Brief Case Description
The patient is a 64 year-old male who presented with sudden onset dyspnea. He has a past medical history of hypertension. Physical examination was remarkable for systolic murmur of mitral regurgitation at the apex.
Transthoracic echocardiography showed type II mitral dysfunction with posterior leaflet prolapse causing severe valve regurgitation. Left ventricular size, wall thickness and systolic function were normal. Left ventricular ejection fraction was 63 %. Echocardiography also showed mild (2+) tricuspid regurgitation. The right ventricle was normal in size and function.
The patient was referred for reconstructive mitral and tricuspid valve surgery. Preoperative cardiac catheterization showed normal coronaries. Pulmonary artery pressure was normal.
Intraoperative Transesophageal Echocardiography
Intraoperative transesophageal echocardiography confirmed the diagnosis of posterior leaflet prolapse involving the P2 segment (mid esophageal four-chamber and long axis views). Doppler echocardiography showed an anteriorly directed jet and mitral regurgitation was graded severe.
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. 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, the short history of systolic murmur and 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)
This was a case of extensive prolapse of P2 segment as more than one third of the length of the free edge of P2 was involved. Therefore, we performed a quadrangular resection of the P2 segment. This technique has the advantages of excising most pathological tissues, creating a more normal geometry of the leaflet, and decreasing the tension on the reconstructed leaflet. 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 tissue around the indentations was not prolapsing and therefore could be preserved.
Approximately 2 to 3 mm from these normal chordae, a blue marker was used to delineate a line of resection from the free margin of the leaflet to the annulus . As shown here, a rectangle was designed which indicated the limits of P2 resection. We were able to preserve both indentations. Following quadrangular resection, secondary chordae close to the edges of the resection were cut to facilitate leaflet mobilization.
As shown below, the height of remnants P1 and P3 was about 12 mm. The gap between the two segments was 10 mm. We used annular plication technique to reduce the size of the posterior annulus and to approximate P1 and P3 segments.
Leaflet continuity was restored with 5-0 monofilament sutures.
Valve analysis following reconstruction showed a similar height between reference P1 and the reconstructed leaflet segment indicating a perfect result. This was later 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.
A saline test was performed and showed a nice symmetrical line of coaptation, parallel to the posterior aspect of the annulus.
The patient also underwent a tricuspid remodeling annuloplasty with a 30 mm Carpentier Edwards Physio tricuspid ring for type I dysfunction due to annular dilatation (not shown).
Postbypass Transesophageal and Postoperative Transthoracic Echocardiography
Postbypass mid esophageal four-chamber view showed a competent mitral valve with no residual regurgitation (Left Echo) . That was further confirmed by postoperative transthoracic echocardiography applying parasternal and four-chamber views (Right Echo).