Follow-up Duplex Ultrasound

after Carotid CEA and CAS

-What to look for & what velocities are significant -

Dennis Bandyk, MD, FACS

Division of Vascular & Endovascular Surgery

U Cal – San Diego School of Medicine

Session 1 – Cerebrovascular Disease

Disclosures

Dennis F. Bandyk, MD, FACS, has no financial or conflict

of interest disclosures to report

What I Learned from Dr Standness

(1983, Ultrasound Med Biology)–duplex was accurate prior to and following

carotid endarterectomy.

(1987, Ultrasound Med Biology) – variability of PSV and EDV in the ICA primarily due to

examiner technique & not patient factors or waveform measurement technique.

(1994, Stroke ) Patient screening for >70% ICA does not require an angiogram since duplex

testing provides a more accurate measurement of carotid stenosis.

(1995, J Vasc Surg) The combination of PSV and EDV should be used to diagnosis severe

carotid stenosis in asymptomatic patients

(2001, Sem Vasc Surg) – intervention is only indicated in symptomatic patient with recurrent

carotid stenosis, and surveillance after carotid surgery should be patient specific

Rationale for Duplex Testing after CEA/CAS

Verify technical success (duplex, IVUS)

Identify recurrent stenosis – occlusion

Monitor contralateral ICA for disease progression*

Duplex testing is accurate for stenosis detection and to

identify disease progression

- Velocity criteria for CEA and CAS stenosis?

- When should re-stenosis be treated?

CREST Trial 9% 12% P - NS

Duplex Imaging & Pulsed Doppler Recording Sites

Transverse Imaging

Peak systolic vel - PSV

Interpretation Criteria

- Stent imaging

- Max. PSV

- End-diastolic vel; EDV

- PSV ratio

- Along stent

- Stent:prox CCA

CREST Core Lab Data: 1 Month after CAS

Comparison of “Suggested” Duplex Criteria for

Interpretation of Residual (>30-50%) Stent Stenosis

PSV EDV PSV - Ratio

Bandyk > 150 cm/s NA > 2

CREST >125 cm/s NA -

NJ –

Hobson

>185 cm/s NA > 2.5

Toledo

Comerota

>150 cm/s NA >2.2

Charleston

AbuRahma

>155 cm/s NA -

• At 2-year: approx 6% restenosis; <1% occlusion

• Restenosis associated with increased stroke risk

Predictors of restenosis

• Female

• Diabetes

• Dyslipidemia

Frequency of restenosis after CEA or CAS with different PSV thresholds

*

NEJM - 2016

>70% stenosis

Factors that May Influence Measured PSVs

after Carotid Intervention

Contralateral disease – compensatory collateral flow

Plaque calcification impeding stent expansion

Stent type (open vs closed cell) and diameter

Balloon diameter if used during stent angioplasty

IVUS – Monitored CAS

Measure vessel diameter

Stent – balloon sizing

Assess final stent deployment

Calcified Plaque

Stent

Xact 10/8 x 40

6 mm Dia Balloon

IVUS

Assessment

Case Study

After 7 mm Balloon

Carotid Duplex @ 1 day

Figure 3

IVUS Monitored CAS - Deployed Stent Anatomy

Circular

Angio Guided 2/90 (2.2%) 129±44 cm/s

IVUS+Angio Guided 10/90 (12%) 98±36 cm/s

Repeat PTA

>20% Residual

Stenosis

After Repeat

Balloon Angioplasty

Max PSVstent

Abnormal Duplex Scan – >50% In Stent Stenosis

- Neointimal thickening

- Increased PSV in stent (250 cm/s)

- Abnormal PSVR-STENT = 3.1

- Poststenotic turbulence detected

Incidence: 8-21%

Location: In-stent 70%

Duplex Surveillance After Carotid Intervention

<50%

Restenosis

50-75%

Restenosis

76-99%

Restenosis

100%

Occlusion

Q 6-mo FU for 1st yr

Then;

Annual

Medical Rx &

Contralateral

ICA Surveillance

Follow-up

every 6 mo

Angiographic

Evaluation/Verification

Endovascular Repair

PSV > 300 cm/s

EDV > 125 cm/s

PSV Ratio > 4Neurologic Event

(TIA, Stroke)

Duplex Criteria:

Stent Stenosis Progression: 6-Month Scan Intervals

>50% stenosis

March 2005September 2005

PSV = 519 cm/s; EDV=163 cm/s

- >80% in-stent stenosis

80%

Stenosis

Comparison of “Suggested” Duplex Criteria for

Interpretation of High-Grade (>70-80%) Stent Stenosis

PSV EDV ICA/CCA Ratio

USF > 300 cm/s >125 cm/s > 4

CREST >125 cm/s > 140 cm/s -

Houston

Lumsden

> 300 cm/s >90 cm/s > 4

Charleston

AbuRahma

> 325 cm/s >119 cm/s > 4.5

Duplex Surveillance after Carotid Intervention

<50%

Restenosis

50-75%

Restenosis

76-99%

Restenosis

100%

Occlusion

Q 6-mo FU for 1st yr

Then;

Annual

Medical Rx &

Contralateral

ICA Surveillance

Follow-up

Q 6mo

Angiographic

Evaluation/Verification

Endovascular Repair

PSV > 300 cm/s

EDV > 125 cm/s

PSV Ratio > 4

Neurologic Event

(TIA, Stroke)

Duplex Criteria:

Duplex Surveillance after Carotid Intervention

An early (<1 mo) post-procedure study is recommended to assess

the CAS/CEA for residual stenosis & serve as baseline

Frequency of follow-up determined by duplex findings of the

repaired ICA, & stenosis severity of the contralateral un-operated

ICA

Progressive recurrent high-grade (>70%, EDV >125 cm/sec) ICA

stenosis should be considered for re-intervention

- Excellent long-term patency & stroke avoidance with angioplasty

- Higher re-intervention rate: CAS-5%; CEA-1%