Makoto Matsumura

Evaluation of biplane color Doppler transesophageal echocardiography in 200 consecutive patients.

Background We developed the first biplane transesophageal echocardiography (TEE) probe with two orthogonal transducers, allowing synchronous side-by-side displays of the heart on a monitor TV, and compared its diagnostic value with that of conventional single-plane TEE using commercially available Doppler equipment in 200 consecutive patients intraoperatively, perioperatively, or on an outpatient basis. Methods and Results Insertion was easy, except in one patient with a mediastinal tumor, and no complications were encountered. Both transverse and longitudinal scans allowed correct identification of true and false lumina in all 30 aortic dissection examinations, but longitudinal scanning was slightly superior in detecting types I and M entry sites. Three entries that were not detected by transverse scanning (two of DeBakey type I and one of type III) were visualized by longitudinal scanning. Among 37 cases of mitral regurgitation (MR), longitudinal scans were significantly superior (p < 0.05) in revealing multiple jets (nine compared with two with transverse scanning). Although both planes yielded almost identical mean values for the maximum jet areas, a difference of over 50% in jet area size on the two planes was observed in 19 cases. The measured jet areas showed significant correlation with the angiographic MR grading, especially for the larger of the biplane measurements (p < 0.01), and different grades showed little overlap. Longitudinal images increased the acoustic window of the heart and aorta from the esophagus. Moreover, longitudinal scanning provided good visualization of both ventricular outflow tracts, the ascending aorta, main pulmonary artery, and superior vena cava. Conclusions This modality greatly facilitates a three-dimensional comprehension of cardiovascular lesions and flow dynamics, especially in aortic dissection and MR, and its safety was demonstrated. Our data demonstrate the usefulness of this new technique in comparison with conventional single-plane TEE.

Utility of biplane transesophageal echocardiography in left ventricular wall motion analysis

The biplane transesophageal echocardiography (BTEE) probe increases capabilities for scanning cardiac structures in cross-sectional and longitudinal planes. The present study was undertaken to determine if BTEE would enhance diagnosis of perioperative ischemia by identification of new segmental wall motion abnormalities (SWMAs), and the initial experience in 94 patients (37 intraoperative and 57 intensive care unit) is presented. The left ventricular wall motion at the midpapillary level was observed and recorded on 0.5-in videotape by both transverse and longitudinal scanning transducers. Using a cinememory loop, biplane images were replayed side by side, within minutes of their acquisition, and were compared and recorded for later off-line analysis by two independent observers. Intraoperatively, the images were obtained at various predetermined intervals, and in the intensive care unit one set of observations was made. In 20 patients, new SWMAs were observed: in 4 patients (20%), the SWMAs were observed only in the cross-sectional scanning, whereas in 7 patients (35%) they were observed only in the longitudinal scanning. In the remaining 9 patients (45%) the SWMAs were detected in both planes. Persistent diagnostic electrocardiographic changes of myocardial infarction and elevation of CK enzymes were observed in 6 of the 20 patients within 3 postoperative days. In conclusion, biplane imaging appears to be superior to the traditional single-plane imaging for evaluation of left ventricular function and myocardial ischemia.

Usefulness of a prototype intravascular ultrasound imaging in evaluation of aortic dissection and comparison with angiographic study, transesophageal echocardiography, computed tomography, and magnetic resonance imaging

The aim of this study was to evaluate the accuracy of information obtained with a prototype intravascular ultrasound (IVUS) system in chronic aortic dissection by comparing results with angiography, transesophageal echocardiography (TEE), computed tomography, or magnetic resonance imaging. We assigned 15 patients to IVUS imaging after they underwent angiography. The detection rate of the intimal flap was 100% in all segments of the aorta, and the detection rate of the intimal tear was 0%, 50%, 50%, and 77.8% in the ascending, arch, descending, and abdominal aorta, respectively. IVUS demonstrated 100% of the celiac and renal arteries, and 80% of the superior mesenteric arteries as well as their relation to dissection. It clarified the origin of 12 of 60 main abdominal branches (20%) which were not clear on the angiogram. It also determined the distal extent of the dissection in all cases. With regard to the size of the vessel, there was a good correlation between IVUS and computed tomographic values (r = 0.98, p < 0.01). No complications occurred in any patient. IVUS accurately demonstrated thrombus or spontaneous echo contrast in the false lumen that was confirmed with computed tomography or TEE, or both. It was especially useful in evaluating the abdominal aorta with regard to determining the size of the vessel, the extent of dissection, the relation of the branches to the false lumen, and the detection of intimal tears--important information for follow-up of patients and for planning surgery.(ABSTRACT TRUNCATED AT 250 WORDS)

Biplane Color Doppler Transesophageal Echocardiography: Its Impact on Cardiovascular Surgery and Further Technological Progress in the Probe, a Matrix Phased‐Array Biplane Probe

