Mitral valve replacement with preservation of valve apparatus

Dr. Md. Rezwanul Hoque BulbulMBBS,MS,FCPS, FRCSG, FRCSEd

Associate ProfessorDepartment of Cardiac SurgeryBSMMU, Dhaka, Bangladesh

Mitral valve- chordal attachment

▪ The chordae of the mitral valve insert either into the free edge or into the rough zone on the ventricular surface of the anterior and posterior mitral leaflets.

▪ The chordae of the anterior leaflet insert on either side of a central clear zone.

▪ There are two papillary muscles - antero-lateral and postero-medial. Each of these gives chordae to both the anterior and posterior mitral leaflets.

Rationale of valve apparatus preservation

▪ The attachment of the mitral valve and the left ventricular wall through the papillary muscles and chordae tendineae play an important role in left ventricular contraction by drawing the mitral ring towards the apex, thereby causing shortening of the axis for the ejection of blood.

Solomon NA, Pranav SK, Naik D, Sukumaran S. Importance of preservation of chordal apparatus in mitral valve replacement. Expert Rev Cardiovasc Ther. 2006;4(2):253-61.

▪ Conventional mitral valve (MV) replacement is known to cause deterioration in the left ventricle function, the major mechanism responsible being disruption of the annulo-papillary continuity, thus favouring preservation of the mitral subvalvular apparatus.

Saad Bader Zakai, Salman-Ur-Rehman Khan, Fazle Rabbi, Habiba Tasneem. Effects of mitral valve replacement with and without Chordal preservation on cardiac function: early and Mid-term results. J Ayub Med Coll Abbottabad 2010;22(1)

▪ The papillary muscles play an important role in ventricular contraction. Secured by the atrioventricular ring, these muscles approximate the anterolateral and posteromedial walls during systole, thus, determining the degree of longitudinal axis lessening and modification of the spheroid ventricle.

Rushmer RF, Finlayson BL, Nash AA. Movements of mitral valve. Circ Res 1956; 4: 337.

▪ The traction, adequate positioning and anchoring of the chordae tendineae in the atrioventricular ring disperse, in a more physiologic manner, the papillary muscle forces that act on the ventricular wall. This break in LV wall expansion during diastole, in the absence of volume overload after correction of valve insufficiency, can create conditions that further reduce the LV longitudinal axis, cause regression of the spherical form and improve systolic function.

Puig LB, Gaiotto FA, Oliveira JL Jr, Pardi MM, Bacal F,Mady C, et al. Mitral valve replacement and remodeling of the left ventricle in dilated cardiomyopathy with mitral regurgitation: initial results. Arq Bras Cardiol. 2002;78(2):224-9.

▪ The residual valve insufficiency after mitral reconstruction ranges from 16% to 33%.

Bolling SF, Pagani FD, Bachi DS. Intermediate mitral reconstruction in cardiomyopathy. J Thorac Cardiovasc Surg 1998; 115: 381-8.

▪ Calafiore et al observed some degree of mitral valve insufficiency in 27 of 29 patients who underwent valve reconstruction. Another factor that warrants consideration is that mitral valve reconstruction does not affect the subvalvular apparatus.

Callafiore AM, Sabina G, Gallina MD, et al. Mitral valve procedure in dilatedcardiomyopathy: repair or replacement? Ann Thorac Surg 2001; 71: 146-53.

▪ Mitral valve replacement should totally correct the valve insufficiency.

▪ Since Lillehei's first pioneering report 30 years ago* suggesting that complete preservation of the subvalvular apparatus (anterior as well as posterior leaflets) during mitral valve replacement (MVR) reduced the incidence of postoperative low-output syndrome and the operative mortality rate, many experimental and clinical studies have demonstrated that chordal sparing MVR is preferable to conventional MVR (e.g. total excision of the chordae tendineae) with respect to postoperative left ventricular (LV) systolic function.

*Lillehei CW, Levy MI, Bonnabeau Re. Mitral valve replacement with preservation of papillary muscles and chordae tendineae. J Thorac Cardiovasc Surg 1964;47:532-43.

Types of preservation

▪ Partial Chordal Preservation: This technique involves excision of the whole of the anterior leaflet and chordae tendinae with preservation of the posterior leaflet and associated subvalvular apparatus. The posterior leaflet is imbricated to the annulus. Alternatively, the leaflet is incised from edge to base at two or three points in between the scallops.

