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Biomedical subjects

K Okamura

Publications and source records attributed to K Okamura.

652 records · Page 37Linked to original sources
PubMedDate not supplied

Left ventricular hypertrophy due to aortic bypass grafting with a long prosthesis.

Progressive left ventricular hypertrophy was observed following operations in which long bypasses were inserted from the ascending aorta to the abdominal aorta for aneurysm exclusion in cases of thoracic aortic aneurysm. This effect was not observed after operations in which there was grafting with a short prosthesis for abdominal aortic aneurysm, wrapping and trans-section of the dissecing aneurysm. Clinical and experimental studies of the hemodynamic aspects suggest that the left ventricular hypertrophy was caused by an increase in systolic blood pressure at the aortic root due to the low distensibility of the long graft, a decrease in the Windkessel effect by exclusion of the proximal aorta and energy loss by turbulence formation of the proximal anastomotic area. Therefore, the distensibility or compliance at the long prosthesis seems to be very important in cases with long grafts of the aorta.

Animals↗
PubMedDate not supplied

Experimental and clinical studies of the inverted autogenous vein grafts.

The vein was inverted (inside-out) and used as a new arterial substitute. Experimental study showed more than 90% patency rate and clinical experiences were satisfactory. Autogenous inverted vein grafting is a safe procedure and should be considered another way to widen the indication of the vein.

Aged↗
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A comparative study between glutaraldehyde-preserved aortic and pulmonary heterograft valves in the tricuspid position in dogs.

Morphological observations have been presented on 10 metaperiodate-glutaraldehyde-preserved aortic heterograft valves and 5 pulmonary heterograft valves implanted into the tricuspid position for periods ranging from 7 to 183 days. It is recognized that there was a relatively minimal histological change in pulmonary valves. However, calcification of implanted aortic cusps was observed in 20% (2 out of 10) of cases and high incidence of thrombus formation on aortic cusps was recognized, although there were none on pulmonary cusps. It seems reasonable to presume that the high incidence of thrombus formation on the aortic valves is primarily due to the decreased pliability and stiffness of the cusps. It is concluded that the pulmonary valves rather than the aortic valves are recommended for tricuspid valve replacement.

Aldehydes↗