Scott L. Stevens, M.D. & Mark A. Farber, M.D. Postgraduate Course: Venous Endovascular Course Directors: Scott L. Stevens, M.D. & Mark A. Farber, M.D.

Introduction Kim Hansen, MD WFU School of Medicine Winston-Salem, NC

Arteriovenous Malformations. Alan B. Lumsden, Chairman Cardiovascular Surgery Houston, Texas

Vascular Lesion Treatment Arteriovenous Malformation (AVM) Definition - Congenital lesion Abnormal arteriovenous communications Feeding arteries Nidus Outflow veins Symptoms Significant shunting / CV compromise Pain, neuromuscular dysfunction, tissue ulceration Hemorrhage An arteriovenous malformation or AVM is a congenital – often deep – lesion. 8 Anatomically, an AVM is comprised of many abnormal communications between adjacent arteries and veins. Feeding arteries lead to this tangled web of dilated vessels – the AVM nidus – while veins provide for outflow. 8 Symptoms of an AVM are dependent upon its size and location. A large AVM produces significant shunting and can lead to cardiovascular compromise. With the local disruption in blood flow, symptoms such as pain, neuromuscular dysfunction or tissue ulceration can occur. AVM rupture results in hemorrhage.

Treatment Absolute indications Hemorrhage Ischemia (steal) Refractory ulceration Congestive heart failure Relative indications Disabling pain Claudication Functional impairment

Treatment Conservative Stockings Limb elevation Surgery 10% lesions Best after embolization 100% success when amenable for resection

Vascular Lesion Treatment AVM Embolization Effective therapy Destruction of the nidus Procedural requirements Superselective access to feeding artery Injection non-resorbable embolic agent into the nidus Therapeutic vascular embolization may provide effective therapy for AVMs. However, unlike other embolization procedures which focus on either proximal or distal arterial embolization… 8 the goal of AVM embolization is destruction of the nidus. Embolization of a feeding artery would merely shift blood supply to an adjacent artery, and the AVM would remain. 8 However, superselective access to the feeding artery and injection of a non-resorbable embolic agent into the nidus may produce durable occlusion. 8 Embolic agents used for AVM embolization include PVA particles and microspheres, coils, absolute ethanol and n-BCA. Contour PVA particles / Contour-SE microspheres Absolute ethanol n-BCA .014”/.035” Coils (Vortx-18 or Vortx-35)

Present understanding phases vascular development. Embryology Stage I Undifferentiated: primitive blood lakes, capillary networks, no veins or arteries Stage II Retiform: Capillaries form large plexiform structures Stage III Maturation: Mature vascular channels

MRI Classification

What do we really need to know? Location: subcutaneous deep to fascia both Proximity to major structures sciatic nerve rectum Localized or diffuse Arterial or venous relative contribution

towel roll

head foot rectus femoris femoral nerve branches tensor fascia lata

venous connection

joint capsule femur

Treatment Embolization Multiple sessions Long-term commitment Usually under general anesthesia Some report 79% success with 20% complications

Steps for safe embolization Good preliminary angiography Think about collateral pathways Use shortest straightest approach, especially when coils used Stable catheter position and verify: Wire if using coils Contrast if soluble agent Use non-heparinized saline to flush and dilute contrast Continuous fluoro during embolization Intermittent runs to evaluate flow

Vascular Lesion Treatment AVM Embolization Hazards Non-Target Distal embolic embolization Venous outflow vessels pulmonary circulation Potentially fatal PE (Pulmonary Embolism) Prevention Proper sizing of PVA microspheres / particles Impact within the nidus Careful injection of liquid embolics Contain effects within nidus Proper sizing of coils Reduce risk of displacement

Non-resorbable Embolic Agents: Liquid Embolic Agent n-Butyl Cyanoacrylate (n-BCA) Description Tissue adhesive or “glue” Treatment of cerebral AVMs Mechanism of action Polymerization upon contact with ionic fluids Formation of a solid cast within the vessel Vessel occlusion Technique Coaxial delivery Flushing with non-ionic dextrose solution Immediate catheter withdrawal

AVM dorsum left hand Draining vein punctured Tourniquet above arterial pressure 2.5cc absolute ETOH via 3Fr catheter

Radial Head AVM, multiple vessels feeding venous component. Catheter inserted into draining vein. Absolute alcohol injected in 4 stages. Venogram at 6 months - ablation of veins

Early Polymerization n-BCA adherent to tip at risk for embolus TRUFILL ® n-BCA mixture solidifies: In the microcatheter - catheter occlusion In the AVM before the desired depth of penetration within a feeding pedicle At the microcatheter tip n-BCA adherent to tip at risk for embolus n-BCA adherent to tip at risk for catheter retention Reflux, polymerization of non-target vessel Complications: Ischemia AVM or vessel rupture

Conclusion: AVM Treatment These patients lack a home Vascular Surgeons see most of AVM,s No single therapeutic option Need broad oversight Emerging advanced endovascular skills in vascular surgery community Rapid growth of excellent imaging MEN -1 of vascular surgery: patient for life Research- clinical- teaching opportunities

TRUFILL® Tantalum Powder Finely ground, irregularly shaped, dark gray metal Used with TRUFILL ® Ethiodized Oil to radiopacify TRUFILL n-BCA liquid embolic agent Mix tantalum with TRUFILL ® Ethiodized Oil prior to mixing with TRUFILL ® n-BCA DO NOT use TRUFILL ® Tantalum Powder alone as a radiopacifying agent for n-BCA

TRUFILL® Ethiodized Oil Straw to amber colored oily fluid Contains 37% iodine organically combined w/ poppyseed oil’s ethyl esters of fatty acids Injectable, radiopaque agent to be used with n-BCA Liquid Embolic System to control polymerization DO NOT use TRUFILL ® Ethiodized Oil alone as a diagnostic agent

TRUFILL® n-BCA Procedure Set-up Inject TRUFILL ® Ethiodized Oil into sterile beaker

TRUFILL® n-BCA Procedure Set-up Add TRUFILL Tantalum Powder to sterile beaker

TRUFILL® n-BCA Procedure Set-up Mix TRUFILL Ethiodized Oil and TRUFILL Tantalum Powder

TRUFILL® n-BCA Procedure Set-up Attach self-piercing cap to the syringe; then attach to the TRUFILL n-BCA vial

TRUFILL® n-BCA Procedure Set-up Aspirate TRUFILL n-BCA into syringe

TRUFILL® n-BCA Procedure Set-up Add TRUFILL n-BCA to mixture in beaker and mix thoroughly

TRUFILL® n-BCA Procedure Set-up Rinse microcatheter hub with syringe of D5W

TRUFILL® n-BCA Procedure Set-up Flush microcatheter with D5W

TRUFILL® n-BCA Procedure Set-up Aspirate TRUFILL n-BCA mixture into syringe; Compare mixture-filled syringe with contrast-filled syringe under fluoroscopy

TRUFILL® n-BCA Procedure Set-up Inject TRUFILL n-BCA mixture through microcatheter

Microcatheters PROWLER® Microcatheter family. TRUFILL ® n-BCA is compatible with: PROWLER® Microcatheter family. PROWLER SELECT ® Microcatheter family. TRANSIT® Microcatheter family RAPIDTRANSIT® Infusion catheter MASSTRANSIT® Max ID catheter TRANSIT® Microcatheter