术前三维CT血管成像评估肠系膜下动脉解剖特征

目的 通过三维CT血管成像（CTA）评估分析直肠癌患者肠系膜下动脉（IMA）分型及解剖特点，为直肠癌手术血管处理提供参考。 方法 回顾分析2018年1月至2019年12月华中科技大学同济医学院附属协和医院接受IMA CTA检查的直肠癌患者临床及影像学资料。通过三维CT血管成像重建IMA图像。对IMA进行分类并测量统计肠系膜下血管各解剖参数。 结果 266例研究对象中男性187例，女性79例。111例（41.7%）左结肠动脉（LCA）从主干独立发出，112例（42.1%）LCA和乙状结肠动脉（SA）共干发出，33例（12.4%）LCA、SA及直肠上动脉（SRA）共干，10例（3.8%）缺乏LCA。全组IMA主干长度（LIMA）为（39.1±10.1）mm、IMA根部至髂血管分叉距离（DIMA）为（44.1±7.4）mm、IMA根部与肠系膜下静脉（IMV）水平距离为（24.6±8.9）mm、IMA分支点与IMV水平距离为（13.0±5.3）mm。LCA走行包括：122例（47.6%）高位型，88例（34.4%）中位型，46例（18.0%）低位型。65例（25.4%）LCA紧贴IMV内侧，136例（53.1%）LCA紧贴IMV外侧，55例（21.5%）LCA外侧远离IMV。 结论 术前利用三维CT血管成像可准确评估IMA分型及肠系膜下血管的形态走行关系，为直肠癌手术中血管处理提供指导。

Anatomy of the inferior mesenteric artery evaluated by three-dimensional CT angiography before radical resection of rectal cancer

Objective To evaluate and analyze the classification and anatomical characteristics of the inferior mesenteric artery (IMA) of patients with rectal cancer by three-dimensional CT angiography (CTA) in order to provide reference for the surgical management of rectal cancer. Methods A retrospective analysis was performed on the clinical and image data of rectal cancer patients received IMA CTA examinations in Union Hospital of Tongji Medical College of Huazhong University of Science and Technology from January 2018 to December 2019. IMA images were reconstructed by three-dimensional CT angiography. Branch types of IMA were classified, and anatomical parameters of the inferior mesenteric vessel were measured and analyzed. Results Among the 266 cases, 187 were males and 79 were females. The left colon artery (LCA) arose independently from the common trunk in 111 cases (accounting for 41.7%). In 112 cases (accounting for 42.1%), the LCA and sigmoid colon artery (SA) had a common trunk, and in 33 cases (accounting for 12.4%), LCA, SA and superior rectal artery (SRA) forked at same point, whereas LCA disappeared in 10 cases (accounting for 3.8%). The length of the IMA (LIMA) was (39.1±10.1) mm, and the distance between the IMA root and iliac aortic bifurcation (DIMA) was (44.1±7.4) mm. The distance from the IMA root to the inferior mesenteric vein (IMV) and the IMA branch point to the IMV were (24.6±8.9) mm, (13.0±5.3) mm, respectively. In 122 cases (accounting for 47.6%), LCA ascended medial to the lateral border of left kidney, while in 46 patients (accounting for 18.0%), LCA arranged below the inferior border of left kidney. LCA located medial to IMV at the level of IMA root in 65 cases (accounting for 25.4%), just lateral to IMV in 136 cases (accounting for 53.1%), and lateral away from IMV in 55 cases (accounting for 21.5%). Conclusions Three-dimensional CT angiography before surgery can accurately assess the IMA branch types and anatomical parameters of the inferior mesenteric vessel, which can provide reference for vascular management in rectal cancer surgery.