Manning Definitive Review on Endovascular Access
Femoral vascular access for endovascular resuscitation
Where is the Inguinal Ligament?
Relationship of Inguinal Crease vs. Ligament
http://www.tamingthesru.com/blog/procedural-education/the-anatomy-of-femoral-vascular-access
Pad Under Butt to Straighten Femoral Vessels
Jason Bartos on How to Troubleshoot Arterial Access
I definitely agree with Joe’s point on patient positioning as we sometimes charge ahead with suboptimal position for speed, but when things aren’t working it’s worth optimizing the position as he described.
Here are some additional thoughts. I’m sure you have done, or did do, some of these already but I mention them all for completeness. I assume that you were using ultrasound given that you knew the vessel size. Fluoro can be helpful in these cases as well but often is not available in a timely manner unless you have contingency plans ahead of time. There are many potential problems and solutions depending on the kits that you’re using for access, patient characteristics, etc. That said, here are a few considerations depending on the problem:
Difficulty getting blood flash through the needle
I say this to distinguish from difficulty getting in the vessel. We have patients that have no arterial pressure whether it’s caused by very poor CPR or thrombus in the aorta or iliacs.
–I would make sure you’re aspirating on the needle using a syringe rather than depending on passive blood flow when you get into the vessel. You may have been doing this, but I mention it for completeness.
Difficulty getting into the vessel because it is small and/or moving
– perhaps even bouncing off your needle due to calcification or high mobility
–Sometimes a 21G micropuncture needle is better than a standard 18G perc needle as it penetrates the vessel with less pressure.
Difficulty getting into the vessel because it’s just a small target
– use a more shallow angle of approach so you have larger margin of error for landing the needle in the lumen. I will sometimes access at a 20 or 30 degree angle.
–Needle bouncing off due to calcium – may need a steeper angle of attack to poke through calcium – sometimes 60-80 degrees is needed
Difficulty getting a wire into the vessel (may be vessel tortuosity severe calcification):
–if you’re using a stiff wire – may be easier to advance with a softer wire – not the wire that comes with the dilator kit as that wire is not helpful – a 0.035″ wire from cordis or similar. If you have great blood flow, you could try a straight wire or even a hydrophilic wire (glidewire)
–Often it is easier to go proximal or distal on the vessel to get around the tortuosity or calcification – if it’s a choice between cannulating the superficial femoral artery or not getting cannulated, I have had to choose the SFA. Distal perfusion catheter placement is even more important in this case.
Wire advances into the vessel but not as far up as needed (sounds like this was not your problem but I mention it for completeness):
–Can upgrade to a stiff wire which will avoid branches on the way up
–If it’s due to tortuosity, a softer wire can be better but it’s difficult to know without imaging
–May need imaging to maneuver around branches or tortuosity
–Could be a chronic occlusion of the iliac – use the other groin
Lastly, remember that the inception trial had a 10% failure rate for cannulation so if you do enough you will run into these cases. You do the best you can and plan for contingencies when you can.