Comparing the anatomy of the intrathoracic systemic central venous system in Iranian pediatrics and adults based on chest CT scan and evaluation of rate of catheter malposition in children

Background: Central venous catheterization is a procedure that is being performed frequently especially in critical clinical settings. In such conditions, good knowledge of the surface anatomy of venous structures is vital to avoid possible complications which could result in life-threatening situations such as bleeding and pneumothorax. Considering the difference between venous anatomy of children and adults and even among different age groups of children, and the fact that our recent knowledge of anatomy is based on studies performed on non-Iranian population, we decided to evaluate the anatomy of the intrathoracic systemic venous system in adults and children and assess the rate of catheter malposition in children. Methods: This was a retrospective cross-sectional study performed in Dr. Shariati Hospital and Children Medical Center of Excellence, Tehran, Iran, from April 2016 to August 2019. In our study, the surface location of brachiocephalic vein (BCV) formation, the junction of superior vena cava (SVC) to right atrium and, formation of SVC were examined in 150 contrast-enhanced chest computed tomography (CT) scans in children. They were classified into three groups based on their age (neonates to three years, three to seven years, and seven to ten years). Also, 100 similar CT scans in adults were being studied. The other category which has been evaluated through 130 pediatric X-rays, was the location of the tip of the central venous catheter. Results: The formation of BCV was mostly depicted posterior to the sternoclavicular joint in adults while in children it’s located posterior to the medial aspect of the head of clavicle. In adults, the SVC formation was at first intercostal space (ICS) in 52% and second ICS in 29%. In first group of children, SVC was commonly at the level of 2nd costal cartilage (CC), but changed to the first ICS or first CC by increasing age. In adults, junction of right atrium to SVC was at the 3rd CC then 4th CC but in the first group of children was located at the 4th CC that changed to 3rd ICS /3rd CC by increasing age. Also, the tip of central venous catheters was located in the proper position in 74.7% of cases. Conclusion: This study indicated the different anatomy of central veins in children and adults which could be a cause for malposed central catheter, so knowing this difference and controlling the tip of the catheter by ultrasound during catheterization could help in avoiding this malpositioning.