Stereotactic Craniotomy and Trans-Sulcal Approach for Small Subcortical Lesions

ABSTRACT

OBJECTIVE: It is difficult to localize accurately the small mass lesions seen in CT, MRI images in the operating field, espacially in the subcortical location. To minimize possible neurologic deficit for intraprenchymal exploration, the stereotactic technique is essential. Authors evaluated the stereotactic craniotomy and transsulcal approach in localizing various small subcortical mass lesions. METHOD: For last 3 years, stereotactic craniotomy was done in 7 patients in our institute. They were 1 cysticercosis, 1 cavernous hemangioma, 1 inflammatory sclerosis, 3 tuberculous granulomas, 1 metastatic tumor. They were all subcortical location and associated with mass effect. According to locations, four of them were located in the somatosensory cortex, 1 in supplementary frontal cortex, 1 in temporal cortex, 1 in parietal cortex. After application of stereotactic frame, the patients were transferred to CT/MR unit for target localization. Multiple target points were obtained from images and the patient were taken to the operating room. Scalp incisions and bone flaps were designed with physical placement method with stereotactic probe. After dural opening, the subcortical mass was traced with stereotactic probe. Transgyral approaches were used in 4 patients and transculcal approach in 3 patients under the stereotactic guidance. RESULTS: Small craniotomy with accurate localization was possible without difficulty in all cases. Furthermore there was no need for intraparenchymal exploration to localize the subcortical mass. There was no operative mortality, 1 patient developed transient hemiparesis lasting 3 weeks. No other patient showed neurologic deficit. CONCLUSION: Stereotactic craniotomy and localization seems to be helpful for removal of small subcortical masses. small craniotomy with accurate localization was possible. In the eloquent areas, transsulcal approach seems to be particularly useful to prevent possible neurologic sequele.