Intraoperative echocardiography for the evaluation of valvular regurgitation: Experience in 263 patients

Because of the limited orifice size and potential complications associated with prosthetic valves, native valve repair and reconstruction is an attractive surgical alternative. However, significant residual valvular regurgitation, which cannot be reliably detected intraoperatively by current methods, increases postoperative morbidity and mortality. Direct epicardial two-dimensional echocardiography with contrast injections can be applied intraoperatively to rapidly and accurately assess the presence and severity of valvular regurgitation in the baseline and postoperative state. Five milliliters of dextrose or saline are injected into the appropriate cardiac chamber, generating echogenic microbubbles (contrast) that normally exist in an antegrade direction, but reflex retrograde in the presence of valvular regurgitation. In a total of 263 patients who underwent intraoperative contrast echocardiography, 177 mitral, aortic, and tricuspid valves were adequately assessed by preoperative catheterization and results were compared with those of intraoperative contrast echocardiography. The sensitivity and specificity of the intraoperative detection of valvular regurgitation by echocardiography were 0.97 and 0.98, respectively, for all valves, 1.00 and 0.90 for mitral valves, and 0.91 and 1.00 for aortic valves. Moreover, intraoperative contrast echocardiography can also provide quantification of valvular regurgitation. In 120 mitral valves evaluated, the correlation between the degree of regurgitation determined by preoperative ventriculography and by intraoperative contrast echocardiography (both on a scale of 0 to 4+) was 0.93. Importantly, 11 patients who had mitral surgery (eight after mitral valve repair, and three after valve replacement) were identified as having significant postprocedure mitral regurgitation by intraoperative contrast echocardiography only, not by other methods. Additionally, nine patients were found to have significant tricuspid regurgitation by intraoperative contrast echocardiography after mitral surgery and underwent successful tricuspid annuloplasty. Therefore, intraoperative echocardiography is a rapid, accurate, on-line technique for assessing the presence and severity of valvular regurgitation after cardiopulmonary bypass before decannulation. Intraoperative echocardiography has the potential for significantly reducing the morbidity and mortality associated with valvular surgery by allowing the surgeon to be more aggressive in retaining native valves and to more accurately diagnose the presence and degree of residual regurgitation.