Nakano Takahito, Kaneda Hiroyuki, Murakawa Tomohiro
Department of Thoracic Surgery, Kansai Medical University, 2-5-1 Shin-Machi, Hirakata, Osaka, 573-1010, Japan.
Gen Thorac Cardiovasc Surg. 2023 Nov;71(11):648-656. doi: 10.1007/s11748-023-01926-7. Epub 2023 Mar 20.
A thrombus can occur in the stump of the pulmonary vein after left upper lobectomy, potentially causing postoperative cerebral infarction. This study aimed to verify the hypothesis that stagnation of blood flow inside the pulmonary vein stump causes thrombus formation.
The three-dimensional geometry of the pulmonary vein stump after left upper lobectomy was recreated using contrast-enhanced computed tomography. Blood flow velocity and wall shear stress (WSS) inside the pulmonary vein stump were analysed using the computational fluid dynamics (CFD) method and compared between the two groups (those with or without thrombus).
The volumes of average flow velocity per heartbeat < 10 mm/s, 3 mm/s, 1 mm/s (p-values 0.0096, 0.0016, 0.0014, respectively) and the volumes where flow velocity was always below the three cut-off values (p-values 0.019, 0.015, 0.017, respectively) were significantly larger in patients with a thrombus than in those without thrombus. The areas of average WSS per heartbeat < 0.1 Pa, 0.03 Pa, 0.01 Pa (p-values 0.0002, < 0.0001, 0.0002, respectively), and the areas where WSS was always below the three cut-off values (p-values 0.0088, 0.0041, 0.0014, respectively) were significantly larger in patients with thrombus than in those without thrombus.
The area of blood flow stagnation in the stump calculated by CFD method was significantly larger in patients with than in those without thrombus. This result elucidates that stagnation of blood flow promotes thrombus formation in the pulmonary vein stump in patients who undergo left upper lobectomy.
左上肺叶切除术后肺静脉残端可能形成血栓，进而导致术后脑梗死。本研究旨在验证肺静脉残端内血流停滞导致血栓形成这一假说。
利用对比增强计算机断层扫描重建左上肺叶切除术后肺静脉残端的三维几何结构。采用计算流体动力学（CFD）方法分析肺静脉残端内的血流速度和壁面切应力（WSS），并在两组（有血栓组和无血栓组）之间进行比较。
每搏平均血流速度<10 mm/s、3 mm/s、1 mm/s的体积（p值分别为0.0096、0.0016、0.0014）以及血流速度始终低于三个临界值的体积（p值分别为0.019、0.015、0.017），有血栓患者均显著大于无血栓患者。每搏平均WSS<0.1 Pa、0.03 Pa、0.01 Pa的面积（p值分别为0.0002、<0.0001、0.0002）以及WSS始终低于三个临界值的面积（p值分别为0.0088、0.0041、0.0014），有血栓患者均显著大于无血栓患者。
通过CFD方法计算得出，有血栓患者肺静脉残端的血流停滞面积显著大于无血栓患者。这一结果表明，血流停滞会促进接受左上肺叶切除术患者的肺静脉残端形成血栓。
