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.
Department of Clinical Pathology, Medical University of Vienna, General Hospital Vienna, Austria. mazal@meduniwien.ac.at
Peter R
PR
Mazal
Martin
M
Stichenwirth
Andreas
A
Gruber
Irene
I
Sulzbacher
Johannes A
JA
Hainfellner
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