Comparison of image quality between a narrow caliber transesophageal echocardiographic probe and the standard size probe during intraoperative evaluation

Background: Transesophageal echocardiography (TEE) has become an integral part of the evaluation and monitoring of patients during cardiac operation. Until recently, the smallest TEE probe with multiplane imaging measured 13 mm in diameter. This size is now standard for adult TEE probes. Recently, a new TEE probe has become available (MiniMulti TEE probe, Philips Medical Systems, Andover, Mass), which has a diameter of 8 nun. Although using a smaller probe is attractive, the quality of images it generates when used in adults has not yet been examined. Objective: The purpose of this study was to compare TEE studies done with both probes. Methods: After informed consent was obtained, full intraoperative TEE studies were performed in 20 patients with a small pediatric probe. The study was then repeated using a standard adult probe. The studies were read in random order by two experienced echocardiographers blinded to probe used. For each study, 18 anatomic cardiac structures and 5 Doppler patterns were subjectively graded as excellent (1), good (2), fair (3), or poor (4) in quality. The average score for each structure or Doppler profile was computed for each probe. Results: The average score for all findings was lower (better) for the adult TEE probe (1.4 +/- 0.4 vs 1.7 +/- 0.4; P =.003). When each finding was compared separately, several cardiac structures (left ventricle [LV], pericardium, right ventricle [RV], interatrial septum, left atrium, left atrial appendage, mitral valve, aortic valve) had better scores with the adult probe, and the differences for the LV and RV were larger than those for the other findings (LV scores differed by 0.7, P =.0004; RV scores differed by 0.5, P =.01). There was no significant difference between probes when evaluating venous structures (coronary sinus, superior vena cava, pulmonary vein), the thoracic aorta, or the right atrium or tricuspid valve. in addition, Doppler patterns were not significantly different with the two probes. There were two findings that were missed with the small probe and seen with the adult probe (one aortic plaque and one left atrial appendage thrombus). Conclusions. In the adult, the larger probe provides better images, particularly of the RV and LV. In addition, important findings may be missed with the smaller probe. However, if the adult probe cannot be passed, the pediatric probe is a reasonable alternative.