Biomedical subjects

Hitoshi Yaku

Publications and source records attributed to Hitoshi Yaku.

29 records · Page 2Linked to original sources

PubMed2005

Strategies for a schizophrenic patient who required aortic valve replacement.

An aortic valve was replaced in a schizophrenic patient with violent behaviour. The usual protocol was altered and strategies to prevent accidents before and after surgery were devised. Minimally invasive surgery, administering sedation during the critical recovery period, and therapeutic use of communication as a psychological intervention were effective strategies. The patient recovered well and was discharged on day 14 after surgery.

Aortic Valve↗

PubMed2004

A novel technique for removal of permanent pacemaker leads.

We removed from 4 patients pacemaker leads that had migrated or become infected. Case 1: A 62-year-old man developed uncontrollable infection of the pacing leads. Case 2: A 78-year-old man, whose infected pacemaker was removed, had a second one implanted in the contralateral side; the pacing lead infection from the first procedure, however, was uncontrollable. Case 3: A 56-year-old woman presented with dyspnea and hepatomegaly subsequent to the second implantation of a pacemaker; the pacing leads from the first procedure caused severe stenosis in both the superior and inferior vena cavae. Case 4: A 60-year-old woman had a ruptured and migrated pacing lead in the right ventricle. We operated using a cardiopulmonary bypass and a specially designed plastic tube for removal of the leads. Although Case 2 required reconstruction of the vena cavae, all patients recovered. When removal of pacing leads is necessary, it should be done as soon as possible with cardiopulmonary bypass.

Aged↗

PubMed2004

Partial translocation for repair of left ventricular rupture after mitral valve replacement.

A new partial translocation technique to repair left ventricular rupture after mitral valve replacement and reimplant a mitral prosthesis is described. We repaired a tear from the interior by using mattress stitches buttressed with strips of Dacron felt, constructed a new annulus with a crescent-shaped piece of bovine pericardium on the left atrial wall above the repaired mitral annulus, and implanted a new prosthesis by using the newly constructed mitral annulus. We consider avoidance of mechanical stress by the prosthesis on the repaired site crucial to a successful outcome, and this new method is useful.

Aged↗

PubMed2004

Left ventricular outflow tract obstruction due to anomalous insertion of papillary muscle.

A 56-year-old man who complained of quadrantic hemianopsia was admitted to determine its etiology. Cerebral angiography revealed no organic stenosis. Echocardiography showed clear direct continuity between a hypertrophied anterolateral papillary muscle and the anterior mitral leaflet, and the left ventricular (LV) outflow tract (LVOT) was narrowed by the presence of an accessory papillary muscle. The LVOT obstruction caused an intra-LV pressure overload that resulted in LV concentric hypertrophy. Arrhythmia, such as paroxysmal atrial fibrillation (PAF), was thought to have caused a cerebral embolism. Mitral valve replacement (MVR), septal myectomy, and myectomy of the abnormal papillary muscle were performed, and complete release of the LVOT obstruction was accomplished. Anomalous insertion of papillary muscle is a rare cause of LVOT obstruction. Echocardiography was useful in identifying the papillary muscle malformation, and surgery was completely curative.

Cerebral Infarction↗

PubMed2003

Impact of myocardial angiotensin-converting enzyme activity on coronary vascular resistance and serum brain natriuretic peptide concentration in coronary bypass surgery.

Angiotensin-converting enzyme (ACE) inhibitors have cardioprotective effects in animals, but whether that occurs in humans is still controversial. The effect of myocardial ACE activity on coronary vascular resistance during coronary artery bypass surgery and on serum brain natriuretic peptide (BNP) concentration after surgery was studied in myocardial tissue sampled from the right atrium of patients during cardiac surgery (n=20). Tissue enzyme activity (nmol/min per mg protein) was measured using a photometric technique, and the flow rate and pressure upon antegrade infusion of a crystalloid cardioplegic solution was measured for calculating the coronary vascular resistance (mmHg. ml(-1). min(-1)). Serum BNP concentration (pg/ml) was measured on days 0 and 5 after the surgery. Linear regression between tissue ACE activity and coronary vascular resistance (y = 0.46x + 0.56, r=0.85) as well as serum BNP concentration on days 0 (y = 129x + 30, r=0.59) and 5 (y = 347x + 180, r=0.73) after the surgery was significant (x: ACE activity; y: coronary vascular resistance/serum BNP concentration). The results indicate that inhibition of myocardial ACE activity might improve coronary circulation during surgery and hence, cardiac function after surgery.

Aged↗

PubMed2003

Off-pump coronary artery bypass grafting in a patient with chronic myelomonocytic leukemia.

We report the case of a 71-year-old man with chronic myelomonocytic leukemia who developed cardiogenic shock twice due to a stenosis of the left main trunk of the coronary artery. We performed coronary artery bypass grafting to the left anterior descending artery with the left internal thoracic artery without using a cardiopulmonary bypass. The patient had no infection, leukemic transformation, or cardiac event after the surgery. Off-pump coronary artery bypass grafting is safe and useful for high risk patients, such as those with leukemia.

