[Operative indication for aortic valvuloplasty by rasping procedure from the point of histopathologic evaluation]

Rasping procedure is proposed by the author as one of the methods of aortic valvuloplasty and defined as shaving the surface of rheumato-degenerative aortic valve by using the electric rasp. Materials were the removed rheumato-degenerative aortic valves as specimen, and classified into 3 groups. The first group (type I) was valve lesion limited to valve free edge, second (type II) was mild thickening entirely, third (type III) was severe thickening with calcified degeneration. Rasping procedure was performed for the thickened portion of the valve specimen by the electric rasp. Morphologic examinations after rasping procedure were evaluated by histopathologic study. Histopathologically, there was hyaline degenerative connective tissue in superficial layer above the collagen fiber's layer in rheumato-degenerative thickened valve in type I. This hyaline degenerative connective tissue was considered to be fragile and pathologic in the tissue structure. Rasping procedure could remove this connective tissue layer. Type II, there was the similar finding to the type I from the free edge to the mid portion of the cusp. So, Rasping procedure was effective for type I and type II valve degeneration. On the contrary, the calcified lesion (type III), rasping procedure was not effective in valve coaptation and the pathological findings showed the fragmentation in the calcified layer. In the pathological comparison with the slicing procedure for type II by the surgical knife, there was a crack and cleft in the collagen fiber's layer in the case of slicing procedure. It can be concluded the results of histopathological study of the rasping procedure proved to be superior to the conventional aortic valvuloplasty (slicing method).