ACA App
Annals of Cardiac Anaesthesia Annals of Cardiac Anaesthesia Annals of Cardiac Anaesthesia
Home | About us | Editorial Board | Search | Ahead of print | Current Issue | Archives | Submission | Subscribe | Advertise | Contact | Login 
Users online: 233 Small font size Default font size Increase font size Print this article Email this article Bookmark this page
 


 

 
     
    Advanced search
 

 
 
     
  
    Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
    Email Alert *
    Add to My List *
* Registration required (free)  


    Abstract
    Introduction
    Pre-Bypass Asses...
    Standard Transes...
    Is the Valve Sui...
    Operative Techniques
    Assessment of Repair
    Conclusion
    Functional Class...
    References
    Article Figures

 Article Access Statistics
    Viewed13956    
    Printed393    
    Emailed33    
    PDF Downloaded1851    
    Comments [Add]    
    Cited by others 2    

Recommend this journal

 


 
E-ACA: ECHO TUTORIAL Table of Contents   
Year : 2010  |  Volume : 13  |  Issue : 1  |  Page : 79-85
Intraoperative transesophageal echocardiographic assessment of the mitral valve repair


Department of Anaesthesiology, Narayana Hrudayalaya Institute of Medical Sciences, Bangalore, India

Click here for correspondence address and email

Date of Submission31-Dec-2008
Date of Acceptance08-Apr-2009
Date of Web Publication11-Jan-2010
 

   Abstract 

The use of intraoperative transesophageal echocardiography (TEE) in assessment of the mitral valve repair is well established. It has significantly contributed to the excellent results of mitral valvuloplasty in the current era. This article reviews various two-dimensional echocardiographic planes to assess the mitral valve apparatus, mechanisms of mitral regurgitation, different surgical techniques of repair, complications, and their recognition using TEE.

Keywords: Transesophageal, echocardiography, mitral valve insufficiency, mitral annuloplasty

How to cite this article:
Banakal SC. Intraoperative transesophageal echocardiographic assessment of the mitral valve repair. Ann Card Anaesth 2010;13:79-85

How to cite this URL:
Banakal SC. Intraoperative transesophageal echocardiographic assessment of the mitral valve repair. Ann Card Anaesth [serial online] 2010 [cited 2018 Dec 17];13:79-85. Available from: http://www.annals.in/text.asp?2010/13/1/79/58848



   Introduction Top


Currently, mitral valve repair is the standard of care for treating patients with mitral regurgitation (MR) whenever feasible. [1] There are several advantages associated with mitral valve repair when compared with mitral valve replacement. These include better preservation of left ventricular function, [2] freedom from anticoagulation in a majority of the patients, low risk of thromboembolism, resistance to endocarditis, and long-term durability and survival benefit similar to the general population in degenerative mitral valve repair. [3],[4] The use of intraoperative echocardiography has undoubtedly contributed to the success of mitral valve repair. This review covers the use of intraoperative transesophageal echocardiography (TEE) in the assessment of mitral valve repair.


   Pre-Bypass Assessment Top


The purpose of pre-bypass assessment is to confirm and define mitral valve dysfunction. However, one should keep in mind that pre-bypass TEE does not replace a thorough preoperative trans-thoracic echocardiographic assessment. A three-dimensional assessment of the mitral valve apparatus can be performed using various standard two-dimensional (2D) echocardiographic planes as described in the recommendations of the American Society of Echocardiography and Society of Cardiovascular Anesthesiologists. [5] The severity of MR can be quantified with various techniques such as color flow jet area, width of the vena contracta, proximal isovelocity surface area (PISA), and systolic reversal of the pulmonary venous flow. [6]


   Standard Transesophageal Echocardiographic Views Top


An understanding of the various transesophageal 2-D echocardiographic planes is important for a detailed assessment of the mitral valve apparatus. [7] According to Carpentier's segmental classification of mitral valve leaflets, the posterior mitral leaflet (PML) is divided into three scallops viz., P1 (the lateral scallop), P2 (the middle scallop), and P3 (the medial scallop). Corresponding areas on the anterior mitral leaflet (AML) that oppose the posterior leaflet are termed A1, A2, and A3 segments.

