经颈静脉肝内门腔静脉分流术穿刺针弯折角的计算方法

Calculation method of puncture needle bending angle for transjugular intrahepatic portal systemic shunt

目的经颈静脉肝内门腔静脉分流术(transjugular intrahepatic portosystemic shunt,TIPS)是用于治疗门静脉高压症的一项综合介入治疗技术,其中由肝静脉到门静脉的穿刺是一个技术难点,而穿刺针前端弯折角的正确选择对于正确穿刺至关重要,本文给出一种符合个体解剖结构的穿刺针前端弯折角计算方法。方法首先采集术前增强CT影像,在门脉期CT影像基础上做术前规划勾画穿刺路径,再结合穿刺针前端几何特征,采用贝塞尔曲线参数方程刻画穿刺针前端形态及弯折变形过程,通过对符合方程组要求的点进行遍历找到正确的针尖位置,进而求解曲率得到穿刺针前端弯折角,实现术前规划中弯折角的量化计算。最后通过术中操作参数主观评价结合术后总结比较的方式进行本计算方法效果评估。结果以两个中心13例患者的临床验证为例,给出平均穿刺次数、穿刺时间及有无并发症等结果。经过本计算方法量化后的术前规划引导后,平均穿刺次数分别为3、2,平均穿刺时间分别为161min、142 min。结论基于贝塞尔曲线参数方程的穿刺针前端弯折角计算方法,在经颈静脉肝内门腔静脉分流术术前规划引导门静脉穿刺应用中具有很好的效果。

Objective Transjugular intrahepatic portal systemic shunt （ TIPS ） is a comprehensive interventional therapeutic technique specially used for the interventional therapy of portal hypertension. During which, the puncture from hepatic vein to portal vein is a key technical difficulty, while the selection of puncture needle front end bending angle is vital to the puncture. The purpose of this paper is to propose a calculation method of puncture needle front end bending angle inaccordance with individualized anatomical structure.Methods Firstly preoperative contrast.enhanced CT was collected, and preplanning of drawing puncture path was conducted on base of the portal vein phase CT image, then considering the geometrical characteristic of puncture needle front end, Bezier curve parametric equation was adopted to depict the shape and bending deformation of puncture needle front end. By traversing each point satisfying the equation set, the appropriate position of needle tip was confirmed. Then puncture needle front end bending angle was obtained through curvature computing, fulfilling the quantitative calculation of bending angle parameter in preplanning. Finally the efficiency of this calculation method was evaluated through subjectiveevaluation of intraoperative operating parameters combined with postoperative summary comparison. Results Thirteen cases clinical verifications from two research centers proved that under the guidance of preplanning with this quantized calculation method, the mean puncture times were 3,2 and mean puncture time were161 min, 142 min, respectively. Conclusions Bezier curved parametric equation based puncture needle front.end bending angle calculation method used in the preplanning of transjugular intrahepatic portal systemic shunt for guiding puncture to portal vein proves good effect.