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Biomedical subjects

K Ataka

Publications and source records attributed to K Ataka.

At least 73 records · Page 4Linked to original sources
PubMed1995

Acute left atrial thrombus causing cardiogenic shock following mitral valve replacement: report of a case.

We report herein the rare case of a 53-year-old woman who developed cardiogenic shock due to an acute left atrial thrombus following replacement of the mitral valve. A definitive diagnosis was not able to be made using precordial echocardiography because of the broad, flat shape of the thrombus; however, transesophageal echocardiography imaged the thrombus in detail. The patient was initially stabilized by percutaneous cardiopulmonary support after which a thrombectomy was successfully performed.

Echocardiography, Transesophageal↗
PubMed1995

Reduction of left ventricular hypertrophy with St. Jude Medical 19 mm valve prosthesis.

To determine the permissible range of the St. Jude Medical 19 mm valve (SJM19) as an aortic prosthesis, transvalvular maximal pressure gradient (maxPG) and postoperative reduction of left ventricular (LV) hypertrophy were examined in 21 patients (body surface area [BSA] 1.28-1.56 m2, mean 1.42 m2). Doppler echocardiographically measured maxPG at rest was 31 +/- 16 mmHg, which showed no significant difference from the differences in patients' diseases (aortic regurgitation = AR or stenosis = AS), or BSA. The maxPG, also measured during dobutamine administration when they were less than 40 mmHg at rest, increased significantly from 21 +/- 11 mmHg to 32.1 +/- 15 mmHg, having no differences from the differences in diseases or BSA. Reduction of LV hypertrophy was achieved postoperatively (mean postoperative period of ten months), with the reduction rates of 26 +/- 19% in LV mass and 21 +/- 15% in LV cross-sectional area. No significant differences were found between the reduction rates and the differences in the patients' diseases or BSA. These results indicate that, following the implantation of SJM19, LV hypertrophy was reduced in patients with AR as well as with AS, when their BSA values were less than 1.6 m2. However, limited use is recommended because the increase in pressure gradient during exercise cannot be ignored.

Adult↗
PubMed1995

[A case of Ebstein's anomaly treated by tricuspid valve replacement].

A 8-year-old girl with Ebstein's anomaly was operated on because of progressive heart failure caused by severe tricuspid regurgitation. At the operation, the tricuspid leaflets were found to be destroyed, and the annulus was very enlarged. The enlarged true tricuspid annulus was constricted using the DeVega method, and the tricuspid valve was replaced on the true annulus using a porcine valve. To avoid injury to the auriculoventricular bundle, the suture line was shifted to the false annulus at the portion close to the course of His' bundle. Postoperative course was uneventful in satisfactory condition. The role of valve replacement in the treatment of Ebstein's anomaly of the tricuspid valve is not only to improve valve formation, but also to secure the function of the right ventricle. It is ideal to replace the tricuspid valve on the true annulus provided that the injury to the His' bundle is safely avoided.

Child↗
PubMed1995

[Simultaneous operations for both the repair of the aortic arch aneurysm and repeated CABG].

A 73-year-old female complaining of left thoracic pain was referred to our hospital. In 1988, she had the first CABG of the left circumflex coronary artery (CX) and right coronary artery. On admission in April 1994, chest X-ray and CT scan revealed a saccular aortic aneurysm, 5 x 5 cm in size, extending to the distal to the left subclavian artery. Coronary arteriography showed a patency of the CX graft, but 99% stenosis of the proximal left anterior descending branch (LAD) with delayed opacification. After the repeated median sternotomy, cardiac arrest was achieved with the aortic cross clamping and St. Thomas Hospital solution infusion. CABG to the LAD branch using a saphenous vein was accomplished. Following this, the replacement of the aortic aneurysmal lesion with a prosthetic graft was performed under the selective cerebral perfusion with deep hypothermia. Proximal anastomosis of the vein graft was completed during a rewarming period. The operation was performed without complications. Postoperative course was satisfactory except a few minor transient complications such as athelectasis of the left upper lobe and the intra-thoracic hematoma. After one month's hospitalization, she was discharged, and currently (six months postoperative) remains asymptomatic.

