Ultrasound-Guided Vascular Access

[Reza Rajebi]

Vascular access is one of the most important steps in performing several interventions. Ultrasound (US)-guidance is extremely popular. Multiple interventions will start with vascular access such as: diagnostic procedures, tube/catheter placement, implantable device placement and therapeutic procedures.

Vascular access could be arterial or venous. Femoral artery is the most common artery used for arterial access in IR. It is mainly used for diagnostic arteriography and therapeutic purposes such as visceral angioplasty.

Jugular vein is the most common vein used for venous access. It can be used for long-term central venous access and central venous therapeutic procedures. Femoral vein is also used for therapeutic purposes.

PICC (Peripherally Inserted Central Catheter) (So, no PICC line, it is redundant) is placed through large upper extremity veins.

After standard surgical preparation and draping, local analgesia with 1% lidocain can be achieved. Access needle measures 21 to 18 Gauge (0.8 mm-1.3 mm Nominal Outer Diameter). A coaxial access wire is required to convert. Peel-away sheaths, side-port vascular sheats and dilators can be used for different applications.

Preaccess US exam is important and should be recorded. To differentiate between artery and vein pressing down on the vessles using the transducer is helpful. Veins compress first.

The transducer usually placed transverse to target vein. Panning the transducer down as advancing the needle helps tracking the tip. The needle can tent the venous wall. However, the tip should be seen in the lumen to confirm the access. A 0.018" wire can be advanced. Fluoroscopic confirmation is needed at this point. Subsequently, a transitional sheath can be used and you are done. Almost always, you will start the actuall procedure now.

Major complications are rare and include bleeding, expansile hematomas, infection and arterial injuries such as dissection.

I hope this is useful. Please let me know.

RR

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[werewethere]

Vascular access is one of the most important steps in performing several interventions. Ultrasound (US)-guidance is extremely popular. Multiple interventions will start with vascular access such as: diagnostic procedures, tube/catheter placement, implantable device placement and therapeutic procedures.

Vascular access could be arterial or venous. Femoral artery is the most common artery used for arterial access in IR. It is mainly used for diagnostic arteriography and therapeutic purposes such as visceral angioplasty.

Jugular vein is the most common vein used for venous access. It can be used for long-term central venous access and central venous therapeutic procedures. Femoral vein is also used for therapeutic purposes.

PICC (Peripherally Inserted Central Catheter) (So, no PICC line, it is redundant) is placed through large upper extremity veins.

After standard surgical preparation and draping, local analgesia with 1% lidocain can be achieved. Access needle measures 21 to 18 Gauge (0.8 mm-1.3 mm Nominal Outer Diameter). A coaxial access wire is required to convert. Peel-away sheaths, side-port vascular sheats and dilators can be used for different applications.

Preaccess US exam is important and should be recorded. To differentiate between artery and vein pressing down on the vessles using the transducer is helpful. Veins compress first.

The transducer usually placed transverse to target vein. Panning the transducer down as advancing the needle helps tracking the tip. The needle can tent the venous wall. However, the tip should be seen in the lumen to confirm the access. A 0.018" wire can be advanced. Fluoroscopic confirmation is needed at this point. Subsequently, a transitional sheath can be used and you are done. Almost always, you will start the actuall procedure now.

Major complications are rare and include bleeding, expansile hematomas, infection and arterial injuries such as dissection.

I hope this is useful. Please let me know.

RR

You mention major complications are rare. What's more, significant central line placement complications when done blind are 4% in the hands of experienced operators.
So, any tips out there on how to minimize complications? How to manage complications such as hematoma, dissection, arterial placement of a venous catheter?

 

[Gvataken]

If you are accessing an artery and have a small dissection ften times ok. If it is retrograde dissection often times not an issue. But, in general I will make sure that I have brisk arterial flow through the 19 gauge needle and then advance a bentson guidewire (very safe atraumatic tip). I will watch it under fluoro to see if it goes smoothly.

The key to preventing hematomas is single stick under ultrasound, and then make sure you see the tip of the needle in the center of the vessel. The nxt thing I do is I will serially dilate it and make sure I put a catheter that tapers up so it tamponades.

