The optimal insertion length of central venous catheter via the femoral route for open-heart surgery in infants and children

Background: The recommended insertion length of central venous (CV) catheter via the internal jugular or subclavian vein has been determined in infants and children. However, the insertion length via the femoral vein has not been well-studied. This study determined the optimal insertion length of CV catheter via the femoral vein. Methods; Infants and children, who had undergone cardiac catheterization via the right femoral vein, were the subjects of the study. After routine cardiac catheterization, the distance from the femoral puncture site to the third lumbar vertebral body (L3) level, was measured and recorded. The femoral-L3 length was termed as the optimal insertion length. Results: This length was measured in 78 infants and children (age: 1-101 months, weight: 3.1-33.8 kg). The body weight of the patient and the length correlated well: the optimal insertion length (cm) = 0.45 x body weight (kg) + 8.13, coefficient of determination (R-2) = 0.84. Conclusions: It has been recommended to place the tip of the catheter below the level of renal veins to avoid blocking free flow of those veins. Therefore, we chose the mid-point, L3 level as the optimal tip position of the femoral venous catheter. The length derived from the above formula could be used as a guideline for CV catheter insertion via the femoral vein in infants and children.