0:01

So here's a little question for you.

0:02

So tell us the different parts of the needle.

0:05

So if we start up top, there's

0:07

the hub, the base of the needle.

0:08

That connects to standard things like

0:11

syringes via a luer lock mechanism.

0:13

There's the shaft, the body of the needle, okay?

0:16

And then there's the bevel, which is a

0:17

little bit of a curved edge, you know?

0:19

And the whole goal with that bevel

0:22

is when we're getting access, we're

0:23

pointing up towards the skin, ventrally.

0:27

So that when we sort of get access, our

0:29

wire then, oop, sort of exits out anteriorly

0:32

and superiorly in order for us to sort

0:34

of maintain our intravascular presence.

0:37

So what are the key components

0:38

of a vascular access toolbox?

0:41

You guessed it, there's the needle.

0:44

What's that?

0:45

That's the guide wire, the mandrel wire.

0:48

There is that, which is what?

0:50

The end.

0:50

inner dilator of a transitional dilator.

0:54

And this transitional dilator is often four

0:56

French, the outer portion that is tapered to 0.035 inches.

0:59

035 inches.

1:00

And this is the inner portion,

1:02

which is either stiff or soft, and

1:05

that's either tapered to 3 French or 0.018 inches.

1:08

018 inches.

1:10

So if you were to look at this, it's

1:11

pretty clear what this is, right?

1:14

This is a micropuncture kit.

1:16

This is our bread and butter as

1:17

it relates to vascular access.

1:18

Here's our 21 gauge needle,

1:20

which we've seen before.

1:21

No surprises there.

1:22

There's our inner transitional

1:24

dilator, 3 French, tapered to 0.

1:26

018 inch.

1:27

And then there's the outer portion

1:29

that allows us to convert to 0.

1:31

035 inches.

1:32

And there's our nice 0.

1:33

018 inch wire, or our mandrel wire.

1:37

If we were to look into the micropuncture

1:38

kit, we look at that sort of transitional

1:40

dilator when it's hooked up together

1:42

as a unit, like a transformer itself.

1:45

There's the outer 5 French catheter.

1:47

There's the inner 3 French diameter.

1:51

That allows us, again, to transition from

1:53

0.018 inch, our micro wire, to our what?

1:56

Our 0.035 inch working wire.

1:56

58 00:01:58,744 --> 00:02:01,404 So when we talk about micropunctures,

2:01

we're always talking about 21 gauge.

2:03

And the beauty of that is that allows

2:04

us to reduce trauma to the vessel,

2:06

which is why a lot of folks use it.

2:08

The negatives is, of course,

2:09

we then need to go from 0.

2:10

018 inch to 0.

2:11

035, but our transitional

2:13

dilator facilitates that.

2:15

In the past, some people would use 18 gauges,

2:17

you know, if you're sort of doing a lot of

2:19

sort of peripheral arterial disease work

2:20

and accessing grafts and things of that

2:22

nature, you may go with an 18 gauge needle.

2:24

And that allows immediate access.

2:25

Boom.

2:26

Transition to 0.035 inch wire, which is our working wire.

2:28

77 00:02:30,760 --> 00:02:33,140 There's a scarred vessel, sort of, scarred sort

2:33

of groin, you know, as they call it, sort of

2:35

a little bit of a hostile groin, 18 gauges,

2:37

allows you to get in and get straight to work.

2:40

Trauma is really one of the downsides, one

2:43

of the negatives, the fact that if you were

2:44

to mistakenly get access and cause issues,

2:48

you know, you really want to make sure

2:50

that you hold good pressure after the fact.

2:55

If we were to sort of think through vascular

2:57

access, there are some other characteristics of

2:59

our access that we need to keep in mind.

3:01

One of which is the single-wall

3:03

versus the double-wall technique.

3:06

The double-wall technique is going through

3:07

the ventral surface of the vessel into the

3:11

intraluminal space out the dorsal posterior

3:15

wall and then pulling back slowly and waiting

3:18

for blood to exit from the hub of the needle.

3:21

Then there's the single-wall, which is

3:23

kind of like the Navy SEALs approach.

3:25

Get in and get to work.

3:27

You go from the outside through

3:28

the skin and then into the what?

3:31

Intraluminal space, right?

3:33

So gets in, sees the blood. Usually, a good

3:36

technique that's used via imaging guidance,

3:40

ultrasound guidance, whereas the 18-gauge

3:42

double-wall approach is

3:45

often used with individuals that are getting

3:47

landmark access, non-image guided access.

3:51

So 18-gauge or 19-gauge double-wall is often used,

3:54

and usually single-wall, 18-gauge or 21-gauge.

3:58

Again, double-wall allows us

4:00

to get access through.

