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Biomedical subjects

S Kyo

Publications and source records attributed to S Kyo.

At least 19 recordsLinked to original sources
PubMed1992

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 III 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 less than 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 less than 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.

Aortic Dissection↗
PubMed1992

Outcome of Stanford type B acute aortic dissection.

BACKGROUND: The optimal timing of surgery in patients with Stanford type B aortic dissection remains controversial. This report reviews retrospectively early and long-term outcomes of patients with Stanford type B acute aortic dissections at our institute. METHODS AND RESULTS: From April 1979 through January 1991, 75 patients were diagnosed with Stanford type B aortic dissection, and 58 of them were hospitalized within 2 weeks from onset. They were treated initially as follows: emergent surgery was performed in 13 patients for rupture or impending rupture, and the remaining 45 were treated medically. In the former group, nine patients (69%) died; in the latter, eight (18%) needed surgery because of enlargement or rupture of the aneurysm in the follow-up period, and only one of these (13%) died. Of the other 37 patients treated medically, three (8%) died within 2 weeks and seven died (19%) in the chronic phase, four of them from rupture. Among 42 discharged patients initially treated medically, rupture occurred in 11.9% (five of 42). CONCLUSIONS: In acute-phase cases, surgical mortality is so high that medical treatment is preferable unless there are major complications. However, even in patients who had undergone successful initial medical treatment, expansion of the aneurysm, requiring surgery, often occurred. If careful observation reveals any sign of expansion, because elective surgery can be performed at low risk, it should be considered as soon as possible before a rupture develops.

Actuarial Analysis↗
PubMed1992

Effect of human recombinant erythropoietin on reduction of homologous blood transfusion in open-heart surgery. A Japanese Multicenter study.

BACKGROUND: Recombinant human erythropoietin (EPOCH) has been shown to increase erythropoiesis; therefore, EPOCH has been used in conjunction with autologous blood predonation (ABP) before surgery. However, the administration methods of EPOCH to obtain an adequate volume of ABP before open-heart surgery have not been determined. METHODS AND RESULTS: The effects of EPOCH on harvesting ABP and decreasing homologous blood transfusion (HBT) in open-heart surgery were examined prospectively in 205 patients treated in a 29-institute multicenter study. Single dose of 3,000, 6,000, or 9,000 IU of EPOCH were administered for 2 weeks (two or three times per week) without ABP (group 1, n = 69) or for 3 weeks (two or three times per week) with ABP (group 2, n = 97) and compared with control subjects (n = 39). Preoperative blood hemoglobin increase (delta Hb[g/dl]) was < 1.0 g/dl in group 1. When EPOCH was given three times a week, the delta Hb in each subgroup of group 2 was 0.6 +/- 1.1 (control), 2.1 +/- 1.3 (3,000 IU), 2.4 +/- 1.4 (6,000 IU), and 2.8 +/- 1.5 (9,000 IU), which was significantly higher than the control (p < 0.05) and was dose dependent. The HBT rates in patients with a moderate perioperative blood loss of between 15 and 50 ml/kg were 75.0% (control), 35.7% (3,000 IU), 52.9% (6,000 IU), and 66.7% (9,000 IU) in group 1, and respective volumes in group 2 were 40.0% (control), 20.0% (3,000 IU), 26.9% (6,000 IU), and 12.5% (9,000 IU). The overall HBT rate of EPOCH-treated patients with a moderate blood loss was 50% (20 of 40) in group 1 and 21% (13 of 62) in group 2. The HBT rate was significantly reduced by combination of preoperative EPOCH treatment (three times per week) and ABP (p < 0.0001). CONCLUSIONS: Dose-dependent increase of blood hemoglobin level was observed by EPOCH treatment with ABP; combination of EPOCH treatment and ABP can reduce HBT during open-heart surgery.

Blood Transfusion↗
PubMed1992

Intraoperative echocardiography for diagnosis and treatment of aortic dissection. Utility of color flow mapping for surgical decision making in acute stage.

