Method for Calculating the Bending Angle of Puncture Needle in Preoperative Planning for Transjugular Intrahepatic Portal Systemic Shunt (TIPS).

Xiaoli Zhu,Wanci Li,Wansheng Wang,Zhao Ran,Xin Gao,Kangshun Zhu,Wensou Huang

doi:10.1155/2018/4534579

Abstract

Transjugular Intrahepatic Portal Systemic Shunt is a comprehensive interventional therapy for portal hypertension. During this intervention, puncturing from hepatic vein into portal vein is a difficult step. Selecting puncture needle with a proper bending angle is vital to accurate puncture. Thus, this prospective study provides a method to calculate the angle of the puncture needle using preinterventional contrast-enhanced CT imaging. According to the geometrical characteristics of puncture needle, Bezier curve equation was adopted to describe its bending part. By testing whether each point in a specific region satisfied the equation set of Bezier curves, the possible position of needle tip was obtained. Then, the bending angle of puncture needle was obtained by calculating curvature. The method was evaluated in 13 patients from 2 centers showing now a success rate of 100% and a duration of the procedure of 141 and 161 minutes. The method based on Bezier curve equation for calculating a proper bending angle of puncture needle was proven to be effective. And the clinical study is preliminary and additional work for clinical evaluation is necessary.

Highlights

Portal hypertension (PH) refers to a group of clinical syndromes characterized by abnormal changes of hemodynamics in portal vein system
Transjugular Intrahepatic Portal Systemic Shunt (TIPS) adopts radiation technology and uses special equipment to build a shunt between inferior vena cava and the branch of portal vein, so part of the bloodstream in portal vein can flow into inferior vena cava
The causes of PH vary with patients, and the structure of intrahepatic vascular system, especially the spatial relationship between hepatic vein and portal vein, varies with patients

Summary

Introduction

Portal hypertension (PH) refers to a group of clinical syndromes characterized by abnormal changes of hemodynamics in portal vein system. It is a major complication of cirrhosis and can even lead to death. Clinical practice indicates that choosing a puncture needle with a proper bending angle is necessary for accurate puncture of the portal vein [5]. The bending angle of puncture needle is adjusted by doctors according to their experiences.

Methods

Results

Conclusion