This document discusses different techniques for chordal preservation during mitral valve replacement surgery. It begins by explaining the importance of preserving left ventricular function during replacement when repair is not possible. Several historical techniques are described, including Lillehei and David's, which aimed to maintain chordal attachments to support left ventricular geometry and function. The advantages of complete chordal preservation are discussed, such as reducing mortality and improving survival by preserving left ventricular structure and function. The document provides an overview of the physiological rationale and technical considerations for different chordal preservation approaches.
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Chordal preservation DR NIKUNJ R SHEKHADA (MBBS,MS GEN SURG ,DNB CTS SR)
1. CHORDAL PRESERVATION DURING
MITRAL VALVE REPLACEMENT
BY DR NIKUNJ
(CTS RESIDENT STAR HOSPITAL)
(Coordinator:DR P.SATYENDRANATH PATHURI)
(16/9/18)
2. AIM OF MITRAL VALVE SURGERY
• to provide a competent, non-obstructed valve without compromising the left
ventricular (LV) function.
• When repair is not feasible- preservation of LV function is an important concern.
• Awareness of the deleterious effects of the loss of annulo-ventricular continuity
has increased, chordal preservation has gained popularity
5. ANNULO VENTRICULAR CONTINUITY
• In 1922, Wiggers and Katz and later Rushmer et al proposed the concept
• ventricular geometry and function are a result of a 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 reducingthe
longitudinal axis of the LV and increasing its short axis.
8. 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.
9. HISTORICAL ASPECTS AND ANIMAL EXPERIMENTS
• In 1964, Lillehei introduced the concept of chordal preservation during MVR to
reduce the problem of post- operative low cardiac output syndrome .
• The concept was re-introduced by David in 1981 after an experimental study of
MVR in dogs. This study showed that LV function deteriorated if the chordae were
transected but remained unchanged when the chordae were intact.
10. PML PRESERVATION-LILLEHEI
• As early as 1964, Lillehei et al. published the technique of preservation of the
posterior mitral leaflet (PML) and chordae tendineae in combination with mitral
prosthesis implantation (MPI).
• In a limited randomized number of 95 patients with MPI the influence of
preservation of PML on hemodynamics and physical capacity at least 46 months
after surgery without (group A) and with preservation of PML (group B) was
investigated.
• Statistically significant differences in favor of group B were found for cardiac index,
pulmonary artery pressure after stress, end-diastolic volume index (EDVI), physical
capacity and survival rate after a complication-free course.
• Basing on these results at rest and after exertion , patients with preservation of
PML and MPI are long- term in a better clinical condition.
12. David’s technique
• 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.
• 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.
14. Feikes technique
• The AML is split from the centre of the free edge towards the annulus.
Incisions are made on either side of this split towards the two
commissures to detach the AML from the annulus. The resulting two
halves of the leaflet along with the intact chordae are trimmed to remove
thickened and calcific areas and then rotated posteriorly and sutured to
the posterior mitral annulus.
• This technique has been reported to be specially useful while implanting
tilting disc prosthesis where disc entrapment by the subvalvular apparatus
is a concern.
• disadvantage of this technique is that it 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
16. Khonsari 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 I technique).
• If the leaflet is thick or calcified, it is divided into 2-5 chordal segments
which are re-attached to the annulus (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.
• With this technique, there has been no reported incidence of LVOTO or
interference with prosthetic valve function.
• It is believed that with the use of this technique, myocardial rupture is
prevented by maintaining the tethering effect of the intact subvalvular
apparatus.
17. • A concern with the Khonsari technique is that the chordae could become
stretched around the struts of the bioprostheses thereby exerting more
stress on the retained chordae.
20. Miki’ s technique
• The AML is separated from the annulus and incised in centre. The anterior
and posterior commissures are incised and papillary muscles are split.
• Excessive cuspal tissue and fibrous and calcific nodules are excised.
• The two chordal segments thus created are sutured to the respective
antero-lateral and postero- medial commissures. The PML is incised in the
centre and the prosthetic valve is sutured in position plicating the PML
and including the AML and chordae in valve sutures.
•
• The technique is simple, and LVOTO is uncommon with good preservation
of LV function.
• This technique is particularly suitable for patients with rheumatic mitral
valve disease and thickened, deformed and calcific cusps
• Also this technique allows placement of a larger prosthesis.
23. Rose and Oz technique
• The AML is stretched posteriorly and its central portion is excised. The rim
of the remaining leaflet tissue contains the marginal chordae. The defect
in the AML is then closed with a running suture placed parallel to the
annulus. This tacks the marginal chordae to the fibrous triagones and
displaces the anterior leaflet chordae to the periphery of the mitral orifice.
Valve sutures are placed to reinforce the previously running suture line.
The prosthetic valve is sutured to orient the leaflets perpendicular to the
native annulus
• advantages of this technique are reduced bulk of the AML which reduces
the possibility of impairment of valve function, low risk of LVOTO, and
reduced risk of thrombosis on the redundant leaflet tissue
25. choosing the technique to be used for chordal preservation
• the factors to be considered are the simplicity and reproducibility of the
technique,
• prevention of post-operative LVOTO due to systolic anterior motion of the
remaining AML and
• 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.
• Care should be taken to prevent excessive shortening of the chordae as it
may cause rupture of a papillary muscle head.
• In patients with pure MS, the papillary muscles should be incised. This
allows the anterior and posterior chordae to fall away and ensures free
movement of the discs
• Further, incision of the PML in the middle allows a larger prosthesis to be
seated
26. 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.
• 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.
27. REFERENCES
• Chordal preservation during mitral valve replacement: basis, techniques and results
• Sachin Talwar, M.Ch., Honnakere Venkataiya Jayanthkumar, MS, Arkalgud Sampath Kumar,
M.Ch.,
• Department of Cardiothoracic & Vascular Surgery, Cardiothoracic Centre, All India Institute of
Medical Sciences, New Delhi