Interventions to Interventions to Improve Access Patency Improve - - PowerPoint PPT Presentation

4/7/2017 1

Interventions to Improve Access Patency

• Mark. W. Wilson, M.D.

Professor of Radiology and Biomedical Imaging UCSF

Interventions to Improve Access Patency

• Mark. W. Wilson, M.D.

Professor of Radiology and Biomedical Imaging UCSF

Disclosures

• Scientific Advisor for Arrow Interventional, Inc.

Hemodialysis Access Fistula Complications:

• 1. Stenosis
• 2. Thrombosis
• 3. Venous or Graft Aneurysms and Pseudoaneuryms
• 4. Arterial Steal

AVF and Graft Monitoring Parameters

• Elevated Venous Pressures

(Sensitivity 86% , Specificity 93%)

• Urea Recirculation

(Sensitivity ? , Specificity 82%)

• Duplex Doppler Sonography

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Dialysis Grafts Distribution of Stenoses

• Venous Anastomosis

47%

• Peripheral Basilic Vein

19%

• W/in 1 cm of Venous Anast.

11%

• Central Basilic Vein

8%

• Subclavian Vein

6%

• Arterial Anastomosis

4%

• Mid-graft

2%

• Axillary Vein

2%

85%

Kanterman, Radiology 195

Dialysis Arteriovenous Fistulas Distribution of Stenoses

Radiocephalic AVF

Rajan, Radiology 232(2)

Dialysis Arteriovenous Fistulas Distribution of Stenoses

Brachiocephalic AVF

Rajan, Radiology 232(2)

Dialysis Fistula Stenosis: Treatment Options

• Surgical Revision
• Balloon Dilatation
• Endoluminal Stenting

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PTA @ Venous Anastomosis PTA @ AV Anastomosis Dual Balloon Subclavian Venoplasty PTA of Long Segment AVF Stenosis

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PTA of arterial-to-arterial graft stenosis

Dialysis Arteriovenous Fistulas Median Primary Patency Post-Angioplasty

Brachiocephalic AVFs: 6 – 7 months Radiocephalic AVFs: 19 – 20 months

Rajan, Radiology 232(2)

Dialysis Arteriovenous Fistulas Median Secondary Patency Post-Angioplasty

Brachiocephalic and Radiocephalic AVFs: 70 mos.

Rajan, Radiology 232(2)

Dialysis Fistula/Graft Stenting: Indications

• Treatment of Stenoses Resistant to Balloon

Dilatation

• Treatment of Venous Rupture or Dissection
• Exclusion of Pseudoaneuryms

4/7/2017 5 Brachiobasilic AVF stenosis

Venoplasty, vein rupture, extravasation of contrast

Treatment: Exclusion by stent graft

• Prospective, multi-center, randomized trial
• 190 pts. With failing AV grafts due to venous anastomotic

stenoses

• Compared AV graft angioplasty with stent graft placement
• Results:

– 6 month patency at treatment area was greater in stent graft grp (p<0.001) – 6 month patency of overall circuit was greater in stent graft grp (p=0.008) – 6 month restenosis rate was lower in the stent graft grp (p<0.001)

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Recurrent outflow stenosis, suboptimal venoplasty result

Treatment: stent graft across stenosis

Hemodialysis Access Fistula Complications:

• 1. Stenosis
• 2. Thrombosis
• 3. Venous or Graft Aneurysms and

Pseudoaneuryms

• 4. Arterial Steal

AVF-AVG Thrombosis: Treatment Options

• 1. Surgical Thrombectomy +/- Revision
• 2. Surgical Creation of a New HDAF
• 1. Percutaneous Interventional

Declotting Techniques: > Pharmacologic Thrombolysis > Mechanical Thrombectomy

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AFV-AVG Declotting Techniques

• Pharmacologic Thrombolysis:

– Transcatheter Pulse-Spray – Lyse-And-Wait – Lyse-And-Go – Continuous Infusion

AFV-AVG Declotting Techniques

• Pharmacologic Thrombolysis:

> Agent: Tissue Plasminogen Activator > TPA Dose Range:

1-2 mg Intra-Graft/Fistula

> Supplemental Heparin:

3000-5000 U Intra-Graft or Systemic

Multi-Sidehole Thrombolytic Infusion Catheter

Fibrin Plug Removal

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AFV and AVG Thrombolysis Patency Rates

Tseke, Artificial Organs 35(1)

40 thrombosed access sites underwent rt-PA thrombolysis

> Primary success rate was 55% > Primary patency was 90.9% and 69.8% at 30 and 90 days respectively > No difference in outcomes between AV fistulas and grafts > No major complications

Dialysis Fistula Fibrinolysis: Complications

• Hemorrhagic
• Local Bleeding

(e.g., puncture sites)

• CNS
• Other Organ Systems

Puncture Site Hemorrhage Controlled by Manual Compression

Treatment: stent graft exclusion

Post Pre

Hemorrhage following thrombolysis and PTA

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AFV/AVG Declotting Techniques

• Mechanical Thrombectomy Devices:

– Treretola PTD – Angiojet Thrombectomy Catheter – Trellis Infusion System – Amplatz Clot Buster – Penumbra Indigo System – Cleaner Device

Treretola PTD Trellis Infusion System Possis Angiojet

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Amplatz Clotbuster

Thrombolysis and Thrombectomy Results Bottom Line: Preserve access sites as long as possible

Hemodialysis Access Fistula Complications:

• 1. Stenosis
• 2. Thrombosis
• 3. Venous or Graft Aneurysms and Pseudoaneuryms
• 4. Arterial Steal

4/7/2017 11 Venous or Graft Aneurysms and Pseudoaneuryms: Etiologies

• 1. Inadequate hemostasis at puncture sites
• 2. Trauma (e.g., venoplasty-induced)
• 3. Flow dynamics
• 4. Infection

Venous or Graft Aneurysms and Pseudoaneuryms: Complications

• 1. Mass effect and AVF compression
• 2. Thrombotic nidus, inducing thrombosis of AVF/AVG
• 3. Rupture, subcutaneously or externally
• 4. Septic emboli if mycotic

Venous or Graft Aneurysms and Pseudoaneuryms: Treatment- Depends on Etiology

• 1. Graft removal
• 2. Surgical revision
• 3. Antibiotic therapy as indicated
• 4. Stent graft exclusion
• 4. US-guided thrombin injection

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Venoplasty-induced venous aneurysm - stent graft exclusion Venoplasty-induced venous aneurysm – thrombin injection

Hemodialysis Access Fistula Complications:

• 1. Stenosis
• 2. Thrombosis
• 3. Venous or Graft Aneurysms and Pseudoaneuryms
• 4. Arterial Steal

Arterial Steal Syndrome

Defn: Vascular insufficiency resulting from an AVF or AVG

Clinical Presentation:

• 1. Ipsilateral hand pain
• 1. Diminished pulses distal to fistula
• 2. Wrist/brachial BP ratio < 0.6
• 4. Necrosis

4/7/2017 13 Arterial Steal Syndrome

Treatments:

• 1. Surgical revascularization (e.g., DRIL procedure)
• 1. Banding or plication (e.g., Miller banding)
• 2. Surgical ligation and placement at alternate site

Arterial Steal Syndrome

Role of IR: Diagnosis Procedure: UE arteriography with and without AVF/AVG compression

Without Compression With Compression

Thank You