In the past eight years until July 1992, 92 patients were admitted in the acute state of aortic dissection within two weeks from the onset of symptoms. 41 were diagnosed as Stanford type A and 51 were type B by transthoracic and transesophageal echography, computer tomography, and surgery. Sensitivity of transesophageal echography to detect the intimal flap and the false lumen was 97.6% in patients with Stanford type A and 100% in patients with Stanford type B. The surgical decision making has been mostly depending on the transesophageal echographic diagnosis. When the intimal flap was detected in the ascending aorta (Stanford type A) surgery was performed in emergency regardless of any evidence of rupture, cardiac tamponade, and severe aortic regurgitation. When the aortic dissection was detected only in the descending aorta (Stanford type B) the main course of therapeutic strategy in our institute was medical treatment. Surgery was performed on 37 patients of type A and nine patients of type B with mortality of 18.9% and 55.5% respectively. Four patients of type A and 42 patients of type B were treated medically with a mortality of 75.0% and 2.2% respectively. The relatively large leakages from the anastomosis of the aortic clamp site were repaired secondarily in two patients, and fenestration of the superior mesenteric artery was performed on one patient due to ischemia of the small intestine depending on the intraoperative direct scanning of color flow mapping. Coronary artery involvement of dissection was strongly suspected in two patients by intraoperative transesophageal echography and aortocoronary bypass grafting was performed on these patients. Perfusion problems was encountered in five of 37 patients with type A aortic dissection (13.5%) during cardiopulmonary bypass. Intraoperative transesophageal echography could clearly detect the hemodynamic changes in the descending aorta resulting from inadequate perfusion which was useful for the management of perfusion control during cardiopulmonary bypass. Secondary repair of the aortic arch was required due to ischemia of the aortic arch vessels in two patients after the primary surgery. The extension of the dissection into the aortic arch vessels can be promptly diagnosed with the combination of transesophageal echography and transcutaneous echography. In conclusion, transesophageal Doppler echography is the most rapid diagnostic tool for decision making in acute aortic dissection, and intraoperative transesophageal echo can provide useful information to resolve the perfusion difficulties during cardiopulmonary bypass.(ABSTRACT TRUNCATED AT 400 WORDS)

Acute Disease↗
PubMed1992

[Estimation of peripheral metabolism under cardiopulmonary bypass by measuring ketone bodies, lactate, and pyruvate].

Both ketone body ratio (KBR) and pyruvate/lactate ratio (P/L) are metabolic indicators related to NAD-linked dehydrogenase system according to the REDOX THEORY. In order to estimate the peripheral metabolic state under the cardiopulmonary bypass (CPB) which is considered to be a moderate and controllable shock state, we measured the pyruvate (P), lactate (L) and ketone bodies (acetoacetate [ACA], 3-hydroxybutyrate[HOB]) pre, during, and post-CPB in 20 open heart surgical patients (Group 1). We also measured ketone bodies in another group (Group 2: 22 patients) of elective coronary artery bypass surgery (CABG). Five patients in Group 2 who developed postoperative organ failure (Group 2-A) were compared with the other 17 cases with uneventful postoperative course (Group 2-B). In Group 1, P and L concentrations progressively increased until the end of CPB, thereafter decreased (P less than 0.001). HOB and TKB significantly increased immediately after the start of CPB, afterward which declined during CPB and returned to the control level after CPB. Both KBR and P/L regression analysis reveal the significant correlation between P/L and KBR (r = 0.51, P less than 0.001). KBR at 1 hour after CPB returned to the control level, however, P/L at 1 hour after CPB still stayed in the significant lower level than the control (P less than 0.001). KBR at the aortic declamping in group 2-A was significantly lower than that in group 2-B. In conclusion, P/L and KBR changed in relation to hemodynamic change during CPB.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

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.

Creatine Kinase↗
PubMed1991

A tubule cell line established from transgenic mice harboring temperature-sensitive simian virus 40 large T-antigen gene.

Immortalization of cell lines with specific functions is important for examination of organ-specific functions in vitro. We established a kidney tubule cell line (TKC2) exhibiting a specific physiological response to hormone from the primary culture of kidneys of adult transgenic mice harboring temperature-sensitive SV40 large T-antigen gene. TKC2 cells showed temperature-sensitive growth in culture and exhibited characters of distal tubule cells such as dome formation at confluent culture and stimulation of cAMP synthesis by arginine vasopressin. These phenotypes are maintained after long passages in culture and may provide a new experimental system for studying renal physiology.

Animals↗
PubMed1991

Transvascular intracardiac applications of a miniaturized phased-array ultrasonic endoscope. Initial experience with intracardiac imaging in piglets.