Color Doppler transesophageal echocardiography has made real-time, online, beat-by-beat study of intracardiac events possible without the inconvenience of a probe in the operative field and without exposing patients to the risk of infection. The use of transesophageal probes is increasing, and since 1988, at least in our heart center, we have rarely ever used epicardial probes for intraoperative evaluation. The use of a color transesophageal echocardiography probe in both intraand perioperative periods has become fairly common’-8 at major heart centers all over the world. However, in the present state of the art there are two major limitations: (1) The size of the probe make it unsuitable for use in pediatric patients; and (2) only a transverse view can be obtained at any one level with the conventional uniplane transesophageal echocardiography transducer. In order to further enhance the color transesophageal echocardiography technique, we recently developed and tested a transesophageal two-dimensional color flow biplane probe in close collaboration with the Biomedical Engineering Department of the Aloka Corporation. This is the first report of successful clinical application of biplane color transesophageal echocardiography, with simultaneous side-by-side display of the biplane

New Direction of Biplane Transesophageal Echocardiography with Special Emphasis on Real‐Time Biplane Imaging and Matrix Phased‐Array Biplane Transducer

This article reports on the technical aspects of an online real‐time biplane transesophageal echocardiographic imaging system and of a single‐matrix, phased‐array transducer capable of transverse and longitudinal scanning.

Impact of transesophageal Doppler echocardiography on pediatric cardiac surgery

De development [1] and advancement of transesophageal echo (TEE) technology in combination with Color Flow Mapping [2] amused immediate interest in the intraoperative echocardiography amongst the cardiac surgeons. However, the size of presently available probe is too large and hence unsuitable for the pediatric patients. To minimize the limitation of size of TEE probe we have recently developed a pediatric TEE probe (Fig. 1, E.D. 6.8 mm), which was tested in small dogs weighing around 4 kg in terms of safety and quality of images. The purpose of this report is to describe the initial clinical experiences of pediatric TEE probe in pediatric cardiac surgery.

Bi-plane color transesophageal Doppler echocardiography (color TEE): Its advantages and limitations

ConclusionThe bi-plane probe provides superior information at least in cases of aortic aneurysms and mitral regurgitation. With further refinement of true real-time technology, in near future it will be possible to use bi-plane probe in real-time, on-line intraoperatively and immediate postoperative period.

Recent Technological Progress in Transesophageal Color Doppler Flow Imaging with Special Reference to Newly Developed Biplane and Pediatric Probes

Color transesophageal Doppler echocardiography (TEE) has made real-time, on-line, beat by beat study of intracardiac events possible without the inconvenience of having a probe in the operative field. The use of transesophageal probes is on the increase and in 1988, at least in our heart center, we hardly used epicardial probes for intraoperative evaluation.

Evaluation of mitral valve prolapse using newly developed real-time three-dimensional echocardiographic system with real-time volume rendering

The development of a real-time three-dimensional (RT3D) image acquisition system and direct digital links between ultrasound equipment and the data processing computer facilitate improved 3D image reconstruction. However, at present time, it is hard to promptly display 3D images and is also ineffective for a practical use. The objective of this study was to assess the feasibility of a new transthoracic RT3D echocardiographic system for evaluation of mitral valve prolapse. Eighteen patients with mitral valve prolapse diagnosed by transthoracic two-dimensional (2D) echocardiography and M-mode were examined through this technique (11 male, mean age 42 ± 17 years). Since visualization of mitral valve from apical four-chamber view was better than that of the parasternal approach, only apical approach was used for mitral valve evaluation. This system is capable of acquiring volumetric data from mechanical scanning of the phased-array transducer (3.5 MHz) as well as displaying the volume rendered images of the structure without storing the image data and reconstruction of the object. The prolapse of leaflet could be seen in 14/18 (77%) of patients with mitral valve prolapse based on conventional echocardiography. The newly developed transthoracic RT 3D ultrasound system without a reconstruction process seemed to be a useful noninvasive tool for diagnosis of mitral valve prolapse and detection of prolapsed leaflet or scallop, which is very important for deciding on a reliable surgical technique.

Transesophageal color Doppler echocardiography during mechanical assist circulation.

Information available to determine the optimal timing for separation of patients (pts) from mechanical assist circulation (MAC) is usually limited, due to the difficulty of transfer of patients with heavy MAC systems. To evaluate the clinical efficacy of transesophageal color Doppler echocardiography (TEE) in management of patients during MAC, we examined 37 pts (32, intra-aortic balloon pumping = IABP; 4, left ventricular assist device = LVAD; 1, right VAD = RVAD) by TEE. In the other 3 pts, thoracic aneurysms (AN) (2, dissecting An; 1, true AN) were detected by TEE, which were contraindications to safe introduction of IABPs. In 29 pts on IABPs, 2 pts with LVADs, and in 1 pt with a RVAD, patients were safely weaned from MACs with confirmation of full recovery of cardiac function by TEE. However, repeat introduction of IABP support was needed in 2 pts due to severe residual mitral regurgitation, even after initial success; these became the cause of late multiple organ failure. In one pt with a LVAD, a detrimental right to left shunt through the patent foramen ovale, which resulted in severe desaturation of the arterial blood oxygenation, was detected by TEE. Left main coronary flow was measured by TEE and found to increase by 55% on IABP and by 67% on a LVAD. In conclusion, TEE is the only currently available diagnostic tool for total evaluation of cardiac function in an intensive care unit, which can provide very important information for management of patients on MACs.