Carbomedics cardiac prosthesis. Ann Thorac Surg 2005;79:784–9. 27. Chan V, Jamieson WR, Lam BK, Ling H, Fradet G, Mesana TG. Influence of the On-X mechanical prosthesis on intermediate-term major thromboembolism and hemorrhage: a prospective multicenter study. J Thorac Cardiovasc Surg 2010;140:1053–8. 28. Kaneko T, Aranki S, Javed Q, et al. Mechanical versus bioprosthetic mitral valve replacement in patients <65 years old. J Thorac Cardiovasc Surg 2014;147:117–26.