How to do a AVF or AVG contrast evaluation with possible angioplasty and/or stenting

 

Review prior records of course, to see where problems were in past

 

use ultrasound to image the anastomosis

want to access the venous end, just central to the anastomosis

 

evaluate the fistula/graft clinically, eval for thrill

ask about high pressures at dialysis or decreased flow rates

can image the arm to evaluate for thrombosis or stenosis, use color flow

can figure out if its a declot, angioplasty or both

 

access using micropuncture kit

advance 21g micro needle towards venous outflow

advance microwire

upgrade to micropuncture sheath

can perform angio through the little sheath to look for stenosis

start peripheral at the level of the arm and image central, evaluating the whole outflow tract for stenosis, thrombosis or occlusion

can do hand injections at the table, use shield

place bentson wire, long one maybe

use 5F short sheath with sidearm

to track through outflow circuit, good choice is 4-5F kumpe and bentson vs. 035 stiff angled glide (SAG, go to wire for ZB)

 

if tracking through previously placed venous stents, make sure to take "single shot" to make sure wire+catheter tracks through stent and not through interstices

would not want to baloon through interstices, causing the advent of 'endotrash'

 

if ballooning, good choice is 4cm x 12mm or 14 mm, start smaller and go up

make note of burst pressures

try to prevent watermelon seeding of balloons

 

do pre and post DSA imaging

 

if burst vein, think about re inflating balloon to prevent bleeding, it will usually stop

 

image short segment of the arterial inflow as well

 

in order to do this, central II over that area

 

occlude the outflow using a hemostat or manual pressure, or possibly inflating a balloon

 

when closing the access site, use the "woggle' technique

scott trerotola

 

good video here:

https://www.youtube.com/watch?v=4mt-Hs8ekcs

 

place dressing and end case

 

work in progress

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how to do AVG pharmacomechnical thrombolysis (beleive this is the most accurate / modern term in 2016)

 

Goal is to declot a fully clotted graft with no internal flow, can be seen clically by lack of blood flow, by palpation, by lack of thrill, ultrasound can show loss of lumen and lack of color flow, and then after the procedure can be documented on fluoro

 

Declot is through these methods:

Tpa infusion:  4 mg of TPA / cathflo in 20 cc of water on table in marked syringe

Mechanical:  cleaner device 15 mm is typical, argon medical

Ballooning:  to macerate clot: use mustang balloons, like 6-10 mm or so

Fogarty balloon pull throughs:  not sure which size but use a fogarty to clean out clot and rinse towards venous end

“PULL THE PLUG” interesting concept which is real:  declot misses a portion of clot at the arterial anastomosis and you have to clear this plug to give the graft flow.  This is real sh** I saw it wit my owns

 

access using micropuncture, upgrading over glidewire or bentson to 6F short sheath (like shortbus)

 

access proximal graft towards outflow

access arterial end towards arterial inflow

 

best first step is to get wire, glide or bentson to the central veins, get 5F kumpe there and then do a pull back venogram (CG method)

you lose wire access but I guess its ok, if wanted, can place safety 018 wire which I might do

 

ok then goal is to lace the area of thrombus with tpa 3-4 mg

 

so basically the pullback venogram will show you the “clot “ area

 

then do the tpa instillation through the clotted area

 

after that start up the cleaner

 

the cleaner goes in no wire, goes through the sheath

 

unlock the cleaner and press button to use it, there is a lcoking mech on it to open it and close it

 

clean the entire area of clot

 

after than balloon the sh** out of the same area, quick up and quick down (as per CG)

make sure balloon size matches the caliber of the vessel

 

balloon across whole area

 

now have to navigate across arterial inflow and into central arteries to check inflow

at this point will have to PULL THE PLUG

 

use a fogarty balloon, 5.5 F size 50 cm length, use small 2 cc syringe to infalte

have to inflate slightly and then pull through cleaning from arterial to venous outflow

 

make sure all along to do venography when needed to document changes

 

can pull fogarty through entire graft to clean out clot

 

when done, do good sheath – o = gram with 20 cc syringe, should see rapid flow through graft going down into central veins

 

should clinlcally have thrill

 

can use US to document open graft an save images

 

what else

 

I think that’s it

 

Listen to patients cuz they know more than you have more experience being sick than you

 

They will bail you out when chips are down

 

And they know your doing only what you can

 

If no one else knows… sgmd

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AVG / AVF declot basic strategies rewrite 2016 Nov:

-access antegrade and retrograde with areas of overlap, ie one towards venous outflow, one towards arterial inflow

-give 3000 U of heparin prior to intervening anywhere

-usually address outflow first, then inflow

-identify areas of thrombosis either thru DSA or "pullback venography" ala CG

-use 4-8 mg of alteplase and "spritz" into clot

-can soften up clot using balloon maceration, 6-8 mm in dia, 4 cm length usu good.  If have focal lesion you wanna kill, use 2 cm balloon for inc pushing power

-hen balloons, don't take baloon off until confirm there is no rupture, saves your a**

