Topographical anatomy of central venous system in extremely low-birth weight neonates less than 1000 grams and the effect of central venous catheter placement.

Central venous catheterization is widely used in neonatology. Although ultrasonic guidance for central venous catheter placement is available, complications occur significantly more frequently in infants, especially neonates, than in adults. This study seeks to determine the characteristics, topographical conditions, regional relationships, and diameters of the venous structures of the upper extremity and the thoracic central venous system in extremely small preterm neonates (mean: 900 g). Nine formaldehyde-fixed preterm stillborns were prepared (mean 27 2/7 weeks' gestational age). The anatomical preparation involved the complete thoracic wall, neck and shoulder region, and preparation of the upper extremities. It was shown that the course of the internal jugular vein can be influenced by rotation of the head. Maximum head rotation (80°) to the contralateral side leads the internal jugular vein to overlap the common carotid artery and sharpens the confluence angle of the internal jugular into the brachiocephalic vein. We propose that this has the potential to result in dislocation of the catheter. Less rotation of the head (<30°) is favorable as the internal jugular vein and common carotid artery run in parallel. Commonly used central venous catheters (2F-4F) may not occlude the vascular lumen completely. Small central venous cannulation using a single-orifice catheter through arm veins (1F) may also not occlude peripheral vessels of the upper extremity (cephalic and basilic veins). The right internal jugular vein has a straight course, appears suitable for central venous access and less hazardous, especially when using stiff catheters. The use of small straight wire guides is recommended.