Remodeling手術後の大動脈基部の動態を把握する

Dynamics Evaluation of Remodeling Operation Using 4-dimentional Computed Tomography

大動脈弁温存基部置換術では，4D-CTにより基部構成要素の詳細な情報［geometric height（GH），effective height（eH），basal ring径，大動脈弁逆流（AR）の機序など］を把握することができる．一方，再建された基部の動態（dynamics），すなわち伸展性も，大動脈弁の生理的開閉を保証し遠隔期成績を左右する重要な評価項目である．

Objectives：The extensibility of the aortic root after the remodeling procedure was evaluated using 4-dimentional computed tomography （4D-CT）.

Patients and methods：Seventeen patients （13 males/4 females）, mean age 52 years, who had undergone the remodeling procedure in the last 3 years were included. To understand the dynamics of the aortic root after reconstruction, the R-R interval on the electrocardiogram was divided into 10 equal parts, and the percentage change in area of the basal ring/Valsalva sinus/sino-tubular junction （STJ） level was calculated to evaluate the extensibility of the aortic root. For the basal ring, changes in ellipticity and circumference were also compared.

Results：Basal ring, Valsalva sinus, and STJ area changes with cardiac cycle were similar to those in the control group. Basal ring showed a regular circle in systole and an oval in diastole, and its circumference was enlarged in systole.

Conclusions：The use of 4D-CT made it possible to evaluate the extensibility of the aortic root after remodeling procedure. In particular, the mobility of the basal ring is large, suggesting that it guarantees the physiological opening and closing of the valve and contributes to its durability.