Shunt stenosis and occlusion: The pattern of reobstruction and how to

approach?

Michael Moche, Tobias Paulus

Disclosure

Speaker name:

Michael Moche

I have the following potential conflicts of interest to report:

Consulting

Employment in industry

Stockholder of a healthcare company

Owner of a healthcare company

Other(s)

I do not have any potential conflict of interest X

LINC 2016

Facts

• Vascular access essential for survival of patients with chronic renal failure

• Arteriovenous fistulae (AVF) best and most durable vascular access for hemodialysis

• Relevant stenosis (>50%) already 3 months after formation in > 54% (Grogan J Vasc Surg 2005, Sivanesan

Nephrol 1999)

• Median problem-free patency period: AVF 3y, arteriovenous grafts (AVG) 1-2y

LINC 2016

Criteria for dysfunction/failure • no pulse, no thrill palpable

• difficult puncture

• reduced flow < 200-300ml/min

• high recirculation (> 15% with 300ml/min)

• increasing retention parameters - incomplete dialysis

stenosis or thrombosis in- or outflow

• elevated venous pressure

• increased pulsation, prolonged bleeding after puncture

• arm swelling, varicosis, collateral veins

central ven. stenosis

• hand ischemia – steal syndrome

• aneurysm

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Diagnosis and pattern of failure

Course of failure

• Early – inflow stenosis (e.g. intima hyperplasia) failure to mature

• Late – venous outflow stasis (e.g. stress triggered focal fibromuscular hyperplasia) thrombosis

Assessment • Clinical examination • Doppler ultrasound • CE-MRI • Direct angiography

Stenosis location • 5% - arterial inflow • 34% - juxa-anastomotic • 43% - venous outflow Grogan et al. J Vasc Surg 2005

Sayed et al. Vascular 2005

CO2 6mm Cutting Balloon

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Endovascular approach

Indications

• Non-mature fistulas

– Distant inflow stenosis

– Distant early outflow stenosis

• Mature fistulas

– Access thrombosis (urgent)

– Isolated venous or outflow

anastomotic stenosis

• Arm edema

– Central vein or double outlet stenosis

Bittl Am Coll Cardiol Interv. 2010

Technical success

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Acute failure - thrombosis

Tordoir et al. J Vasc Surg 2009

Endovascular vs. surgery

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Declotting Thrombolysis

Thrombectomy • Aspiration

• Mechnical / hydrodynamic (Arrow-Trerotola, AngioJet, Aspirex etc. )

Wen Act Cardiol Sin 2011 – n=135

Angiojet

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Which balloons? Advanced force!

“Buddy wire technique” – High pressure ballon

• Precision

• Safety – less dissections

• Larger luminal gain

RCT

n = 516

2. patency after 3m

CBA 96%

HPBA 80%

Aftab et al. J Vasc Interv Radiol 2014

p = 0.03

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AVF & AVG: PTA vs. Stent

Fu, Sem Dialysis, 2015 Metaanalysis: 10 studies, n = 860

6mm PTFE AVG 6mm Cutting Balloon

Nitinol

Bare metal

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AVG: PTA vs. Stentgraft/PTA

Procedural success: 94% graft vs. 74% PTA

2010

Haskal NEJM 2010

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Central venous stenosis (CVS)

Asif et al. Seminars in Dialysis 2009

9% at 12m

86% at 12m

2.1 procedures per year

Bakken et al. J Vasc Surg 2007

No evidence to treat asymptomatic CVS!

Renaud at al. Nephrol Dial Transplant 2012

Take home

• Able to increase mean survival

AVF from 3 up to 7y

AVG from 1-2 up to 3y

• Thrombosis – urgent treatment!

• Peripheral stenosis PTA and bailout stent

• Evidence for “advanced focused forces” PTA

• AVG evidence for covered Stents

• Treat only symptomatic central venous stenosis

LINC 2016

Shunt stenosis and occlusion: The pattern of reobstruction and how to

approach?

Michael Moche, Tobias Paulus