Twenty studies met the inclusion criteria: 13 evaluated IOTEE and seven evaluated EAU (total numbers of patients unclear). Thirteen further studies were included: one for it's academic value, nine for test accuracy, two for surgical quality control and one for IOTEE safety. Most studies were observational. Only two were prospective randomised studies and another two were prospective with consecutive recruitment. Five prospective and five retrospective studies employed non-consecutive recruitment.
Prior to cardiopulmonary bypass grafting (eight studies, 15,540 patients) IOTEE changed the planned surgical procedure in 11% (range 6% to 29%) of cases and post cardiopulmonary bypass grafting IOTEE prompted second pump runs in 4% (range 0% to 7%) of cases. Accuracy in the evaluation of mitral valve regurgitation was 95% to 97% (one study). TEE and IOTEE were associated with a 0.2% complication rate (five studies, more than 25,000 patients). Correlations between pre-cardiopulmonary bypass grafting TEE and IOTEE for a range of outcomes were reported. Surgical quality control was also discussed.
EAU was shown to have better sensitivity and specificity than IOTEE for stroke prevention. The results for EAU in terms of stroke prevention was mixed across the studies. Compared to IOTEE, one study showed a reduction in stroke markers (n=191) and another reported a decreased stroke rate (n=6,051). A third study reported a reduction in the incidence of stroke with EAU compared to aortic palpation (n=2,172). Two studies showed no difference in the incidence of stroke between EAU and IOTEE (n=3,773).