spherical embolics: so many choices, so little time

Jean-Pierre Pelage, MD PhDpelage-jp@chu-caen.fr

GEST 2016 US, New-York

Spherical Embolics:

So Many Choices So Little Time

Jean-Pierre Pelage, M.D., Ph.D.

• Consultant/Advisory Board: Merit Medical, Terumo, ALN, Cook Medical,Guerbet, Boston

Scientific

• Research Grants: BTG, Terumo, ALN

Embolic Microspheres (Non resorbable)

Calibrated microspheres

Allow targeted devascularization / occlusion

Injectable through microcatheters (even large sizes)

Different presentations: visible, syringe, …

Different properties

Specific instructions for use

How to make your choice?

Embolization Microspheres

Hydropearl

Embozene

Presentation

• Prepacked syringes (1 or 2 mls) vs vials

• Visible:

- blue: Bead Block

- transparent: Embosphere (purple: EmboGold)

- color-coded by size: Embozene or Hydropearl

• Calibration (granulometric distribution):

- Range of sizes (300-500 µm): Bead Block and

Embosphere

- Narrow calibration (600 µm): Embozene and Hydropearl

Granulometric Distribution

700-900 µm Product A

Characteristics

• Compressibility = ability to be compressed (microcatheter,

vessel)

Compressibility > 30% = ability of 700-900 µm

microspheres to be injected through a >.025 ID microcatheters

>30% risk of rupture except soft microspheres

• Elastic recovery = time required to get back to its initial

spherical shape

Slow recovery = distal traveling

Before compression 30% compression Sudden Release

Soft product

Rigid product

Compression / Decompression Test

Tris-Acryl Microspheres

Embosphere,

Merit Medical (Biosphere Medical)

Mechanisms of Occlusion

Spherical particles

No aggregates

Complete lumen occlusion

Various Clinical Indications

and Long-Term Tolerance

6 years

1 year

Facial AVM

Intravascular Location of Embolic Particles

Pre-operative Embolization of Meningiomas

0%

10%

20%

30%

40%

50%

60%

70%

absent arteriolar capillar

MS 100-300µm

PVA 45-150µm

PVA 150-250µm

Bendszus. AJNR 2000;21:255-61

Embolization of the Sheep Uterus

Diameter of occluded arteries (µm)

ES

100/3

00

ES

300/5

00

ES

50

0/7

00

ES

700/9

00

0

100

200

300

400

500

600

Dia

mete

rof

art

eries

(µm

)

Pelage, et al. Radiology 2002;224:436-45

Acrylamido-PVA microspheres

Bead Block, BTG (Biocompatibles)

Compressibility Evaluation (900-1200µm)

(Mean SD - 5 samples)

Déformation (%)-5

0

5

10

15

20

25

30

35

40

0% 10% 20% 30% 40% 50% 60% 70% 80%

Embosphere

BeadBlock

Contour

Force (g)

Acrylamido-PVA Microspheres

• Bead Block 700-900 µm is equivalent to

500-700 µm tris-acryl microspheres

PMMA hydrogel with polyzene F coating

Embozene, Boston Scientific (Celonova)

Embozene

Embozene

Embozene

• Non-resorbable

• Spherical

• Compressible

• Easy to inject (microcatheter)

• Very narrow calibration (600µm

≠ 500-700 µm)

• Microspheres color-coded

• Very compressible

• Specific technique of use

≠ tris-acryl MS

• Secondary redistribution

Deformation Embosphere vs Embozene

Embozene Embosphere

Top Tips

Because more compressible than

Embospheres, consider upsizing for safety

i.e. Embozene 900 µm recommanded for

uterine fibroid embolization

Secondary redistribution more significant

PolyEthlyleneGlycol (PEG) Microspheres

Hydropearl, Microvention-Terumo

Hydropearl

75µm

400µm

600µm

800µm 1,100µm200µm

Hydropearl

• Non-resorbable

• Spherical

• Compressible

• Easy to inject (microcatheter)

• Very narrow calibration (600µm

≠ 500-700 µm)

• Microspheres color-coded

• Compressibility?

• 800 µm recommanded

for uterine fibroid

embolization

• Just released in Europe

(november 2015)

Conclusion

Calibrated microspheres

Easy to handle

Easy injection of large microspheres through

microcatheterswithout clugging

Targeted embolization achievable

Conclusion

Be aware of mechanical differences between

products (trisacryl vs PVA vs PEG, …)

Extensive data available with Embosphere

Limited data at this point with Embozene and

Hydropearl

Future of particulate embolization: drug-eluting,

imaging detectable, resorbable, …