Objective: To analyze the influencing factor of catheter placement length in totally implantable central venous port (TICVP) via right internal jugular vein

and to establish a regression equation based on the right third intercostal space as an anatomical landmark to measure the length of the catheter. Methods: A total of 190 patients with right internal jugular vein TICVP in First Affiliated Hospital of Xi'an Jiaotong University from September 2017 to July 2018 were collected. Intraoperative fluoroscopy was used to determine the length of the catheter and the distance from the puncture site to the right third intercostal space (SK-ICS) was recorded. Pearson correlation analysis was used to analyze the correlation between the actual catheter length and the patients'age

height

weight

BMI and SK-ICS. The regression equation was established by multiple linear regression analysis and other three commonly used formulas were used to compare. Results: Catheter length had a positive correlation with patients'height

weight and SK-ICS (P<0.05)

while had a negative correlation with BMI (P<0.05). The regression equation of L=1.01×SK-ICS+0.151 was obtained through multiple linear regression analysis. The estimated value of the equation had no significant difference compared with the actual length (P>0.05)

while the other three formulas were longer than the actual value. The absolute error and percentage value of the regression equation were relatively lower

with higher accuracy for predicting catheter length. Conclusion: The regression equation established by the surface anatomical landmark has certain clinical guiding values and promotion significance for the estimation of catheter length.