The Role Of Endothelial Progenitor Cells In Aneurysm Neck Re-endothelialization After Coil Embolization

Intracranial aneurysm (Intracranial aneurysms) is the first cause of spontaneous subarachnoid hemorrhage. Aneurysm embolization with coil is now broadly used clinically. However, the recurrence of aneurysms after embolization has always plagued neurosurgeons, one of the main reasons is incomplete endothelialization of aneurysm neck after embolization. Bone marrow-derived endothelial progenitor cell (BM-EPC) could incorporate into injuried endothelium and differentiate into mature endothelial cells during vascular repairing processes. The aim of our study is to explore the effects of BM-EPC on aneurysm repairing and remodeling in a rat embolization model of abdominal aortic aneurysm. BM-EPC proliferation, migration and tube formation were not affected by SPIO labeling compared to the controls (p>0.05). The number of SPIO-labeled cells was greatly increased in EPC transplanted rats compared to in the human umbilical cord vascular endothelial cells (HUVEC) and phosphate buffered saline (PBS) control rats. SPIO-labeled EPC mainly located in the aneurysm neck and surrounded by fibrous tissue. Histology study showed that the aneurysm orifice was closed by neointima, and filled with newly formed fibrous tissue. The SPIO-EPCs accumulated in the aneurysm neck, which might accelerate focal fibrous tissue remodeling, suggesting BM-EPC played a crucial role in re-endothelialization of the aneurysm neck orifice after embolization with coil.