Surgical Repair of the Mitral Valve Presenter: Graham McCrystal Cardiothoracic Surgeon Christchurch Public Hospital

Transcription

1 Mitral Valve Surgical intervention Graham McCrystal Chairs: Rajesh Nair & Gerard Wilkins Surgical Repair of the Mitral Valve Presenter: Graham McCrystal Cardiothoracic Surgeon Christchurch Public Hospital Background The Mitral Valve Open heart surgery became possible in the second half of the 20 th Century. Mitral surgery was well established by 1980s when the first reports of reproducible and durable mitral repair surgery emerged. Rheumatic Valve disease was becoming less common and degenerative disease more so. French Correction challenged surgeons to understand and respect the mitral valve (c.f. MVR for RMVR) Anatomy Nomenclature 1

2 Surgical Pathology of Degenerative Mitral Valve Disease. Chords: Elongation or rupture of chords Leaflets Thickening and excess mitral leaflets Annulus Dilated and circular Classification of Mitral Dysfunction Surgical Approach to the Degenerative Mitral Valve - Intraoperative Analysis Key Points of Analysis Free edge of leaflet should reach but not go beyond plane of annulus, (set by chord length) look for excursion above or below this. P1 is usually reference to compare leaflet excursion. PMVL Height (i.e. distance from free edge to annular insertion) should be about the same, P2 usually tallest Perforations, nodules, vegetations, calcification Annular calcifications, abscess. Subvalvular apparatus intact, calcified 2

3 The Classic Repair Ruptured chords to P2 Virtually all of P2 segment is prolapsed with normal looking P1 and P2 segments of PMVL and anterior leaflet. No perforations, calcifications of leaflet, no atrial vegetations. Annulus is normal configuration being wider than higher Step 1 Identify Normal chords adjacent to the prolapsing segment Line from mid point of anterior annulus to posterior annulus crossing PMVL at transition point from normal to prolapsed Cut along lines connecting cut by continuing parallel with the annulus. Step 2 Plicate the annulus at the site of leaflet resection Tie sutures bringing leaflet edges together Step 3 Close defect in leaflets 3

4 Step 4 Choose size of annuloplasty ring/band If sizes are even numbered size to commissure if odd to the trigones. Place a stitch at the appropriate landmarks annulus Stitches should pass through notches in the sizer The surface area of the anterior leaflet should be all but be covered by sizer if anterior leaflet is bigger upsize, if a lot smaller downsize Annuloplasty Rings Many and varied Remodel the annulus to systolic configuration with optimal dimensions for anterior leaflet size and keep it there. This reduces stresses on each element so repair is more durable. Maximises coaptation surface Step 5 Place annular sutures Parallel with annulus which is about 2mm behind the hinge point. Care at the aorto mitral curtain not to injure aortic valve cusps. Step 6 Secure the annuloplasty ring/band using annular sutures for the finished result. 4

5 Developed by Carpentier in the 1960s and it achieves three things that he believes are essential 1. Preserve or restore full leaflet motion 2. Create a large surface of coaptation 3. Remodel and stabilise the entire annulus Modifications to Classic Repair Sliding valvuloplasty If height of posterior leaflet or the annular extent of leaflet resection is greater than 20mm a slide must be performed Cut along base of leaflet and excise a wedge of tissue to lower height of the leaflet. Place annuloplasty sutures to reduce the distance between the cut edges of the posterior leaflet. Bring the leaflet halves across to meet and suture leaflet to leaflet and leaflet to annulus. Modifications to Classic Repair Triangular Resection When prolapsed portion only affects 1/3 of the free edge of the scallop involved Avoids annular plication sutures. Neochords 4-0 or 5-0 Gore-Tex Suture to papillary muscle head and tied Up to prolapsing edge and secured to it Length is determined by annular plane Loops can be used There are percutaneous systems that can do this on the beating heart 5

6 Techniques for the Anterior Leaflet: Triangular Resection Techniques for the Anterior Leaflet: Chordal Transposition Only used if prolapsed portion </= to 1/5 of the length of anterior leaflet free margin Only 10% of surface area is resected. Use normal PMVL to patch prolapsing AMVL Repair resulting defect in PMVL Alternative to neochords/alfieri stitch The Alfieri Stitch Edge to edge prolapsing leaflet to normal adjacent leaflet, described by Octavio Alfieri (Milan) First described for Anterior leaflet prolapse Led to mitraclip Creates a shot gun double orifice Mitral valve. Prevents SAM Is not stenotic even with annuloplasty ring Bileaflet Prolapse 6

7 Replace? Or Repair? Figure 1 Figure 2 A comparison of outcomes of mitral valve repair for degenerative disease with posterior, anterior, and bileaflet prolapse Tirone E. David, MD, Joan Ivanov, PhD, Susan Armstrong, MSc, Debbie Christie, RN, Harry Rakowski, MD The Journal of Thoracic and Cardiovascular Surgery Volume 130, Issue 5, Pages (November 2005) The Journal of Thoracic and Cardiovascular Surgery , DOI: ( /j.jtcvs ) Copyright 2005 The American Association for Thoracic Surgery Terms and Conditions The Journal of Thoracic and Cardiovascular Surgery , DOI: ( /j.jtcvs ) Copyright 2005 The American Association for Thoracic Surgery Terms and Conditions 7

8 Figure 3 Figure 4 The Journal of Thoracic and Cardiovascular Surgery , DOI: ( /j.jtcvs ) Copyright 2005 The American Association for Thoracic Surgery Terms and Conditions The Journal of Thoracic and Cardiovascular Surgery , DOI: ( /j.jtcvs ) Copyright 2005 The American Association for Thoracic Surgery Terms and Conditions Results improve with experience Why not replace then? JOU RNAL OF THE AME R I CAN COL L EG E OF CARD I OLOGY VOL. 6 7, NO. 5, Probability of survival (death from any cause) among patients having mitral valve repair versus replacement for posterior leaflet prolapse (A) and bileaflet prolapse (B). (From Suri RM, Schaff HV, Dearani JA, et al: Survival advantage and improved durability of mitral repair for leaflet prolapse subsets in the current era. Ann Thorac Surg 2006;82: ) 8

9 Mitral Valve Repair Expert Centres Bibliography. Can we justify less than the best outcomes in patients with complex lesions? In USA there is pressure for Centers of Mitral Repair Excellence In small volume centres can there be subspecialisation or should we refer? Carpentier et al, Carpentier s Reconstructive Valve Surgery: From Valve Analysis to Valve Reconstruction. Saunders Elsevier David et al, A comparison of outcomes of mitral valve repair for degenerative disease with posterior, anterior, and bileaflet prolapse, JTCVS Volume 130, Issue 5, Pages (November 2005) Suri et al, Effect of recurrent Mitral Regurgitation Following Degenerative Mitral Valve Repair. JACC 2016; 67: Coutinho et al, Long-term results of mitral valve surgery for degenerative anterior leaflet or bileaflet prolapse: analysis of negative factors for repair, early and late failures, and survival. EJCTS, Volume 50, Issue 1, 1 July 2016, Pages 66 74,. 9