Sono-anatomy of the supraclavicular region for ultrasound-guided subclavian vein catheterization: revaluation of a former method

Ultrasound-guided subclavian vein (SCV) catheterization offers an alternative approach to the classical jugular vein catheterization for central venous catheter placement. The objective of this study was to evaluate the anatomy of the supraclavicular region in healthy volunteers using ultrasonography, specifically for the catheterization of the subclavian vein. Additionally, we aimed to determine specific sonographic measurements of this anatomic region. This was a prospective observational study and received approval from the local ethical board. Twenty healthy volunteers (10 male and 10 female) were included in the study. The supraclavicular region of the volunteers was scanned using ultrasonography. The diameter of the subclavian vein (SCV), the distance from the SCV to the skin, the distance from the SCV to the sternocleidomastoid muscle (SCM), as well as the distances from the SCV to the pleura and from SCV to the clavicle were measured. The changes in the SCV-skin distance and SCV diameter before and after performing a caudal traction maneuver on the arm were noted. Additionally, we determined the optimal probe position for visualizing the SCV in the long axis at supraclavicular fossa and identified the ideal needle insertion point. The mean diameter of the subclavian vein (SCV) was 9.47 ± 1.78 mm. The mean distance from the SCV to the skin was 10.55 ± 2.01 mm, the mean distance from the SCV to the pleura was 9.16 ± 1.26 mm at the medial one-third of the clavicle. The optimal angle for probe positioning was determined 12.75 ± 7.16 degrees from the coronal plane. The ideal needle insertion point was found 4.53 ± 0.70 cm lateral to the medial head of the clavicle. The SCV diameter and SCV-skin distances did not significantly differ from the neutral position after caudal traction of the arm. In the present study, the normal sonographic anatomy of the subclavian vein, the optimal ultrasound (US) probe angle to visualize the SCV, and the ideal needle insertion point for SCV cannulation in the supraclavicular region were identified for adults. This information serves as a valuable guide for clinicians performing either a blind or ultrasound-guided placement of SCV catheter at the supraclavicular fossa. Additionally, the diameter of the SCV did not change significantly after applying caudal traction to the arm, indicating that this maneuver is unnecessary.