VS perspective on deep venous stents, by David Greenstein
David Greenstein
Northwick Park
Pros and cons of deep venous stenting
stents in veins need to be big and need to be long
bad place to end a venous stent is at the U bend (picture of cistern to explain)
slide highlighting radial force versus crush resistance
Veneti stent with strong radial force has been taken off the market due to migration to heart
veneti was closed cell - is off market
Open cell is more oblong and compression resistant - the open cell had more radial force
high variation in vein size with filling.
The degree of venous stenosis that is ‘significant’ on duplex is not clear. With IVUS the figure is deemed 50% - but IVUS is dependent on whether patient is supine or prone.
Ambulatory venous pressure predicts risk of venous ulceration
If 90 mmHg then 100% risk ulceration
If 31 - 40 mmHg then 14% risk
IR perspective on Iliac venous stenting, by Peter Schnatterbeck
DVT causation: flow, endothelial injury and hypercoagulability
Stenting increases the endothelial injury in veins!
stent can still occlude with good flow
very important to have pneumatic boots and to get out of bed early.
thrombus in vein incites a lot of inflammatory process - leads to vein fibrosis and valve disruption
Rationale to treat acute DVT
- 50% of ileofemoral DVT cases get PTS
- 15% approx get ulceration
- 45% approx remain symptomatic with non op Rx
PS says surgery has a place in UL DVT because there is limited endo to offer in UL DVT
The ATTRACT trial showed no difference - states need to be cautious after this trial
what to see on imaging
Does the DVT enter the IVC
Is there a mass lesion like cancer
Is there a PE? Is there right heart strain?
Is there a May Thurner?
new devices: FlowTriever is similar to ClotTriever. FT can suck out PE clot.
for IVC or ileofemoral DVT wthout PE consider ClotTriever with FlowTriever protection discs.
You can’t put an IVC filter in through a popliteal puncture because the device shaft length wont be enough
Can’t use a mechanical thrombectomy device on an occluded stent; you can use an aspiration device though.
Picture of the ICVO classification system
when you use TPA use a checklist for the contraindications
FU measures (5)
Anticoagulation
pneumatic boots overnight
Then pneumatic compression stockings
DUS on day 1 post op and CT / MRV at 6 months
Early mobility v important
CHRONIC DVT
is a different beast
no clear consensus on what is a significant lesion
Imaging to use is much more complex. US is of limited use.
Intraoperatively need combination of multiplanar venography and IVUS
can reconstruct an occluded IVC even with only about 5 cm patent in the infrahepatic segment
you would almost always end up having to overstent across orifice of the right CIV when you stent the left CIV; of little consequence.
Deep venous thrombectomy, by Emma Wilton.
Emma WILTON - OUH
PTS incidence is 30-50% ater DVT
10% will have severe DVT
Persistent venous symptoms at 1 month and residual thrombus on U/S more likely to cause more PTS symptoms
Clear DVT study
Single arm cohotrt
Looking at PTS
after pharamcomechanical therapy (I think, she said)
No PTS in 96%
Who to Rx
-phlegmasia
— severe sx with minimal impreovemnt
- low risk patients
ACT over 250 during the case
Thrombus options:
CDT
EKOS
Angiojet
Indigo
ClotTriever
Aspirex
images shown
IVUS indispensable