Tissue reactions induced by different embolising agents in cerebral arteriovenous malformations: a histopathological follow-up.
OBJECTIVE
Comparative histopathological analysis was performed in 47 incompletely embolised and resected cerebral arteriovenous malformations (AVMs).


METHODS
Thirty-three AVMs were embolised with n-butyl-cyanoacrylate (NBCA), four with iso-butyl-cyanoacrylate (IBCA), seven with polyvinyl alcohol particles (PVA), one with a fibrin mixture, one with silicon pellets, and one with microcatheter balloons. Maximum exposure time (MET) of the embolising agent (interval between embolisation and surgery) ranged from <24 hours to 80 months. All AVMs were investigated regarding angionecrosis, angiofibrosis, acute inflammation, chronic inflammation, foreign-body reactions, vascular calcification, blood admixture to embolising cast, and capillary recanalisation within the AVMs. These parameters were correlated with MET, comparing different embolising agents, age, and sex.


RESULTS
A typical sequence of events depending on MET is observed in all embolised AVMs: acute inflammation with mural angionecrosis is soon replaced by prominent chronic granulomatous vasculitis, which remains stable and is detectable for a very long time, even in AVMs with a MET of more than 6 years.


CONCLUSIONS
Capillary recanalisation is always present in incompletely embolised AVMs, detectable after 3 months of MET, irrespective of the embolising agent used. Age and sex does not influence pattern and time course of tissue lesions and recanalisation in incompletely embolised AVMs.
Mazal
Peter R
PR
Department of Clinical Pathology, Medical University of Vienna, General Hospital Vienna, Austria. mazal@meduniwien.ac.at
Stichenwirth
Martin
M
Gruber
Andreas
A
Sulzbacher
Irene
I
Hainfellner
Johannes A
JA
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002015:Bucrylate / Q000627:therapeutic use*; D002196:Capillaries / Q000473:pathology; D002404:Catheterization; D002648:Child; D003487:Cyanoacrylates / Q000627:therapeutic use*; D004621:Embolization, Therapeutic; D004659:Enbucrilate; D005260:Female; D005337:Fibrin / Q000627:therapeutic use; D005500:Follow-Up Studies; D006801:Humans; D002538:Intracranial Arteriovenous Malformations / Q000473:pathology* / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D011142:Polyvinyl Alcohol / Q000627:therapeutic use*; D012825:Silicon / Q000627:therapeutic use; D013997:Time Factors; D014657:Vasculitis / Q000473:pathology
D003487:Cyanoacrylates; D002015:Bucrylate; D005337:Fibrin; D011142:Polyvinyl Alcohol; D004659:Enbucrilate; D012825:Silicon