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Ann Thorac Surg 2006;81:1612-1617
© 2006 The Society of Thoracic Surgeons

Original article: Cardiovascular

Midterm Results of the Edge-to-Edge Technique for Complex Mitral Valve Repair

Derek R. Brinster, MD, Daniel Unic, MD, Michael N. D'Ambra, MD, Nadia Nathan, MD, Lawrence H. Cohn, MD *

Division of Cardiac Surgery and Cardiac Anesthesia, Brigham and Women's Hospital, and the Department of Surgery and Anesthesia, Harvard Medical School, Boston, Massachusetts

Accepted for publication December 1, 2005.

* Address correspondence to Dr Cohn, Division of Cardiac Surgery, Brigham and Women's Hospital, 75 Francis Street, Boston, MA 02115; (Email: lcohn{at}partners.org).


This article has been selected for the open discussion forum on the CTSNet Web Site: http://www.ctsnet.org/sections/newsandviews/discussions/index.html

 

   Abstract
Top
 Abstract
Introduction
 Patients and Methods
 Results
 Comment
 References
 
BACKGROUND: The edge-to-edge technique (E2E) has been advocated for the complex repair of myxomatous mitral valves. We compared outcomes of E2E performed in patients at risk for systolic anterior motion (SAM) versus outcomes in patients with residual mitral regurgitation (MR) after repair completion.

METHODS: A total of 1,612 patients had repair of myxomatous mitral valves between June 1997 and December 2003 at Brigham and Women's Hospital. The E2E was used in 72 (4.5%) patients. Fifty-two patients (52/72; group I) had E2E for persistent MR after complex repair. Twenty patients (20/72; group II) had E2E for high risk of post-repair SAM and left ventricular outflow tract obstruction. Mean age of the patients was 61 ± 14 years; 47 were male, average New York Heart Association class at admission was 2.4 ± 0.6, and mean left ventricular ejection fraction was 56 ± 12%.

RESULTS: The operative mortality was zero. Immediate postoperative MR was significantly improved in all patients compared with the preoperative grade (p value < 0.0005). Mean follow-up was 388 days. In those in whom E2E was used for residual MR without SAM risk (group I), postoperative MR (≥ 2+) was detected in 15 of 52 patients at 6 months. In group II, SAM was completely eliminated and the mean MR grade in the immediate postoperative period was 0.5 ± 0.7. There was no long-term recurrence of MR in group II.

CONCLUSIONS: This study suggests that E2E eliminates SAM and long-term MR in patients with pre-repair echocardiographic predictors of SAM. The E2E is not efficacious in preventing long-term recurrent MR if performed for residual MR after complex mitral repair.

Myxomatous degeneration of the mitral valve is the most common etiology of mitral regurgitation (MR) in developed countries. The benefits of repairing the regurgitant mitral valve over replacement include improved long-term survival and better preservation of left ventricular function, as well as greater freedom from endocarditis, thromboembolism, and anticoagulant-related hemorrhage [1–6]. Repair may be technically challenging in the face of complex MR, especially when there is a large anterior mitral leaflet or bileaflet prolapse with Barlow's syndrome. The potential for creating systolic anterior motion (SAM) of the anterior mitral leaflet and consequent obstruction of the left ventricular outflow tract (LVOT) can also add significant morbidity and the need for a second exposure to cardiopulmonary bypass (CPB).

Although the standard mitral valve repair techniques, including leaflet resection, leaflet advancement, chordal shortening, and insertion of an annuloplasty ring are usually sufficient, the edge-to-edge technique (E2E) has been advocated for eliminating residual MR that occasionally occurs after complex repair of the myxomatous valve [7–9]. We postulated that use of the E2E technique might also be appropriate when there is high risk for developing SAM based on pre-bypass echocardiographic criteria or when it develops postrepair. This report describes our early and medium term experience with the E2E technique in myxomatous mitral valve repair in those patients with high SAM potential, postoperative SAM, and those in whom the E2E technique was used for persistent MR after complicated MV repair without SAM.