-can use Argon Cleaner 15 device to roto rooter clot (industry term).  Nice device

-use 5.5F 40 cm length Fogarty to push clot around

-don't forget to "pull the plug".  Means accessing arterial inflow with angled cath and glidewire either distal to anastomosis or proximal or both and then inflating balloon and running all the clots thru.  Can check thrill after this procedure.  rember you're sending clots to the lungs so make sure you heparinze

-DSA the graft/ fistula after to see what flow looks like

-look for arterial inflow problems ie stenosis

-think about stents for venous outflow problems if resistent to balloons

-remeber stenting is an endgame and patency rates suck but the other option is another surgical access so make sure you're in line with that

-to close access sites: basically run a prolene suture around the sheath access and tighten it closed just as you pull the sheath.  can augment with a "little piece o plastic" if you want.  don't overthink it, z stich etc

-have fun -sg

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How to Place a Stent

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learned on Bard Flair and Fluency Stents

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Cross lesion with wire

baloon lesion with preferably Conquest baloon

Advance stent sheath delivery system over wire and position past lesion

bring stent back to lesion

make sure roadmap or other guide sequence is being used for preceise placement

remove handle thing from stent

very slowly and gently hold stent in place with back hand and pull back sheath with front hand

can choke up on stent to give better control

natural tendency is to push stent if can't unsheath, be careful

with flair, try to pull back to see "martini glass" and then pull complex back to engage lesion

very slowly and smoothly unsheath rest of stent

use conquest baloon to baloon stent, use 1 to 1 sizing (ie 8 mm stent, 8 mm baloon, no upsizing in covered stent)

do repeat angio 

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Some notes on AVF and AVG procedures

 

AVF- direct sutural connection from brachial artery to either cephalic or basilic vein.  Sometimes its in the radial artery to cephalic then its called Brescia- cimino fistula

 

AVG- usually from brachial to cephalic or brachial to basilica vein.  Theres a large loop of graft material that is sutured to one then sutured to the other.  There will be a defined loop of material usually in the meaty part of the upper arm. 

 

It appears from my investigation that AVG clot up and AVF are somewhat different

 

AVG Declots:

Basically will access the AVG antegrade and retrograde to evaluate the venous outflow, the arterial inflow and clear out thrombus

In theory could investigate the entire outflow to the RA and could evaluate the entire inflow from the aortic arch but who has the time

 

First you want to image the entire outflow to check for stenosis

Then you lace the clot with TPA 4-5 mg diluted in like 20 cc of NS

Then wait

 

Once the clot is laced you want to break up and get rid of the clot.  Can in theory use almost any device, zelante catheter, “egg beater”, cleaner device

 

This is a form of mechanical thrombectomy

 

You can also balloon macerate the clot

 

You then use like a 5F fogarty to clear the thing completely by running the balloon through

 

You have to clear the arterial plug which is a real thing

 

Of note, you can send clots down the arm artery antegrade and cause a big problem, that’s why they say to check arm pulses prior to proceding

 

Apparently you can visualize these clots on angio if it happens

 

You use the fogarty to clear the arterial plug and inflow carefully without sending anything down the arm

 

You can then touch up the graft using fogarty or PTA balloon

 

I think that’s it

Work in progress

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keep in mind, cutting balloons can really affect tight stenoeses in nice way.  can pop those stenoses and restore flow.  seen this happen twice and the previous balloon would not efface the lesion

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for HD fistula remember:  plasty plasty plasty

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How to do AV Fistulagram / AVG Study

as per BI, VAMC

dude is the truth

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does a bunch and ton of exp

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image the anasomotis with US

look at Arterial anastomsis

if looks good, no need to do reflux shot

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access with micpunc, upsize to 5F sheath and do your runs with the injector

just set up the tubing and do your runs

start from the arm, make sure to window and all that

then go to chest

breath eht patient when imaging th echest

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based on results, get to your treatment

per BI, plasty plasty plasty, very rarely stent, and if stent, think covered

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use 6-7F sheath

get a angled catheter (65 kumpe) and coons wire (or use amplatz,) get acces to IVC

if dificult stenosis, use glide

14 mm balloon will go through 7F

after you plasty do a post run- you might have ruptured the vein

when you plasty leave it up 2 min- use a timer

careful how and when you dose heparin- dont want to give it if the vein ruptured

if ruptured, do prolonged baloon inflation, if still ruptured, use a covered stent

make sure to check stock of covered stents before starting the case- this is the bailout

careful of dilatitng too many mm in one session, bring pt back and do the rest

careful dilating inside of grafts- dont't over dilate the graft.  Check the graft diameter either on fluoro or on ultrasound

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How to do declot w/ DJU West Covina

access graft two sites, opposing each other

do very light angiogram, dont want to shove clot into artery

inject heparin

use treratolo device - advance up to far edge of clot, turn on and bring it back to the sheath

do it x3 both arterial and venous

by now you should have some thrill restored

treat a venous stenosis with a balloon

do a couple more light injections

do some outflow and inflow imaging

basically done

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