VASCULAR PLUGS: CURRENT USE

SHORT SEMINAR

Satyam Rajvanshi

INTRODUCTION

• Embolization is defined as the "therapeutic introduction of various substances into the circulation to occlude vessels, either to arrest or prevent active hemorrhage; to devitalize a structure, tumor, or organ by occluding its blood supply; or to reduce blood flow to an arteriovenous malformation."

Stedman T. Stedman's Medical Dictionary. 27th ed. Lippincott Williams & Wilkins. 2000.

• Endovascular embolization, or embolotherapy, is performed by interventional cardiologists or interventional radiologists

Embolization therapeutic goals:• An adjunctive goal (preoperative, adjunct to

chemotherapy or radiation therapy)• A curative goal (aneurysms, arteriovenous fistulae

[AVFs], arteriovenous malformations [AVMs], and traumatic bleeding)

Medical conditions treated by using embolotherapy can be grouped as follows:

• Vascular anomalies (eg, AVM, AVF, venous malformation [VM], lymphatic malformation [LM], and hemangioma)

• Hemorrhage (eg, pseudoaneurysms, GI tract, pelvic, posttraumatic, epistaxis, and hemoptysis bleeding)

• Other conditions (eg, tumors, varicoceles, organ ablation, BPF)

EMBOLIZATION MATERIALS AND SUBSTANCES

• Permanent vessel occlusion– Particulate material

• Polyvinyl alcohol• Gelatin-acrylic microspheres

– Sclerosing agents• Alcohols

– Glue• Cyanoacrylate• Sodium Tetradecyl Sulfate

– Metallic• Coils• Vascular Plugs

• Temporary occlusion– Gelfoam

VASCULAR PLUGS

VASCULAR PLUG

• Self-expandable devices made of nitinol wire mesh (or other material) which can be cylinderized into a sheath and deployed precisely at embolization targets

Vascular plug vs. Coil

• Speed: Reduction in procedure times• Radiation Exposure: Reduction in radiation times• Cost-effectiveness: Reduction in procedural costs

– specially in large vessels• Efficiency: Reduction in materials used,

uncommon recanalisation or persistent flow, device embolisation rare

• Precision: Recapturable and redeployable for precise placement

• Amplatzer vascular plugs• Cera vascular plugs• Medusa vascular plug• Microvascular plug

AMPLATZER VASCULAR PLUG

• Manufactured by St. Jude Medical (USA)• First approved by USFDA on May 3, 2004, for

peripheral vascular embolizations• 1st study reporting successful use of the AVP was

published in 2004

Hijazi ZM (2004) New device for percutaneous closure of aortopulmonary collaterals. Catheter Cardiovasc Interv 63(4): 482–485

• Designed as a permanent occluding flexible cylindrical device derived as a modification of the family of Amplatz septal occluders and Amplatzer Duct Occluder

• Excellent alternative to coils or detachable balloons in the embolization of medium to large vessels with high flow - otherwise require multiple coils

• All AVP models - 2 basic components: a vascular plug and a delivery wire

• Plugs built with nitinol braids, self-expandingradiopaque platinum marker bands at both

ends that allow for high visibility under fluoroscopy

Stainless-steel screw on one of the platinum marker bands attaches to a delivery

cable

• Ability to recapture and reposition the device as needed

• After satisfactory positioning, counterclockwise rotation of connecting cable releases device

• Single model has evolved into 4 models • For use in various types of anatomy,

hemodynamics, and lesion entities

• AVP I and II – USFDA approved 2004, 2007• AVP III – 2008 CE marked but not available in

US• AVP 4 – USFDA approved 2012

AVP or AVP I

Single lobar plugGuide 5-8 FrSheath 4-6 FrDiameter 4-16 mmIncrements 2 mmLength 7-8 mmLesion with short landing

zone requiring high radial force to secure AVP

Select a device with a diameter approximately 30-50% larger than the vessel diameter at the occlusion site

AVP IIMulti (6)-layered Tri-lobar plug

with increased lengthGuide 5-9 FrSheath 4-7 FrDiameter 3-22 mmIncrements 2 mmLength 6-18 mmRapid occlusionUsed when Variable landing

zone – can be shortened by compression

Minimises migration and recanalization

Select a device with a diameter approximately 30-50% larger than the vessel diameter at the occlusion site

Large Left Segmental Pulmonary Artery Pseudoaneurysm

AVP 4

Multi (4)-layered Bi-lobar plug with small profile, more flexible delivery wire

Simple delivery - 0.038” guidewire compatible diagnostic catheter (Guide/Sheath not required)

Diameter 4-8 mmIncrements 1 mmLength 10-13.5 mmSmall, tortuous vesselRapid occlusion

Select a device with a diameter approximately 30-50% larger than the vessel diameter at the occlusion site

AVP 4 completely occluding coronary fistula originating from proximal RCA draining into the right upper lung field

AVP III

Oblong plug with 2 extended rims

Guide 6-9 FrSheath 4-7 FrDiameter 4-14 mm (Long Axis)

Increments 2 mm (Long Axis)

Length 2-5 mm (Short Axis) Fastest occlusion of all AVPsEnhanced stability in high

flow statesNiche device for suitable

anatomy

Like ASD occluder stretched sideways!

