 This procedure typically utilizes an 8-cm, 18-gauge needle that is inserted between the xiphoid process and the left costal margin until it enters the pericardial sac, when it can then be used to drain the fluid from the sac.A catheter is often left in the pericardium to continue draining any remaining fluid after the initial procedure.The catheter can be removed when the hemopericardium no longer persists.