Brief Case Description
The patient is a 67 year-old female with a known history of mitral regurgitation. She is completely asymptomatic. Physical examination is remarkable for systolic murmur of mitral regurgitation.
Transthoracic echocardiography showed type II mitral dysfunction with posterior and anterior leaflets prolapse and severe mitral regurgitation. The left ventricle was dilated with an end diastolic diameter of 6.4 cm. The left ventricular function was normal with an ejection fraction of 65%. Echocardiography also showed minimal 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 systolic pressure was 32 mmHg.
Intraoperative Transesophageal Echocardiography
Intraoperative transesophageal echocardiography confirmed the diagnosis of type II dysfunction with bileaflet prolapse (mid esophageal long axis, commissural and two-chamber views). Doppler echocardiography showed two jets posteriorly and anteriorly directed and mitral regurgitation was graded severe (Left Video). Three-dimensional rendering of the mitral valve showed bileaflet prolapse involving the A2 and P2 segments (Right Video).
Mitral Valve Analysis
Following the exposure of the mitral valve, jet lesions were visualized on the endocardium of the left atrium mostly at the anterolateral trigone indicating a posterior leaflet prolapse. Then, we 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 A2 and P2 segments due to chordae elongation and rupture. There was excess valvular tissue compatible with the diagnosis of form fruste of Barlow's disease. The mitral annulus was dilated.
Following this complete valve analysis, we can summarize the pathophysiological triad as follows:
Etiology: form fruste of Barlow's disease
Lesions: Chordae elongation and rupture, secondary annular dilatation
Dysfunction: Type II posterior and anterior leaflets (A2-P2 segments)
This was a case of extensive prolapse of P2 segment. We performed a more detailed valve analysis confirming that both indentations were not prolapsing. Two 4-0 stay sutures were passed at the limits of the prolapsed portion of the leaflet. Approximately 2 mm from the normal chordae, a quadrangular resection of the P2 segment was performed.
Following the resection of the P2 segment, we took advantage of this opening to address the anterior leaflet prolapse. Two 4-0 stay sutures were passed at the limits of the prolapsing A2 segment. Valve analysis confirmed normal leaflet motion of A1 and A3. The length of the free margin of the prolapsing A2 was 12 mm.
The anterior leaflet prolapse was corrected using a composite technique combining:
1) Leaflet fixation on secondary chordae
2) Limited leaflet triangular resection
3) Secondary chordae transposition
Following the correction of the anterior leaflet prolapse, we turned our attention to the posterior leaflet to finalize the reconstructive procedure. We used annular plication technique, using three sutures, to reduce the size of the posterior annulus and to approximate P1 and P3 segments. Finally, leaflet continuity was restored with 5-0 monofilament sutures.
Valve analysis following reconstruction showed a similar height between reference P1 and the reconstructed leaflet segments indicating a perfect result.
Finally, a remodeling annuloplasty was performed . We first measured the intercommissural distance using a 32 mm sizer which was the appropriate size. Second, we measured the height of the anterior leaflet. The 32 mm sizer was covering the entire anterior leaflet surface area. Therefore, a 32 mm Carpentier Edwards Physio ring was selected and implanted.
Postbypass Transesophageal and Postoperative Transthoracic Echocardiography
Postbypass mid esophageal four-chamber, commissural, two-chamber and long axis views showed a competent mitral valve with no residual regurgitation. Three-dimensional rendering of the mitral valve showed a competent mitral valve. The prosthetic ring was visualized and correctly inserted.