Mid-esophageal five-chamber view

This view is developed by inserting the TEE probe to a depth of about 30 cm from the incisors at a multiplane transducer angle of zero degrees [Figure 1]. It cuts across the mitral valve at the level of anterolateral commissure. The right atrium, left atrium, part of the aorta, right ventricle, and left ventricle are seen in this view. The A1 segment of the AML is to the left and the P1 scallop of the PML is seen on the right side of the imaging sector.

Mid-esophageal four-chamber view

Gently pushing the probe further by a few millimetres, maintaining the transducer angle at zero degrees, will reveal the mid-esophageal four-chamber view [Figure 2]. This view cuts the middle of the mitral valve that corresponds to A2 and P2 scallops of the mitral valve. Four chambers of the heart viz., the right atrium, left atrium, right ventricle, and left ventricle are seen. The mitral annulus is often measured in this view.

Lower-esophageal four-chamber view

Advancing the probe a little at a transducer angle of zero degrees, the mitral valve would be cut at a lower level exposing the posteromedial commissure. Thus, A3 and P3 segments of the mitral leaflets come into view. This view is similar in appearance to the mid-esophageal four-chamber view.

Mid-esophageal commissural view

The commissural view is developed in the mid-esophageal position at about 60 to 70 degrees transducer angle [Figure 3]. This view shows the commissural scallops where P3 is to the left, A2 is in the middle, and P1 is to the right of the imaging sector. This is a good view to assess the P1 and P3 scallops of the mitral valve. The left atrium, left atrial appendage, and left ventricle are seen in this view.

Mid-esophageal two-chamber view

Rotating the multi-plane probe angle to about 90 degrees will image the heart in a two-chamber view showing the left atrium, left atrial appendage and left ventricle [Figure 4]. This view is orthogonal to the mid-esophageal four-chamber view. Here P3 is to the left and A1, A2, and A3 segments of AML are seen on the right side of the imaging sector.

Mid-esophageal long axis view

Both the left ventricular inflow and outflow regions, along with the aortic valve in its long axis are seen between 120 and 150-degree transducer angle in the mid-esophageal position [Figure 5]. The left ventricular outflow tract (LVOT) measurement, assessment of aortic valve regurgitation, and systolic anterior motion (SAM) of the AML are best performed in this view.

Transgastric short axis view

Pushing the probe further into the stomach, to about 40 to 45 cm at zero degree transducer angle, and anteflexing the tip of the probe, will expose the mitral valve in its short axis [Figure 6]. Postero-medial commisssure is nearer to the probe and antero-lateral commissure is at the far field; AML is on the left and PML is to the right of the imaging sector.

Transgastric two-chamber view

Rotating the transducer angle to 80 to 100° will develop the two-chamber view where the papillary muscles and their chordae are clearly seen [Figure 7]. A detailed assessment of the mitral sub-valvular apparatus can be performed in this view.


   Functional Classification of Mitral Regurgitation (Carpentier's) Top


The pioneering cardiac surgeon Alain Carpentier has described a widely followed functional classification of MR.

Type 1: Normal leaflet motion (MR is due to annular dilatation, perforation, or cleft in the leaflet)

Type 2: Excessive leaflet motion (due to degenerative mitral prolapse, ruptured chordae due to ischemia or infarction)

Type 3: Restricted leaflet motion

3a: Rheumatic disease (both systolic and diastolic restriction of leaflets)

3b: Ischemic or dilated cardiomyopathy with globular left ventricle (systolic restriction)

The mechanism of MR could be due to any or a combination of the above mentioned types. In the western world, MR is caused by degenerative disease in 50% of patients, rheumatic disease in 20% of patients, and ischemic heart disease in 17% of patients; infection and other pathologies are the main causes in the remaining 13% of patients. [8] In India, majority of the cases of MR are caused by rheumatic heart disease. Rheumatic disease affecting the mitral valve might cause dilatation of the mitral annulus alone or a combination of annular dilatation, restriction or prolapse of the leaflets resulting in MR.

Degenerative mitral valve disease is characterized by annular dilatation and leaflet prolapse. This disease has been further differentiated into Barlow's disease and fibroelastic disease. [9] In Barlow's disease, there is a gross annular dilatation, excess of leaflet tissue with elongated chordae, and a billowing valve. In addition to the above, the annulus and the leaflets may have calcium deposits. Though the billowing of leaflets exists for a long time, MR appears only later on in life and patients are relatively young during presentation. The fibroelastic disease presents usually during the sixth decade, and except for the isolated prolapsing segment, rest of the mitral apparatus is usually normal.

