The airway device preference may affect the overlapping of the common carotid artery by the internal jugular vein

Background: Anatomical variation in the internal jugular vein (IJV), as well as its small size, tendency to collapse, and proximity to the common carotid artery (CCA) makes central venous cannulation via the IJV a technically challenging procedure, especially in pediatric patients. Aim: We evaluated the effects of laryngeal mask airway insertion and endotracheal intubation (ETT) on the anatomical relationship between the IJV and the CCA in neutral and 40° head away positions. Method: After parental consent 92 patients with ASA physical status I-II, aged 0–17, undergoing elective urological surgery were enrolled and divided into two groups according to the airway management device used for anesthesia: Group laryngeal mask airway (n = 63) and Group ETT (n = 29). An ultrasonographic evaluation was performed before and after airway instrumentation at neutral and 40° head rotation. The IJV position in relation to the CCA was noted, and the overlap percentage of the CCA was calculated as the ratio of the CCA length covering by the internal jugular vein to the transverse diameter of the CCA. Results: With no airway device insertion, the position of the IJV was found to be anterolateral to the CCA in the majority of patients (48.8% vs 35.3%, right vs left IJV) in the neutral head position. While there was no significant change in the overlap percentages of the CCA after laryngeal mask airway insertion in the neutral head position [48.71% vs 57.30% for the right IJV (difference in median: −21.20; 95% confidence interval (CI) of difference: −56.92 to 14.52; P = 0.133); 52.54% vs 60.36% for the left IJV (difference in median: −10.3; 95% CI of difference: −41.49 to 20.89; P = 0.128)], it increased significantly in the 40° head away position on both sides [50.11% vs 64.83% for the right IJV (difference in median: −55; 95% CI of difference: −84 to −25.24; P = 0.01); 53.82% vs 71.20% for the left IJV (difference in median: −46; 95% CI of difference: −86.85 to −5.15; P = 0.004)]. However, the overlap percentages of CCA decreased significantly on the right side with patients in a neutral head position (31.23% vs 6.27%, difference in median: 19; 95% CI of difference: −5.68 to 43.68; P = 0.002) and on both sides in the 40° head away position [29.50% vs 16.19%, difference in median: 26; 95% CI of difference: 2.84 to 49.16; P = 0.03 and 47% vs 31.94%, difference in median: 9.50; 95% CI of difference: −40.87 to 59.87; P = 0.03 for the right and left sides, respectively] after ETT insertion. Conclusions: Laryngeal mask airway with 40° head rotation increases, whereas ETT decreases, the overlap percentage of CCA by IJV. Both head position and airway management methods have an influence on the overlap of the CCA by the IJV in pediatric patients.