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Biomedical subjects

T Sueda

Publications and source records attributed to T Sueda.

At least 55 records · Page 3Linked to original sources
PubMed2000

Echocardiography-assisted surgery in transaortic endovascular stent grafting: role of transesophageal echocardiography.

OBJECTIVE: Transesophageal echocardiography was applied to visualizing endovascular procedures during transaortic stent grafting for aneurysm and dissection at the distal arch, and the use of transesophageal echocardiography was evaluated. METHODS: The 16 consecutive patients (13 with aneurysms and 3 with dissections) were examined. Transesophageal echocardiography was used for (1) determining graft size, (2) guiding placement of the catheter in the descending aorta at an appropriate position without intimal damage, (3) guiding graft tailoring with a balloon catheter, and (4) examining the results after the procedures. RESULTS: Visualization was disturbed in one patient who had undergone a previous operation. The graft size was appropriate, except in one patient as a result of underestimation. Transesophageal echocardiography was helpful for navigating the graft placement and tailoring without intimal damage. We tried to keep a distance from the diaphragm of 9 cm and an attachment portion of 4 cm. In one patient the graft was placed too distally (7 cm from the diaphragm) to cover the thick atheromatous plaque with the graft. The patient had paraplegia. Transesophageal echocardiographic assessment of endoleak and thromboexclusion was identical to that of postoperative computed tomography or angiography, with a sensitivity of 100% (1/1) and a specificity of 100% (13/13). Leakage at the proximal suture and graft kinking were found in 3 patients. Successful thromboexclusion by transesophageal echocardiographic assessment (13 patients) was predictive of subsequent regression of aneurysm and dissection in the midterm follow-up period: there was complete and partial regression in 5 and 8 patients, respectively. CONCLUSION: Transesophageal echocardiography enables echocardiography-assisted operations with secure step-by-step endoluminal procedures and immediate intraoperative assessment, which is predictive of the postoperative results.

Adult↗
PubMed2000

Cardiac tumor biopsy under the guidance of intracardiac echocardiography.

Transthoracic echocardiography or transesophageal echocardiography is sometimes useful in intracardiac tumor biopsy. Intracardiac echocardiography was used as an alternative to either of these for performing a biopsy of a right cardiac tumor in a 79-year-old woman. The procedure was well tolerated and no complications occurred. Histopathological findings and immunohistological staining were compatible with the diagnosis of neurogenic sarcoma.

Aged↗
PubMed2000

Newly designed eccentric roller type total artificial heart.

We have produced an eccentric roller type total artificial heart (ERTAH). As the first step in the development of this ERTAH, we conducted simulations such as a numerical simulation, a mock test, and an acute animal experiment using DeBakey roller pumps to analyze the left-right balance during its operation. The next step was redesigning the blood chambers to improve energy efficiency and implanting the ERTAH with an interatrial shunt into an animal for evaluation of the in vivo performance of the device. In the simulations, shunt flow through the bronchial arteries was approximately 500-600 ml/min, and the interatrial resistance was varied from 2.9-7.7 mmHg.min/liter. Redesigning the blood chambers resulted in the mock test in a 20% increase in energy efficiency, about a two-fold increase in cardiac output and improved durability compared to the previous type in the mock test. In the animal experiment the ERTAH operated with a left flow rate of 6.0 liters/min and a right flow rate of 5.4 liters/min. The interatrial shunt flow rate was 250-400 ml/min. Creating an interatrial shunt is a useful method for balancing the blood flow between the left and right heart of the ERTAH. A decrease in friction resistance and the prevention of backward flow resulted in an increase in energy efficiency, cardiac output, and improved durability, in spite of downsizing the blood chambers.

Animals↗
PubMed2000

Ruptured sinus valsalva with infectious endocarditis: a technique of defect closure with an autologous-xenologous pericardial sandwich patch.

We report a case of ventricular septal defect with acquired rupture of sinus Valsalva induced by infectious endocarditis. After irrigati on of all infectious tissues, the defect was closed twice using two different patches. One was an autologous pericardial patch from the right ventricle and the other was a composite patch made of an autologous pericardium and axenologous pericardium from the left ventricle. As a result, the xenologous pericardium was sandwiched between autologous pericardiums. We thought that this "sandwiched patch" would compensate for the shortcomings of each type of pericardium and resist left ventricular pressure and infection. Despite the development of antibiotic therapy, infectious endocardit is (IE) is still one of the most difficult disease to cure. In the case of a rupture of sinus Valsalva, because of the rapid spread of infection into any of the cardiac chambers, surgical intervention is necessary. In this report, we describe a case treated successfully.