BACKGROUND: Recent advances in miniaturization of phased-array and mechanical ultrasound devices have resulted in exploration of alternative approaches to cardiac and vascular imaging in the form of transesophageal or intravascular imaging. Preliminary efforts in adapting phased-array endoscopes designed for transesophageal use to a transvascular approach have used full-sized phased-array devices introduced directly into the right atrium in open-chested animals. The purpose of this study was to assess the feasibility of using a custom-made, very small phased-array endoscope for intracardiac imaging introduced intravascularly through a jugular venous approach in young piglets. METHODS AND RESULTS: Experimental atrial septal defects created in four piglets (3-4 weeks old) had been closed with a buttoned atrial septal defect closure device consisting of an occluder in the left atrium and a counteroccluder in the right atrium. Five to 15 days after atrial septal defect closure, the piglets were returned to the experimental laboratory, where a 6.3-mm, 17-element, 5-MHz phased-array probe mounted on a 4-mm endoscope was introduced through a cutdown incision of the external jugular vein and advanced to the right atrium. From the right atrium all four cardiac chambers, their inflows and outflows, and all four valves were well imaged with minimal superior and inferior rotation. High-resolution imaging of the atrial septum defined with anatomical accuracy, later verified by autopsy, the exact placement of both the occluder and counteroccluder in the left and right sides of the atrial septal defects and the absence of any shunting across the atrial septum in any of the four animals. CONCLUSIONS: Our efforts indicate that transvascular passage of small phased-array probes can be easily accomplished and is a promising technique for detailed visualization of cardiac structures. This approach may provide an alternative to transesophageal echocardiography, particularly for guiding interventional procedures such as placement of transcatheter closure devices in pediatric patients.

Animals↗
PubMed1991

[Detection of HPV DNA in the uterine cervical lesions by polymerase chain reaction and in situ hybridization].

Human papillomavirus (HPV) is found in close association with carcinogenesis of the uterine cervix. We applied a new in vitro gene amplification technology, the polymerase chain reaction (PCR) to detect HPV 16 and 18 in cervical exfoliated cells. HPV infections were detected in 5 (16%) of 31 women with no pathological lesions of the uterine cervix (normal), 16 (24%) of 67 with cervical intraepithelial neoplasia (CIN) and 6 (38%) of 16 with invasive cervical cancer. Moreover, 10% formalin-fixed and paraffin-embedded tissue sections were prepared from the uterine cervix of these 27 women with PCR-proven HPV infection and were examined for the histological localization of HPV-DNA by in situ hybridization with biotin-labeled DNA probes of HPV types 6/11, 16/18 and 31/33/35. HPV-DNA type 16/18 was detected in 3 of 5 normal women, 2 of 4 CINs I, 2 of 3 CINs II, 6 of 9 CINs III and 6 of 6 invasive cervical cancers. HPV-DNA type 6/11 was detected in 6 of 6 condylomas. Viral DNA sequence was detected in the superficial cells of CIN I and II, and it was distributed through entire thickness layer of undifferentiated cells derived from CIN III and squamous cell carcinoma. In addition, the staining intensity became weak as the lesion progressed. These differences between lesions might be due to the difference in the viral form in the nuclei, ie whether an episomal or integrated form. Thus, an in situ hybridization technique with a biotin-labeled DNA probe as well as the PCR method is useful for the detection of HPV in clinical samples.

Base Sequence↗
PubMed1991

[Regional myocardial perfusion and function after coronary bypass surgery: evaluation using handgrip exercise Doppler echocardiography].

To evaluate myocardial perfusion and function of the interventricular septum after coronary artery bypass surgery, 29 patients with internal mammary artery grafts (IMAG) were examined using handgrip exercise Doppler echocardiography. IMAG flow was measured by color flow Doppler. Septal excursion and percent thickening of the interventricular septum during systole were measured as indicators of regional left ventricular function by M-mode echocardiography. Myocardial perfusion was estimated by thallium-201 exercise myocardial scintigraphy using a treadmill. 1. At rest, there were no significant correlations between IMAG flow and septal excursion and percent thickening or myocardial perfusion. 2. After the isometric handgrip exercise test, IMAG flow increased 20.0 +/- 3.9% from at rest, and the percentage of change in IMAG flow correlated significantly with changes in septal excursion (r = 0.63) and percent thickening (r = 0.72). It was found that a response of bypass graft flow to exercise has a correlation with contractility of cardiac muscle. 3. The rate of increase in IMAG flow in patients with normal myocardial scintigraphic findings (31.8 +/- 6.2%) was higher than that in patients with ischemia (15.3 +/- 5.6%) or infarction (15.0 +/- 11.3%). 4. A greater increase of percent thickening was observed in patients with normal exercise myocardial scintigraphic findings. These results suggest that the responses of the bypass graft flow to handgrip exercise may reflect viability and contractility of cardiac muscles perfused by the graft. Thus, exercise Doppler echocardiography is useful for evaluating regional myocardial perfusion and function of the interventricular septum after coronary artery bypass surgery.

