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Biomedical subjects

Yoshio Misawa

Publications and source records attributed to Yoshio Misawa.

At least 37 records · Page 2Linked to original sources

Modified Bentall operation in a patient with hemophilia A.

We detail a successful modified Bentall operation in a patient with hemophilia A. A 53-year-old man with mild hemophilia A and a history of few bleeding episodes was diagnosed with annuloaortic ectasia. Surgical repair was planned. Simple bolus infusions of factor VIII concentrate were given before and after cardiopulmonary bypass to achieve 100% blood levels and postoperatively every 12 hours for 7 days to maintain 50% levels. The patient received no transfusion other than 10 units of platelet concentrate. We used routine operative and cardiopulmonary bypass techniques. The patient recovered well postoperatively with no excessive bleeding despite warfarin therapy.

Aortic Aneurysm↗

When and how does nonstructural mechanical prosthetic heart valve dysfunction occur?

OBJECTIVE: We discuss the clinical aspects related to mechanical valve dysfunction based upon 20 years' experience of our cases. METHODS: Between January 1982 and December 2001, 21 patients underwent surgical interventions because of mechanical valve dysfunction. Thirteen men and 8 women (mean age 47 +/- 20, range 3-75 years-old), were included. RESULTS: Mitral valve dysfunction was observed in 12 patients. Prosthetic valve stenosis occurred in 6 patients between 2 and 224 months, and paravalvular leaks in 4 between 1 and 71 months after surgery. The other 2 patients suffered from hemolytic anemia with mild paravalvular leaks between 102 and 104 months after surgery. Aortic valve dysfunction was observed in 8 patients including 3 stenotic lesions between 48 and 97 months and 5 paravalvular leaks between 3 and 150 months after surgery. Tricuspid regurgitation was seen in 1 patient with a huge right atrium at 42 months after surgery. Early death was seen in 1 patient. Late death occurred in 1 patient, 17 years after operation. Survival, including early death, was 95.2%, at 10 and 15 years. One valve-related complication of bioprosthetic valve endocarditis at the mitral and tricuspid positions occurred 12 years after a reoperation. The freedom from complications was 95.2% at 10 years, and 76.2% at 15 years. CONCLUSIONS: Paravalvular leaks without overt endocarditis had latency periods of up to 12 years, and pannus formation was observed 20 years after surgery. Early and late clinical results after surgery for mechanical valve dysfunction were excellent.

Adolescent↗

Isolated traumatic vertebral pseudoaneurysm: report of a case.

We report a case of isolated traumatic pseudoaneurysm of the vertebral artery in a 20-year-old man who suffered blunt injury to the left foreneck and arm in a traffic accident. A chest computed tomography (CT) scan on admission showed an upper mediastinal hematoma, but the patient's vital signs were stable. A CT scan of the head and neck showed a cerebral mass, and an elective cerebral four-vessel angiography was performed, which revealed a pseudoaneurysm in the proximal portion of the left vertebral artery. At surgery, about 2 cm of the left vertebral artery was found to be lacerated, and suture ligation was done on each side of the laceration. Postoperative intravenous digital subtraction angiography showed an intact right vertebral artery with no residual pseudoaneurysm. There were no neurological complications and the patient was discharged on the 16th postoperative day.

Adult↗

A repair of funnel chest without sternal dissection in aortic root replacement.

A 46-year-old man with Marfan syndrome was admitted for repair of annuloaortic etasia and funnel chest. Before median sternotomy, seven transverse skin incisions were made for resection of deformed ribs. The convex portions at the costochondral junctions of the right 4 approximately 7th and left 5 approximately 7th ribs were removed. Thereafter, the conventional median sternotomy was safely performed. Aortic root was replaced. After weaning from the cardiopulmonary bypass, the redundant distal end of the sternum was resected, fractured sites of the concave sternum were straightened and secured with wire fixation, and the split sternum was sutured with wires in an ordinary fashion.

Aorta↗

Paravalvular leakage causing hemolytic anemia at 8-9 years after mitral valve replacement.

We report two similar cases of women, aged 52 and 71 years, who developed shortness of breath or easy fatigability at 8-9 years after mitral valve replacement of the mitral valve in each patient, the echocardiographic study revealed paravalvular leakage. Previous examination before the appearance of symptoms had revealed a well-functioned prosthetic valve, and no hematological abnormality had been detected. The hemoglobin levels at admission were 6.4 and 6.6 g/dl, and their serum lactate dehydrogenase levels were 5218 and 4608 mU/ml. Each successfully underwent another valve replacement, and after surgery, the hemolytic anemia and the symptoms disappeared.

Aged↗

Successful surgical treatment of chronic traumatic thoracic aneurysm in two patients.

We successfully treated two patients with chronic traumatic aneurysm of the thoracic aorta. The first, a 40-year-old man involved in an automobile accident 24 years earlier, was treated by thoracic aorta graft replacement via left thoracotomy under femoro-femoral partial bypass. The second, a 57-year-old man with a 3-month history of hoarseness who had suffered blunt chest trauma 17 years earlier, was treated similarly. Both had a calcified pseudoaneurysm at the isthmus of the descending aorta, but neither had atherosclerosis other than at the aneurysm site. They have done well after surgery. We believe chronic traumatic thoracic aneurysm at the aortic isthmus should be treated surgically soon after diagnosis because elective surgery presents low risk of morbidity and mortality.

Adult↗

Management of anomalous right coronary arteries encountered during aortic valve surgery.

We experienced three cases with anomalous right coronary arteries during aortic valve surgery. By rotating a Freestyle bioprosthesis by a subcoronary technique, the anomalous artery was secured in one patient. The anomalous artery was injured during the routine aortotomy incision in another patient; a saphenous vein graft was interposed between the ascending aorta and the separated artery. In the third patient, a subannular prosthetic valve was chosen to avoid obstructing the anomalous orifice.

Aged↗

Single-center experience with the bicarbon bileaflet prosthetic heart valve in Japan.

We analyzed midterm results using the Bicarbon valve in a single center. Forty-four patients had aortic valve replacement (AVR), 48 had mitral valve replacement (MVR), and 13 had both aortic and mitral valve replacement (DVR). The mean age of the 105 patients was 61.2 +/- 11.3 years. The mean follow-up was 1.8 +/- 1.1 years with a cumulative follow-up of 188 patient-years. There were 5 early deaths (4.7%: 4 in the AVR group and 1 in the MVR group) and 5 late deaths (2.7% per patient-year: 3 malignancy, 1 cerebral hemorrhage, 1 myocardial infarction). Survival at 3 years was 91 +/- 4% in the AVR group, 92 +/- 5% in the MVR group, and 66 +/- 23% in the DVR group. The linearized incidence of thromboembolic complications, hemorrhagic complications, and paravalvular leaks in all patients was 1.06 +/- 2.34%, 1.60 +/- 2.53%, and 0.53 +/- 2.22% per patient-year, respectively. No other complications were observed. In conclusion, the Bicarbon prosthetic heart valve has shown excellent clinical results associated with a low incidence of valve-related complications.

Aged↗