大野 栄三郎¹, 廣岡 芳樹², 川嶋 啓揮¹, 石川 卓哉¹, 田中 浩敬¹, 酒井 大輔¹, 石津 洋二¹, 葛谷 貞二¹, 中村 正直¹, 本多 隆¹

Eizaburo OHNO¹, Yoshiki HIROOKA², Hiroki KAWASHIMA¹, Takuya ISHIKAWA¹, Hiroyuki TANAKA¹, Daisuke SAKAI¹, Yoji ISHIZU¹, Teiji KUZUYA¹, Masanao NAKAMURA¹, Takashi HONDA¹

¹名古屋大学大学院医学系研究科消化器内科学, ²名古屋大学医学部附属病院光学医療診療部

¹Department of Gastorenterology and Hepatology, Nagoya University Graduate School of Medicine, ²Department of Endoscopy, Nagoya University Graduate School of Medicine

キーワード : EUS elastography, shear-wave elastography, EUS-SWM (EUS shear-wave measurement), autoimmune pancreatitis (AIP)

目的：自己免疫性膵炎（AIP）の診断および治療における，新開発された超音波内視鏡検査（EUS）のshear-wave（せん断波）elastography法（EUS shear-wave測定：EUS-SWM）の臨床的実現可能性と有用性を評価する．方法：患者160名の膵臓の組織弾性を測定した．EUS-SWMの成功率，shear-wave速度（Vs, m/s），およびVs測定の信頼度指数（VsN）を評価し，弾性（平均Vs）をAIP群（n＝14）および正常対照群との間で比較した．結果：有害事象はなく合計3,837件のEUS-SWMを実施した．全体の測定成功率は97.6％（3,743/3,837）であった．平均VsNは74％であった．膵臓の平均Vsは，次のとおりであった．膵頭部（十二指腸球部より観察：プッシュポジション）では2.22 m/s，膵頭部（十二指腸下行脚より観察：プルポジション）では2.36 m/s，膵体部では1.99 m/s，そして膵尾部では2.25 m/s．AIP群（2.57 m/s）の平均Vsは，正常対照群の平均Vs（1.89 m/s）（P＝0.0185）に比べて有意に高かった．平均Vsは，ステロイド治療（n＝6）（P＝0.0234）後，3.32 m/sから2.46 m/sへと有意に減少した．結論：EUS-SWMは臨床的に実現可能な手技であり，信頼性のある結果が得られた．EUS-SWMは，AIP患者へのステロイド治療の効果を評価する上で有効な方法である．

Purpose: To assess the feasibility and the clinical usefulness of a newly developed endoscopic ultrasonography (EUS) shearwave elastography technique (EUS shear-wave measurement: EUS-SWM) in the diagnosis and treatment of autoimmune pancreatitis (AIP). Methods: Tissue elasticity was measured in the pancreas in 160 patients. The success rate of EUS-SWMs, the velocity of the shear wave (Vs, m/s), and the reliability index of the Vs measurement (VsN) were evaluated, and the elasticity (median Vs) was compared between AIP patients (n=14) and normal controls. Results: A total of 3837 EUS-SWMs were performed without adverse events. Overall, 97.6% (3,743/3,837) were successful. The median VsN was 74%. The median Vs values of the pancreas were as follows: 2.22 m/s in the pancreatic head (push position), 2.36 m/s in the head (pull position), 1.99 m/s in the body, and 2.25 m/s in the tail. The median Vs of the AIP group (2.57 m/s) was significantly higher than that of the normal controls (1.89 m/s) (P=0.0185). The mean Vs significantly decreased from 3.32 m/s to 2.46 m/s after steroid therapy (n=6) (P=0.0234). Conclusion: EUS-SWM is feasible and generates credible results. EUS-SWM was a useful method for assessment of the effect of steroid therapy in AIP patients.