The anterior jugular venous system: variability and clinical impact.

The anterior jugular venous system, with its interconnections to the subclavian and deep jugular veins, provides a collateral venous network across the midline of the neck area, which is especially important in unilateral occlusion of an innominate vein. We illustrate the variability of this system and its clinical impact on catheterization by three cases of landmark-guided central venous cannulation. Case 1: Cannulation of the left internal jugular vein with a central venous catheter and of the left innominate vein (LIV) with a pulmonary artery catheter resulted in correctly positioned catheter tips. However, these catheters were actually not placed in the innominate vein but coursed through the jugular venous arch. Case 2: Cannulation of the left subclavian vein was complicated by resistance of guidewire advancement at 13 cm. Occlusion of the LIV and enlargement of the jugular venous arch were present. Case 3: Insertion of a pulmonary artery catheter and a central venous catheter through the LIV. The pulmonary artery catheter was correctly placed. The tip of the central venous catheter was mistakenly positioned in the left anterior jugular vein. We describe the normal anatomy of the anterior jugular venous system and its role as a major collateral. Correct placement of central venous catheters may be possible via the anterior jugular venous system. Conversely, central venous catheters malpositioned in the anterior jugular vein can increase the risk for complications and should be removed.