Gastric Artery Embolization with Xrayvisible Embolic Beads and

Gastric Artery Embolization with X-ray-visible Embolic Beads and C-arm Cone Beam CT for Increased Accuracy Clifford R. Weiss MD 1, Paul Di. Camillo MD Ph. D 2, Weijie Beh 3, Tza-Huei Wang Ph. D 4, Hai-Quan Mao Ph. D 5, Dara L. Kraitchman VMD Ph. D 2, 6 (1) Radiology/Vascular and Interventional Radiology, The Johns Hopkins University School of Medicine (2) Radiology, The Johns Hopkins University School of Medicine (3) Biomedical Engineering, The Johns Hopkins University School of Medicine (4) Mechanical Engineering, The Johns Hopkins University Whiting School of Engineering (5) Materials Science, The Johns Hopkins University Whiting School of Engineering (6) Molecular and Comparative Pathobiology, The Johns Hopkins University School of Medicine

What you’ve just learned! No Data ≥ 30% <10% 10%– 14% 15%– 19% 20%– 24% 25%– 29%

What you’ve just learned!

What you’ve just learned! Gastroenterology and Endoscopy News: April 2008 | v: 59: 04

What you’ve just learned! Paxton et al, SIR 2012

Weight change after bariatric embolization (relative to untreated animals) 6% % wt gain 4% 2% Week 4 0% % wt loss Week 7 untreated -2% -4% -6% Bariatric embolization -8% -10% -12% Paxton et al, SIR 2012

Challenges Facing Embolic Therapy • Complicated Vascular Anatomy • Non-target embolization to spleen / liver / esophagus / pancreas / intestine or “non-fundal” portions of stomach

Challenges Facing Embolic Therapy

Challenges Facing Embolic Therapy +

Challenges Facing Embolic Therapy BETTER SEE WHERE WE’RE GOING KNOW WHERE WE’VE BEEN

CT using Conventional Angiography C-arm Cone Beam CT (CBCT) • Flat panel angiography • 8 s acquisition

Oleic Acid Check Valve Prototype Microfluidic Device Ca 2+ Cl 2 IPA/ C /Ca IPA Ca 2+ a Cl 2 Palginate>Pvalve>Poil Barium-sulfate Alginate

X-Ray Visible Embolic Beads (XEB) Microfluidic Device • Size determined by nozzle size & flow rate • Pressurized system prevents clogging of nozzles at high generation rates • Scale up by parallelization of device allows production of microbeads at rates of ~1 k. Hz.

SEM of XEBs

Fundal Anatomy and Arterial Map

Overall Approach Pre-embolization Celiac DSA CBCT C-Arm Cone Beam CT (CBCT): • Dyna. CT: AXIOM Artis d. FA (Siemens Healthcare, Forchheim, Germany) • 8 s DSA or DR, • 210° rotation, • 0. 5°/ step, • contrast 25% iohexal Directly Visualized Embo Repeat for each site Post-embolization CBCT DSA Pathology/Histology

Celiac Axis

“Fundal Branch” Embolization Pre-embolization Post-embolization

Beads are Visible During Delivery

“Fundal Branch” CBCT Sagittal Coronal Axial Pre Contrast Post

“Fundal Branch” CBCT Post Embolization

Left Gastric?

Right Gastric Embolization Pre Embolization Post Embolization

Right Gastric CBCT Sagittal Coronal Axial Pre Contrast Post

Procedure Summary Post “FB” Post RG Sagittal Coronal Axial Pre N= 3 swine

CBCT Post Embolization

Return to Site #2 to Find Left Gastric

Gross Pathology

Fundus 2 x 10 x

Body 2 x 10 x

Conclusions • Combination of XEB and CBCT allows the interventional radiologist to: • Better see where they are going • See where they have been • Allows for complete fundal embolization • Better assessment of treatment successes and failures • Should allow for “long term” • Allow Interventional Radiologist to determine if re-embolization is needed

Broader Implications • Not only promising for improving Bariatric Arterial Embolization (BAE/BE) • Current embolic therapy is growing market: – Hepatocellular Carcinoma – Other Tumors – Uterine Fibroids – Bronchial Artery Embolization