▪ Total Chordal Preservation: The anterior leaflet is predominantly managed by Khonsari I and II techniques. In some patients, the Miki’s technique or the Feike’s technique are used.

▪ No Chordal Preservation: In cases of calcified mitral valves or severe subvalvular fusion, the whole of the mitral valve including the leaflets and subvalvular apparatus are completely excised.

Puig technique

▪ In this method both the anterior and posterior leaflets of the mitral valve were divided into hemi leaflets. The resultant four pedicles were displaced under traction toward the left atrium and anchored between the mitral annulus and an implanted valvular prosthesis. Post operative Doppler echocardiography revealed evidence of LV remodeling in some of these patients, including lateral wall changes and a tendency of the LV cavity to return to its elliptical shape.

Puig LB, Gaiotto FA, Oliveira JL Jr, Pardi MM, Bacal F,Mady C, et al. Mitral valve replacement and remodeling of the left ventricle in dilated cardiomyopathy with mitral regurgitation: initial results. Arq Bras Cardiol. 2002;78(2):224-9.

The AML is incised at its base, 2-3 mm from its attachment. The incision is carried to both the sides and brought down centrally towards the free edge of the leaflet and a triangular segment of the AML is thus excised leaving the chordae attached to the remaining AML which is re-suspended to the mitral annulus by sutures used to secure the prosthetic valve. The PML with its chordae is left intact. In patients with myxomatous MR undergoing MVR, the chordae are shortened by imbricating the PML in the mitral annulus using the sutures used for prosthetic valve fixation.Alternatively, a part of the posterior leaflet is excised and reattached to the mitral annulus during fixation of the prosthetic valve.Advantages of the David technique are the maintenance of the chordae in their natural anatomic orientation, reduced risk of LVOTO and reduction in the bulk of leaflet tissue.

David’s technique

David’s technique: (a) Normal Mitral valve. AML = anterior mitral leaflet, PML = posterior mitral leaflet (b)A triangular portion of the AML and a crescent of PML are excised.

David TE. Mitral valve replacement with preservation of chordaetendineae. Rationale and technical considerations. Ann ThoracSurg 1986; 41: 680-82.

Feikes technique: Posterior chordal sparing(a)The AML is incised in the midline andthe incision is extended sideways (b)The 2 segments of the AMLare turned backwards and sutured to the posterior mitral annulus.

Feikes HL, Daugharthy JB, Perry JE, Bell JH, Hieb RE, Johnson GH. Preservation of all chordae tendineae and papillary muscles during mitral valve replacement with a tilting disc valve. J Card Surg 1990; 5: 81-5.

After the AML is detached from the annulus between the two commissures, an ellipse of tissue is excised and the rim of the leaflet tissue containing the chordae is reattached to the anterior annulus (Khonsari I technique). If the leaflet is thick or calcified, it is divided into 2-5 chordal segments which are re-attached to theannulus (Khonsari II technique). The PML is retained completely and the redundant leaflet tissue is folded up into the annulus by passing the valve sutures through the annulus and bringing them through the leading edge of the leaflet tissue.

Khonsari technique

Sintek CF, Pfeffer TA, Kchamba TA, Khonsari SR. Mitral valve replacement: technique to preserve the subvalvular apparatus. Ann Thorac Surg 1995; 59: 1027-29.

Miki procedure

▪ The mitral valve is carefully inspected. If the repair is ruled out then the anterior mitral leaflet is pulled out carefully to inspect it.

▪ An incision is then made few millimetres from the annulus along the anterior mitral ring. The anterior leaflet is divided in the middle into anterior and posterior parts. The area in the middle is usually devoid of chordae and is excised in order to debulk the unnecessary tissue so that decent size prosthesis could be used.

▪ The anterior and posterior parts of the anterior leaflet are attached to the mitral ring, near the anterolateral and posteromedial commissures, respectively, with 2-0 pledget supported Ticron sutures that are taken from the ventricular to the atrial side of the leaflet and slightly away from the free margin of the annulus .

▪ These sutures are left untied and are subsequently taken through the prosthetic valve ring along with the other valve sutures.

