Step-by-step transthoracic cannulation
For educational purposes only
Setting up the room
Distribute a surgical hat and mask on the scrub nurse, surgeons, bedside nurse, and all in room. All providers in the room must be in scrubs.
As the surgical team prepares the surgical field (as described below), the medical team should prepare the following:
1. Attach push line for medication administration. Use the most central catheter possible (e.g. RA line or IJ). If using RA or CA line, ask surgeon whether the venous cannula will take that position (otherwise the catheter may have to be removed during the cannulation).
2. Place two dedicated suction canisters and regulators at back of room for surgical field. Also move bovie to back of room before surgical equipment moved in. It may be helpful to have a nurse stay in the back of room to change infusions, change suction canisters, and change bovie settings.
3. Attach pacing wires to pacing box and move box to an accessible place for once the sterile field is established. Consider changing to asynchrous pacing (e.g. DOO) mode if bovie will be used.
4. Place bovie ground onto patient and plug it into the electrocautery machine.
5. Place roll under neck of patient. Recall that this moves the ETT farther from the carina – confirm EtCO2 after repositioning.
6. Consider hand ventilation.
7. Consider placement of ice on head (in neonates in a CPR or near-CPR situation). When creating ice pack, place water into bag of ice to create a cold slush (make sure to seal), which helps to cool the head most efficiently.
8. Once everyone in room is in scrubs with hats and masks, the surgical team will remove the sternal dressing. Be very careful not to remove atrial lines, wires, or chest drains which are closely adherent to the dressing.
Scrub the surgical site, including all wires and tubes in field.
Surgical team prep
The scrub nurse and surgical team will scrub with sterile scrub and gown as shown. All members of the medical team who will be the surgical field – such as those performing CPR – need to do the same. Surgical gowns are to be tied in the back and then the sterile party rotated around while the tag in the front is held stationary by a bystander. Hold the tag firmly so that the sterile string remains sterile when it is pulled out of the tag.
Preparing the surgical table
Position the surgical table so that the doors and drawers open AWAY from the patient. This allows others to access the drawers to retrieve what you need.
Open the surgical pack. Create a sterile field on the table.
Set up the table as shown above. The most critical part of this is the instrument ‘stringer’. These should be set up as follows.
Setting up the instrument string is simple but easily messed up (which makes it MUCH harder to find what you need quickly).
1. Roll up a sterile towel TIGHTLY.
2. Pull the instrument string out of the crate and place them so that the dead space of the instruments fits snugly into the tightly rolled sterile towel. This will keep the instruments upright when the stringer is removed.
3. With one hand on top of the instruments, remove the short end of the stringer and then remove the stringer carefully from the instruments. This should leave a NEAT row of instruments that are standing straight up like this.
Prepping the patient
After prepping the sternum and all hardware in the field, remove the Esmark, and then place drapes around the surgical field as shown above. These can be secured around the edges with towel clamps (called ‘Ednas’).
Then place the sterile drape over the field and secure further. A window that is tight to the surgical field is cut using scissors. Suction and the Bovie pen are also attached and sent to the head of the bed. Someone should be prepared to receive suction (attach to suction canisters) and Bovie (attach to electrocautery device – usually set at 10 cut and 10 coag). Ensure suction is working sufficiently well.
The first step is to open the sternum. If an Esmark is in place, the surgeon will just need scissors (curved scissors, called Metsenbaums, or ‘Metsies’). Otherwise, they will need a scalpel and wire cutters.
Once the sternum is open, a sternal retractor is placed. Larger sized sternal retractors are needed for adults, and are available in the mediastinal cart.
Sometimes, a ‘stay suture’ is used to retract pericardium out of the way. Some surgeons call this a ‘V7’, named for the needle code. Typically, this is a 2-0 or heavier suture material, often Ethibond (orange packaging). In a pinch, this step is often skipped or may be unnecessary. However, it can be critical to help obtain exposure to the aorta.
The first step in the cannulation itself is to isolate the arterial cannulation site. In a transthoracic cannulation, this may be either done in one of two ways.
1. Through a ‘chimney graft’, which is a tube of goretex that was sewn onto the innominate artery for CPB and has been left behind for moments like this. This is typically the case in a stage 1 palliation who returns with an open sternum, for example. In this case, a needle driver (see above) will be used to remove the clips that were placed on the graft, a small amount of blood/thrombus allowed to bleed back, and then a ‘curved snap’ placed. An arterial cannula is then easily placed through this with the tip just into the innominate artery.
2. Otherwise, the surgical team will isolate the ascending aorta, typically using the Bovie (preferably including a shielded Bovie tip, which has to be provided separately) and pickups as instruments. In a transthoracic cannulation, this is typically quick since the patient will have had surgery in the past 7-10 days.