Aged↗
PubMed1995

[A surgical case of aortic dissection Stanford type A caused by blunt chest trauma--a report of a successful case].

A case of successfully repaired traumatic aortic dissection was reported. A 66-year-old woman with a blunt chest trauma from the car accident was transferred to our hospital. The radiological examination revealed Stanford type A aortic dissection without aortic regurgitation. Because of disturbance of consciousness and respiratory failure due to the associated blunt lung injury, she was treated in the intensive care unit, and, after 1 month, a graft replacement of the ascending aorta by using deep hypothermia with retrograde cerebral perfusion was carried out. The postoperative course was uneventful. Blunt chest trauma is very rare to cause aortic dissection, and the operative indication should be determined with careful consideration of the associated organ injuries.

Aortic Dissection↗
PubMed1995

[Use of epicardial leads for transvenous pacing lead insufficiency with venous thrombosis: a case report].

Recent progress in the electrode tip to prevent dislodgement makes difficult to extract itself in some patients. And when multiple leads are placed through a transvenous route, more frequent occurrence of venous thrombosis is easily suspected. We experienced a case of transvenous lead insufficiency with venous thrombosis. In this patient, two of unextractable transvenous leads were already placed, and venous thrombosis was detected by venography, so we implanted the new epicardial leads instead. In case of long-term placement of transvenous leads, especially when multiple, the possibility of venous thrombosis is ever thought, and the use of the extractable leads or anticoagulant therapy is recommended.

Aged↗
PubMed1994

A differential cloning procedure of complex genomic DNA fragments.

We have developed a differential cloning procedure designed for cloning of anonymous restriction DNA fragments whose molecular sizes differ between two genomic DNA preparations from higher organisms. The procedure, which was extensively revised from the original one, consists of several steps as summarized below. (i) Digestion of two DNA preparations (target and reference DNA) with the same restriction enzyme (4 base cutter). (ii) Biotinylation of target DNA and conversion of reference DNA to nonamplifiable form by terminal dephosphorylation. (iii) Electrophoresis of the two DNA preparations through a synthetic gel with a large excess of reference DNA as a competitor. (iv) In-gel alkaline dissociation of DNA, followed by reassociation (in-gel competitive reassociation). (v) Elution of DNA from the gel and PCR after adapter ligation and adsorption of DNA onto streptavidin-coated matrix. By repeating these steps, we attained substantial enrichment (approximately 10,000-fold) of DNA fragments which were originally present at one copy or less per complex mammalian genome. The details of the procedure and its unique characteristics in cloning of altered genomic DNA fragments, particularly from mammalian genome, are discussed.

Adenine Phosphoribosyltransferase↗
PubMed1994

Mitral valve replacement after atrioventricular canal repair in adults: report of three cases.

Three cases of adults who required a mitral valve replacement (MVR) following repair of an atrioventricular (AV) canal are presented herein. In adult patients with an AV canal, the deformity of the mitral valve is sometimes too advanced for adequate repair, and therefore, residual mitral regurgitation frequently causes intractable cardiac failure despite appropriate medical management. Thus, for adults with an AV canal associated with severe valvular deformities, MVR should be considered from the initial operation to obtain a significantly better outcome.

Adult↗
PubMed1994

Myocardial cytosolic calcium accumulation during ischemia/reperfusion: the effects of aging and cardioplegia.

Cytosolic calcium in the myocardium is rapidly accumulated during ischemia and has been correlated with the attenuation of functional recovery in the myocardium. The aged myocardium is more sensitive to ischemia and accumulates significantly more cytosolic calcium than either the newborn or the mature myocardium. Modification of the age-related propensity to increased cytosolic calcium accumulation may be achieved through the use of magnesium or potassium/magnesium cardioplegia. Improved postischemic ventricular function obtained with magnesium or potassium/magnesium cardioplegia may have important implications in the reduction of myocardial morbidity and mortality.