4:02

And then, in contrast to the single-wall

4:04

technique, we're hitting ventral and dorsal walls,

4:07

and then we're pulling back in order to

4:09

ensure that we're in the vessel, ensuring that

4:12

blood is actually exiting the hub, as we see here.

4:17

So one of the things that's, I think, most

4:19

important as we sort of move through our guidance

4:22

is really understanding when do we use one

4:25

versus the other, single versus double wall.

4:28

So when should you use this double-wall technique?

4:30

Well, if you have patients that have

4:33

significant plaque, you may consider

4:36

that a single-wall may not be achievable.

4:40

So, maybe let's do a double-wall technique to

4:43

get through the ventral surface, through the

4:44

dorsal surface, and then be able to retract

4:46

that needle to ensure that we're in place.

4:49

So, this significant plaque actually

4:50

increases the difficulty of the single

4:52

wall access, so an alternative double

4:54

wall access may actually be appropriate.

4:57

So what is the advantage of using

4:59

a double wall versus a single-wall

5:00

needle?

5:01

So let's sort of break this down.

5:03

So, as I mentioned, one of the

5:06

things about the double-wall technique

5:08

is it's a technique that sort of

5:09

ensures access, but it's more trauma.

5:12

One of the beautiful things about it is that

5:14

what we often don't consider is that if somebody

5:17

has a lot of plaque in their vessel, perhaps

5:20

in the ventral wall, if we're going with the

5:21

single-wall technique, what can often happen is

5:24

that we may actually think we're intraluminal,

5:26

part intraluminal, part within the wall, the

5:29

ventral wall, and we send a wire, and the

5:31

wire then dissects the vessel, okay?

5:34

The beauty of the double-wall

5:35

technique is we go through and through.

5:38

The risk of dissection actually has been reduced.

5:41

But again, it cannot be overstated that

5:43

we are causing additional trauma

5:46

to the vessel with the double-wall

5:47

technique in the posterior wall puncture.

5:51

And this is one of the many reasons why

5:53

the interventionists around the globe

5:56

very much prefer the single-wall entry.

6:00

So one of the things that I am particularly, uh,

6:03

a proponent of is being mindful of complications.

6:06

If we don't anticipate something and

6:10

are aware that things can happen,

6:13

we may actually succumb to those things.

6:16

If we don't know that a dissection or a

6:19

thrombosis or a non-target embolization

6:23

is a potential complication of our

6:25

procedure, we may, unbeknownst to us,

6:28

end up falling prey to this very thing.

6:32

So let's look at this case of a 57-year-old

6:34

woman who presents with a complaint

6:35

of right leg numbness about two days

6:37

after a common femoral artery access.

6:40

What does her angiogram show?

6:41

It reveals a bit of

6:42

an intramuscular dissection.

6:43

And what we see is a spiral dissection through the

6:47

vessel, and we see different layering of contrast

6:51

within the common femoral and external iliac

6:55

arteries, and we see an abrupt cutoff of contrast in

6:59

this patient who has a flow-limiting dissection.

7:03

There are times when the dissection

7:04

is not flow-limiting and it may

7:07

actually resolve spontaneously.

7:09

A non-resolving dissection may

7:10

actually require surgical repair.

7:13

This is another dissection in an

7:16

individual who had claudication

7:19

of his left arm, left upper

7:21

extremity, after he had a bit of a

7:24

complicated brachial artery access, okay?

7:27

So he had intended superior mesenteric artery

7:29

stenting from a brachial access at an outside

7:32

hospital, and then came in with this sort

7:35

of arm claudication, not presyncope, which is

7:38

one of the things that can actually occur in this

7:40

patient, but what we see is this nice dissection

7:43

flap, nice and clean, very subtle, at the origin,

7:47

extending to the origin of the left subclavian

7:51

artery in this patient who subsequently had an

7:53

aborted access because of this flow-limiting,

7:58

or in the case of this procedure, that was

8:00

aborted catheter and wire obstructing dissection.

8:05

So what's the advantage of using a 21-gauge

8:07

versus an 18-gauge single-walled needle?

8:10

Well, if the operator is unsuccessful

8:12

with the initial stick, time to

8:15

hemostasis actually could be faster.

8:17

An unsuccessful stick with the large

8:19

18-gauge needle requires a 5-minute compression for hemostasis.

8:20

212 00:08:22,419 --> 00:08:24,380 If you are trying to maybe get to the

8:24

vein, the common femoral vein,

8:25

and you hit the artery, oh, not great.

8:28

Got to wait five minutes, pull that needle out,

8:30

and achieve compression-facilitated hemostasis.

8:34

But, you know, the 21-gauge is less

8:37

traumatic, and the 21-gauge needles are smaller

8:39

and, in these situations, they can allow

8:42

you to sort of, you know, transition to that

8:44

0.018 inch that, again, in theory,

8:47

requires you to then transition to the

8:50

0.035 inch wire, which is, as we know, the working wire.