Ryozo Omoto

Technical and biologic sources of variability in the mapping of aortic, mitral and tricuspid color flow jets.

The quantification of valvular regurgitation by 2-dimensional Doppler imaging depends on identifying and minimizing variability. Aortic, mitral and tricuspid regurgitant jet areas were measured in 50 patients with sinus rhythm or atrial fibrillation to analyze the variables of reading error, valve site, jet size, rhythm and frame rate. One technician recorded jet velocities at 1 frame/cycle at a triggered interval after the electrocardiographic R wave and at frame rates of 7.5 and 15 frames/s. Jet areas from 5 consecutive beats were measured by planimetry by 1 observer. Coefficients of variation between and among groups were compared by analysis of variance; mean values were 14 to 22%. Jets grouped less than 2.5, 2.5 to 5 and greater than 5 cm2 showed the variance of small jets exceeding that of medium and large jets. Aortic regurgitant jets were largest and had smaller variance than mitral tricuspid jets. Variability due to atrial fibrillation and the slower frame rate was marginal. Intraobserver error was 4.3% and interobserver 15.4%. Thus, reproducing jet areas carries a minimum variability of 15% or higher, depending on jet size. Valve site could not be excluded as a separate variable. Comparative quantification is best limited to 1 observer.

Left and Right Ventricular Flows by Doppler Echocardiography: Serial Measurements in Patients with Aortic Regurgitation During Exercise, Cold Pressor Stimulation, and Vasodilation

To test the practicality of Doppler echocardiography to measure serial change, biventricular outputs were measured in 15 patients with aortic regurgitation during control periods and during interventions of bicycle exercise, cold pressor stimulation, and vasodilation. Biventricular stroke volumes were measured in 10 normal subjects for validation of methods and differed by 2.8%. Reading errors were 3.7%. Signal quality improved between the first and last observation (p less than 0.05). Velocity signals were corrected for intercept angles, which averaged 12 and 19 degrees for right heart flows and 31 and 32 degrees for the left side of the heart in all subjects. Negative correlations occurred between intercept angles and the chronologic order in which the patients were studied for left (p = 0.02) and right (p = 0.05) flows. Mean flow areas varied 9% in the left ventricle and 20% in the right ventricle. Total variability for measuring flow determined from control values was 11% to 13%. When twice the variability was used as the detectable level of change, only exercise provoked real increases in biventricular flows in the majority of patients. We conclude that serial measurements of flow by Doppler echocardiographic methods had to exceed 20% to 25% to achieve significant change. Measuring intercept angle, resolving flow area, and learning are variables that need greater emphasis.

Die farbigkodierte Blutflußdarstellung abdomineller Gefäße in Echtzeit mit dem zweidimensionalen Dopplerverfahren

Die ersten Versuche, mit Hilfe des Ultraschalldopplerverfahrens den Blutflus nichtinvasiv nachzuweisen, bezogen sich uberwiegend auf die Untersuchung der A. carotis. So konnte Hokanson [2] 1971 erstmals mit dem gepulsten Dopplerverfahren den Blutflus in der A. carotis nachweisen. Im Jahre 1972 folgten die Untersuchungen von Reid und Spencer [6] an der A. carotis mit dem Dauerschalldopp-lerverfahren (CW-Doppler). Curry und White [1] konnten erstmals den Blutflus der A. carotis mit dem CW-Doppler farbig, jedoch nicht in Echtzeit abbilden.

Does color flow mapping Doppler echocardiography allow the catheterization laboratory to be bypassed in surgery of congenital heart disease

The purpose of this study is to demonstrate the clinical usefulness of color flow mapping real-time two-dimensional Doppler echocardiography (2-D Doppler) in establishing the diagnosis of congenital heart disease (CHD) and its application for intraoperative use. In the past two years we examined a series of 278 patients (pts) with CHD including 97 infants and 105 children. With this device, real-time two-dimensional intracardiac and major vascular blood flow images on B-mode echocardiography have been clearly displayed by red color (flow towards the transducer) and blue color (flow away from the transducer) mixed with green color (variance of blood flow velocity) and graded brightness (average blood flow velocity). Patients suffered from ASD (75 pts), VSD (76 pts), TOF (23 pts), TGA (12 pts), PDA (23 pts), ECD (13 pts), PS (13 pts) or miscellaneous CHD, (47 pts). These diagnoses were confirmed by cardiac catheterization and/or surgery with the exception of PDA in premature infants. In 271 patients (97%) abnormal intracardiac blood flow (shunt flow, stenotic flow, and regurgitant flow) was clearly visualized by 2-D Doppler. In 31 patients several palliative procedures (Blalock-Taussig shunt operation: 8, Brock operation: 2, pulmonary arterial banding: 10, BAS: 11) were performed mostly based on 2-D Doppler diagnosis. Fifteen premature infants with PDA and respiratory failure were followed up using 2-D Doppler during Sulindac (prostaglandin antagonist) therapy and 3 infants resistent to Sulindac therapy underwent surgery. In 10 patients intraoperative 2-D Doppler evaluations were performed for confirmation of the diagnosis, confirmation of the completeness of surgery, and for 2-D Doppler echo guided blade atrioseptostomy by direct right atrial approach in the case of d-TGA with bilateral iliac venous obstraction. In conclusion, 2-D Doppler diagnosis was satisfactory in about 90% of corrective surgical cases. Therefore, 2-D Doppler can be a useful non-invasive diagnostic tool for CHD. Also, 2-D Doppler is effective for intraoperative evaluation of multiple cardiac abnormalities in complex CHD and for confirmation of the completeness of surgery. It is suggested that surgery can be carried out without cardiac catheterization in a significant number of congenital heart diseases.

