By approaching the cephalic vein with an incision placed high in the deltopectoral triangle, instances in which the cephalic vein is absent or too small to cannulate will almost always result in the successful cannulation of an alternative vein located in this region. In those rare instances in which there is no vein which can be cannulated on one side, contralateral dissection is likely to be successful. Occasionally, a catheter will be seen to pass over the clavicle into the external jugular vein. The catheter should be withdrawn and rethreaded because repeat attempts at central placement will usually be successful.