Abstract
In surgical treatment of aortic valve dysfunction, “particuarly aortic insufficiency”, prosthetic valve are widely used for aortic valve transplantation, while aortic homograf is are used in some patients recently.
Although many of these valve substituts have shown considerable promis, non is entirely satisfactory, and it is unsolved whether these procedures are advantageous or disadvantageous.
Therefore, instead of orthotopic homotransplantation of aortic valve, the author intended to insert the aortic valve or pulmonary valve into the descending aorta and also to perform aortic valve replacement at the subcoronary position using mono cusp in dogs.
Experimental study was performed by using occlusion of descending aorta beneath the branching part to the subclavian artery under normothermia and mild hypothermia at 30°C. of rectal temperature, and mono cusp aortic valve replacement was studied under deep hypothermia at 20°C. of rectal temperature.
The results were obtained as follows.
1) Safety interruption time of descending aorta under normothermia which caused no palaplegia was about 20 minutes.
2) It was safely occluded over 20 minutes under hypothermia at 30°C. of rectal temperature without palaplegia.
3) In homotransplantation of the aortic valve with a piece of segment from ascending aorta which was sutured as a cuff to the myocardial side of the valve, it takes shorter time to transplant than without segment, but thrombosis was more frequently seen in segment series.
4) In homotransplantation of the pulmonary valve at descending thoracic aorta, it had similary normal function of valve, but pulmonary valve was disadvantegeous for reason of thin arterial wall and making rupture on the suture line. Accordingly, it was effective to overlap the suture line with a piece of pericardium.
5) The homoaortic mono cusp valve replacement was the most difficult technically, because of the anatomical peculiarity on the myocardial side of aortic valve ring. The results were poor.
6) Infection was the most unpref erable complication on the all of these studies, and due to forming thrombosis or rupturing suture line, long term survivals were not obtained.
