Procedure

1. After haemostasis of the median sternotomy wound, apply an internal mammary retractor to elevate the left hemi-sternum. The pericardium may be left closed.
2. Position the patient so the internal sternal edge is just above eye-level. This would mean raising the bed and rotating it away from the operator. The operator may be standing.
3. A large swab is placed on the pericardium and lungs to protect them.
4. A long diathermy spatula blade is used with the blade bent at about 30 degrees. Diathermy setting is 4. The blade is cleaned of any charred materials and a scratch pad is used intermittently to ensure it is clean throughout the procedure.  Char can cause inaccurate diathermy and unintended thermal injury to surrounding structures. By staying <1mm above the intended cutting surface, the diathermy current performs the cutting and not the physical action of the blade. The blade can be used to perform blunt dissection.
5. A long non-toothed pair of forceps is used to grab the fascia and hence to provide retraction of the vessels. It is not used to grab the vessels between its blades. The blunt closed tip may be used to push down the vessel from the chest wall.
6. Start near a rib where there is likely to be no collaterals. Feel the ITA pulsation to determine its location. Visualise the ITA.
7. Cut longitudinally not more than 1cm away medial to it to create a window into the plane between the endothoracic fascia and the parietal pleura. This avoids the artery as well as its surrounding pair of venae comitantes. Keep as much of the pleural fat on the side of the parietal pleura when creating this plane. Create marks parallel to the mammary pedicle and connect them.
8. Open this plane completely from the 2nd intercostal space towards the xiphoid, where the ITA branches into the musculophrenic and superior epigastric arteries. Now the ITA and ITV are covered only by the endothoracic fascia and intermittently by the transversus thoracis muscle.
9. Retract the fascia and cut into it 1cm medially to the medial ITV to create a window into the plane between the vessels and the overlying endothoracic fascia. Use the blade to bluntly dissect away the fascia and the current to cut. When a branch is encountered, clip it close to the vessel. On the sternal side, coagulate or clip depending on the size of the branch.
10. The vessels are pushed away from the sternum using the closed forceps.
11. Once all the vessels are mobilised and the pedicle freed, heparin can be given.
12. The distal end is clipped and cut. The ITA should bleed freely. A ligaclip is used to clip the end. The proximal end is freed to the first intercostal space.
13. The vessel is placed in a papaverine-soaked swab and treated liberally with papaverine solution sprayed on it. The vessel is then rolled with the swab and placed into the left pleura.