   Patients and Methods
Top
 Abstract
 Introduction
 Patients and Methods
Results
 Comment
 References
 
Patients
The Partners' Institutional Review Board approved this clinical study in September 2003. All patients included in the study signed a consent form allowing collection and use of their records.

From June 1997 to December 2003, 1,612 MV repairs were performed at Brigham and Women's Hospital. Of these, 72 (4.5%) patients had repair of a myxomatous mitral valve for which the E2E technique was applied. Of 72 patients, 52 (72%) had persistent leak after a complex repair (group I); and 20 of 72 patients (28%) had either high SAM potential assessed by transesophageal echocardiography (TEE) intraoperatively or severe SAM after CPB (group II). The mean age was 61 ± 14 years, 47 were male, the average New York Heart Association (NYHA) functional class at admission was 2.4 ± 0.6, and the average ejection fraction was 56 ± 12%. Three patients (3/72) underwent reoperative mitral valve surgery. The clinical data by group are summarized in Table 1.


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  		Table 1. Clinical Data
 
Mitral regurgitation was graded on a scale of 0 to 4 based on echocardiographic measurements. All patients had 3+ to 4+ MR before surgery (mean 3.8 ± 0.4). The pathology of the MR in all 72 patients is summarized in Table 2. The MR was assessed using preoperative transthoracic echocardiography (TTE), intraoperative TEE, and postoperative TTE. Follow-up data were acquired using patient chart review, phone interview, and postoperative TTE reports. Follow-up was complete in 92% of patients, with a mean follow-up of 1.1 years (range, 1 month to 4 years).


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  		Table 2. Pathology of Mitral Regurgitation
 
Statistics
The statistical software package, STATA 7.0 for Windows (STATA, College Station, TX), was used to calculate the data in this report.

Operative Details
The operative details are summarized in Table 3 . The operative approach to mitral valve repair was through the left atrium by Sondergaard's groove after establishing CPB. The valve was inspected intraoperatively to confirm the echocardiographic findings and to identify any additional lesions. The majority of patients underwent a posterior leaflet quadrangular resection with a modified sliding annuloplasty. All patients received a prosthetic annuloplasty ring. The average ring size was 33 ± 4 mm for group I and 35 ± 2 mm for group II (Table 3).


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  		Table 3. Operative Details
 
The E2E repair was used in two principal circumstances: group I to correct complex MR jets in 52 of 72 patients in whom a combination of the standard repair techniques were used, and group II to prevent SAM or correct severe SAM in 20 of 72 patients. In group I, a single figure-of-8 E2E stitch with 3-0 Ethibond (Johnson and Johnson, Piscataway, NJ) was placed at the location of the persistent regurgitant jet. Mitral valve calipers were used to ensure that each of the two residual orifice areas was greater than 2 cm2. In group II, the E2E stitch was placed to prevent SAM of the anterior mitral leaflet in the left ventricular outflow tract (LVOT) at the coaptation point of A2 and P2. This group included 2 patients with SAM who were identified by TEE after initial termination of CPB (Fig 1). In 18 of 20 patients, SAM potential was determined by intraoperative pre-repair TEE assessment of the mitral valve before CPB was instituted.


Figure 1
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  		Fig. 1. The SAM after mitral valve repair. The SAM developed on initial separation from cardiopulmonary bypass after mitral valvuloplasty and Cosgrove annuloplasty ring for flail PM2. Preoperatively (A), marked asymmetry between AM1 (37 mm) and AM2 (32 mm) was apparent, as well as a C-septal distance of 19 mm. Although the height of the posterior mitral leaflet is reduced to 0.9 cm, SAM was noted post-bypass in (B). In (C), the E2E suture relieved SAM and the associated mitral regurgitation (MR) seen in (B). (AM1 = A2 anterolateral segment; AM2 = A2 posteriomedial segment; C-Sept = interventricular septum distance; E2E = edge-to-edge; PM = posterior medial; SAM = systolic anterior motion; TEE = transesophageal echocardiography.)