But, really practice makes perfect. The more you do the better feel you will get. Alot of IR is a feel of how much to push etc.

 

[HalO'Thane]

I am a pediatric anesthesiologist. Lately I have been practicing with the ultrasound for peripheral IV and radial arterial line access. In the past I had been going in the transverse plane but I have recently been experimenting with the in plane view for line placement. I feel that I can better visualize the needle in the vessel this way. When I turn the ultrasound probe 90 degrees to the in plane view, I notice that the back wall of the vessel turns hyperechoic. Is this usually the case? If so, is this because it is in stark contrast to the hypoechoic blood? Finally, does this apply to both arteries and veins? If this is the case, then it seems like it would be a very useful landmark for knowing that you are in the vessel. This may seem like a basic question to you guys but I am just getting started with this technique and wanted to get insight from the experts. Thanks.

 

[shark2000]

Good discussion.
It is a must skill for general radiologist. I recommend rad residents to get good at it.
It is relatively easy. These are common procedures for hospital based practice, that you may be required to do. Though, these days in pp senior partners prefer to hire an IR newbie to take care of these stuff to make it easier for them.

 

[RedMorning]

I am a pediatric anesthesiologist. Lately I have been practicing with the ultrasound for peripheral IV and radial arterial line access. In the past I had been going in the transverse plane but I have recently been experimenting with the in plane view for line placement. I feel that I can better visualize the needle in the vessel this way. When I turn the ultrasound probe 90 degrees to the in plane view, I notice that the back wall of the vessel turns hyperechoic. Is this usually the case? If so, is this because it is in stark contrast to the hypoechoic blood? Finally, does this apply to both arteries and veins? If this is the case, then it seems like it would be a very useful landmark for knowing that you are in the vessel. This may seem like a basic question to you guys but I am just getting started with this technique and wanted to get insight from the experts. Thanks.

What you are describing may be related to a term we call "posterior acoustic enhancement" and is caused by sound waves travelling at different speeds through fluid compared to soft tissue. This may be more apparent on a longitudinal view, but if you look closely you can probably see it along the posterior aspect of the vessel on the transverse view as well.

We use this a lot to determine if lesions are solid or cystic, but I've never really heard it described in blood vessels before, I assume because the vessels are so small and this artifact is less pronounced. Also if we think something is a vessel we put doppler on it.

 

[HalO'Thane]

What you are describing may be related to a term we call "posterior acoustic enhancement" and is caused by sound waves travelling at different speeds through fluid compared to soft tissue. This may be more apparent on a longitudinal view, but if you look closely you can probably see it along the posterior aspect of the vessel on the transverse view as well.

We use this a lot to determine if lesions are solid or cystic, but I've never really heard it described in blood vessels before, I assume because the vessels are so small and this artifact is less pronounced. Also if we think something is a vessel we put doppler on it.

Thanks for the input everyone. My use of the longitudinal view is still a work in progress, especially on the infants/neonates with tiny (1 mm) vessels. It is the preferred method for the Interventional Radiologists in our hospital for vascular access and it is pretty cool to watch them in action.

 

[kubIR]

Its true that with the longitudinal view it is easier to see your needle, but it does take some accuracy away in terms of hitting the true center of the vessel, increasing the potential to 'skive' off the vessel wall. I would recommend at least turning back to the transverse view when you are right on top of the vessel to make sure you are hitting the middle. This is not as big of a deal in venous, but one clean stick is important in arterial access.

 

[IRneuroIR]

In the longitudinal view requires extreme precision with the needle to keep it in the plane of the US -- very easy to have millimeter changes take the needle out of plane and potentially hit the sidewall of the vessel or adjacent structures.

Just this week, I had a case of a popliteal artery pseudoanuerysm caused by a vascular surgeon attempting popliteal venous access using the longitudinal view -- he hit the artery a couple of times with a micropuncture (21-G) needle and proceeded with thrombolysis in the vein despite this. We had to bail him out with US-guided thrombin injection for the pseudoaneurysm.