Author + information
- Michael Lipinski1,
- Eduardo Acampado2,
- Qi Cheng2,
- Lila Adams3,
- Sho Torii2,
- David Hellinga4,
- Rebecca Torguson5,
- Philine Zumstein6,
- Frank Kolodgie2,
- Renu Virmani2 and
- Ron Waksman1
- 1Medstar Washington Hospital Center, Washington, District of Columbia, United States
- 2CVPath Institute, Inc., Gaithersburg, Maryland, United States
- 3CVPath Institute, Gaithersburg, Maryland, United States
- 4MedStar Health Research Institute, Washington, District of Columbia, United States
- 5Washington Hospital Center, Washington, District of Columbia, United States
- 6Biotronik AG, Buelach, Switzerland
We previously demonstrated the Magmaris sirolimus-eluting bioabsorbable magnesium scaffold had significantly reduced thrombogenicity compared with ABSORB BVS and performed well compared with Orsiro Hybrid DES, which has much thinner struts. We therefore sought to determine whether the magnesium stent has platelet repelling properties by comparing the acute thrombogenicity of Magmaris with an identical stent composed of stainless steel in a porcine arterio-venous shunt model.
An ex-vivo porcine carotid jugular arteriovenous shunt was established and connected to Sylgard tubing containing the Magmaris BRS with fully absorbable magnesium scaffold with sirolimus-eluting PLLA coating (strut thickness 150 μm) and an identical 316L Magmaris stent with stainless steel scaffold and allowed to run in the shunt for a maximum of one hour. Six shunts (2 shunt runs per pig) were run comparing the two scaffolds (n=9) in alternating order. Nested generalized linear mixed models were employed to compare variables between scaffold groups while adjusting for variability between shunt runs.
Confocal fluorescent microscopy costaining CD61/CD42b demonstrated that the stainless steel 316L Magmaris (5.8%) had significantly greater platelet coverage of the total scaffold compared with Magmaris BRS (5.8% vs 2.8%, Rate ratio 2.21 [1.41, 3.47], p=0.012, Figure). Scanning electron microscopy demonstrated significantly greater thrombus deposition on 316L Magmaris as a percentage of the total scaffold compared with Magmaris BRS (8.0% vs 5.3%, Rate ratio 1.65 [1.26, 2.16], p=0.009). 316L Magmaris also had significantly greater CD14 positive monocyte deposition (Rate ratio 4.73 [2.15, 10.42], p=0.008) and a trend toward less PM-1 positive neutrophil compared with Magmaris.
Despite having identical scaffold characteristics, the Magmaris sirolimus-eluting bioabsorbable magnesium scaffold had significantly less thrombogenicity and inflammatory cell deposition compared with the 316L Magmaris stent with stainless steel backbone in an ex vivo porcine arteriovenous shunt model. This data suggests bioabsorbable magnesium scaffolds may have inherent properties that repel platelets and inflammatory cells.
CORONARY: Bioresorbable Vascular Scaffolds