Adult↗
PubMed2000

Is communication to endocardium necessary for angiogenesis in transmyocardial laser revascularization?

There is evidence of angiogenesis being induced after transmyocardial laser revascularization (TMLR), although the precise mechanism has not been fully elucidated. This study was designed to examine whether or not blood flow from the left ventricle through the channels is essential for angiogenesis following TMLR. Ten dogs underwent the creation of two types of laser channels in the left ventricle: 1) a transmural channel (TMC), which penetrates the myocardium, and 2) a non-transmural channel (NTMC), which does not open to the epicardium. The animals were sacrificed on the 28th postoperative day and the vascular density was examined. Vessels with smooth muscle media were seen within or around the channel remnant. The vessel density was compared between TMC and NTMC. The outer and inner halves of the myocardium in the TMC region were compared in the same way. The density of vessels within and around the channel remnants was significantly higher in TMC than in NTMC (1.439 versus 0.685 vessels/microscopic visual field (mvf=40X); p=0.0025). The vascular density was significantly higher in the region adjacent to TMC than in a distant region (>3 mm from the channel center). The vascular density was significantly higher in the outer half than in the inner half of the myocardium (1.730 versus 1.180 vessels/mvf: p=0.0459). These findings demonstrate that communication to the left ventricular lumen enhances angiogenesis of TMLR, although blood flow in the channel did not exist 4 weeks after TMLR and angiogenesis tended to be more highly enhanced in the outer half than in the inner half of the myocardium.

Animals↗
PubMed1999

Relationship between left atrial spontaneous echo contrast and the features of middle cerebral artery territory in nonvalvular atrial fibrillation.

We investigated the relationship between left atrial spontaneous echo contrast (SEC) and cerebrovascular features in nonvalvular atrial fibrillation (NVAF). Few reports have been published to compare cardiac and cerebrovascular imaging in patients with NVAF. Forty-four patients with NVAF were studied using transesophageal echocardiography and non-invasive imaging including magnetic resonance imaging (MRI), magnetic resonance angiography (MRA), and transcranial color Doppler imaging (TCD) in the middle cerebral artery (MCA) territory. The symptomatic severity was divided into asymptomatic, transient ischemic attack (TIA), and stroke. The severity of the MRI findings was divided into normal, small, and large infarcts. The severity of the MRA findings was divided into normal, attenuation, and occlusion. MCA was bilaterally scanned and a side-to-side asymmetry ratio of pulsatility index (PI) was measured. The severity of SEC was divided into normal, SEC, and thrombi. Five patients with other thromboembolic risk or poor results of TCD were excluded. SEC and thrombi were detected in 12 (30%) and in 3 patients (5%), respectively. TIA and stroke were detected in 8 (21%) and in 17 patients (44%), respectively. Small and large infarcts were detected in 9 (23%) and in 18 patients (46%), respectively, on MRI. Attenuation and occlusion were detected in 14 (36%) and in 8 patients (21%), respectively, on MRA. PI ratio was 1.21 +/- 0.25. SEC severity was highly associated with PI ratio and MRA severity in monovariate analysis (P < 0.005), P < 0.01, respectively). SEC severity was highly associated with PI ratio and MRA severity in stepwise multiple regression analysis (P = 0.0001, r = 0.630, n = 39). In patients with NVAF, left atrial SEC was highly related to attenuation or occlusion on MRA and imbalance of cerebral blood flow on TCD in the MCA territory.

Aged↗
PubMed1999

Stent-grafting to descending thoracic aorta during coronary artery bypass grafting.

We report on 2 patients who underwent successful concomitant operation of coronary artery bypass grafting and stent grafting to descending thoracic aortic aneurysms. The device was inserted through a small linear incision on the anterior wall of the aortic arch. Intraoperative stent grafting to descending thoracic aortic aneurysms is an alternative therapeutic option for patients who require concomitant coronary artery bypass grafting and descending aortic replacement.

Aged↗
PubMed1999

Influence of different curette insertion depths on the outcome of non-surgical periodontal treatment.

