Yoshiki Takahashi

Awake partial sternotomy pacemaker implantation under thoracic epidural anesthesia

An 82-year-old man with symptomatic bradycardia had infective endocarditis with tricuspid vegetation. The patient also had severe obstructive pulmonary disease, and endotracheal general anesthesia was contraindicated. Under satisfactory epidural anesthesia with catheterization at the T5/6 level, lower partial sternotomy was performed, and dual pacing electrodes were placed on the heart. Throughout the surgery, spontaneous breathing was maintained with a sufficient level of oxygenation. The postoperative course was uneventful. Although awake cardiac surgery under thoracic epidural anesthesia is challenging, this less invasive technique was useful for epicardial pacemaker implantation in this patient with severe pulmonary dysfunction.

The Influence of a Heparin‐Coated Oxygenator During Cardiopulmonary Bypass on Postoperative Lung Oxygenation Capacity in Pediatric Patients with Congenital Heart Anomalies

Abstract Background: Cardiopulmonary bypass (CPB) causes an inflammatory response and remarkably depresses the oxygenation capacity of the lung in pediatric patients with pulmonary hypertension. Although a heparin‐coated circuit is more biocompatible than an uncoated circuit, the beneficial effect of a heparin‐coated circuit on the postoperative lung function in the pediatric patients remains unknown. Methods: Sixty patients younger than 3‐years‐old undergoing heart operations for ventricular septal defect were divided into three groups: group I = children (n = 11) without pulmonary hypertension who underwent CPB with an uncoated oxygenator; group II = children (n = 32) with pulmonary hypertension who underwent CPB with an uncoated oxygenator; and group III = children (n = 17) with pulmonary hypertension who underwent CPB with a heparin‐coated oxygenator. A respiratory index (RI) was used to assess the oxygenation capacity of the lung. Results: RI in group II was significantly higher than in group I and intubation time in group II was significantly longer than in group I. There was a positive correlation between preoperative pulmonary‐systemic blood pressure ratio and RI at 3 hours post‐CPB. Three and six hours post‐CPB, RI in group III was significantly lower than in group II, but there was no significant difference in RI between both groups at 12 hours post‐CPB. Conclusions: Pulmonary hypertensive pediatric patients were vulnerable to postperfusion lung injury. Beneficial effects of a heparin‐coated oxygenator in a CPB circuit was limited to the early hours post‐CPB and the postoperative clinical course was not modified by the heparin‐coating of a membrane oxygenator.

Effects of spiraprilat, an angiotensin-converting enzyme inhibitor, on anesthetized dogs in a new model of acute left ventricular failure.

Summary Spiraprilat, a new angiotensin-converting enzyme (ACE) inhibitor, was compared with enalaprilat for its ability to improve left ventricular (LV) function and metabolism in anesthetized open-chest dogs with a new model of acute LV failure (ALVF) induced by embolization of the left coronary artery with 50 μm plastic micro-spheres followed by intravenous (i.v.) infusion of methoxamine. With this procedure, LV end-diastolic pressure (LVEDP) increased from 4.2 ± 0.7 to 12.8 ± 1.3 mm Hg and remained at ±12 mm Hg throughout the experiment. Cardiac output (CO) decreased from 1.25 ± 0.12 to 0.79 ± 0.06 and 0.55 ± 0.02 L/min at 30 and 90 min after meth-oxamine infusion, respectively. L±dP/dtmax and dP/dt/P decreased, while total peripheral resistance (TPR) increased. These hemodynamic changes indicated establishment of stable ALVF of a moderate degree. More over, decreases in myocardial lactate consumption and contents of creatine phosphate in the myocardium indicated the existence of moderate ischemia. The new ACE inhibitor, spiraprilat, as well as enalaprilat (30 μg/kg i.v.) effectively decreased mean aortic pressure (30%), LVEDP (20%), and TPR (30%) and increased stroke volume (SV) CO, and dP/dt/P. Both agents decreased myocardial oxygen consumption (20%) and caused a significant increase in myocardial creatine phosphate contents. These data indicate that the beneficial effects of both inhibitors extended not only to LV function but also to myocardial energy metabolism in ALVF.