Adult↗
PubMed1991

[Diagnosis of acute aortic dissection with transesophageal echocardiography and results of surgical treatment].

Forty-four consecutive patients with acute aortic dissection from April 1987 to April 1990 were diagnosed with the use of transesophageal echocardiography (TEE) and treated at our institute. In 43 of them (98%, type A: 22 cases, type B: 21 cases), diagnosis was accurate and there were no complications. In one patient with type A dissection, the small intimal flap could not be detected. Emergency operations were performed in the patient with type A and ruptured type B. In type A, operated before cardiac arrest, the operative mortality rate was 20% (4/20). In ruptured type B, the operative mortality rate was 50% (2/4). The result of conservative therapy in the patient with nonruptured type B (17 cases) was satisfactory. The investigation by TEE was carried out without difficulty at the bed side and in the operating room as well, giving precise and rapid information and could be a useful diagnostic mean for acute aortic dissection.

Acute Disease↗
PubMed1991

Emergency surgical intervention of acute aortic dissection with the rapid diagnosis by transesophageal echocardiography.

Forty-five serial patients with acute aortic dissection were examined by transesophageal color Doppler echocardiography (TEE), and the diagnosis was made without aortography. No complications related to TEE occurred. Sufficient information for surgery was immediately obtained at the bedside by the TEE examination. Forty-four of 45 patients (98%) were diagnosed accurately, and 20 emergency operations for patients with type A aortic dissection and six emergency operations for patients with type B aortic dissection were performed. In only one patient, a small intimal flap in the ascending aorta was not detected by TEE. The operative mortality rate was 20% and 50% for types A and B aortic dissections, respectively. As a result of the progress of biplanar TEE technology, an easier and more accurate diagnosis of patients with acute aortic dissection can be achieved. The immediate and accurate diagnosis of acute aortic dissection can be achieved by TEE at the bedside, and treatment strategy can be more precisely determined.

Adult↗
PubMed1990

[On-line angle correction of color flow mapping images using a personal computer].

To quantitatively assess flow area or kinetic energy in color flow mapping (CFM), angle correction, which has been totally ignored using current systems, is now considered indispensable. To reconstruct flow images using angle-corrected velocity mapping, we incorporated a personal computer (NEC PC-LT) in the cine-memory of a CFM system (Aloka SSD-870). To demonstrate the effect of angle correction on CFM, the maximum left ventricular diastolic flow images were obtained in seven normal adults using the apical long-axis views where the angle of incidence was less than 10 degrees, and the parasternal long-axis view, where the angle of incidence was between 40 and 60 degrees. A 3.5 MHz probe with a 4 KHz pulse repetition frequency at a frame rate of 10/sec was used. Flow area and kinetic energy of the original and angle correction images in the aliased parts and the total flow areas were calculated and expressed as percent values of the control (color correction image of total flow area in the apical view). The total flow area of the original image in the apical view was 96.4% and 87.2% in the parasternal view, or 98.6% by effective angle correction, and the kinetic energy of the original image in the apical view was 94.0% and 58.8% in the parasternal view, or 93.3% by angle correction. In conclusion, although flow area and kinetic energy of the original image in the parasternal view were significantly less than those of the original and the angle correction images in the apical view (p less than 0.05), they could effectively be evaluated by angle correction. Thus, this system can contribute to quantitative assessment of CFM.

Adult↗
PubMed1990

[Evaluation of patency of internal mammary artery grafts: a comparison of two-dimensional Doppler echocardiography with coronary angiography].