 
SAM Potential
The mitral valve was determined to have SAM potential based on evaluation of the leaflets, as well as the interaction between the anterior leaflet and the subvalvular apparatus. In 1999, Maslow and colleagues [10] proposed a formula for predicting the risk of SAM using anterior (AL) and posterior (PL) leaflet length, annular diameter, and the ratio between AL and PL (AL/PL ratio). When these measurements are combined with the shortest distance between the mitral valve (MV) coaptation point and the interventricular septum (C-Sept distance), so-called "SAM potential" can be quantified. Valves with a low AL/PL ratio less than 1.3 and C-Sept distance less than 2.5 cm were considered to have a moderate risk of developing SAM [10]. Most important,valves with asymmetry of the AL greater than 5 mm, in which the A2 anterolateral segment (AM1) was larger than the A2 posteriomedial segment (AM2), were considered to have a moderate-to-high risk of SAM with risk proportional to the degree of asymmetry (Fig 2 and Table 4).


Figure 2
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  		Fig 2. The systolic anterior motion (SAM) potential pre and post edge-to-edge (E2E) repair. This figure demonstrates a valve with high SAM potential pre and post E2E repair in a patient with Barlow's myxomatous degenerated mitral valve. Panels A, B, and C demonstrate the measurements that are considered in determining the degree of SAM potential. Panel A shows a markedly enlarged annulus diameter and a coaptation point to septal distance (C-Sept) of 2.1 cm. The C-Sept values less than 2.4 cm contribute to SAM potential. Panel B demonstrates the ratio of the anterior and posterior leaflet lengths (AL/PL). The AL/PL ratio 1.3 or less contributes to SAM potential. The full length of AL and PL and not just annulus to coaptation distance is measured. Panel C demonstrates anterior leaflet length in AM1 of 3.38 cm and relative to AM2 of 3.31 cm (panel B). Thus AM1 is 3 mm longer than AM2, another factor predictive of SAM. Panel D shows the postoperative result (trace mitral regurgitation [MR] and no SAM) after a repair that included sliding valvuloplasties of the right and left portions of P2, Cosgrove ring annuloplasty, and an E2E repair placed between PM1 and AM1. Note that there was no mitral stenosis. (AM1 = A2 anterolateral segment; AM2 = A2 posteriomedial segment.; LA = left anterior; LV = left ventricular; LVOT = left ventricular outflow; MVP = mitral valve repair; RV = right ventricular; TEE = transesophageal echocardiography.)

 

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  		Table 4. AM1 and AM2 Leaflet Lengths (mm)
 

   Results
Top
 Abstract
 Introduction
 Patients and Methods
 Results
Comment
 References
 
There was no operative mortality in either group. The degree of correction of MR evident on preoperative echocardiography compared with immediate postoperative echocardiography data was statistically significant (p < 0.0005). The average degree of mitral regurgitation in the immediate postoperative period was 0.5 ± 0.7. Postoperative functional status improved significantly; the mean NYHA improved from 2.4 ± 1.3 preoperatively to 1.2 ± 0.4 postoperatively, with a mean follow-up of 388 days. There were two late deaths in group I. One patient died from a stroke one year after surgery, and the other patient died 3 months after surgery from unknown cause.

The development of late MR was assessed in the postoperative period by routine follow-up TTE assessment. For those who had E2E repair for myxomatous MR (MMR), 15 of 52 patients (30%) developed 2+ MR in the late postoperative period. All patients with follow-up greater than 3 years had developed moderate-to-severe MR (Fig 3). The presence of mitral stenosis (MS) was also assessed by TTE postoperatively. Mild postoperative stenosis developed in 5 patients (7%), moderate MS developed in 2 patients (3%), and 4 patients (6%) developed severe MS (> 10 mm Hg) after surgery. All four patients who required reoperation were the patients who developed severe MS post-repair in all in group I. Two of the four patients required early reoperation (< 30 days from original surgery) to correct their MS. Of the patients who had the E2E repair performed for high SAM potential (group II), no patient developed MS and none developed SAM or progressive MR on postoperative follow-up echocardiography. The freedom from reoperation was 95% at 4 years for group I and 100% for group 2 (Fig 4).


