田端 強志^{1, 2}, 粕谷 秀輔³, 木下 利雄^{2, 4}

Tsuyoshi TABATA^{1, 2}, Syusuke KASUYA³, Toshio KINOSHITA^{2, 4}

¹東邦大学医療センター佐倉病院臨床検査診断センター, ²東邦大学医療センター佐倉病院臨床生理機能検査部, ³東邦大学医療センター佐倉病院放射線科, ⁴東邦大学医療センター佐倉病院循環器内科

¹Toho University Medical Center Sakura Hospital Clinical Laboratory and Diagnostic Center, ²Department of Clinical Physiology, Toho University Medical Center Sakura Hospital, ³Department of Radiology, Toho University Medical Center Sakura Hospital, ⁴Department of Internal Medicine, Toho University Medical Center Sakura Hospital

キーワード : renal arteriovenous fistula, renal biopsy, Doppler ultrasonography, hemodynamics, transcatheter arterial embolization

腎生検は腎疾患の診断に有用であるが，腎動静脈瘻（renal arteriovenous fistula；RAVF）などの出血性合併症を生じることがある．症例は80代女性．急性腎障害の精査目的に腎生検を施行後，肉眼的血尿が出現した．超音波検査ではカラードプラ法で腎内に著明なエイリアシングを伴うモザイク状血流およびループ状血管構造を認め，パルスドプラ法では最高血流速度2.2 m/s，resistive Index 0.26の高速低抵抗な連続性動脈波形に加え，静脈側の拍動化を認めた．これら血流動態の異常からRAVFを強く疑い，造影CTで確定診断後，コイルを用いた経カテーテル動脈塞栓術を施行した．術後，超音波検査にてシャント血流は消失し，各血流指標および静脈波形の正常化を認めた．腎生検後RAVFの病態把握および治療効果判定において，ドプラ超音波検査による詳細な血流動態評価は極めて有用であった．

Renal biopsy is essential for diagnosing renal diseases but can lead to hemorrhagic complications such as renal arteriovenous fistula （RAVF）. A woman in her 80s developed gross hematuria after a renal biopsy performed for acute kidney injury. Color Doppler ultrasonography revealed a mosaic flow pattern with marked aliasing and a loop-like vascular structure within the kidney. Pulsed Doppler demonstrated a high-velocity, low-resistance arterial flow （peak systolic velocity: 2.2 m/s, resistive index: 0.26） and pulsatile changes in the draining vein. Based on these hemodynamic abnormalities, RAVF was strongly suspected and subsequently confirmed via contrast-enhanced CT. Transcatheter arterial embolization using coils was performed, after which follow-up ultrasonography showed disappearance of the shunt flow and normalization of hemodynamic parameters and venous waveforms. Doppler ultrasonography, integrating color and pulsed Doppler, is effective for both hemodynamic assessment and post-treatment monitoring of post-biopsy RAVF.