Takei Yusuke, Itatani Keiichi, Miyazaki Shohei, Shibasaki Ikuko, Fukuda Hirotsugu
Department of Cardiac and Vascular Surgery, Dokkyo Medical University Hospital, Mibu-Machi, Tochigi, Japan.
Cardio Flow Design, Inc., Chiyoda, Tokyo, Japan.
Interact Cardiovasc Thorac Surg. 2019 Mar 1;28(3):413-420. doi: 10.1093/icvts/ivy271.
The purpose of this study was to calculate the changes in the blood flow direction and volume in the aortic lumen and at the entry and re-entry sites using 4-dimensional (4D) phase-contrast magnetic resonance imaging (MRI) after performing entry closure with thoracic endovascular aortic repair for chronic DeBakey IIIb aortic dissection.
Aortic blood flow was analysed at 3 phases with 4D phase-contrast MRI in a single therapeutic DeBakey IIIb aortic dissection case.
Primary entry was in the distal arch, and there were 4 re-entry sites downstream in the diaphragm. Preoperatively, the entry site formed a large antegrade flow (1082 ml/min) to the 4 re-entry sites, but soon after the closure of the entry site, re-entry sites 1 through 3 became a new entry site whose flow pattern changed retrogradely, resulting in increased volume in the false lumen in the acute phase, whereas the flow at the previous re-entry sites from the true lumen to the false lumen decreased gradually, resulting in aortic remodelling with a reduction in the size of the false lumen: the preoperative, postoperative and 6-month postoperative mean flow volumes (ml/min) were 23, 254 and 173 at re-entry site 1; 59, 887 and 279 at re-entry site 2; and 303, 608 and 103 at re-entry site 3. The changes in the flow volume of the false lumen followed a similar trend expect for the area around the abdominal aorta.
The volume of flow at the entry site was high, and closure of the primary entry site during thoracic endovascular aortic repair is very important. These changes in the flow volume of the re-entry sites and the false lumen may affect volume changes in the false lumen.
本研究的目的是在对慢性DeBakey IIIb型主动脉夹层进行胸主动脉腔内修复术封闭入口后，使用四维（4D）相位对比磁共振成像（MRI）计算主动脉腔内以及入口和再入口部位的血流方向和流量变化。
在一例接受治疗的DeBakey IIIb型主动脉夹层病例中，使用4D相位对比MRI在三个阶段分析主动脉血流。
主要入口位于远段主动脉弓，在膈肌下游有4个再入口部位。术前，入口部位形成大量向前血流（1082毫升/分钟）流向4个再入口部位，但在入口部位封闭后不久，再入口部位1至3变成了一个新的入口部位，其血流模式变为逆向，导致急性期假腔内血量增加，而从前真腔流向假腔的先前再入口部位的血流逐渐减少，导致主动脉重塑，假腔尺寸减小：再入口部位1术前、术后及术后6个月的平均血流量（毫升/分钟）分别为23、254和173；再入口部位2分别为59、887和279；再入口部位3分别为303、608和103。假腔血流量的变化除腹主动脉周围区域外遵循类似趋势。
入口部位的血流量很高，在胸主动脉腔内修复术中封闭主要入口部位非常重要。再入口部位和假腔血流量的这些变化可能会影响假腔的容积变化。
