Surgical treatment of traumatic rupture of the normal aortic valve.

Blunt trauma followed by aortic valvular insufficiency is a rare occurence. In one case, a male high-school student who had sustained a non-penetrative chest injury suffered from aortic regurgitation resulting from the rupture of the normal aortic valve. A sizable tear in the non-coronary cusp caused aortic insufficiency. The case was treated successfully by surgical replacement of the aortic valve with a No. 21 SJM prosthesis.

[A case report of active infectious endocarditis caused by MRSA with chronic renal failure].

A 62-year-old female, who had chronic renal failure treated by HD, was admitted to our hospital with fever. MRSA was identified by blood culture examination. Echocardiography revealed vegetations attached to the mitral valve. Mitral abscess was detected during operation. Mitral valve replacement was performed. We used ECUM and HD for the chronic renal failure during peri- and postoperative days. The postoperative clinical course was uneventful.

[A case of mitral valve aneurysm associated with infective endocarditis].

A case of mitral valve aneurysm associated with infective endocarditis is reported. The patient is a sixty-four year old male suffering from shortness of breath under slight exertion. He has been febrile since receiving dental treatment five months ago. The patient came to the hospital due to a continuous fever above 39 degrees C. Hematological studies suggested inflammation, and an echocardiogram revealed moderate dilatation of the left atrium, mild MR, and moderate AR. At the time of the operation, a protuberant lesion, shaped like a dome and having a size of 10 x 12 mm in diameter was found at the anterior mitral leaflet toward the left atrium. The resected specimen of the saccular lesion had a smooth surface, and the ceiling of the aneurysm was extremely thin. Microscopic study showed that the inner cavity of the lesion was covered by endothelial cells. In addition, there was granulomatous degeneration with neo-vascularization. The inferior surface of the resected valve tissue and chorda was characterized by active inflammation associated with the assembly of neutrophils and colony formation of gram-positive cocci. It was concluded that the mitral valve aneurysm was caused by weakened tissue of the anterior mitral leaflet due to sibilant inflammatory change, which resulted in protuberance of the leaflet toward the left atrium caused by left ventricular pressure.

Microcomputer-based automatic regulation of extracorporeal circulation: a trial for the application of fuzzy inference.

Since its establishment many researchers have been trying to automate the process of extracorporeal circulation (ECC). We developed a preliminary experimental model of an automatic regulatory system for ECC. The purpose of the system was to regulate basic hemodynamic parameters such as pump flow and withdrawal blood volume. It was divided into three main components: data sampling unit, central processing unit, and controlling unit. Based on this model we were able to achieve autoregulation of ECC using minimum configuration; however, the system lacked smoothness. This was partly because it was based on a "static" regulation system which used conditional statements having multiple parameters. In this study, we applied fuzzy logic to the former model to achieve more accurate and reliable regulation. We report experimental results for the new system and compare the data between clinical circulation in 13 infants (mean body weight, 13.32 +/- 5.99 kg) and experimental regulation in 7 mongrel dogs (mean body weight, 11.9 +/- 2.53 kg). The comparative study revealed no statistical difference between the two groups. This result suggests that the automatic regulation of ECC may be an alternative to manual operation by a professional perfusionist in the near future.

Correction of tetralogy of Fallot accompanied by malignant hyperthermia. Case report.

A 5-year-old girl susceptible to malignant hyperthermia underwent total repair of tetralogy of Fallot. The initial operation was canceled because of abrupt hyperthermia and metabolic acidosis of unknown cause. Dantrolene was given orally as preoperative treatment and administered intermittently during surgery. Postoperative hyperthermic crisis was successfully treated with intravenous dantrolene combined with surface cooling, gastric tube irrigation with cold saline, and alcohol vaporization.

Successful surgical treatment of subaortic stenosis caused by an accessory mitral valve.

A 22-month-old boy with subaortic stenosis was found to have relatively mature mitral valve tissue beneath the aortic valve, associated with a hypertrophic and prominent interventricular septum. This tissue caused obstruction of the left ventricular outflow tract and resulted in a pressure gradient of 70 mmHg between the aorta and the left ventricle. Surgical treatment was successfully performed to excise the tissue and part of the hypertrophic ventricular septum. Results of microscopic examination of the resected specimen are shown and discussed.

[A successful surgical case report of subaortic stenosis due to accessory mitral valve tissue associated with partial ventricular septal hypertrophy].

One-year- and ten-month-old male infant with subaortic stenosis due to the accessory mitral valve tissue associated with asymmetrical myocardial hypertrophy was treated successfully with surgery. Preoperative diagnosis of "discrete subaortic stenosis" was achieved by echocardiography and angiography. A 70 mmHg of preoperative pressure gradient from left ventricle through ascending aorta could be reduced to 25 mmHg by the operative excision of this accessory mitral valve tissue and partial resection of this septal hypertrophy. This patient was supposed to be complicated with the ventricular septal aneurysm according to the angiographic study, even though this aneurysm was not visualized at the time of the operation. According to our knowledge, only fifteen cases of stenosis due to accessory mitral valve tissue was reported. The pathological findings of the excised specimens of these anomalous tissue were presented and developmental genesis of this intracardiac anomalous tissues, perhaps based on the developmental anomaly of the primitive organ of the endocardial cushion, was discussed in this report.

[A case of concomitant association of discrete subaortic stenosis in Kelly type I and hypertrophic cardiomyopathy in early stage].

A 1-year-old baby boy with discrete subaortic stenosis in Kelly type I had coexisting echocardiographic evidence for probably indicating the presence of hypertrophic cardiomyopathy in early stage. At surgery, a discrete subaortic "fibrous membrane" was excised: although the thickening of upper ventricular septum was not thought to be so prominent, the prognosis is related to the natural history of hypertrophied muscle despite successful surgical removal of the subaortic diaphragm.