[Transcallosal approach to para-ventricular tumors].

Our experience with the transcallosal approach to para-ventricular tumors is reviewed and our operative technique is described. A group of 7 patients with a variety of tumors affecting the lateral ventricle, 3rd ventricle and basal ganglia have been treated using an anterior transcallosal approach. Using a posterior transcallosal approach, we operated upon 2 patients with thalamic tumors. The anterior part of the body of the corpus callosum is divided in the anterior transcallosal approach and the posterior part of the body of the corpus callosum is divided with preservation of the splenium in the posterior transcallosal approach. The division amounting to approximately 2-3 cm is sufficient exposure. With the exception of tumors affecting the basal ganglia, thalamus and anterior 3rd ventricle, complete excision of each lesion was effected. There were no operative deaths. The complications in this group of patients were primarily related to the nature and location of the primary tumor, but four complications were directly related to the transcallosal approach. Venous infarctions occurred in 2 patients and subdural fluid collections occurred in 2 patients. Therefore, planning of the flap placement and the extent of brain retraction must be based on preoperative angiographic assessment of parasagittal venous tributaries. We performed some detailed studies of the interhemispheric transfer of somesthetic and perceptual motor tasks, as well as psychometric testing post-operatively in 2 patients. No significant clinical deficit subsequent to dividing the anterior part of the body of the corpus callosum could be demonstrated. The results and clinical material indicate that transcallosal approach is a safe, feasible alternative in the management of the tumors in these regions.