In situ tissue engineering: endothelial growth patterns as a function of flow diverter design
Department of Radiology; New England Center for Stroke Research; Department of Cell Biology
Biomedical Devices and Instrumentation | Molecular, Cellular, and Tissue Engineering | Neurology | Radiology | Surgery
BACKGROUND: Vascular remodeling in response to implantation of a tissue engineering scaffold such as a flow diverter (FD) leads to the cure of intracranial aneurysms. We hypothesize that the vascular response is dependent on FD design, and CD34+ progenitor cells play an important role in the endothelialization of the implant.
METHODS: Sixteen rabbit aneurysms were randomly treated with two different single-layer braided FDs made of cobalt-chrome alloys. The FD-48 and FD-72 devices had 48 and 72 wires, respectively. Aneurysm occlusion rate was assessed during the final digital subtraction angiogram at 10, 20, 30, and 60 days (n=2 per device per time point). Implanted vessels were analyzed with scanning electron microscopy for tissue coverage, endothelialization, and immuno-gold labeling for CD34+ cells.
RESULTS: Complete aneurysm occlusion rates were similar between the devices; however, complete or near complete occlusion was more frequently observed in aneurysms with neck < /=4.2 mm (p=0.008). Total tissue coverage at 10 days over the surface of the FD-48 and FD-72 devices was 56.4+/-11.6% and 76.6+/-3.6%, respectively. Endothelial cell growth over the surface was time-dependent for the FD-72 device (Spearman's r=0.86, p=0.013) but not for the FD-48 device (Spearman's r=-0.59, p=0.094). The endothelialization score was marginally correlated with the distance from the aneurysm neck for the FD-48 device (Spearman's r=1, p=0.083) but not for the FD-72 device (Spearman's r=0.8, p=0.33). CD34+ cells were present along the entirety of both devices at all time points.
CONCLUSIONS: This study gives preliminary evidence that temporal and spatial endothelialization is dependent on FD design. Circulating CD34+ progenitor cells contribute to endothelialization throughout the healing process.
Aneurysm, Flow Diverter
DOI of Published Version
J Neurointerv Surg. 2017 Oct;9(10):994-998. doi: 10.1136/neurintsurg-2016-012669. Epub 2016 Oct 5. Link to article on publisher's site
Journal of neurointerventional surgery
Marosfoi, Miklos G.; Langan, Erin T.; Strittmatter, Lara; van der Marel, Kajo; Vedantham, Srinivasan; Arends, Jennifer; Lylyk, Ivan R.; Loganathan, Siddharth; Hendricks, Gregory M.; Szikora, Istvan; Puri, Ajit S.; Wakhloo, Ajay K.; and Gounis, Matthew J., "In situ tissue engineering: endothelial growth patterns as a function of flow diverter design" (2017). Radiology Publications and Presentations. 400.