The mechanism of MR in ischemic heart disease is more complex and involves a combination of (1) dilated and a flat annulus (2) displacement of papillary muscles due to abnormal function and geometry of the left ventricle (which is dilated and globular).


   Is the Valve Suitable for Repair ? Top


Whether a valve is suitable for repair or not depends on the pathology and expertise of the surgeon. Generally, isolated mitral annular dilatation, perforation, or clefts in the leaflets are the easiest to repair. Repair of PML prolapse has excellent results. Although the results of AML prolapse are less satisfactory than the PML prolapse, there has been an improvement in the results due to current surgical techniques. [3],[10] Complexity of the operation increases with the involvement of more than one leaflet and calcification of the leaflets or the annulus.

Rheumatic disease may present with mitral annular dilatation alone or in combination with elongated or ruptured chordae with leaflet prolapse, thickened, calcified, and shrunken leaflets with commissural fusion. Patients with severe sub-valvular disease may not be suitable for mitral valve repair.

In Type 3b MR, left ventricular dilatation and separation of the papillary muscles results in tenting of the leaflets, thus, restricting the movement of mitral leaflets. An attempt should be made to repair moderate to severe MR caused by ischemic heart disease.

Systolic anterior motion

About four to 14% of patients with myxomatous mitral valve disease, who undergo mitral valve repair, develop SAM of the AML obstructing the LVOT. [11] People with a narrow LVOT and increased PML length are at a high risk of developing SAM. [12] Maslow, et al. described certain predictors of post-repair SAM like C-Sept distance less than 2.5 cm, increased PML length, and the ratio of AML length to PML length 1.3 or less [Figure 8]. [13]


   Operative Techniques Top


Ring annuloplasty

Mitral ring annuloplasty is often the concluding step in almost all the mitral valve repairs. It could be the sole technique in patients with isolated mitral annular dilatation. Mitral rings are available in various sizes and shapes to suit a particular individual according to their age and pathology. Generally, larger rings are used in patients at risk of developing postoperative SAM [9] and smaller rings are advocated in patients with ischemic MR. The mitral annulus is not a two-dimensional structure. Thus, the currently available mitral rings are made to mimic the natural three-dimensional saddle shape of the normal mitral annulus.

Triangular and quadrangular resection of the mitral leaflets

Isolated prolapse of a scallop could be treated by a limited triangular or quadrangular resection. If the predictors of post-repair SAM exist, a sliding annuloplasty in addition to quadrangular resection of the PML is carried out to reduce the length of the PML.

Commissural plication and Alfieri edge to edge repair

Commissural scallop prolapse can be treated by plication of the commissures. Alfieri technique involves stitching the edges of both A2 and P2, thus restricting the mobility of the leaflets. Single orifice mitral annulus is converted into a double orifice structure. The Alfieri technique has been proposed to be a simple useful alternative to other techniques of repair, especially when the disease is of complex pathology such as bileaflet prolapse in Barlow's disease, anterior leaflet prolapse, etc. [14]

Chordal transfer, chordal shortening, and artificial chordae insertion

Chordal transfer technique involves a limited quadrangular resection of the PML having the normal chordae and transferring it to the flail AML whose chordae is ruptured. Shortening of the chordae can treat leaflet prolapse due to elongated chordae. On the other hand, one may use artificial chordae made of Gore-Tex to reconstruct the torn or elongated chordae which was the cause of prolapse and regurgitation.


   Assessment of Repair Top


TEE can be used to assist the surgeon to separate the patient from the cardiopulmonary bypass. With the help of TEE, one can ensure complete de-airing of the cardiac chambers before coming off cardiopulmonary bypass so that coronary air embolism and subsequent right or left ventricular dysfunction is minimised. Left ventricular dysfunction could be due to pre-operatively impaired left ventricle, problems with intraoperative myocardial preservation or accidental ligation of circumflex coronary artery which lies close to the antero-lateral commissure.