This study was undertaken to compare the effects of scaling and root planing (Sc/RP) performed from approximately 1 mm coronal to (test Sc/RP) or at the bottom of (control Sc/RP) the probeable pocket to the gingival margin. 2 male and 5 female patients with moderate to severe periodontitis participated in the study. Initial examination was performed with respect to probing pocket depth (PPD) and probing attachment level (PAL) using a pressure-controlled periodontal probe and stents. The patients received repeated instruction in oral hygiene, and their plaque control reached an excellent level. Baseline examination including PPD and PAL measurements was then performed. Following the baseline examination, single-rooted teeth in 1 quadrant of each dentition were randomly selected and subjected to the test Sc/RP (test teeth) or control Sc/RP (control teeth). The PPD and PAL were measured 1 and 3 months following Sc/RP. It was demonstrated that: (i) the PPD reduction following Sc/RP was larger at the sites with initially deep pockets than at the sites with shallow pockets; (ii) the mean PPD reduction at the sites with an initial PPD > or =3.5 mm was significantly larger in the control teeth than in the test teeth; (iii) there was a significant PAL gain in the initially deep pockets but not in the initially shallow pockets; (iv) the PAL gain in the initially shallow pockets was significantly larger in the control teeth than in the test teeth. In the treatment of periodontitis, trauma caused by Sc/RP to the most coronal part of the connective tissue attachment seems to be of minor importance compared to the effective removal of subgingival deposits.

Adult↗
PubMed1999

Flow balance between the left and right cardiac output of an eccentric roller type total artificial heart.

We have made an eccentric roller type total artificial heart (ERTAH). The ERTAH is a positive-displacement device comparable to a DeBakey roller pump. Its left and right outputs are determined by the size of its blood chambers, and the ratio of its left and right output is almost constant. We focused on an interatrial shunt to achieve left-right balance. We have conducted numerical simulation, a mock test, and an acute animal experiment to analyze left-right heart balance during ERTAH operation. Numerical simulation was performed under conditions in which the flow of the left artificial heart was fixed at 6 L/min, the flow of the right artificial heart was varied from 4.8 to 6 L/min, and the interatrial resistance was also varied. The relationship between the interatrial shunt flow rate and the output of the left and right artificial hearts was balanced when the flow of the right artificial heart was at 5.45 L/min. In a mock test, 2 DeBakey roller pumps were connected to the left and right sides of a Donovan mock circulatory system, and an interatrial shunt was created between the inlet ports of the left and right roller pumps. The interatrial resistance of the mock system was varied from 7.7, to 4.3, and to 2.9 mm Hg x min/L when the inner diameter of the interatrial shunt was 6, 8, and 10 mm, respectively. As in the mock test, 2 roller pumps were used to bypass the right and left hearts of a goat weighing 60 kg. The flow rate of the left heart was almost constant (4.7 L/min). The flow of the right heart was approximately 4.1 L/min when the interatrial shunt flow rate was zero. A leading consideration was that the left to left shunt through the bronchial arteries in this goat was approximately 0.6 L/min. In developing the ERTAH, we considered that creating an interatrial shunt between the inlet ports of the ERTAH as well as making a difference between the chamber volumes might be effective in balancing the left-right sides of the artificial heart.

Animals↗
PubMed1999

Left atrial tachycardia after right atrial separation for chronic atrial fibrillation with atrial septal defects.

A right atrial separation procedure was performed for the ablation of chronic atrial fibrillation in four cases, concomitant with the repair of the atrial septal defect. After the operation, chronic atrial fibrillation disappeared in three of them and left atrial tachycardia occurred in the other one. Left atrial tachycardia is an arrhythmia encountered after a right atrial separation procedure.

Aged↗
PubMed1999

Cardiac disease late after chest radiotherapy for Hodgkin's disease: a case report.

This report presents a case of occult constrictive pericarditis and mitral valve insufficiency following chest radiotherapy. A 44-year-old man had received radiotherapy for the treatment of Hodgkin's disease 8 years ago. At age 40 years, effusive pericarditis occurred and he was treated with intrapericardial drainage. Biopsy revealed a fibrotic and thickened pericardium. He developed congestive heart failure 3 years later. The patient was found to have occult constrictive pericarditis and mitral valve insufficiency. He underwent mitral valve replacement, tricuspid annul plasty, and pericardiectomy. Although there is the benefit of cure for the Hodgkin's disease, the prognosis after treatment is affected by radiotherapy-induced heart disease. After radiotherapy of the chest and mediastinum, long-term cardiological follow-up is recommended in order to detecting patients with radiation-induced heart disease, such as the present case.

Adult↗
PubMed1999

Transcatheter coil embolization of large-size patent ductus arteriosus in adult patients: usefulness and problems.

