[Stereotactic technique in the surgical treatment of deeply located cerebral masses]

The paper analyzes the use of a Leibinger Stryker stereotactic frame system (Germany) for surgical interventions for deeply located cerebral masses. Twenty three patients were operated on, by applying this system. Twenty five supratentorial masses were removed; of them 12 masses were paraventricularly located, including 5 masses being present close to the subcortical nuclei and internal capsule or immediately in them. In 9 patients, the foci were located subcortically in the projection of the sensorimotor region and motor zone of speech. Four masses were positioned in the substantia alba of the hemispheres. The patients having foci measuring not greater than 30-35 mm in diameter were selected for the study. Most cases were metastatic medullary lesions (11 single cases, 2 cases with multiple metastases, 3 cavernous angiomas, 2 arteriovenous malformations, 5 glial tumors). An algorithm for the stereotactic planning of approaches to masses of various localization and a procedure for there removal are presented in the paper. All the patients showed satisfactory postoperative results. Only did 4 patients with metastases being adjacent to the motor zone of the cortex and with a significant perifocal edema in the postoperative period display a recess of preoperative contralateral hemiparesis that regressed due to therapy. There were no other surgical complications. The method has proved to be effective against minor tumors (not more than 30 mm); whose access trajectory is over a length of more than 40-50 mm and against metastatic processes with a significant perifocal edema. This stereotactic system that considers the individual anatomic features of the patients' brain altered due to a pathological process provides convenience and precision when the deeply located brain masses are removed, by minimizing surgical trauma.