Cavernous malformations: from frame-based to frameless stereotactic localization.

An exact surgical approach to cavernous malformations, in particular those located in areas of critical brain function, is important for their microsurgical resection without putting too much strain on the patient. During a two-year period, 29 cavernoma resections were performed. Stereotactic guidance was performed in 16 cases (55.2%). Nine cavernomas located in the supratentorial region were resected using the stereotactic operating microscope "MKM", which represents 21.6% of a total of 51 MKM-navigated operations; in one further case system referencing failed. The experience gathered with this frameless stereotactic system is compared to a retrospective analysis of 5 frame-based stereotactic cavernoma localizations. Frameless stereotactic localization has been shown to be sufficiently accurate but more advantageous than frame-based techniques in terms of utility, ease of integration, and detailed image-guided anatomical information. Software improvements have resulted in a high stability of the frameless stereotactic system.