▪ The posterior leaflet is usually left as it is; on occasions it is incised in its middle vertically a few millimetres shy off the annulus so that proper size prosthesis can be used. When taking sutures in the posterior leaflet annulus the free edge of the leaflet should be included so that the leaflet is compressed between the prosthetic ring and the annulus and does not impinge on prosthesis causing it to malfunction. Miki S, Kusuhara K, Ueda Y, Komeda M, Ohkita Y, Tahata T. Mitral valve

replacement with preservation of chordae tendineae and papillary muscles. Ann Thorac Surg.1988;45(1):28-34.

The mitral valve, dotted line is the area of incision in the anterior mitral leaflet

The anterior mitral leaflet is retracted by a hook. Chordae tendineae and papillary muscles of are shown. Dotted line is thechordae free portion to be excised

The anterior and posterior parts of the anterior leaflet arere-attached to the mitral ring near the anterolateral andposteromedial commissures

These sutures are left untied and are subsequently takenthrough the prosthetic valve ring along with the other valve sutures

MIKI procedure

Rose and Oz technique : (a) An ellipse of AML is removed,(b)The defect in AML is closed is closed with a runningpolypropylene suture and valve sutures are placed.

Rose EA, Oz MC. Preservation of the anterior leaflet chordae tendineae during mitral valve replacement. Ann Thorac Surg 1994;57: 768-69.

Crossed papillopexy

▪ After left atriotomy and adequate exposure of the mitral valve, the anterior cusp is excised from the annulus and centrally spilt into two halves with its chordae tendineae complex, fixed to the opposite commissure by its medial end.

Otoni Moreira Gomes, Eros Silva Gomes; Geraldo Paulino Santana Filho; José Carlos Dorsa Vieira Pontes; Ricardo Adala Benfatti. New technical approach for crossed papillopexy in mitral valve replacement surgery: short term results. Rev Bras Cir Cardiovasc vol.20 no.3 São José do Rio Preto July/Sept. 2005

(A) Schematic of mitral valve.

Sasaki H , Ihashi K Eur J Cardiothorac Surg 2003;24:650-652

© 2003 Elsevier B.V.

(A) Schematic of mitral valve. In detaching the ellipsoid of tissue from the anterior leaflet, incision B is nearly straight and shorter than incision A. (AL=anterolateral commissure, PM=posteromedial commissure).

(B) (B) The strip to the annulus is reattached beginning at the posteromedial commissure in a counter clockwise direction with pledgeted mattress sutures that will also be used for the valve replacement.

New technique of total preservation

Problems of preservation

▪ Mechanical- Valve obstruction( Low profile valve gives better benefit), Relatively smaller sized valve is placed.

▪ Thromboembolic

▪ Infective

▪ Small increase in operating time

▪ Experiments by Hansen and associates have clearly demonstrated that LV function was superior with an intact subvalvular apparatus, intermediate with preservation of either the AML or PML and poorest with loss of all chordae.

Hansen DE, Cahill PD, Derby GC, Miller DC. Relative contributions of the anterior and posterior mitral chordae tendineae to canine global left ventricular function. J Thorac Cardiovasc Surg 1987; 93: 45-55.

▪ Buffolo et al proposed that, in the treatment of DCM, the anterior leaflet chordae could be anchored in commissural areas to reduce the LV longitudinal axis and re-establish its elliptical shape.

Buffolo E, Machado IAP, Palma H, Rodrigues JNB. Nova abordagem cirúrgica para o tratamento de pacientes em insuficiência cardíaca refratária com miocardiopatia dilatada e insuficiência mitral secundária. Arq Bras Cardiol 2000; 74: 129-34.

Advantages of chordal preservation

▪ Complete chordal preservation during MVR confers several advantages as compared to conventional MVR without chordal preservation or partial chordal preservation.

▪ It preserves LV geometry and function, reduces the operative mortality, improves early and long-term survival and reduces the risk of ventricular rupture.

▪ With appropriate surgical technique even large size prosthetic valves can be implanted and the risk of prosthetic valve dysfunction and LV outflow tract obstruction can be eliminated.

▪ There is emerging evidence which suggests that RV function may improve significantly after LV chordal preservation.

Talwar et al Chordal preservation. IJTCVS, 2005; 21: 45–52

▪ drrhbulbul@yahoo.com

▪+8801711560305