Percutaneous cannulation of internal jugular vein is difficult in pediatric patients because of its small size and anatomic variation. The aim of this study is to investigate cross-sectional area and relative anatomy of right internal jugular vein with respect to the carotid artery in two approaches and thereby to find ideal cannulation site in young children.

The cross-sectional area of right internal jugular vein and the degree of the carotid artery overlap was evaluated in 47 children using ultrasound at two levels; 1) at the cricoid cartilage (high approach) and 2) at the junction of the two heads of the sternocleidomastoid muscle (low approach).

The cross-sectional area was significantly larger by about 28.8% in the low approach than that of the high approach (P < 0.01). The internal jugular vein was partially overlapping the carotid artery in 48.9% and completely overlapping in 42.6% in the low approach and in 44.7% and 34.0% in the high approach respectively. The carotid artery overlap was significantly higher in the low approach when compared with the high approach (P < 0.02).

In terms of cross-sectional area, the low approach with larger size is optimal for internal jugular vein cannulation. Although the degree of the carotid artery overlap was higher at the low approach, the internal jugular vein was partially or completely covering the carotid artery in most patients in both approaches. When attempting to cannulate the internal jugular vein, clinicians should be aware of the large anatomic variations.