Development of a new method for predicting aneurysm enlargement after EVAR using 4D-flow MRI

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K16492
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 55030:Cardiovascular surgery-related
• Research Institution: Hamamatsu University School of Medicine
• Principal Investigator: Katahashi Kazuto 浜松医科大学, 医学部, 助教 (60839091)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 腹部大動脈瘤 / ステントグラフト / エンドリーク / 4D-flow MRI

Outline of Final Research Achievements

This study focused on cases in which endovascular aneurysm repair (EVAR) was performed for abdominal aortic aneurysm (AAA) from January 2013 to December 2019. Preoperative 4D-flow MRI analysis was conducted to measure the total flow volume (TFV) in the aneurysm side branches. A retrospective comparison was made between the group with aneurysm enlargement due to type II endoleak one year after EVAR and the group without enlargement. TFV was significantly higher in the enlargement group and established a TFV cutoff value of 13.6 ml/min for predicting aneurysm enlargement after EVAR. Currently, a prospective study is ongoing. Patients with preoperative TFV values above the cutoff are undergoing pre-emptive aortic side branch embolization before EVAR. The primary endpoint is aneurysm enlargement one year after EVAR (CRB4180008, study number 21-112).

Free Research Field

心臓血管外科

Academic Significance and Societal Importance of the Research Achievements

腹部大動脈瘤（AAA）に対するステントグラフト内挿術（EVAR）においてII型エンドリーク（II型EL）による術後の瘤径増大が生じうるが、その予防法や治療法は確立されていない。現在、術前分枝塞栓を実施する施設もあるがII型ELの発生を予防するための術前の分枝塞栓をどの症例に行うべきか明確ではなく、術後II型ELにより瘤径増大を認めた場合に塞栓術や瘤縫縮術の適応を検討している施設も多い。本研究の結果から術前に術後のII型ELによる瘤径増大が予測され、瘤径増大が予測される症例に対してのみ術前に選択的分枝塞栓を実施することが可能となればII型ELによる術後瘤径増大の予防法となりうると考えられる。