Chordal preservation in mitral valve replacement aims to maintain left ventricular function by preserving the continuity between the mitral annulus and the ventricular wall. Several techniques have been developed to preserve either the posterior or both anterior and posterior leaflets. Complete chordal preservation is advantageous as it best maintains left ventricular geometry and function, reducing mortality and improving survival outcomes compared to partial or no preservation. The appropriate surgical technique can allow for implantation of adequately sized prostheses while avoiding complications such as left ventricular outflow tract obstruction.

1. CHORDAL
PRESERVATION in
MITRAL VALVE
REPLACEMENT
BY
DR.VASANTHI
DNB-CARDIAC SURGERY
MADRAS MEDICAL MISSION

2. PLAN
 INTRODUCTION
 ANATOMY & PHYSIOLOGY
 HISTORICAL ASPECT
 EFFECTS OF CHORDAL PRESERVATION
 PHYSIOLOGICAL ALTERATION
 TECHNIQUES OF CHORDAL PRESRVATION
 RESULTS
 TAKE HOME MESSAGE

3. INTRODUCTION
 Aim of mitral valve surgery - to provide a competent, non-obstructed
valve without compromising the left ventricular (LV) function.
 Above aims are met with valve repair .

4.  When repair is not feasible- preservation of LV function is an
important concern.
 Awareness of deleterious effects of the loss of annulo-
ventricular continuity has increased, chordal preservation
has gained popularity

5.  Despite the clear advantages of complete chordal preservation ,many
surgeons still retain only the posterior leaflet
 greater technical complexity
 longer operating time
 fear of potential interference with mechanical leaflet motion
 need to undersize the mitral prosthesis possibility of LVOTO.

6. ANATOMY

9. ANNULO VENTRICULAR
CONTINUITY
 In 1922, Wiggers and Katz and later Rushmer et al proposed
the concept.
 left ventricular geometry and function -dynamic interaction
between the mitral annulus and the LV wall.
 The attachments between the mitral annulus and the LV wall
moderate the LV distension during diastole and wall tension
during systole.
 When the papillary muscles contract during the isometric
phase of the cardiac cycle,the closed MV is drawn into the LV
cavity thus reducing the longitudinal axis of the LV and
increasing its short axis.
 Diastolic recoil.

13. Effects of chordal transection
 Hansen -- transection of chordae to AML reduced the LV function
to a greater degree as compared to the transection of chordae to
PML.
 Chordal transection also appeared to shorten the long axis of the
LV with an increase in the short axis and dilatation of the
chamber.
 Transection of the chordae produced dyskinetic areas at the
insertion of severed papillary muscles

14. The parallel bars are the mitral annulus. (b) The arms of the gymnasts are
chordae and their bodies the papillary muscles. The floor is the left ventricular
wall.

15. Effect of chordal resection-Note dilatation & ventricular wall thickness where
chordae are resected partially or completely (a)Partial chordal resection (b)
Complete chordal resection.

16. Physiological changes
 Chronic MR- LV function gradually declines.
 Regurgitant stroke volume added to forward stroke
volume- increase EF in early phase.
 Progressive LV dilatation- increase Afterload.
 After MVR with chordal transection- EF determined by
contractility,preload ,afterload.

17. Historical aspect
 In 1964, Lillehei introduced the concept of
chordal preservation during MVR to reduce
the problem of post-operative low cardiac
output syndrome.
 David in 1981 reintroduced the concept- LV
function deteriorated if the chordae were
transected .

18.  Only those patients in whom the chordae
had been spared could increase the LV
ejection fraction (EF) and stroke volume
index.
 Also in the chordal preservation group, there
was better long-term systolic function and LV
performance both at rest and during exercise

19. TECHNIQUES
1.Preservation of posterior leaflet

20. 1.PML Preservation-Lillehei

21. 2.TOTAL CHORDAL
PRESERVATION
 With the development of low profile bi-leaflet mechanical
valves, and refinements in surgical technique, various
methods of total chordal preservation have been
described
 to preserve the LV systolic function
 to avoid interference with the mechanical prosthesis
function by portions of the retained subvalvular
apparatus
 to prevent left ventricular outflow tract obstruction
(LVOTO).

22.  In addition to these considerations, it is important to
adjust tension on the chordae during chordal
preservation as too much stress on the chordae can lead
to chordal rupture and entanglement with the prosthesis.
 Method of AML preservation should avoid the systolic
anterior motion of the AML which has the potential to
produce LVOTO.

23. 3.DAVID’S TECHNIQUE

26.  Advantages :
 maintains the chordae in their natural anatomic
orientation
 reduced risk of LVOTO
 reduction in the bulk of leaflet tissue

29.  ADVANTAGES :
 specially useful while implanting tilting disc prosthesis where disc
entrapment is less
 Chordal continuity to the AML is well maintained.
 DISADVANTAGE :
 disturbs the normal geometric relationships of the mitral subvalvular
apparatus
 which could alter the distribution of regional LV wall stresses and disturb
chordal tension during papillary muscle contraction thereby reducing
global LV systolic and diastolic function

33.  Khonsari I technique -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 II technique-If the leaflet is thick or calcified, it is divided
into 2-5 chordal segments which are re-attached to the annulus

34.  ADVANTAGE :
 no reported incidence of LVOTO or interference with
prosthetic valve function.
 It is believed that myocardial rupture is prevented by
maintaining the tethering effect of the intact subvalvular
apparatus.
 CONCERN :
 chordae could become stretched around the struts of
the bioprostheses thereby exerting more stress on the
retained chordae

38.  Advantages :
 reduced bulk of the AML which reduces the
possibility of impairment of valve function
 low risk of LVOTO,
 reduced risk of thrombosis on the redundant
leaflet tissue.

39. MIKI’s TECHNIQUE

41. Advantage
 Simple, and LVOTO is uncommon with good preservation of LV
function
 Suitable for patients with RHD and thickened, and calcific cusps
 Allows placement of a larger prosthesis.
 Use of a low profile prosthesis further reduces the incidence of
leaflet obstruction from retained chordae.

43. Vander-Salm andYu
technique

46. ADVANTAGE:
 If the AML is large, it is reefed within the sutures and
the prosthetic valve is seated and tied.
 The native leaflet is reefed and compressed
between the prosthesis and the native annulus and
also chordal tension is evenly maintained

56. Safeguards-Ideal method
 The factors to be considered are the
 Simplicity
 reproducibility of the technique
 prevention of post-operative LVOTO due to systolic
anterior motion of the remaining AML risk of interference
with the prosthetic valve function.
 The technique used should allow for implantation of an
adequate size prosthesis to prevent post-operative
patient-prosthesis mismatch..

57. TAKE HOME MESSAGE
 Complete chordal preservation advantages.
 It preserves LV geometry and function
 reduces the operative mortality
 improves early and long-term survival
reduces the risk of ventricular rupture.

58.  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.