造影超音波検査による虫垂壁微小血流評価の試み : 小児の不可逆的な虫垂炎症を術前画像評価できるか?  [in Japanese] A Trial for Preoperative Imaging of the Irreversible Acute Appendicitis in Children With Levovist^[○!R] : Enhanced Power Doppler US  [in Japanese]

小児急性虫垂炎が保存的に治癒し得る可逆的炎症であるのか,手術の絶対適応と考えられる不可逆的炎症であるのかを検討した報告はない.【目的】疎血がすすみ壊疽性変化へ進行過程にある症例も含め,不可逆的な虫垂炎症を的確に術前画像評価することを目的とし,本研究をデザインした.【方法】手術適応と判断した20症例において超音波診断用造影剤(Levovist^[○!R]:300mg/mlの溶解液を5ml使用)を経静脈的に投与し,虫垂壁微小循環の画像評価を試みた.血流シグナルを定性的にrich,poorの2段階で評価し,病理組織所見と比較検討した.【結果】血流シグナルpoorと評価した16例中14例は壊疽性虫垂炎であり,血流シグナルrich例は4例中3例が蜂巣炎性虫垂炎であった.Fisher検定を用いて評価すると,病理所見はLevovist^[○!R]血流シグナルで異なり(p=0.032),相関があることが示された.すなわちrichシグナルは蜂巣炎性変化を,poorシグナルは壊疽性変化を反映するといえた.【結論】Levovist^[○!R]評価をとりいれることで,術前画像診断精度は向上した.不可逆的炎症では虫垂壁の微小血流は減退しており,これをシグナルとして検出することによって壊疽性変化を術前に予見することが可能である.造影超音波検査は保存的治療の対象を広げ,手術適応をしぼり込む判断材料になり得ると思われた.

There is no report which makes reference to whether the inflammation of an appendix is reversible or irreversible in acute appendicitis in children. If the inflammation is reversible, it will be thought that it may recover conservatively, and if irreversible, it can be an absolute indication of an operation. Purpose: To evaluate the irreversible appendicitis precisely before an operation, this clinical study was designed. Methods: Levovist^[○!R], contrast media for ultrasonic diagnoses (5ml of 300mg/ml solution) was given intravenously to 20 cases. The blood-flow signal was evaluated qualitatively in two steps, rich and poor. All the cases underwent appendectomy, and the picturized minute circulation of the appendix wall and the histopathological findings were weighed. Results: Among 16 examples estimated as poor signal, 14 were gangrenous appendicitis, while 3 out of 4 cases which showed rich signal were phlegmonous appendicitis. It was statistically indicated that histopathology views differed between the levels of the Levovist^[○!R] blood-flow signal by Fisher's exact test (p=0.032). It can be said that a rich signal foresees phlegmonous change and a poor signal may foresee gangrenous change. Conclusions: By the preoperative Levovist^[○!R] examination, diagnostic imaging accuracy was improved. The minute blood flow of an appendix wall is decreasing in the state of irreversible inflammation. Detecting this as a Levovist^[○!R] signal, its gangrenous change can be foreseen correctly before an operation. Conservative medical treatment can be applied more widely, and operative indication can be narrowed down by the contrast-enhanced US.