Hidden compartments in AVMs--a new concept.

Purpose: The concept of hidden compartments in cerebral arteriovenous malformations (AVMs), which is hereby launched, offers a new explanation for the neurosurgical and neuroradiological controversies concerning patients with AVMs.

Material And Methods: Three patients who were considered completely cured of their AVMs, subsequently developed new areas of malformed vessels as revealed by later angiograms.

Results: These 3 cases support our hidden compartment hypothesis and are reported on here, illustrated with relevant angiograms. The clinical implications of the hidden compartment concept refer to phenomena such as AVM growth, AVM recurrence after surgical excision, irradiation or embolization as well as per- or postoperative hemorrhage and swelling.

Conclusion: The incidence of hidden compartments in the AVM population is unknown but further studies, particularly in the realm of superselective embolization, could reveal their presence.