• 作者： 李英雄; 周雲英
• 作者服務機構： 長庚紀念醫院心臟血管內科
• 中文摘要： 　　隨著年齡的增長，人類左心瓣膜，特別是主動脈漸漸發生鈣化變性，導致瓣膜結構上之改變而引起瓣膜狹窄，最後需要以手術來治療，方能改善病症。目前在西方國家之老年人口中，主動脈瓣疾病中最常見的是鈣化變性所引起之主動脈瓣狹窄。雖然在東方國家之老年人主動脈瓣疾病仍以風濕性病因佔優勢，但近年來老年鈣化性主動脈瓣狹窄已有顯著增加之趨勢。因此，從事探討老年鈣化性主動脈瓣狹之文章報告陸續出現。雖然如此，以電子顯微鏡來研究老年鈣化性主動脈瓣狹窄所發表之論文仍然是屈指可數。因此，本篇研究之目的在利用高解析度掃描電子顯微鏡與透射電子顯微鏡來觀察老年鈣化性主動脈瓣膜組織之超微表面型態與內部結構。希望藉此能發現結構變化之新知，有助於瞭解老年鈣化性主動脈瓣狹窄之致病機轉。　　鈣化性主動脈瓣膜組織取自於十位開心手術患者所切除之鈣化主動脈瓣。經常規的掃描與透射電子顯微鏡之標本處理法後，所有組織標本置於高解析度掃描電子顯微鏡（日立，S-5000型）與透射電子顯微鏡（日立，H-500型）下，做廣泛與細微觀察。　　在兩種顯微鏡互相配合下所觀察到的結果顯示，超微結構上之病理變化與鈣質沉積已侵犯瓣膜組識之各層次，從表層之內皮細胞至其下之基底膜，而深入纖維之膠原組織。值得注意的是鈣質沉積常發生於內皮細胞層損傷處之周圍及損傷處下之組織結構。鈣質沉積量與內皮層損傷之嚴重度有直接正比之關係。且沉積量由表面內皮層往探層的膠原纖維組織層逐漸遞減。有興趣的是發現瓣膜組織內之細胞，特別是纖維細胞呈現各種程度之細胞凋亡特徵。凋亡的細胞碎片與內容物常伴隨著鈣質之沉積。 綜合上述的觀察結果，瓣膜組織上內皮細胞層完整性之改變，是導致原發性鈣化發生機轉之推測獲得足夠的證明。因鈣質不斷的沉積，遂引起瓣膜組織內細胞之凋亡及膠原組織等結構上之變化，最後引起整個主動脈瓣狹窄。
• 英文摘要： Calcific degeneration of aortic valves were investigated in 10 patients with senile calcific aortic stenosisby means of high resolution scanning electron microscopy (HR-SEM) and transmission electron microscopy(TEM). All the specimens obtained during aortic valve surgery HR-SEM and TEM examinations consis-tently showed various degrees of pathological alterations and calcification involving surface endothelium,underlying basement membranes and deeper layers of interweaving networks of collagen fiber bundles in thepars fibrosa of the valve tissues. Calcific deposits in the valve tissues always occurred in the vicinity of theendothelial defects and in the subendothelial structures just beneath the defective endothelium. The amountof calcific deposits in the valve tissues increased in proportion to the severity of endothelial damage andgradually decreased from the defective endothelial surface to the deeper layer of collagen tissue. In addition,apoptotic cell death, particularly of the fibrocytes in the valve tissue, was closely related to the severity ofendothelial injury. Cellular fragments derived from the apoptotic cells were always associated with calciumdeposits. Based on the above findings, our results provide evidence that the alteration of endothelial integrityplays a contributory role in calcific degeneration in the aortic valve leading to the development of senilecalcific aortic stenosis.
• 中文關鍵字： senile calcific aortic stenosis; apoptosis; electron microscopy.
• 英文關鍵字： --