Paracentesis is usually done in a lateral decubitus position (or supine, for large volumes). The level of the ascites fluid is percussed and a needle is inserted in either in the midline(2-3 cm below umbilicus) or lateral lower quadrant (lateral to rectus abdominus muscle, 2-4 cm superomedial to anterior superior iliac spine). This positioning prevents puncture of the inferior epigastric arteries; visible superficial veins and surgical scars should be avoided too. To reduce risk of ascites fluid leak, the needle is inserted either with a z-tracking technique, or at a 45-degree angle.