To examine the clinical feasibility of color flow mapping Doppler echocardiography (CFM) in diagnosing the patency of internal mammary artery (IMA) grafts, 41 patients who had had coronary bypass surgery were examined by both CFM and coronary angiography (CAG) within one week of the CFM examination. Coronary bypass surgery was performed one to eight months prior to this study, and the average number of bypass grafts was 2.7 +/- 0.7. The patency of the IMA grafts was confirmed in all except one patient by CAG; whereas, the flow in the IMA grafts was clearly visualized in all 22 patients by CFM from the left parasternal echo window. Peak velocities of the IMA graft flow in the 22 patients were 31.7 +/- 12.0 (19-49) cm/sec in diastole and 14.9 +/- 8.5 (5-36) cm/sec in systole. No false positive diagnosis was made in the CFM examination. The sensitivity, specificity, negative predictive value, and positive predictive value of CFM in the diagnosis of IMA graft patency were 55%, 100%, 5.3% and 100% respectively. In conclusion, although the sensitivity of color Doppler still remains relatively low, its specificity in the diagnosis of IMA graft patency is 100%. Thus, color Doppler is expected to be valuable for long-term follow-up of IMA graft patencies.

Adult↗
PubMed1990

[Advantages of transesophageal color Doppler echocardiography in the diagnosis and surgical treatment of cardiac masses].

To determine the clinical advantages of transesophageal color Doppler echocardiography (TEE) for imaging cardiac tumors and left atrial thrombi, 24 cases with intra- or extracardiac masses were examined by transthoracic color Doppler echocardiography (TTE) and TEE before and after cardiac surgery. Five with left atrial myxomas, two with lung tumors, five with mediastinal tumors and 12 with mitral stenosis coexisting left atrial thrombi were included in this study. The echocardiographic findings of the cardiac masses were compared with the surgical findings in all cases. In all of the five cases with left atrial myxomas, the tumors were detected. However, the sites of attachment and a stalk in three cases were not observed by TTE. TEE clearly imaged the left atrial myxomas, and evaluated the size and shape of the tumors, the sites of their attachment and a stalk arising from the interatrial septum, and mobility in four cases, except for one in which there was a broad attachment to the endocardium. Mitral regurgitation was detected in only two cases using the color Doppler mode of TTE, but in all cases using TEE. Both techniques failed to recognize tissue characterization. Among seven cases with secondary cardiac tumors or mediastinal tumors, extracardiac masses were detected in five; however, an intracardiac tumor attached to the interatrial septum and an extracardiac tumor extending to the superior vena cava and an upper part of the right atrium could not be imaged using TTE. TEE detected all tumors at all sites in the heart and vessels, and estimates of their extents were in accord with the operative findings in 17 of 18 sites. One exceptional case had a tumor which extended to the right ventricle. Neither technique could detect infiltration of the heart which was present in five of the seven cases. Multiple left atrial thrombi were observed in eight of 12 cases, resulting in 21 thrombi and they were diagnosed by TEE in six of 12 cases. Thrombi, when attached to the left atrial posterior or inferior walls, were easily detected in four of five cases, but were not identified in four of six and in eight of nine cases at the lateral wall or in the left atrial appendage by TTE. However, TEE detected all thrombi in every site in the left atrium and left atrial appendage in 11 of 12 cases. TEE was thus superior to TTE in detecting cardiac masses, recognizing abnormal flow and estimating anatomical relationship between tumors or thrombi and cardiac structures.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1990

Early diagnosis and surgical intervention of acute aortic dissection by transesophageal color flow mapping.

To determine whether transesophageal color Doppler echocardiography (TEE) is useful for the early diagnosis and surgical intervention in acute aortic dissection, 57 serial patients with acute aortic dissection were examined. These patients were evaluated by TEE with either the single-plane probe (39 patients) or the biplanar probe (18 patients) just after admission. The intimal flap was detected in all patients, and there were 18 patients with type A dissection and 39 patients with type B dissection. The entry was visualized in 83% of type A dissection cases and in 90% of type B dissection cases. In two of 18 patients examined with the biplanar probe technique, the entry was detected in the longitudinal view only. Emergency operations were performed in 18 patients with type A dissection and in 10 patients with ruptured type B dissection. Twenty-nine of 39 patients with type B dissection were treated conservatively. The operative mortality rate of patients with type A dissection was 22%, and that of patients with ruptured type B dissection was 60%. The major advantage of TEE is its ease of application at the bedside or in the operating room, which allows immediate and accurate diagnosis of acute aortic dissection for emergency surgical intervention. Biplanar TEE provides additional acoustic windows, ease of spatial orientation, and more accurate visualization of entry. TEE is a useful and powerful diagnostic tool for acute aortic dissection, and by using this method, one may achieve a more rapid and aggressive surgical approach for patients with acute aortic dissection.

Acute Disease↗