The initial experience with the miniaturized multiplane micro-transesophageal echocardiographic probe (MTEE) reported high-quality diagnostic imaging in small infants. The aim of this study was to compare the diagnostic accuracy and image quality of the intraoperative MTEE with the pediatric multiplane transesophageal echocardiographic probe (PTEE).

Infants weighing <5 kg who underwent intraoperative transesophageal echocardiography were identified. Studies using the MTEE were matched 1:1 with those using the PTEE by cardiac diagnosis. The postoperative transesophageal echocardiograms, obtained using either probe, were reviewed for the presence of 11 cardiac abnormalities. Postoperative transesophageal echocardiograms were compared with predischarge transthoracic echocardiograms to assess accuracy. Using receiver operating characteristic curves, the areas under the curve for the MTEE and PTEE were compared. Two pediatric cardiologists scored six image quality metrics on equal numbers of studies obtained with the MTEE and the PTEE. Composite scores from both reviewers were used to compare image quality.

The study included 110 transesophageal echocardiograms per probe type. The mean weight for the MTEE was lower than for the PTEE (3.15 ± 0.58 vs 3.70 ± 0.52 kg, P < .001). There was no significant difference in the diagnostic accuracy of the MTEE and PTEE using receiver operating characteristic curves. The numbers of residual anatomic lesions missed by the MTEE and PTEE were similar (19 vs 22, respectively). The composite image quality score was worse for the MTEE compared with the PTEE (81% vs 92%, respectively, P < .0001).

Although the image quality of the MTEE is inferior compared with the PTEE, its diagnostic accuracy in infants weighing <5 kg is comparable.