Abstract: ［Abstract］ Objective To investigate the angle of inferior mesenteric vein （IMV） into the portal venous system and its relationship with the distribution of left?sided colorectal liver metastases. Methods Clinical data of 113 cases of colorectal liver metastases were collected from Jan 2012 to Jan 2017， including the site of primary tumor， metastases number and site， and the type of portal venous system based on the three?dimensional images we reconstructed defining “IMV input into superior mesenteric vein （SMV）， IMV input into splenic vein （SV） and IMV input into the venous angle”. Results In 113 cases， 17 are the type of IMV input into the venous angle， 100% metastases are in the left lobe of liver due to the obtuse angle of IMV input into SMV， 75% metastases are in the right lobe of liver and 25% metastases are in the left lobe of liver due to the acute angle of IMV input into SMV. The constituent ratio of liver metastases was statistically different （P<0.05）； none metastases are in the left lobe of liver， 25% metastases are in the right lobe of liver and 75% metastases are in the two lobes of liver due to the obtuse angle of IMV input into SV，80% metastases are in the left lobe of liver， 20% metastases are in the right lobe of liver and none metastases are in the two lobes of liver due to the acute angle of IMV input into SV. The constituent ratio of liver metastases was statistically different （P<0.05）； 31 are the type of IMV input into SMV， 66.7% metastases are in the right lobe of liver， 8.3% metastases are in the left lobe of liver and 25% metastases are in the two lobes of liver due to the obtuse angle of IMV input， 26.3% metastases are in the right lobe of liver， 36.8% metastases are in the left lobe of liver and 36.8% metastases are in the two lobes of liver due to the acute angle of IMV input. The constituent ratio of liver metastases was statistically different （P<0.05）； 65 are the type of IMV input into SV， 50% metastases are in the right lobe of liver， 35.7% metastases are in the left lobe of liver and 14.3% metastases are in the two lobes of liver due to the obtuse angle of IMV input， 21.6% metastases are in the right lobe of liver， 25.5% metastases are in the left lobe of liver and 52.9% metastases are in the two lobes of liver due to the acute angle of IMV input. The constituent ratio of liver metastases was statistically different （P<0.05）. Conclusion The angle of IMV input into the portal venous system is deeply related with the distribution of left?sided colorectal liver metastases， especially to predicting， monitoring the liver metastases， guiding clinic diagnosis and treatment due to the obtuse angle of IMV input.

Key words: colorectal neoplasms, left?Sided, inferior mesenteric vein, splenic vein, angle of IMV input, liver metastases, superior mesenteric vein

摘要： ［摘要］ 目的 分析肠系膜下静脉（IMV）汇入门静脉系统角度与左半结直肠癌肝转移灶分布的关系。方法 中山大学附属第六医院2012年1月至2017年1月期间收治的113例行全腹部+盆腔CT 检查的左半结直肠癌肝转移患者的影像学资料。根据门静脉系统重建三维图像，将门静脉系统的解剖类型分为IMV汇入门静脉角、IMV汇入肠系膜上静脉（SMV）、IMV汇入脾静脉（SV）3种类型，分析IMV汇入门静脉系统分型和成角情况以及成角与肝转移灶分布关系。结果 全组男性68例，女性45例，平均年龄58.4岁；同时性肝转移93例（82.3%），异时性肝转移20例（17.7%）；其中结肠脾曲癌2例（1.8%），降结肠癌7例（6.2%），乙状结肠癌42例（37.2%），直肠上段癌62例（54.8%）；肝内单发病灶共38例（33.6%），多发病灶共75例（66.4%）。根据三维重建结果将IMV汇入门静脉系统情况分为3型：IMV汇入门静脉角（17例，15.0%），IMV汇入SMV（31例，27.4%），IMV汇入SV（65例，57.6%）。113例左半结直肠癌伴肝转移患者中，IMV汇入门静脉角共17例，IMV与SMV成角>90°患者转移灶100%位于肝左叶，IMV与SMV成角<90°患者转移灶位于肝右叶（20%）和肝左叶（80%），肝转移灶分布构成比的差异有统计学意义（P<0.05）； IMV与SV成角>90°患者转移灶位于肝右叶（25%）、肝左叶（0%）和肝左右叶（75%），IMV与SV成角<90°患者转移灶位于肝右叶（20%）、肝左叶（80%）和肝左右叶（0%），肝转移灶分布构成比的差异有统计学意义（P<0.05）。IMV汇入SMV共31例，IMV与SMV成角>90°患者转移灶位于肝右叶（66.7%）、肝左叶（8.3%）和肝左右叶（25%），IMV与SMV成角<90°患者转移灶位于肝右叶（26.3%）、肝左叶（36.8%）和肝左右叶（36.8%），肝转移灶分布构成比的差异有统计学意义（P<0.05）。IMV汇入SV共65例，IMV与SV成角>90°患者转移灶位于肝右叶（50%）、肝左叶（35.7%）和肝左右叶（14.3%），IMV与SV成角<90°患者转移灶位于肝右叶（21.6%）、肝左叶（25.5%）和肝左右叶（52.9%），肝转移灶分布构成比的差异有统计学意义（P<0.05）。结论 根据IMV汇入方式进行门静脉系统的三类分型中，IMV汇入门静脉系统的角度均与左半结直肠癌肝转移灶分布密切相关，尤其在IMV以成角>90°汇入门静脉系统时，能更好地预测左半结直肠癌肝转移灶分布区域，对于疾病的临床预判、监测和治疗具备相当参考价值。

关键词: 结直肠癌, 左半肝转移, 脾静脉, 肠系膜下静脉, 汇入角度 , 肠系膜上静脉