Brief Case Description

The patient is a 66 year-old female who presented with dyspnea on exertion and fatigue. Physical examination was remarkable for systolic murmur of mitral regurgitation at the apex.

Transthoracic echocardiography showed type II mitral dysfunction with posterior leaflet prolapse and severe mitral regurgitation. The PISA radius measured 1.0 cm. Left ventricular end diastolic diameter was increased to 6.2 cm. Left ventricular systolic function was preserved (ejection fraction 60 %). Echocardiography also showed mild tricuspid regurgitation. The right ventricle was normal in size and function.

The patient was referred for reconstructive mitral valve surgery. Preoperative cardiac catheterization showed normal coronaries. Pulmonary artery pressure was mildly increased (50/25 mmHg).

Operative Procedure

Intraoperative Transesophageal Echocardiography

Intraoperative transesophageal echocardiography confirmed the diagnosis of posterior leaflet prolapse involving the P2 segment (mid esophageal four-chamber, two-chamber, mitral commissural, and long axis views). Doppler echocardiography showed an anteriorly directed jet and mitral regurgitation was graded severe (Left video). Three-dimensional rendering of the mitral valve showed type II- P2 dysfunction (Right video).

Mitral Valve Analysis

Following the exposure of the mitral valve, we first performed  valve analysis using Carpentier’s reference point technique. We confirmed the normal leaflet motion of P1 by pulling its free edge upward with a nerve hook. The P1 segment was neither prolapsing as its free edge was not overriding the plane of the mitral annulus nor restricted. Using a second hook, other valve segments were examined in a systematic  manner and compared to P1 to verify if they were prolapsing. In this particular case, valve analysis confirmed the prolapse of P2 segment due to chordae elongation. Both indentations were normal. The anterior leaflet had normal leaflet motion with no prolapsing segments. The mitral annulus was moderately dilated.

Following this complete valve analysis, we can summarize the pathophysiological triad as follows:

Etiology: Fibroelastic deficiency (the age of the patient and the morphology of the valve on echocardiography and during intraoperative valve analysis were all in favor of this etiology)

Lesions: Chordae elongation, secondary annular dilatation

Dysfunction: Type II posterior leaflet (P2 segment)

Reconstructive Procedure

This was a case of limited prolapse of P2 segment. Therefore, we performed a triangular resection of the P2 segment.

Annular sutures were placed circumferentially to optimize the exposure of the valve.  Two 4-0 stay sutures were passed at  the limits of the prolapsed portion of the leaflet. Valve analysis, as shown here, confirmed that the valvular tissues around the indentations were not prolapsing and therefore could be preserved.

Approximately 2 mm from these normal chordae, a blue marker was used to delineate the limits of the triangular resection. As a principle rule, the height of the triangle should be slightly longer than its base.

A limited triangular resection was performed. Following the resection, leaflet continuity was restored with interrupted 5-0 monofilament sutures (Left video). The amount of resected tissue is shown here (Right image).

Valve analysis following reconstruction showed a similar height between reference P1 and the reconstructed leaflet segment indicating a perfect result. This was confirmed by the saline test which showed a symmetrical line of coaptation with no residual regurgitation.

Finally, a remodeling annuloplasty was performed. We first measured the intercommissural distance using a 28 mm sizer which was the appropriate size. Second, we measured the height of the anterior leaflet. The 28 mm sizer was positioned and covered the entire surface area of the anterior leaflet. Therefore, a 28 mm Carpentier Edwards Physio ring was selected and implanted.

As there was mild tricuspid regurgitation on preoperative transthoracic echocardiography, we decided to explore the tricuspid valve. The tricuspid annulus was not dilated. A 32 mm sizer was selected and it covered the orifice of the tricuspid valve. We then assessed the amount of valvular tissue by measuring the anteroposterior leaflet surface area.  The latter was perfectly covered by the 32 mm sizer. As the two golden relationships were respected and there was an optimal relationship between the tricuspid orifice and the surface area of the leaflets, we did not perform a ring annuloplasty.

Postbypass Transesophageal Echocardiography

Postbypass mid esophageal four-chamber, two-chamber, and mitral commissural views showed a competent mitral valve with no residual regurgitation (Left video). Three-dimensional rendering of the mitral valve also showed an excellent result (Right video).

Postoperative transthoracic echocardiography showed a competent mitral valve with a large surface of coaptation and no residual regurgitation.The mitral valve area by Doppler was 2.9 cm². The mean transvalvular gradient was 2.5 mmHg.