Coaptation of leaflets

Following repair, individual scallops and segments should be thoroughly evaluated for the adequacy of coaptation. Any residual or new restriction or prolapse might be the cause of residual MR. The coapted segment of the mitral leaflets during peak systole can be measured and is known as the leaflet coaptation height. If this height is five mm or more the repair is considered to be satisfactory. [9] Following the repair, PML is fixed and the mitral closure occurs solely due to the movement of AML. The role of PML has been described akin to a doorstop.

Residual MR

The color flow Doppler is used to screen for any residual MR following a repair. Residual MR could be due to residual leaflet prolapse, excessive restriction, or inadequate reduction of the mitral annulus. Para-valvular leak or leaflet perforation may occur due to technical difficulties. Patients with greater than mild residual MR should return to the cardiopulmonary bypass for further correction or replacement of the mitral valve, which usually is a collective decision of the surgeon and the echocardiographer. It is important to quantify the leak by using objective parameters such as width of the vena contracta, pulmonary venous flow characteristics, or effective regurgitant orifice area. The risk of re-operation is reported to be high whenever a residual regurgitation of more than mild is left behind.

Mitral stenosis

The mitral valve gradient should be measured postoperatively to assess if the repair has resulted in mitral stenosis. Pressure half time to assess the mitral stenosis is not reliable during the postoperative period because of the changing compliance of the left atrium and left ventricle. Mitral stenosis is common with rheumatic mitral valve repairs or when the surgeon has over-enthusiastically reduced the mitral orifice by commissural plication or by the use of a smaller annuloplasty ring. A mean mitral valve gradient of more than five mm Hg is not acceptable and should be corrected by further repair or valve replacement.

Systolic anterior motion

SAM is seen exclusively in degenerative mitral valve repairs with narrow LVOT and excessive length of PML. In these patients, the mitral coaptation point moves towards the LVOT causing obstruction that would also result in posteriorly directed MR. The SAM is made worse by an empty and hyper-contractile heart typically seen while coming off bypass. Filling the left ventricle to its optimal volume and stopping all the inotropes would treat a milder form of SAM. In severe cases, the surgeon may need to go back on bypass and perform a sliding annuloplasty, put a larger annuloplasty ring, or even replace the mitral valve.

Aortic regurgitation

A stitch taken through the AML in close proximity to the aortic left coronary cusp and non coronary cusp, might distort the aortic valve causing aortic regurgitation.

Circumflex artery occlusion

The circumflex artery may get kinked or occluded by a stitch taken during the repair as it lies close to the anterolateral commissure. This would result in severe left ventricular dysfunction postoperatively.


   Conclusion Top


Intraoperative use of TEE has now become the standard of care in assessing the mitral valve repair. With a greater level of accuracy, the echocardiographer can guide the surgeon in taking a decision on repair, and also assess the adequacy of a repair and make a significant impact on the outcome of surgery. It is well known that a less satisfactory repair would risk a re-operation in the early follow-up period. In order to achieve a high level of success with mitral repairs, it is important for the echocardiographer to understand the patho-anatomy of MR by utilizing various 2-D echocardiographic planes and be aware of the complications frequently encountered during mitral valve repairs.

