[Comparison of conventional and miniaturized biplane echoscope: initial clinical results]

A subset of patients experiences substantial discomfort on examination with transesophageal echocardiography using the conventional echoscope, whereby the dimensions of the probe play a decisive role. Miniaturized biplane transducers have recently become available (2 x 32 crystals; dimensions 9.5 x 8.7 mm; circumference approx. 30% less than the conventional echoscope), which allow ultrasound examination at 3.5, 5.0 and 7.0 MHz. A prospective study was carried out in 70 patients to compare difficulties on insertion of the probe, subjective evaluation by the patient during examination, and the 2D-image as well as Doppler and color-coded Doppler quality of the miniaturized biplane echoscope. In 43 patients, intubation of the esophagus proved less difficult with the smaller instrument, it was more difficult in 8 cases. 54 patients reported that the discomfort was definitely easier to bear on use of the narrow instrument. Concomitant parasympathicolytic medication was needed with the smaller probe in 4 cases, and 11 times with the conventional echoscope. The quality of the 2D-image attained by the miniaturized probe was naturally lower. Employing multi-Hertz technology at a frequency of 7 MHz, however, imaging of the anatomy was excellent in the near field of 5-6 cm, and nearly equivalent to that of the conventional probe (5 MHz). The quality of PW-and CW-Doppler as well as color-coded Doppler information was identical. Whenever examination with a conventional echoscope promises to be difficult, or when sedation is contraindicated due to a severe illness or respiratory insufficiency, transesophageal echocardiography should be considered with a smaller biplane probe at higher frequencies.