Surgery of cavernous malformations with and without navigational support--a comparative study.

Background: The aim of this descriptive study was the comparison of the clinical and surgical data of patients who suffered from cavernoma and were treated surgically with and without intraoperative navigation (ultrasound, neuronavigation).

Method: Between 1995 and 2002, 40 patients were treated for cavernous malformations microsurgically: 24 patients (group I) using a neuronavigation system (STP 4.0, SNN, Germany), 7 patients (group II) using ultrasound (Siemens Omnia with 5.0 MHz Probe) and 9 patients (group III) without any image guidance using anatomic landmarks.

Findings: With the use of neuronavigation the mean sizes of cavernous malformations, which were resected, were reduced from 25.6 mm (group III) and 24.4 mm (group II) to 16.3 mm (group I) (p > or = 0.05). Corresponding to the reduction of the cavernoma size, the mean distances of the vascular lesion to the cortical surface increased from 13.9 mm (group III) and 17.8 mm (group II) to 24.4 mm under neuronavigational support (p > or = 0.05). All cavernomas were resected completely in all 40 patients. Postoperative neuroradiological control (MRI) confirmed complete resection in all cases. No significant differences in the clinical outcome could be evaluated in all three groups up to three months postoperatively.

Conclusions: Use of neuronavigation was associated with a more comfortable and safer surgery of smaller and more deeper-seated cavernomas. In spite of the lack of significance between all groups, the advantages of neuronavigation in planning and realising surgery could be documented, which justify the additional costs and time-consuming acquisition of planning image data and postprocessing as well as intraoperative navigation.