Adult↗
PubMed1994

Fura 2 determination of [Ca2+]i in isolated perfused heart using R wave-gated electromechanical shutters.

We describe a novel and relatively inexpensive spectrofluorescence system that supplies rapidly alternating wavelengths to either a standard cuvette or an isolated perfused heart. Its use is illustrated by determining changes in cytosolic intracellular Ca2+ concentration ([Ca2+]i) by using the Ca(2+)-sensitive fluorescent dye fura 2 in a rabbit heart preparation. The system uses two precision electromechanical shutters (capable of gating with respect to the electrocardiographic R wave for signal averaging) allowing alternate fura 2 excitation wavelengths (340 and 380 nm) without moving optical components and uses a fiber optic for conducting excitation and collecting epifluorescence. Sample recordings tracing the [Ca2+]i transient in an entire cardiac cycle and in capturing specific isolated regions (diastole and systole) of the cycle are presented. Limitations of this low-cost but easily implemented system are discussed.

Animals↗
PubMed1994

[Severe ascending aortic stenosis after one-stage repair of aortopulmonary window and interrupted aortic arch].

A 33-day-old girl was transferred to our hospital because of severe cyanosis and tachypnea. The diagnosis of aortopulmonary window and interrupted aortic arch was established by echocardiogram and cineangiocardiogram. Reconstruction of aortic arch by extended direct anastomosis and simple patch closure of aortopulmonary window were performed by means of profound hypothermia and circulatory arrest on 36 days of age. Her postoperative clinical course was uneventful, but at 2 months after operation, stenosis of the ascending aorta was noticed by echocardiographic examination. As her physical growth had been satisfactory, she was managed under close observation at outpatient clinic. At seven months after operations, she fell into progressive left heart failure, and emergency operation was carried out for the relief of stenosis of the ascending aorta, but she could not come off bypass. A stenosis of the ascending aorta is a fatal complication that may occur after one-stage repair of interrupted aortic arch with aortopulmonary window consisting of extended direct anastomosis and simple patch closure. We now consider that division of ascending aorta and pulmonary artery and repair of both of the defect is indispensable for the correction of aortopulmonary window, especially in neonate and small infant with this lesion associated with interrupted aortic arch.

Aorta↗
PubMed1994

[Redo valve replacement for primary tissue failure of bioprosthetic heart valve].

We evaluated long-term results of valve replacement with bioprosthesis in 59 patients. Freedom from primary tissue failure and reoperation declined more than seven years after valve replacement. Seven patients underwent repeat operations because of primary tissue failure in our hospital. Their ages ranged from 32 to 54 years, two cases were male and five were female. At repeat operation, mechanical valve prosthesis were implanted to mitral position in all seven patients, tricuspid annuloplasty was added in five patients, and aortic valve replacement was added in one patients. The New York Heart Association (NYHA) functional classifications were grade II for 1 patient, III for 1, and IV for 5 preoperatively. Five patients had severe pulmonary hypertension preoperatively, and three of them were died after operation. The removed bioprostheses showed tears, perforations or calcifications of cusps and commissural detachments.

Adolescent↗
PubMed1994

[Surgical repair of aortic dissection associated with compression of true lumen during retrograde perfusion--report of two cases].

Two cases of acute aortic dissection which developed compression of the true lumen due to retrograde perfusion during cardiopulmonary bypass were reported. In the first case, coronary reperfusion could not be achieved when the aortic cross-clamping was removed after Collins' method of aortic dissection. There was no blood flow from the true lumen through the aortic root while the false lumen was distended by the retrograde perfusion. After completion of antegrade perfusion through the arterial cannula inserted into the anastomosed site of the ascending aorta, coronary reperfusion was established and the heart beating could be thereby obtained. In the second case, the false lumen was gradually expanded, and the true lumen was completely obstructed by it. Reexpansion of the true lumen was achieved by initiation of antegrade perfusion through the cannula inserted into the graft replaced in the ascending aorta. Fortunately cerebral and cardiac complications were not found in both cases postoperatively. Compression of the true lumen is rare, but fatal complication that may occur during retrograde perfusion in surgical repair for aortic dissection of Stanford type A. Therefore, it is very important to replace the perfusion cannula in the true lumen of the reconstructed aorta for preventing insufficiency of coronary and cerebral circulation.

