RT Journal Article
SR Electronic
T1 Histopathological analysis of in vivo specimens of recurrent aneurysms after coil embolization
JF Journal of NeuroInterventional Surgery
JO J NeuroIntervent Surg
FD BMJ Publishing Group Ltd.
SP 734
OP 739
DO 10.1136/neurintsurg-2021-017872
VO 14
IS 7
A1 Chao Wang
A1 Mengxing Li
A1 Huiyuan Chen
A1 Xinjian Yang
A1 Ying Zhang
A1 Dong Zhang
YR 2022
UL http://jnis.bmj.com/content/14/7/734.abstract
AB Background Aneurysm recurrence after coil embolization remains a challenging problem.Objective To determine the histopathological features of recurrent aneurysm specimens and explore the mechanism of aneurysm recurrence.Methods Nine aneurysm specimens were collected from eight patients who underwent clipping for aneurysm recurrence within 2 years after embolization. All specimens were sectioned and embedded in resin, stained with hematoxylin-eosin (H&E), Masson stain, and immunohistochemical staining for smooth muscle actin (SMA) and CD68+ antibodies, and were examined under light microscopy.Results Five aneurysms were surgically clipped owing to post-embolic subarachnoid hemorrhage, while the other four aneurysms had dangerous recanalization detected on follow-up imaging. Five aneurysms had self-growth and four aneurysms had coil compactions. Gross observation showed that each recurrent aneurysm was wrapped by a thrombus and the aneurysm wall; some coils protruded from the pseudocapsule in some ruptured aneurysms. Microscopically, H&E staining showed that three types of thrombi (fresh thrombus, granulation tissue, and scar tissue) coexisted in one section. In addition, characteristic unstable and unorganized thrombi with empty spaces were found in the neck cavity. Immunohistochemical staining showed that the SMA stain was discontinued and incomplete, and CD68+ antibody and H&E staining revealed inflammatory infiltrate in the aneurysm wall.Conclusion The coexistence of three types of thrombi is the main characteristic of recurrent aneurysms. The formation of stable thrombus may be one of the key points of aneurysm recurrence. Smooth muscle cell damage and infiltration of inflammatory cells in the aneurysm wall probably contribute to the recanalization.Data sharing not applicable as no datasets generated and/or analysed for this study.