Week 11: LE arterial angioplasty & stent assessment & duplex Flashcards
What are the 4 treatment options for PAD?
- Medical treatment
- Excersise therapy
- Endovascular therapy
- Surgical reconstruction/bypass graft.
What do the type of interventions depend on?
Depends on the severity of symptoms, disease location and extent.
Stents are being used________in LE.
More frequently.
What is the duplex protocol for LE stents?
It is the same for LE native artery duplex but ass images/velocities:
- Pre-stent
- Prox. stent
- Mid. Stent
- Distal Stent
- Post-stent.
What are the 2 types of endovascular treatment types?
- Percutaneous transluminal angioplasty
- Endovascular Intervention.
Which endovascular treatment is preferred for focal, <5 cm in length regions of stenosis?
Endovascular intervention.
What are some percutaneous transluminal angiplastly treatment?
- Subintimal ballon angioplasty
- Stent-graft angiplasty
- Mechanical atherectomy.
What are some endovascular interventions?
- Iliac angiplasty: has a higher patency rate than femoral-pop.
- more severe disease has lower stenosis-free patency rate.
What is the main mechanism for a balloon angioplasty?
Lumen dilation.
What is the lesion anatomy for a balloon angioplasty?
Focal, <5 cm stenosis or occlusion.
What is the “stenosis-free” patency at 1 year for a balloon angioplasty?
40-50%
What is the “failure mode” for a balloon angiplasty?
- Plaque dissection.
- Myointimal hyperplasia.
What is the mechanism for a stent angioplasty?
Lumen dilation.
What is the lesion anatomy for a stent angioplasty?
Focal & longer (>10 cm) stenosis or occlusion.
What us the “stenosis-free” patency at 1 year for a stent angioplasty?
50-60%
What us the “failure mode” for a stent angioplasty?
- Myointimal hyperplasia.
- Stent fracture.
What is the mechanism for atherectomy?
Plaque excision.
What is the lesion anatomy for atherectomy?
Focal & longer (>10 cm) stenosis.
What is the “failure-mode” for atherectomy?
- Myointimal hyperplasia
- Atherectomy site thrombosis.
What is the mechanism of subintimal angioplasty?
Lumen dilation.
What is the lesion anatomy for subintiml angioplasty?
>10 cm stenosis or occlusion.
What is the “stenosis-free” patency at 1 year for subintimal angioplasty?
55-60%
What is the “failure-mode” for subintimal angioplasty?
- Myointimal Hyperplasia
- Angioplasty site thrombosis
What is the mechanism for stent-graft angioplasty?
Lumen dilation.
What is the lesion anatomy for a stent-graft angioplasty?
Long, >15 cm stenosis or occlusion.
What is the “stenosis-free” patency at 1 year for a stent-graft angioplasty?
60-70%
What is myointimal hyperplasia?
Abnormal proliferation of smooth muscle cells.
What should you look for when scanning a stent?
Look for bright lines/circumferential dots in trans.
Areas of distrubanes or stenosis should be carefully evaluated with a spectral doppler by doing what?
- Sample volume should be “walked” through area using a 60 degree angle.
- PSV should be measured.
Velocity ration_______ indicates 50% stenosis.
>2
What can also be used to classify stenosis?
End diastolic volume.
How will a waveform look if:
<50% DR
<180 PSV
<2 Vr
Normal
How will a waveform look if:
>50% DR
180-300 PSV
2-3.5 Vr
>0 EDV
Monophasic
How will a waveform look if:
>77% DR
>3.5 Vr
>300 PSV
>45 EDV
Damped, monophasic, low velocity.
Why might Psv be higher in area with angioplasty and stenting?
Doesnt remove plaque which causes:
- plaque dissection
- stent geometry
- myointimal hyperplasia
- decreased arterial wall compliance
What is angioplasty failure defined as?
occlusion.
>70% stenosis
What are 4 dupex findings on in-stent-stenosis?
- Lumen reduction
- Elevated PSV values (200-300)
- Reduction in ABI’s
- Damped, low velocity spectral waveform distally.
What is the LE stent critera?
- >50%
- PSV >180 cm/s in fem-pop stent that has a ratio of >2.5
- >75-80%
- PSV >275-300 cm/s and ratio >3.5
- no color, no doppler= occluded.
How should you report an image with disease?
Either inside stent or outside stent.
What 3 criteria is considered as a post-intervention success?
- Increase in ABI’s >.15
- Resolution of limb ischemia sign and symptoms.
- <50 DR stenosis by duplex or angioplasty
What is considered a post-intervention failure?
>70% DR stenosis or occlusion.
Requires further intervention.
The rationale for surveillance testing is to?
Identify PTA site abnormalities before failure occurs.
What are 4 post-intervential abnormalities?
- In-site stenosis
- Stent deformation/kinking.
- Myointimal hyperplasia.
- Thrombosis/embolism.