Reflect the anterior thoracic wall to expose the contents of the thoracic cavity.   (G 3.24;N 193;Gl 8.1B)

1. Use the bone shears to cut ribs and intercostal muscles 2 - 5 along the mid-axillary line. Be careful of the sharp edges of the severed ribs.
2. Use a scalpel to cut the intercostal muscles from their attachments to the superior border of the 6th rib (from the mid-axillary line to the sternum).
3. Use a saw to cut the body of the sternum at the level of the 5th intercostal space.
4. Use a saw to cut both clavicles immediately lateral to the attachments of the sternocleidomastoid muscles.   (G 3.23;N 195;Gl 25.18)
5. Use the bone shears to cut the 1st rib in line with the cut through the clavicle.   Attempt to avoid cutting the subclavian vein.
6. Elevate the anterior thoracic wall and use your fingers to separate the thoracic wall from the underlying lungs and pericardial sac. You may need to tear adhesions between the parietal pleura attached to the thoracic wall and the visceral pleura surrounding the lungs.
7. Fold the thoracic wall back (superior direction) as far as possible while still leaving it attached through the sternocleidomastoid muscles.  
8. Use the bone shears to remove the 6th and 7th ribs from their fused costal cartilages to the mid-axillary line. Avoid damaging the diaphragm and attempt to avoid further damage to the internal thoracic vessels (and/or their terminal branches). These vessels were previously cut with the sternum.