Figure 3
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  		Fig 3. Kaplan-Meier survival curve. Freedom from the development of late mitral regurgitation (MR) in patients with post-bypass MR.

 

Figure 4
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  		Fig 4. Freedom from reoperation.

 

   Comment
Top
 Abstract
 Introduction
 Patients and Methods
 Results
 Comment
References
 
Myxomatous mitral valve regurgitation is best treated by repair rather than replacement because of the retention of the normal mitral subvalvular apparatus. While most valves can be adequately treated by conventional repair techniques, in patients with complex mitral valve and persistent MR or those repairs at high risk for the development of SAM the E2E repair has been suggested to be a beneficial adjunct [11].

In our study, the use of the E2E repair as an adjunct to mitral valve repair had a zero in-hospital mortality rate and low late mortality rate. The early postoperative TTE data demonstrated significant improvement in regurgitation and all patients had an improvement in NYHA status.

The lack of long-term durability of this repair type in patients with MMR without SAM (group I) is noteworthy. While other studies have suggested durable results of the E2E repair [[12], our findings indicate a progression to moderate or severe MR in all patients followed for greater than three years postoperatively who had E2E suture for residual MR. The progression of MR postoperatively could be related to a number of factors, including further degeneration of the valve, poor durability of the E2E technique due to high stress on the leaflet repair, or progressive annular dilation [13]. Because follow-up echocardiograms were primarily transthoracic studies performed at multiple centers, detailed evaluation of the exact failure mechanisms was not possible. These findings are significant, and should be compared with findings after new percutaneous repair device implantation [14].

The use of E2E to prevent post-repair SAM was recently described by Mascagni and colleagues [15] in four patients. In our study, we used pre- and post-bypass TEE to assess high SAM potential in 18 patients. Other groups have identified predictors of SAM to include a redundant anterior leaflet, a long myxomatous posterior leaflet, and anterior displacement of coaptation surfaces into the LVOT [10, 11, 16–20]. On the basis of certain predictive pre-repair characteristics, an E2E repair was used prophylactically to prevent the development of SAM post-repair. All patients undergoing the E2E repair for high SAM potential had no SAM post-repair and did not develop mitral stenosis. In two patients early in the series who did develop SAM post-repair, the E2E repair successfully completely reduced SAM. This study suggests that the use of the E2E repair may eliminate SAM post-repair in patients with pre-repair echo findings that suggest a high probability of SAM. The use of E2E repair in this group was not associated with long-term mitral regurgitation or stenosis. The analysis and quantification of the predictive value of the various components of our SAM assessment protocol require further prospective study (Fig 5).


Figure 5
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  		Fig 5. Mitral anterior leaflet measurement for the prediction of systolic anterior motion. The surgeon's view of the mitral valve is shown with the left side being the anterior lateral (AL) and the right being posterior medial (PM) aspects of the valve. The central scallop of the anterior leaflet is divided in half. The AL side being termed AM1 and the PM side termed AM2. Measurement of the individual lengths of AM1 and AM2 can be easily determined by transesophageal echocardiography and are the distances between the aortic annulus and the tip of the leaflet for each valve segment. When AM1 is greater than 5 mm longer than AM2, systolic anterior motion potential is high.