Aged↗

PubMed2003

Papillary fibroelastoma of the aortic valve: evaluation with transesophageal echocardiography and magnetic resonance imaging.

A 74-year-old Japanese male was admitted to hospital with episodes of chest pain. Cross-sectional echocardiography showed a mobile mass adherent to the noncoronary cusp of the aortic valve. We employed transesophageal echocardiography and magnetic resonance imaging to evaluate the mass. Based on the findings, a papillary fibroelastoma of the aortic valve was suspected. To avoid systemic embolization, urgent surgery was performed. The histopathologic diagnosis was papillary fibroelastoma. When a tumor of the aortic valve exists, these examinations are useful in detecting and characterizing the tumor for optimal treatment.

Aged↗

PubMed2002

An operative case of inferior vena cava stenosis due to fibrosis around permanent pacemaker leads.

A 56-year-old woman presented with general fatigue, dyspnea on exercise, and hepatomegaly subsequent to secondary implantation of a pacemaker. On admission, cardiac echo examination showed tricuspid valve regurgitation due to a migrated looped lead. At surgery, there was evidence of severe stenosis at both orifices of the superior and inferior vena cavae due to fibrous tissue around the leads. We removed the fibrous tissue, pacing leads, and generator. New leads were anchored onto the epicardium and a generator was inserted under the rectus muscle. The postoperative course was satisfactory and the symptoms disappeared.

Electrodes, Implanted↗

PubMedDate not supplied

Identification of exercise-induced left ventricular systolic and diastolic dysfunction using gated SPECT in patients with coronary artery disease.

BACKGROUND: We investigated whether poststress left ventricular dysfunction in patients with coronary artery disease may be confirmed at 30 minutes after exercise using newly modified quantitative gated single photon emission computed tomography (QGS) software that can evaluate systolic and diastolic function. METHODS AND RESULTS: In this study 28 control subjects, 26 patients with angina pectoris (AP), and 27 patients with old myocardial infarction (MI) who had undergone revascularization were included. Same-day exercise/rest gated technetium 99m tetrofosmin single photon emission computed tomography was performed. QGS was used with a temporal resolution of 32 frames per R-R interval, and a left ventricular volume curve was reconstructed. From the fitted volume curve and its first derivative curve, we derived the ejection fraction (EF), peak ejection rate (PER), peak filling rate (PFR), and time to PFR (TPFR). In patients with AP and MI, the values for EF, PER, and PFR were lower after stress than at rest. TPFR was significantly prolonged in patients with MI after stress. In control subjects, EF, PER, PFR, and TPFR were not changed. CONCLUSIONS: Modified QGS software successfully indicated the changes in systolic and diastolic function. In patients with AP and MI, poststress systolic and diastolic dysfunction was identified 30 minutes after exercise.

Angina Pectoris↗

PubMedDate not supplied

Hemodiafiltration during cardiac surgery in patients on chronic hemodialysis.

BACKGROUND: We have developed a hemodiafiltration (HDF) protocol used during cardiac surgery to preserve fluid and electrolyte balance and prevent postoperative bleeding in patients on chronic hemodialysis. This retrospective study examined the operative results associated with our new protocol. METHODS: The study included 33 consecutive patients on long-term hemodialysis who underwent cardiac surgery at our hospital between January 2001 and April 2005, including off-pump coronary artery bypass grafting (CABG) in 19 patients. Vascular access was achieved via a 12-French double-lumen catheter inserted into the left femoral vein under general anesthesia, and HDF begun when the operation was started. After completion of cardiopulmonary bypass or, in patients who underwent off-pump CABG, after the distal anastomoses were completed, HDF was continued until target hematocrit between 30% and 35%, central venous pressure between 3 and 5 mmHg, and serum potassium concentration between 3.0 and 3.5 mEq/L were reached. The chest was closed after confirmation of hemostasis. RESULTS: There was no in-hospital death. Three patients were extubated in the operating room. There were no postoperative wound infection, mediastinitis, respiratory tract infection, or hemorrhage. The patients were discharged at a mean of 15.6 days after operation. CONCLUSIONS: These results suggest that intraoperative HDF lowers postoperative morbidity and mortality in chronic dialysis patients. Other advantages include early extubation and ambulation, and a shortened hospitalization.

Adult↗

PubMedDate not supplied

Mobile stenosis in a left internal mammary artery graft: a case report.

The authors report a case of percutaneous transluminal angioplasty (PTA) with coronary stent for stenosis in a left internal mammary artery (IMA) graft, which led to newly developed stenosis at both sides of the stent in the IMA graft. The intravascular ultrasound (IVUS) revealed that the stenotic lesion consisted of intramural hematoma, which had shifted owing to the stent deployment. They suggest that the cause of stenotic lesions in IMA grafts at the early postoperative period is luminal compression by intramural hematoma, which can be visualized by use of IVUS. The strategy of PTA for IMA grafts performed at the early postoperative period should include consideration for hematoma shift.

Aged, 80 and over↗