Amplatzer Vascular Plug III 12/5 device implant in aortic position. A: in systole, the device does not interfere with the prosthesis. B: in diastole, the device does interfere with the prosthesis. C: an Amplatzer Duct Occluder 12/10 device implant that does not interfere in systole. D: or in diastole

CERA VASCULAR PLUG SYSTEM

• Manufactured by Lifetech Scientific Corp., China• Single lobe device coated with Titanium Nitride –

prevent thrombosis and improves endothelialisation• PTFE coated – shorter occlusion time

Single lobed, PTFE coveredGuide 4-9 FrDiameter 4-24 mmIncrements 2 mmLength 7-14 mmRapid occlusion due to PTFE

MEDUSA VASCULAR PLUG• Manufactured by Endoshape, USA• USFDA approved in Nov,2013• Constructed from multiple 0.018” polymer coils• Highly trackable in tortuous anatomy

MEDUSA VASCULAR PLUG• Manufactured by Endoshape, USA• USFDA approved in Nov,2013• Constructed from multiple 0.018” polymer coils• Highly trackable in tortuous anatomy• Better Imaging - Minimal metal content reduces

artifacts; follow up can be with a CT/MRI versus an angiogram

MICROVASCULAR PLUG

• Manufactured originally by Covidien, USA • Covidien later bought by Medtronic, USA• MVP plug - The first plug deliverable through a

micro catheter• Enables super-selective embolization of distal

vessels• PTFE coated Nitinol design – rapid occlusion

• Length 12 mm• Diameter 5.3 mm and 6.5 mm• 3 mm MVP™ plug: recommended delivery through .021"

micro catheter2• 5 mm MVP™ plug: recommended delivery through .027"

micro catheter

APPLICATIONS

VASCULAR

• ARTERIAL: Parent artery occlusion– Internal iliac – Carotid– Vertebral– Renal– Gastroduodenal– Aberrant right subclavian artery– Popliteal artery aneurysm– Hepatic artery pseudoaneurysm – Hepatic cavernous hemangioma

VASCULAR

• VENOUS– Portal Vein –Preoperative embolization of tumor

side portal vein stimulates contralateral liver lobular hypertrophy - improves resection rate

– Gastric varix in conjunction with a TIPS– Varicocele embolization for infertility – Ovarian vein embolization for female pelvic

congestion syndrome – Saphenous vein graft aneurysm– Large inferior vena cava aneurysm

ABNORMAL VASCULAR CONNECTIONS

• CONGENITAL – Pulmonary AVMs; renal AVMs; Hepatic AVMs– PDA– PDV – intrahepatic portosystemic shunt– Splenorenal shunt– Spontaneous mesocaval shunt in SMA– Scimitar vein to left atrium– Congenital coronary artery fistula

ABNORMAL VASCULAR CONNECTIONS

• ACQUIRED– HD-AVF– TIPS– Blalock-Taussig shunt– Traumatic arteriovenous fistula

CARDIAC

• Paravalvular leak closure– Mechanical MV/AV– TAVI

• PDA• LAA

MICROVASCULAR PLUGS• Hepatic artery skeletonisation – before

radioembolisation/chemoembolisation of tumor• Gastroduodenal artery - during radioembolization• Recanalized pulmonary arteriovenous malformation

previously coil embolised• Splenic artery hemorrhage secondary to tumoral

erosion• Lower gastrointestinal hemorrhage• Temporary vessel occlusion by undeployed MVP plug

- Whenever only temporary occlusion of a critical vessel is desired - during complex vascular procedures; or Radio/chemo embolisation

NON-VASCULAR

• EXTRA VASCULAR– Bronchopleural fistula!– Vesicovaginal fistula!– Intraperitoneal bile leak!

CONCLUSION• Vascular plugs as occlusion devices are valuable in managing

a wide variety of disease processes• Easy to use, can be precisely deployed in the target vessel,

high resistance to migration, low recanalization rate• Vessel size, high-flow status, and coagulopathy can prolong

the occlusion time. The addition of coils, gelfoams as an adjunct can achieve rapid and reliable occlusion with minimal cost

• Continued evolution in product design has improved occlusion properties and decreased device profile – alongwith interventionalist’s innovative usage – has truly widened the spectrum of clinical indications for these versatile devices

CARDIOLOGY IS NOTHING BUT ‘JUGAAD’ WITH EXPERTISE

- Dr. Ranjeet Nath