Factors affecting the occurrence and degree of luminal protrusion of carotid plaques after angioplasty stenting: an ex-vivo clinical study.

Objective: To investigate possible protrusions through stent cells, and the factors affecting protrusions after carotid angioplasty and stenting (CAS).
Methods: This ex-vivo clinical study was performed between July 2010 and August 2011 at the Department of Radiology, Ege University School of Medicine, Izmir, Turkey. After approval by the Institutional Board, 15 successive carotid plaques, which were obtained intact after endarterectomies were included in the study. Plaques were placed into vascular grafts. Stent implantations and balloon angioplasties were performed. Afterwards, models were scanned with multislice CT and inner surfaces of stents were observed via fiberoptic endoscope. Protrusion measurement was carried out on endoscopic images according to a scale assuming the width of stent cell as one unit in the same level of each plaque protrusion.
Results: Symptomatic plaques were lighter, less calcified. Plaque weights were inversely correlated to protrusion numbers and diameters of the narrowest segments of stents. Although they did not reach to statistically significant level, plaques having high protrusion numbers were more symptomatic and less calcified.
Conclusion: Plaque protrusions into the lumen were apparent in our ex-vivo CAS model. The main factor increasing protrusions appeared to relate to the presence of symptoms before endarterectomy.