Anatomical variations of the internal jugular vein in relation to carotid artery : an ultrasound study

Abstract

Background: In developing country like India, central venous catheter is still inserted using anatomical landmark guidance with success rate up to 97.6% and complications up to 15%. Aims & Objective: This study was aimed to determine the anatomical variations of the internal jugular vein (IJV) in relation with carotid artery (CA) with the help of 2-D ultrasound. Material and Methods: This prospective randomized study was conducted in a teaching and tertiary care hospital on 100 young healthy volunteers of either sex, aged 20 years to 40 years. Each volunteer was placed supine with 15˚ down trendlenberg position with 45˚ neck rotation on contra-lateral side. Linear array probe with 7.5 M Hz of “Sonosite Micromaxx” ultrasound machine was placed perpendicular to the apex of the triangle formed by two heads of sternocleidomastoid muscle and clavicle. Vessels were visualized in transverse section in 2-D ultrasound. Exact location of IJV was identified in relation to the CA on ultrasound and recorded as lateral, antero-lateral, anterior, medial, and posterior. The diameter of IJV and CA, distance from skin to IJV were recorded on both sides of neck for each volunteer. Anterior position of IJV in relation to CA was defined as dangerous position. Small sized IJV was defined as diameter ≤7 mm. Data were analyzed using Graphpad prism software version 5.1. P value < 0.05 was taken as significant. Results: The mean diameter of IJV was 13.23 (2.52) mm in right and 10.25(2.29) mm in left side of neck (p=0.0001). Small sized IJV was in 1% in right and 8% in left side (p=0.0349). 15% and 28% of volunteers had dangerous position of IJV in relation to CA on right and left side of neck respectively (p=0.0381). Conclusion: Significant number of healthy young volunteers had anatomical variations in terms of size and position of IJV (left side > right side) in relation of CA by ultrasound screening. Thus, anatomical landmarks are not sufficient, alternative measures like ultrasound scanning should be implemented prior to catheterization to identify the individual with potentially difficult catheterization.