Two years clinical experience with color-coded real-time two-dimensional Doppler cardiography

A noninvasive method for real-time blood-flow Doppler imaging has long been needed in the fields of cardiology and cardiovascular surgery. In 1982, two research groups, Namekawa et al. [1] in Japan and Bommer et al. [2] in the United States, independently described the new technologies of real-time two-dimensional Doppler echocardiography. Namekawa et al., the co-authors of this paper, developed two-dimensional Doppler echocardiography [1, 3] (hereafter abbreviated as 2-D Doppler or color flow mapping) for clinical use, which allows us to obtain intracardiac blood-flow images in real time noninvasively. In April of 1983, the authors first reported [4] on the wide range of clinical applications of real-time two-dimensional Doppler echocardiography using the new device. The authors’ group has confirmed the diagnostic effectiveness in acquired valvular disease [5, 6, 7], congenital heart disease [8, 9, 10], and aortic aneurysm [11]. Furthermore, an intraoperative use for various cardiovascular lesions has been found effective [12, 13].

Surgical Management of Coincidental Gastric or Colorectal Carcinoma and Abdominal Aortic Aneurysm.

消化器悪性疾患に腹部大動脈瘤 (AAA) を伴った6例を経験したので報告する.1991年1月～1994年12月までに経験した非破裂性AAAは57例で, その内消化器癌を合併した6例を対象とした.男5例, 女1例で胃癌4例, S状結腸癌1例, 直腸癌1例であった.AAAの手術適応は径5cm以上とし, 無症状の場合はまず癌に対して手術し, 2期的に人工血管置換術を施行.合併疾患, AAA最大径, 癌の進行度, 術後合併症, 予後について検討した.6例すべて経過良好で退院したが, 冠動脈病変のほか貧血, 腎機能, 呼吸機能障害を認めた胃癌の1例は術後6か月後急性心不全で死亡.胃癌のみ手術を施行した2例中1例は7か月後癌性腹膜炎, 他の1例は2年2か月後再発で死亡.その他の3例は生存中である.以上より, 2期的な手術は安全だが, 進行癌および冠動脈病変など合併疾患を有する症例に対しては術後厳重なフォローが必要であると思われた.

Color flow evaluation of coronary anastomosis

Surgical intraoperative assessment of the technical adequacy of coronary artery bypass graft anastomoses has been difficult due to a lack of appropriate tools and technology [1], Several clinical attempts have been reported using intraoperative epicardial ultrasonic techniques to assess the anatomical structure [2], the color blood flow image [3], and the blood flow velocity profile [4] of the native coronary artery and/or of the aorto-coronary bypass graft. In the surgeon’s point of view, the color flow mapping real-time two-dimensional Doppler echocardiography (2-D Doppler) is considered to the most appropriate technology to assess the coronary artery intraoperatively among current ultrasonic equipments, because this technology can provide the information about the anatomical structure and blood flow dynamics of the coronary artery simultaneously, which can minimize the interruption of the surgery for the evaluation of the technical adequacy of the results of aorto-coronary bypass surgery [5].

Intraoperative color flow Doppler imaging in valvular heart disease

In the short time since its introduction to the cardiovascular field [1–3], realtime two-dimensional Doppler echocardiography, or color flow Doppler imaging, has convincingly demonstrated and proved its practical value and diagnostic effectiveness in acquired valvular disease, congenital heart disease and aortic aneurysms. The use of intraoperative color flow Doppler imaging in the cardiovascular field is a new application of the technique. There have already been reports from several cardiac centers on the usefulness of this application [4–7] and we can expect substantial development in this field in the future. The color flow Doppler technique has been employed during cardiac surgery at the author’s institute since 1984. There are two approaches to its use in surgery. One is to place the probe in direct contact with the surgical field and to take echograms from the surface of the heart (epicardial approach). The other approach uses a transesophageal probe (transesophageal approach [8], transesophageal echocardiography; TEE). Both methods are necessary, but transesophageal echocardiography is likely to develop into the slightly more effective method because color flow mapping by the transesophageal route has made study of intracardiac and intra-aortic flow continuously accessible without the inconvenience of a probe in the operative field or the risk of infection.

Color flow Doppler guiding of atrial septostomy

In a significant number of the patients with severe cyanotic congenital heart disease and a critical cardio-respiratory failure, an adequate interatrial opening is essential for survival in their early stages of life [1]. In such critical patients, quick establishment of diagnosis is required to determine proper therapeutic managements for their survival. Cardiac catheterization was considered to be the standard means of diagnosing most congenital heart disease in the past, however, angiography entails the use of radiation and contrast medium and is associated with morbidity and mortality [2]. Color Flow Mapping real-time, two-dimensional Doppler Echocardiography (2-D Doppler) has become as a tool for the diagnosis in congenital heart disease with definitive anatomic and intracardiac blood flow information [3, 4]. Therefore, it also has potential use in directing medical or surgical management and in changing the indications for cardiac catheterization. In our institution, there has been a shift toward the non-invasive technique either to supplement or to replace cardiac catheterization in selected situations, particularly in critically ill infants [5].

Intraoperative Doppler color flow mapping in dissecting aneurysm of the aorta

Dissecting aneurysm of the aorta (DAA) is a severe disease, frequently involving a broad area of the thoracic and abdominal aorta, the mortality of which is still high even in intensive medical or surgical treatment due to the complicated pathophysiology of the dissection of the aorta [1, 2]. Preoperative assessments of DAA by 2-D echography [3, 4], CT scanning [5], RI angiography [6] and cine-aortography [7] have their own limitations.