Acute Disease↗
PubMed1994

[Clinical study of optimal bypass flow for temporary bypass with centrifugal pump in surgical treatment of aneurysm of the descending thoracic aorta].

Since 1987, 33 patients were operated on for aneurysm of the descending thoracic aorta using temporary bypass with a heparin-coated centrifugal pump and heparin-coated tubes at Kobe University Hospital. Sixteen patients had true aneurysms of the descending thoracic aorta, 7 had thoraco-abdominal aneurysms and 10 had aortic dissection (DeBakey's type III). Heat exchanger and oxygenator were not included in the bypass circuit in all cases. Perfusion time was from 42 to 205 minutes (average 90 minutes). Left heart bypass was established with 1 mg/kg of systemic heparinization in 5, 0.5 mg/kg in 5, and 0 mg/kg in 23 cases. There were no complications such as perioperative embolism, acidosis, or hypothermia. During aortic cross-clamping, the arterial pressure of the lower extremity was maintained over 70 mmHg, but there was no relationship between the distal perfusion pressure and bypass flow. The urine output during temporary bypass was significantly related to the distal perfusion flow by centrifugal pump (r = 0.455, p < 0.01). Seven out of 23 patients who were bypassed under 40 ml/kg/min of distal perfusion flow showed transient renal dysfunction postoperatively, and two developed postoperative renal failure, while the other patients bypassed over 40 ml/kg/min of pump flow stayed in the normal range of the renal function, where there were statistically differences (p < 0.05). Postoperative paresis occurred in 2 patients who were also perfused under 40 ml/kg/min of bypass flow. Therefore, it is concluded that temporary bypass with centrifugal pump is a safe and well acceptable circulatory support in the surgical treatment of aneurysm of the descending aorta.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

[A case of acute aortic dissection with aortic regurgitation successfully treated by postoperative ECMO].

A case of acute aortic dissection (Stanford Type A) with severe aortic regurgitation successfully treated by postoperative ECMO was reported. The patient was 41-year-old man in shock condition and was transferred to Kobe University Hospital. Chest CT scan and echocardiogram revealed acute aortic dissection with severe aortic regurgitation. An emergent operation by Collins' method and resuspension of aortic valve were carefully performed. Consequent ECMO was necessitated because of postoperative left ventricular and respiratory failure. Thereby, ECMO using heparin-coated CBAS-MAXIMA membrane oxygenator, centrifugal pump, and tubes was established by arterial cannulation via the anastomotic site of the ascending aorta to prevent the obstruction of the aortic true lumen by the false lumen which may be enlarged by retrograde perfusion via the femoral artery. Left ventricular function and pulmonary function were improved after 6 hours and 20 minutes, thus ECMO was successfully weaned without any complications.

Adult↗
PubMed1994

[A successful surgical correction of the intermediate type of common atrioventricular orifice--report of an adult case].

A 42-year-old female was admitted to our hospital because of exertional dyspnea. Preoperative color Doppler echocardiogram revealed massive left to right shunt through the ostium primum defect, moderate mitral and tricuspid regurgitation, and trivial shunt via the small ventricular septal defect. Preoperative cardioangiogram also demonstrated goose neck deformity of the left ventricle. At the operation, the piece of atrioventricular valve fused on the summit of the small scooped ventricular defect was detected, and the total correction consisted of patch closure of the ostium primum defect and mitral and tricuspid valvuloplasty was performed. Postoperative course was uneventful. This is the first adult case reported in Japan who was operated on for the intermediate type of common atrioventricular orifice.

Adult↗