Intraoperative Evaluation of Valvular Function Using Transesophageal and Epicardial Echocardiography

Abstract

Objectives and Background. Intraoperative transesophageal echocardiography (TEE) and epicardial echocardiography (ECE) offer the opportunity to assess valvular function before and after cardiopulmonary bypass. Valve reconstruction offers many advantages over prosthetic valve replacement. The purpose of this study was to assess the utility of TEE and ECE during the surgical treatment of mitral, aortic, and tricuspid valve diseases.

Methods. Intraoperative echocardiography was performed in 50 patients undergoing surgery for valvular heart disease. In 21 recent patients, concurrent TEE with Doppler color flow mapping was performed. The severity of mitral stenosis (MS) was assessed by the intraoperative echocardiographic mitral valve area (MVA) and morphologic findings of the mitral apparatus. The severity of mitral regurgitation (MR) was visually graded on a semiquantitative scale of 0-4+ according to the ratio of the maximal regurgitant jet area to the left atrial area (JA/LAA) indicated by transesophageal and epicardial Doppler color flow mapping. The severity of aortic regurgitation (AR) was similarly graded on a scale of 0-4+ according to the ratio of the maximal regurgitant jet area to the left ventricular area (JA/LVA) in end diastole. The severity of tricuspid regurgitation (TR) was similarly graded on a scale of 0-4+ according to the ratio of the maximal regurgitant jet area to the right atrial area (JA/RAA). These criteria for the severity of valvular regurgitation were compared with conventional nonsimultaneous angiographic criteria and operative criteria according to fluid injection into the flaccid ventricles. Tricuspid annulus diameter during systole was measured before and after tricuspid annuloplasty.

Results. There was a good correlation (r = 0.78, P < 0.001) between intraoperative two-dimensional echocardiographic MVA and operative MVA by direct measurement. Epicardial two-dimensional MVA and transthoracic MVA measured by mitral pressure half time method were similar (r = 0.88, P < 0.005). Mitral commissurotomy was performed in 4 (27%) of 15 patients with MS. Comparison of mitral JA/LAA measurements as assessed by epicardial and transesophageal color flow mapping revealed an excellent correlation between the techniques (r = 0.94, P < 0.001). Intraoperative TEE and ECE assessment of the severity of MR showed good agreement with preoperative angiographic gradings and with operative gradings. Mitral valve repair was performed in 10 (48%) of 21 patients with MR. Postrepair intraoperative Doppler studies showed satisfactory surgical results in all. No significant residual MR (grade > 2+) was identified in this series. Comparison of aortic JA/LVA measurements as assessed by epicardial and transesophageal color flow mapping showed an excellent correlation between the techniques (r = 0.96, P < 0.001). Intraoperative echocardiographic assessment of the severity of AR showed good correlation with preoperative angiographic assessment. Aortic valve repair was performed in 1 (11%) of 9 patients with AR. There was a good correlation (r = 0.77, P < 0.005) between tricuspid JA/RAA ratios as assessed by epicardial color flow mapping and operative gradings for TR. Tricuspid annulus diameter during systole measured by epicardial technique was significantly (P < 0.001) decreased after tricuspid annuloplasty.

Conclusions. Both intraoperative TEE and ECE are useful for the evaluation of valvular function in the mitral, aortic, and tricuspid positions. Doppler color flow mapping is a reliable method of assessing valve regurgitation. Combined intraoperative use of transesophageal and epicardial techniques is recommended.