Stage 2: Placement of ECLS Cannulas
We will assume for a moment that your patient hasn’t achieved ROSC.
Continuing our operating room-quality sterile technique we now place a long wire (found in most of the commercially available ECLS cannula kits) through each of the lines placed in Stage 1. Those original catheters are removed. The vessels are dilated using serial dilators (ours are included in the ECLS cannula kits we use) and the large ECLS cannulas are placed in each of the respective vessels.
A simulation of that procedure can be seen here:
[vimeo 85416517 w=740]
And a real-life version of Stage 2:
[vimeo 85418501 w=740]
Choose size of venous and arterial catheters
For Adults:
Venous 17-21 F
Arterial 15-19F
Depth of Arterial Catheter
In adults, the arterial catheter is placed until its full length is inserted
Estimate the Depth of the Venous Catheter
Lay the catheter against the groin to the umbilicus and then to the xiphoid, note this length
Upsize the Catheters
Place a wire into the existing stage I catheter and remove the catheter Make a larger cruciate incision above the wire (Joe prefers a single, deep stab incision) with the scalpel blade facing away from the wire. Both the skin and the subcutaneous tissues will need to be incised.
Sequential dilation
May be aided by placing saline on the dilators The dilators must be placed parallel to the vessel (otherwise the wire is easily kinked and then badness ensures) A twisting motion aids in placement. You or preferably an assistant should hold on to the wire and frequently gently advance and pull back to make sure the wire is still moving freely in the dilator (i.e not kinked). Joe has discovered that the Amplatz Superstiff wires may be far superior to what is included in the ECMO catheter kits. These wires are kink resistant, but with soft vascular tips.
Place the Catheter
After dilation., the last dilator goes inside the catheter when placing the catheters there is a tendency for the dilator to be pushed backwards as you advance the catheter. THis can cause buckling of the catheter tip and make insertion difficult or impossible without getting a new catheter. So you will need to hold the catheter and dilator together as a unit as advancing (a locking mechanism like those on many trancutaneous pacemaker sets would be helpful, but oh well).
Pull the Wire
Pull the wire and cover the hole in the dilator with your finger. Doing this before pulling the dilator allows immediate clamping of the cannula as soon as the dilator comes out.
Pull the Dilator
In one smooth motion, pull the dilator, allow the cannula to back bleed until blood is nearly at the proximal end. Clamp with a tubing (atraumatic) clamp.
