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Biomedical subjects

Shigeru Hosaka

Publications and source records attributed to Shigeru Hosaka.

7 recordsLinked to original sources

Mycotic aneurysm of the right coronary artery.

Mycotic embolism in patients with infective endocarditis is not uncommon, however, mycotic aneurysm of a coronary artery is very rare. We report the case of a 62-year-old woman with mitral valve endocarditis complicated by mycotic aneurysm of the right coronary artery. Mitral valve replacement and resection of the mycotic aneurysm with coronary artery bypass were performed.

Aneurysm, Infected↗

Nonocclusive mesenteric ischemia after cardiopulmonary bypass.

Nonocclusive mesenteric ischemia (NOMI) is a rare abdominal pathology caused by mucosal hypoperfusion without actual obstruction to the mesenteric arteries. We present a case of NOMI after a cardiopulmonary bypass operation. The patient was a 79-year-old woman with a history of hypertension and diabetes mellitus. A coronary bypass operation was performed with stable hemodynamic conditions, and continuous venovenous hemodialysis was performed on the second postoperative day because of renal insufficiency. After 24 h of hemodialysis, the hematocrit level increased from 29.1% to 36.1%. The patient had some vague abdominal pain on the third postoperative day with abnormal laboratory values: leukocytes 17.10 x 10(3)/microl, creatine kinase 1085 U/l, glutamic-oxyloacetic transaminase 6188 U/l, and lactate dehydrogenase 8695 U/l. Selective angiography showed diffuse stenosis of the superior mesenteric artery (SMA) without any occlusive findings on the major branches; the patient was therefore diagnosed with NOMI. An infusion of urokinase and prostaglandin E1 was started; however, disseminated intravascular coagulopathy had developed and the patient died on the 21st postoperative day as a result of multiple organ failure. The autopsy demonstrated extensive necrosis and hemorrhage in the small intestine without any occlusive findings on the major branches of the SMA.

Aged↗

Critical values of hematocrit and mixed venous oxygen saturation as parameters for a safe cardiopulmonary bypass.

OBJECTIVE: Mixed venous oxygen saturation (SvO2) is high despite a low hematocrit implies that the relationship between oxygen demand and supply is in a safe state. This study was sought to determine the critical values for hematocrit and SvO2 for safe cardiopulmonary bypass. METHODS: Study 1: To evaluate the limit of hemodilution without cardiopulmonary bypass, normovolemic hemodilution with Dextran 40 (10%) was performed in 14 rabbits. SvO2 was monitored from the right atrium, and the hemodynamic parameters were recorded continuously. Study 2: To determine the critical values for hematocrit and SvO2 during cardiopulmonary bypass, normothermic and hypothermic cardiopulmonary bypass were performed in 13 rabbits and hemodynamic parameters were corrected. RESULTS: Study 1: The heart rate decreased to unsafe levels abruptly, when the SvO2 was < or = 43% or the hematocrit was < or = 10%. The lactate concentration increased when the SvO2 was < or = 46% or the hematocrit was < or = 12%. Study 2: When the hematocrit was < or = 12%, the SvO2 decreased gradually. Even when weaning was possible, the animals with a hematocrit < or = 12% collapsed hemodynamically within 40 minutes after cardiopulmonary bypass. Most of the animals could not be weaned from cardiopulmonary bypass during either normothermic or hypothermic cardiopulmonary bypass when the SvO2 was < or = 46%. CONCLUSIONS: Continuous monitoring of hematocrit and SvO2 provides evidence-based guidelines for safe cardiopulmonary bypass. The lower limits of critical range for a safer cardiopulmonary bypass are hematocrit of 12% and SvO2 of 46%.

Animals↗

Partial left ventriculectomy in pediatric end-stage dilated cardiomyopathy.

