Intraoperative Echocardiography and Doppler Color Flow Mapping in Freehand Allograft Aortic Valve and Root Replacement

Intraoperative epicardial echocardiography and color flow Doppler were performed before and after cardiopulmonary bypass in 17 consecutive patients undergoing 20 freehand allograft aortic valve replacements. Native aortic valves were replaced in 12, and prostheses in 8 patients. Precardiopulmonary bypass echocardiography estimates of annular diameter guided allograft selection and predicted length of allograft aortic root required, defined coronary situs, and revealed other cardiac abnormalities. These included unanticipated severe mitral regurgitation (which precluded allograft aortic valve replacements in one patient), left-to-right shunts in the membranous septum, ascending aortic dissection, and aortic root pathology requiring coronary reimplantation or bypass. Postcardiopulmonary bypass echocardiography demonstrated acceptable competency of 18/19 allograft valves (mild or no aortic insufficiency), and successful repair of 3/4 shunts. Mild mitral regurgitation was detected more often at postcardiopulmonary bypass than precardiopulmonary bypass (15 vs 11 cases) and postcardiopulmonary bypass estimates of mitral regurgitation severity corollated well with subsequent postoperative follow-up. IOE allows selection and thawing of the allograft valves prior to aortic cross clamping, minimizing cross-clamp time. It detects important concomitant cardiac abnormalities, and predicts postoperative allograft valve and mitral competency. Intraoperative echocardiography Doppler, is therefore, a useful adjunct for allograft aortic valve replacements or aortic root replacement.