A case of rectal obstruction caused by bilateral internal iliac artery aneurysms.

In this article, we report a rare case of rectal obstruction caused by bilateral internal iliac artery aneurysms that required open surgical repair. A 73-year-old man was admitted to our hospital complaining of abdominal pain and persistent constipation for >1 month. Computed tomography demonstrated bilateral internal iliac artery aneurysms, 5.0 and 7.0 cm each in diameter, which occupied the intrapelvic space. An urgent surgery was performed to reduce the volume of the aneurysms and release the obstructed rectum. The postoperative course was uneventful, in which he had good evacuation. Aneurysms in the iliac region can be a good indication for the use of newly developed endovascular devices; however, open surgery should be considered without delay to avoid ileus or subileus symptoms when the aneurysms cause space-occupying complications.

Cardiac myxosarcoma with thoracic spinal metastasis.

Echocardiography revealed a left atrial tumor in a 59-year-old man with back pain that concurrently worsened with left foot drop and loss of the left ankle reflex soon after admission to our hospital. Magnetic resonance imaging of the spine revealed an epidural tumor extending from Th5 with spinal cord compression. The patient was immediately treated by emergency Th4–5 laminectomy and epidural decompression. One month later, a cardiac tumor excised via the left atrial approach was histopathologically diagnosed as myxosarcoma, and the Th5 tumor was consistent with this finding. This is the first report to describe spinal metastasis of cardiac myxosarcoma.

Array calibration techniques for DOA estimation with arbitrary array using root-MUSIC algorithm

In recent years, high-resolution Direction of Arrival (DOA) estimation with an array antenna has become indispensable for various applications such as microwave-power transmission and reception. In actual measurement, however, DOA estimation accuracy is deteriorated by many error factors. Furthermore, almost all the computationally efficient DOA estimation algorithm can apply to the uniform arrays. In this report, we proposed the calibration method for Root-MUSIC which is low computationally efficient method with an arbitrary array.

Transcatheter Embolization of Aortopulmonary Collateral Arteries Prior to Intracardiac Repair in Patients with Congenital Heart Disease.

心内修復術前に側副血行路カテーテル塞栓術 (TAE) を施行した先天性チアノーゼ性心疾患7例について検討した. 側副血管は25本 (1症例当り1～5本, 平均3.6本) で, 気管支動脈は7本中7本(100%), 肋間動脈は18本中17本 (94%) の完全閉塞が得られ, 全体では側副血管の25本のうち24本 (96%) の塞栓に成功した. 合併症は1例で金属コイルの大腿動脈への脱落を認め, 外科的に摘出をした. TAE後の5例で体動時のチアノーゼの増強や呼吸困難等の自覚症状が出現し, 1例では低酸素血症増強のため緊急に心内修復術が必要となり, 2例で一過性の発熱が認められた. TAE後, 労作時のチアノーゼ増強等の自覚症状, 更には低酸素血症の危険があることから心内修復術直前の施行が適切と思われた.

Effects of Angiotensin Converting Enzyme Inhibitors on Acute Heart Failure Induced in the Anesthetized Dog with Microsphere Injection

To study the effects of angiotensin converting enzyme (ACE) inhibitors on myocardial energy metabolism together with their effects on hemodynamic parameters in acute left ventricular failure (ALVF), a new model of ALVF was developed by embolization of the left coronary artery with 50 urn plastic microspheres followed by intravenous infusion of methoxamine. With this procedure the left ventricular end-diastolic pressure (EDP) rose from 4.2 ± 0.7 mmHg to 12.8 ± 1.3mmHg and remained at around 12mmHg during the entire course of the experiment. Cardiac output (CO) decreased from 1.25 ± 0.121/min to 0.79 ± 0.061/min and 0.55 ± 0.021/min at 30 and 90 min after methoxamine, respectively. Left ventricular max dP/dt and dP/dt/P decreased, while total peripheral resistance (TPR) increased. Creatine phosphate contents in the myocardium decreased.