 
   References Top

1.Fedak PW, McCarthy PM, Bonow RO. Evolving concepts and technologies in mitral valve repair. Circulation 2008;117: 963-74.  Back to cited text no. 1  [PUBMED]  [FULLTEXT]  
2.Goldman ME, Mora F, Guarino T, Fuster V, Mindich BP. Mitral valvuloplasty is superior to valve replacement for preservation of left ventricular function: an intraoperative two-dimensional echocardiographic study. J Am Coll Cardiol 1987;10:568-75.  Back to cited text no. 2  [PUBMED]    
3.Suri RM, Schaff HV, Dearani JA, Sundt TM 3rd, Daly RC, Mullany CJ, et al. Survival advantage and improved durability of mitral repair for leaflet prolapse subsets in the current era. Ann Thorac Surg 2006;82:819-26.  Back to cited text no. 3  [PUBMED]  [FULLTEXT]  
4.Braunberger E, Deloche A, Berrebi A, Abdallah F, Celestin JA, Meimoun P, et al. Very long-term results (more than 20 years) of valve repair with Carpentier's techniques in nonrheumatic mitral valve insufficiency. Circulation 2001;104:I8-11.   Back to cited text no. 4  [PUBMED]  [FULLTEXT]  
5.Shanewise JS, Cheung AT, Aronson S, Stewart WJ, Weiss RL, Mark JB, et al. ASE/SCA guidelines for performing a comprehensive intraoperative multiplane transesophageal echocardiography examination: recommendations of the American Society of Echocardiography Council for Intraoperative Echocardiography and the Society of Cardiovascular Anesthesiologists Task Force for Certification in Perioperative Transesophageal Echocardiography. J Am Soc Echocardiogr 1999;12:884-900.  Back to cited text no. 5  [PUBMED]  [FULLTEXT]  
6.Zoghbi WA, Enriquez-Sarano M, Foster E, Grayburn PA, Kraft CD, Levine RA, et al. Recommendations for evaluation of the severity of native valvular regurgitation with two-dimensional and Doppler echocardiography. J Am Soc Echocardiogr 2003;16:777-802.  Back to cited text no. 6  [PUBMED]  [FULLTEXT]  
7.Savage RM, Shiota T, Stewart WJ, Wallace L, Gillinov AM. Assessment in mitral valve surgery. In: Savage RM, Aronson S, editors. Comprehensive textbook of intraoperative transesophageal echocardiography. Philadelphia; Lippincott Williams and Wilkins: 2005. p. 443-533.  Back to cited text no. 7      
8.Iglesias I. Intraoperative TEE assessment during mitral valve repair for degenerative and ischemic mitral valve regurgitation. Semin Cardiothorac Vasc Anesth 2007;11:301-5.  Back to cited text no. 8  [PUBMED]  [FULLTEXT]  
9.Adams DH, Anyanwu AC, Sugeng L, Lang RM. Degenerative mitral valve regurgitation: Surgical echocardiography. Current Cardiology Reports 2008;10:226-32.  Back to cited text no. 9  [PUBMED]  [FULLTEXT]  
10.David TE, Ivanov J, Armstrong S, Christie D, Rakowski H. Comparison of outcomes of mitral valve repair for degenerative disease with posterior, anterior and bileaflet prolapse. J Thorac Cardiovascular Surg 2005;130:1242-9.  Back to cited text no. 10      
11.Mihaileanu S, Marino JP, Chauvaud S, Perier P, Forman J, Vissoat J, et al. Left ventricular outflow obstruction after mitral valve repair (Carpentier's technique): proposed mechanisms of disease. Circulation 1988;78:I78-84.  Back to cited text no. 11  [PUBMED]  [FULLTEXT]  
12.Jebara VA, Mihaileanu S, Acar C, Brizard C, Grare P, Latremouille C, et al. Left ventricular outflow tract obstruction after mitral valve repair. Results of the sliding leaflet technique. Circulation 1993;88:II30-34.  Back to cited text no. 12      
13.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 1993;34:2096-104.  Back to cited text no. 13      
14.Alfieri O, Maisano F, De Bonis M, Stefano PL, Torracca L, Oppizzi M, et al. The double-orifice technique in mitral valve repair: A simple solution for complex problems. J Thorac Cardiovasc Surg 2001;122:674-81.  Back to cited text no. 14  [PUBMED]  [FULLTEXT]  

Top
Correspondence Address:
Sanjayakumar C Banakal
Department of Anaesthesiology, Narayana Hrudayalaya Institute of Medical Sciences, 258/A, Bommasandra Industrial Area, Bangalore 560 099
India
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/0971-9784.58848

Rights and Permissions


    Figures

  [Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7], [Figure 8]

This article has been cited by
1 Transoesophageal echocardiographic evaluation of the mitral valve
Authors of Document Lau, G., Hebballi, R.
Source of the Document International Journal of Perioperative Ultrasound and Applied Technologies. 2012;
[Pubmed]
2 Intraoperative transesophageal echocardiographic assessment of the mitral valve repair surgery [Mitral kapak onarim cerrahisinin i̇ntraoperatif transözefageal ekokardiyografi ile deǧerlendirilmesi]
Kudsioǧlu, T. and Tuncel, Z.
Gogus-Kalp-Damar Anestezi ve Yogun Bakim Dernegi Dergisi. 2011; 17(3): 55-63
[Pubmed]



 

Top