Masahiro Kase

Morphologic Alterations and Cytokinetic Studies of Tracheal Autograft Epithelium in Rabbits

BACKGROUND Although tracheobronchoplasty has been used widely in the field of thoracic surgery, few details of the morphologic changes in and cytokinetics of the graft epithelium have been reported. The aim of this study was to focus on these aspects in autografted rabbit tracheas. METHODS Resected cervical tracheas were anastomosed immediately after removal, retrieved on postoperative days 1 through 28, and examined morphologically. Mitotic and bromodeoxyuridine-labeling indices of the graft epithelium were analyzed. RESULTS On postoperative days 1 to 4, the graft epithelium showed focal desquamation at the anastomoses. Ciliated cells disappeared during postoperative days 4 to 7 and then increased gradually. Nonciliated cells retained a somewhat columnar shape on postoperative days 4 to 7, except at denuded foci. Thereafter, the grafts were covered completely with pseudostratified mucociliary epithelium. On postoperative day 4, both indices were maximal and appeared higher at the anastomotic than midgraft sites. CONCLUSIONS Most of the graft epithelium was preserved during acute ischemia and then started to regenerate. The increased regenerative activity near the anastomoses may be attributable to mechanical damage or different nutritional conditions.

A Case of Aortic Regurgitation in Behcet's Disease.

ベーチェット病に合併した大動脈弁閉鎖不全症に対し大動脈弁置換術を行った. 人工弁は左冠尖側から右冠尖側にかけては大動脈内壁に短冊状のフェルトを当て, 無冠尖側は大動脈外壁に短冊状のフェルトを当てて固定した. 右冠動脈入口部の狭窄により心筋保護が十分行えず, 術中心筋梗塞を生じたが, 遠心ポンプによる右心補助を行い救命した. 本症例は術前の冠動脈造影にて異常はなかったが, 手術待機中に病変が進行したものと思われた. 手術に際しては大動脈弁のみならず冠動脈の病変にも注意を払うことが大切であるとともに術前, 術後を通してステロイド剤による炎症のコントロールも重要であると思われた.