Intraoperative echocardiography in valvular heart disease: an evidence-based appraisal

Intraoperative (IO) transesophageal echocardiography (TEE) is widely used for assessing the results of valvular heart disease (VHD) surgery. Epiaortic ultrasonography (EAU) has been recommended for prevention of perioperative strokes. To what extent does high-quality evidence justify the widespread use of these imaging modalities? In March 2009, we searched MEDLINE (PubMed and OVID interfaces) and EMBASE for studies published in English using database-specific controlled vocabulary describing the concepts of IOTEE, cardiac surgery, VHD, and EAU. We found no randomized trials or studies with control groups assessing the impact of IOTEE in VHD surgery. Pooled analysis of 8 observational studies including 15,540 patients showed an average incidence of 11% for prebypass surgical changes and 4% for second pump runs, suggesting that patients undergoing VHD surgery may benefit significantly from IOTEE, particularly from postcardiopulmonary bypass IOTEE in aortic repair and mitral repair and replacement, but less so in isolated aortic replacement. Further available indirect evidence was satisfactory in the test accuracy and surgical quality control aspects, with low complication rates for IOTEE. The data supporting EAU included 12,687 patients in 2 prospective randomized studies and 4 nonrandomized, controlled studies, producing inconsistent outcome-related results. Despite low-quality scientific evidence supporting IOTEE in VHD surgery, we conclude that indirect evidence supporting its use is satisfactory and suggests that IOTEE may offer considerable benefit in valvular repairs and mitral replacements. The value of IOTEE in isolated aortic valve replacement remains less clear. Evidence supporting EAU is scientifically more robust but conflicting. These findings have important clinical policy and research implications.