One of the skills I had to learn as an attending was antegrade arterial access. Being in a training program with no PAD performed by IRs, antegrade access was an entirely foreign and daunting task when it became necessary in practice.
So what is antegrade femoral access? It’s basically sticking downhill, or downsticking the groin. Why would you ever consider doing this? When working from the other groin going “up and over,” it’s easy to lose pushability as the force you exert on your wire and catheter is transmitted over a round-about way to the lesion of interest. Going antegrade is essential for dealing with below the knee and below the ankle disease.
Thankfully, even without having formal training in this technique, I was able to use my existing skill set of safe-femoral ultrasound guided arterial access to gain access going the other way. There are several steps that need to be taken in order to do this safely:
- Consider alternative access first.
If you can achieve your intended results going from the contralateral groin, left radial or ipsilateral pedal approaches, then by all means go for it. Personally, I have not found left radial access to be very helpful for PAD work. The toolset is somewhat limited at this point. Contralateral femoral access is generally safe and accepted, however as discussed above it is difficult to intervene on distal lesions from this approach. I’m a huge fan of pedal access which I’ll discuss on another day, including antegrade pedal access for treatment of below the knee lesions. Long story short, consider alternative access if it’s feasible because groin complications are real.
- Aggressively retract pannus.
When you’re putting pressure on the groin with an ultrasound probe prior to sticking, it’s easy to get lost in a sea of soft tissue as your needle enters the skin. It’s hard to get a good sense of your needle trajectory which can make access complications more likely. Furthermore, as you let go of pressure after achieving access, the pannus can more or less rebound and flip your access to a retrograde direction if you stick too upright and not at a flatter angle.
So how do you retrace pannus? Some people use a pannus retraction system (Google it). I have my technologists aggressively tape. Do whatever works for you.
- Confirm sonographic compressibility.
Groin bleeds happen when your closure device fails or you can’t exert appropriate pressure at the arteriotomy. Most trainees are commonly taught to stick over the femoral head since that site is compressible. While this is true, the fact of the matter is any vessel can be safely stuck with a needle as long as you can compress it. There is no better way to assess compressibility than with a live ultrasound. So don’t waste your time fluoroing before accessl Just find the common femoral artery and proximal SFA and compress these sites and see what’s possible. If the proximal SFA is visible and compressible, go for it. It will make the process a lot easier.
- Approach the artery at an angle of less than 45 degrees.
Approaching the artery at a flatter trajectory than typical retrograde common femoral access is essential for ensuring that you can pass a wire into the SFA and not the profunda. Oftentimes, when you stick the CFA and pass a wire, it will want to take the profunda because the angle of needle entry will promote deeper wire access. When the needle bevel is facing towards the top half of the artery, the wire will tend to take a more superficial course. Wire passage into the SFA should be confirmed with ultrasound. Alternatively, ipsilateral angulation of the image intensifier 25-40 degrees can be used to confirm wire passage into the SFA as opposed to the profunda.
- Once access is achieved, confirm appropriate access with contrast injection through the inner dilator of a micropuncture sheath.
If you don’t like your position, you can safely remove the inner dilator and hold pressure for 5 minutes before resticking. Don’t commit to sheath placement until you know your access is safe.
So those are my tips for getting antegrade access. There are other ways to do this. Some people like to put a curve on the micropuncture wire. Others like to put a wire in the profunda, place a sheath in the CFA then use an angled catheter to direct into the profunda. I personally don’t find the wire trick all that useful, and I find overall the flatter angle of entry being key for me. I really don’t like to put a sheath in unless I’m confident with my access site because you really don’t have a lot of working room in the CFA to maneuver. You’d hate for your sheath to buckle out and be stuck holding pressure for 10-15 minutes.
Hopefully these tips help you.