OBJECTIVE: Although a recent survey on pediatric cardiomyopathy in Japan showed that 48% of patients died despite the medical treatment, pediatric cardiac transplantation is not legal in Japan. We determined the feasibility of partial left ventriculectomy as an alternative to end-stage dilated cardiomyopathy. METHOD: We retrospective analyzed partial left ventriculectomy in 4 pediatric patients with end-stage dilated cardiomyopathy. RESULTS: In case 1, an 8-month-old girl underwent semiemergency partial left ventriculectomy. Her ejection fraction increased from 10% to 25%, and her condition improved initially, but she developed heart failure and underwent cardiac transplantation 6 months later in the US. In case 2, a 3-year-old boy developed severe heart failure 2 months after ventricular septal defect repair. Intensive medical therapy failed, so partial left ventriculectomy was done, which increased his ejection fraction from 15% to 35%. His condition is stable 35 months after surgery. In case 3, a 2-year-old girl with a chromosomal anomaly undergoing ventricular septal defect repair developed progressive heart failure 1 year later. Despite emergency partial left ventriculectomy, she died of hemoptysis 2 weeks postoperatively. In case 4, a 2-year-old girl developing progressive heart failure unresponsive to medical therapy after 10 months underwent elective partial left ventriculectomy and remains in stable condition 18 months postoperatively. CONCLUSION: Partial left ventriculectomy is appropriate for selected patients with end-stage dilated cardiomyopathy if medical therapy is not effective and heart transplantation is not possible.

Cardiac Surgical Procedures↗

Indications for partial left ventriculectomy in pediatric dilated cardiomyopathy.

The purpose of this study was to define the role and indications of partial left ventriculectomy (PLV) in children with end-stage dilated cardiomyopathy (DCM). Clinical data were collected by retrospective chart review of children with DCM who were treated from 1997 to 2000. Four patients underwent PLV (PLV group) and 5 patients were managed without PLV (non-PLV group). In the PLV group, 2 patients are well 18 and 35 months postoperatively. One infant survived 6 months and then successfully underwent heart transplantation, and the other child died of hemoptysis 2 weeks postoperatively. Factors affecting outcome were preoperative status, in particular whether surgery was performed urgently or electively. In the non-PLV group, 4 patients were well controlled by medical treatment and 1 infant underwent mitral valve replacement for severe mitral regurgitation. The cardiothoracic ratio ranged from 72% to 76% in the PLV group and from 45% to 60% in the non-PLV group. The percentage of the expected left ventricular diastolic dimension ranged from 184% to 218% in the PLV group and from 109% to 163% in the non-PLV group. Ejection fractions in the PLV group were from 10% to 22% and from 36% to 56% in the non-PLV group. The serum brain natriuretic peptide concentration was above 1,200 pg/ml in the PLV group and below 168 pg/ml in the non-PLV group. In conclusion, PLV is indicated for selected children with end-stage DCM, and is most appropriate when medical therapy is not effective and heart transplantation is unavailable.

Adolescent↗

Accessory hepatic vein complicating extra-cardiac total cavopulmonary connection.

We encountered unexpected, severe hypoxia after the right heart bypass operation in a patient with isomerism. A 2-year-old girl with polysplenia had a complex cardiac anomaly consisting of a single atrium, single ventricle, pulmonary stenosis, absence of the right superior vena cava, hemiazygos continuation of the left inferior vena cava, and d-malposition of the great arteries. After a total cavopulmonary shunt, we performed an extra-cardiac total cavo-pulmonary connection with a 14 mm tube graft. The postoperative course was complicated by severe hypoxia. Angiography performed 20 days after the operation showed that contrast medium in the conduit poured into the hepatic vein, and through the intrahepatic communications, it passed into a left-sided accessory hepatic vein, which was connected directly to the left side of the aspect of the atrium. As the intrahepatic communication was adequate, we ligated the accessory hepatic vein within the pericardial cavity. The SpO2 returned to normal and no hepatic dysfunction was detected. We conclude that surgeons performing extra-cardiac total cavopulmonary connection need to pay closer attention to the possibility that an accessory hepatic vein might exist.

Child, Preschool↗