 


   References
Top
 Abstract
 Introduction
 Patients and Methods
 Results
 Comment
 References
 

  1. Yun KL, Miller DC. Mitral valve repair versus replacement Cardiol Clin 1991;9:315-327.[Medline]
  2. Sand ME, Naftel DC, Blackstone EH, Kirklin JW, Karp RB. A comparison of repair and replacement for mitral valve incompetence J Thorac Cardiovasc Surg 1987;94:208-219.[Abstract]
  3. Perier P, Deloche A, Chauvaud S, et al. Comparative evaluation of mitral valve repair and replacement with Starr, Bjork, and porcine valve prostheses Circulation 1984;70:I187-I192.
  4. Lawrie GM. Mitral valve repair vs replacementCurrent recommendations and long-term results. Cardiol Clin 1998;16:437-448.[Medline]
  5. Goldsmith IR, Lip GY, Patel RL. A prospective study of changes in the quality of life of patients following mitral valve repair and replacement Eur J Cardiothorac Surg 2001;20:949-955.[Abstract/Free Full Text]
  6. Cohn LH, Couper GS, Aranki SF, Rizzo RJ, Kinchla NM, Coolins Jr JJ. Long-term results of mitral valve reconstruction for regurgitation of the myxomatous mitral valve J Thorac Cardiovasc Surg 1994;107:143-150.[Abstract/Free Full Text]
  7. 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;126:1987-1997.[Abstract/Free Full Text]
  8. Alfieri O, Maisano F, De Bonis M, et al. The double-orifice technique in mitral valve repaira simple solution for complex problems. J Thorac Cardiovasc Surg 2001;122:674-681.[Abstract/Free Full Text]
  9. Gillinov AM, Cosgrove DM, Blackstone EH, et al. Durability of mitral valve repair for degenerative disease J Thorac Cardiovasc Surg 1998;116:734-743.[Abstract/Free Full Text]
  10. Maslow AD, Regan MM, Haering JM, Johnson RG, Levine RA. Echocardiographic predictors of left ventricular outflow tract obstruction and systolic anterior motion of the mitral valve after mitral valve reconstruction for myxomatous valve disease J Am Coll Cardiol 1999;34:2096-2104.[Abstract/Free Full Text]
  11. Lee KS, Stewart WJ, Lever HM, Underwood PL, Cosgrove DM. Mechanism of outflow tract obstruction causing failed mitral valve repairAnterior displacement of leaflet coaptation. Circulation 1993;88:II24-II29.
  12. Maisano F, Torracca L, Oppizzi M, et al. The edge-to-edge techniquea simplified method to correct mitral insufficiency. Eur J Cardiothorac Surg 1998;13:240-245discussion 245-6.[Abstract/Free Full Text]
  13. Bhudia SK, McCarthy PM, Smedira NG, Lam BK, Rajeswaran J, Blackstone EH. Edge-to-edge (Alfieri) mitral repairresults in diverse clinical settings. Ann Thorac Surg 2004;77:1598-1606.[Abstract/Free Full Text]
  14. Vassiliades Jr TA, Block PC, Cohn LH, et al. The clinical development of percutaneous heart valve technology J Thorac Cardiovasc Surg 2005;129:970-976.[Free Full Text]
  15. Mascagni R, Al Attar N, Lamarra M, et al. Edge-to-edge technique to treat post-mitral valve repair systolic anterior motion and left ventricular outflow tract obstruction Ann Thorac Surg 2005;79:471-473discussion 474.[Abstract/Free Full Text]
  16. Grossi EA, Steinberg BM, LeBoutillier III M, et al. Decreasing incidence of systolic anterior motion after mitral valve reconstruction Circulation 1994;90:II195-II197.
  17. Obadia JF, Janier M. Second order anterior mitral leaflets play a role in preventing systolic anterior motion Ann Thorac Surg 2002;73:1689-1690author reply 1690.[Free Full Text]
  18. Timek TA, Nielsen SL, Green GR, et al. Influence of anterior mitral leaflet second-order chordae on leaflet dynamics and valve competence Ann Thorac Surg 2001;72:535-540discussion 541.[Abstract/Free Full Text]
  19. Timek TA, Green GR, Tibayan FA, et al. Aorto-mitral annular dynamics Ann Thorac Surg 2003;76:1944-1950.[Abstract/Free Full Text]
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