Transcatheter coil embolization of the patent ductus arteriosus (PDA) has been frequently used in children, especially for small lesions. It was attempted in 3 adults using Cook detachable coils. For 2 of the patients, relatively old age and heart failure were the reasons for choosing coil embolization of the PDA. In the remaining patient, who had Wolff-Parkinson-White syndrome, coil embolization was performed after radiofrequency catheter ablation of Kent's bundle. Their respective minimal PDA diameters were 5.0 mm, 4.5 mm and 4.0 mm measured by transesophageal echocardiography. Two coils were placed in 2 patients and 1 coil in the remaining patient. After the procedures, the size of the left ventricle decreased and heart failure was improved in 2 patients, although all 3 patients had a residual shunt, which caused hemolytic anemia in 2 patients. Repeat coil-embolization procedures resulted in complete occlusion and the hemolysis disappeared in these patients. In adult patients who have heart failure due to large PDA, coil embolization with detachable coils, even if residual shunt persists, is useful for improvement of the heart failure. In cases of hemolysis related to residual shunt, a second coil-embolization procedure can improve it completely.

Adult↗
PubMed1999

Effective periodontal treatment in a patient with type IIA von Willebrand's disease: report of a case.

von Willebrand's disease (vWD) is one of the most common hereditary hemorrhagic disorders. A mild to moderate deficiency of factor VIII and von Willebrand factor (vWf) often is associated with gingival bleeding. In this case report, the periodontal treatment of a patient with vWD is described. A 45-year-old woman with type IIA vWD was referred for periodontal therapy because of an episode of gingival hemorrhage and percussion pain of teeth #18 and #47. The periodontal findings included probing depths ranging from 2 to 6 mm, horizontal bone loss, and Class II furcation involvement of tooth #46. After consultation with a hematologist, apically positioned flap surgery and hemisection were performed on tooth #46 following completion of oral hygiene instruction, scaling and root planing, and endodontic therapy. The patient was given 500 units of factor VIII including vWf multimer 30 minutes before surgery. After healing of the periodontal tissue, prosthodontic treatment was undertaken on the posterior mandibular sextants. At follow-up, the probing depths ranged from 2 to 3 mm, and gingival bleeding on probing was minimal. The patient's children all had vWD. They had mild to moderate periodontitis with probing depths ranging from 2 to 5 mm and gingival bleeding on probing. With the combined efforts of the periodontist and hematologist, effective periodontal treatment can be provided to patients with von Willebrand's disease.

Adolescent↗
PubMed1999

Effects of complement suppression on xenograft survival in hyperacute rejection.

To examine the significance of complement in discordant cardiac xenograft rejection, morphological changes in the rejection reaction were investigated following administration of FUT-175 (FUT), an anticomplement reagent. Guinea pigs were the cardiac donors, and Wistar rats were the recipients. Four groups of rats were constituted as follows: Group 0 was the control group. FUT of 40 mg/kg was injected intraperitoneally in group I. It was followed by continuous intravenous infusion (20 and 40 mg/kg/hr) in groups II and III. In one series, the effects of FUT on complement suppression was examined. In the FUT groups of rats (groups I to III), the serum levels of CH50 and ACH50 were measured at 0, 1, 2 and 4 hr following injection of FUT. In the second series of rats with identical treatments, the graft heart beating time following cardiac transplantation was measured. Cardiac transplantation into untreated rats was also performed as a control (group 0). In another series, the graft hearts in the FUT groups were extracted after 15, 30, 60 and 90 min of coronary reperfusion for morphological examination with scanning electron microscopy. The complement levels decreased significantly in the FUT-treated rats in a dose-dependent manner. Although the graft heart beating times in the FUT-treated groups were significantly longer than in group 0 (103, 106, and 112 min versus 14.7 min, p < 0.01), there was no significant difference in the graft heart beating time or in the morphological changes among the three FUT groups. Our results suggest the presence of factors other than complements contribute to the cardiac xenograft rejection.

Animals↗
PubMed1999

Possibility of focal activation around the left upper pulmonary vein during chronic atrial fibrillation with mitral valve disease.

Focal regular activations were sometimes observed during chronic atrial fibrillation (AF) associated with mitral valve disease. We present a 58 year-old male diagnosed with mitral valvular stenosis and regurgitation with chronic atrial fibrillation. Intraoperative mapping of both atria was performed during mitral valvular surgery. Regular and repetitive activations around the left superior pulmonary vein were observed, in contrast to irregular and chaotic activations of the right atrium. This regular activation was supposed to be the focus of chronic AF. Surgical ablation of the posterior left atrium was successfully performed and eliminated the chronic AF, concomitant with mitral valve replacement.

Atrial Fibrillation↗