Introduction: Residual mitral regurgitation (MR) immediately after mitral valve plasty (MVP) in the operating room is a well-known risk factor for late re-intervention. We sought to determine the feasibility of 3D IOTEE in clarifying the mechanism of residual MR and whether it has an impact on the conversion rate of mitral valve replacement (MVR).
Methods: We investigated consecutive 871 patients scheduled for MVP in our institute between January 2009 and December 2016. All patients underwent preoperative and intraoperative 3DTEE by experienced cardiologists trained in echocardiography. Ninety-four patients (10.8%) introduced immediate reinstitution of cardiopulmonary bypass (second bypass). The indication of second bypass was a residual MR with jet area more than 1.0cm2 or eccentric jet flow. The mechanism of residual MR were classified as following five groups and compared with conversion rates to MVR. Group1; inter-scallop malcoaptation, Group2; suture dehiscence, Group3; prolapse, Group4; systolic anterior motion of the MV (SAM) and Group5; tethering (Figure).
Results: The total intraoperative success rate of MVP was 98% (N=857/871). Total of 94 patients received second bypass. Fifteen percent underwent MVR in second bypass, 63% in group1(N=10/16), 0% in group2(N=0/26), 3% in group3(N=1/40), 22% in group4(N=2/9) and 33% in group5(N=1/3) (Table).
Conclusions: Almost all patients in group2 and 3 had a successful MVP on the second bypass with clarifying precise mechanism and origin of residual MR by 3D IOTEE. On the other hand, the rate of MVR conversion was relatively higher in group1 and 5 compared to group2 or 3. Repairing MR due to interscallop degenerative change and left ventricular dilatation may be a complicated procedure nevertheless the mechanism is clear. 3D IOTEE is essential in the assessment of mitral regurgitation to determination the origin, lesion localization, and severity, which is required to select the suitable surgical techniques.