藤崎 純¹, 金子 南紀子¹, 佐々木 有沙¹, 来住野 雅¹, 高橋 奎太¹, 大山 貴衣¹, 宇都宮 誠², 中村 正人², 久保田 義則³, 前谷 容¹

Jun FUJISAKI¹, Makiko KANEKO¹, Arisa SASAKI¹, Masashi KISHINO¹, Keita TAKAHASHI¹, Kie OOYAMA¹, Makoto UTSUNOMIYA², Masato NAKAMURA², Yoshinori KUBOTA³, Iruru MAETANI¹

¹東邦大学医療センター大橋病院臨床生理機能検査部, ²東邦大学医療センター大橋病院循環器内科, ³松尾クリニック

¹Department of Clinical Functional Physiology, Toho University Ohashi Medical Center, ²Division of Cardiovascular Medicine, Toho University Ohashi Medical Center, ³Matsuo Clinic

キーワード : ultrasonography, R-P time, R-P time ratio (RPR), lower limb artery disease, hemodynamic evaluation

目的：下肢動脈における血管内治療（EVT）前後で，鼠径部と足関節部のドプラ波形よりR-P時間を計測し，その比を用いて下肢の血行動態的評価の指標になり得るか検討した．対象：2019年4月から2020年9月までに下肢動脈に病変を認めなかった108例を対照群とし，総大腿動脈（CFA）以遠病変に対するEVTを行い，術前後に下肢動脈エコーおよび足関節/上腕血圧比Ankle Brachial Index（ABI）を検査し得た67人78病変（膝上病変46例，膝下病変32例）を病変群とした．方法：CFA，足関節部の前脛骨動脈（ATA）・後脛骨動脈（PTA）にてR-P時間を計測し，CFAのR-P時間を基準にATA/CFA R-P時間比（R-P time ratio : RPR），PTA/CFA RPRを算出した．対照群と病変群を比較し，さらに病変群のEVT前後でRPRとABIの比較検討した．結果：RPRは病変群で有意に高値を示し，RPRの基準値を1.41とした場合に，総大腿動脈以遠に有意な病変を有さず，良好な下肢血流動態と判断できる場合の感度は96％であった．EVT前後の比較では膝上病変はABIと同様にEVT前後で有意差を認め，膝下病変ではABIで有意差を認めなかったが，RPRは有意差を認めた．結論：RPRは，下肢全体の血行動態的評価が行え，特に膝下動脈の血行動態的評価をABIよりも鋭敏に行える可能性が示唆された．

Purpose: We measured R-P time using the inguinal and ankle Doppler waveforms before and after endovascular treatment (EVT) in the lower extremity arteries, and examined whether the ratio could be used as an index for hemodynamic evaluation of the lower limb arteries. Subjects and Methods: We enrolled 108 patients who did not have any stenotic lesions in the lower limb arteries between April 2019 and September 2020 as a control group, and 67 patients with 78 lesions (46 above-the-knee lesions, 32 below-the-knee lesions) who underwent EVT, duplex echo, and ankle brachial index (ABI) measurement before and after EVT. R-P time was measured at the common femoral artery (CFA), anterior tibial artery (ATA), and posterior tibial artery (PTA) at the ankle joint, and ATA/CFA R-P time ratio (R-P time ratio: RPR) and PTA/CFA RPR were calculated based on the R-P time of the CFA. Results and Discussion: The value of RPR was significantly higher in the diseased group than the control group. When the cutoff value was set to 1.41 based on the control group data, the sensitivity was 96%. Before and after EVT for above-the-knee lesions, RPR was significantly changed as well as ABI. On the other hand, ABI showed no significant difference before and after EVT for below-the-knee lesions, but RPR was significantly shortened. Conclusion: RPR was easily measured for evaluation of the hemodynamics of the lower limbs with high sensitivity. It could be suggested that RPR was able to achieve more precise evaluation of lower limb hemodynamics, especially in below-the-knee arteries, than ABI.