gms | German Medical Science

Objective: Deep-seated small intra-parenchymal cavernomas are difficult to be localized intraoperatively with conventional frameless navigation due to the "brain shift" effect. we conducted this study to compare the results of cavernomas resection with frameless navigated endoscopic port surgery (EPS) versus conventional frameless navigation, and to assess the clinical usefulness of navigated EPS.

Method: Between 2009 and 2012, 28 patients with deep-seated (distance longer than 2 cm from cortex), small (diameter less than 2 cm), intra-parenchymal cavernomas were enrolled into this study. Conventional frameless navigation guided surgery was performed in 15 (53.6%) patients, while in 13 (46.4%) patients, frameless navigated EPS was performed. A 1.5T Intra-operative MRI (iMRI) was used in all cases for the compensation of "brain shift" and to update the navigation system. The frequency of iMRI scans and the total time of procedure for all the cases were analyzed. The flexibility of procedures and postoperative clinical morbidity was also evaluated in each patient.

Results: Regarding the average iMRI scan times, the frameless navigated EPS was superior than the conventional navigation (mean scan times: 1.23 times versus 1.67 times, p<0.05). There was also significant difference between two groups concerning the average total time of procedure (navigated EPS : conventional navigation; 170 minutes versus 280 minutes; p<0.05).

Conclusions: Navigated EPS is helpful for fast localization of deep-seated small intra-parenchymal cavernomas. Image guided EPS provides high accuracy and efficiency for lesion targeting and permits excellent anatomic orientation. Accordingly, small and tailored safe exposure can be obtained with navigated EPS and multimodal neuronavigation.