Technical strategies for the transcallosal transforaminal approach to third ventricle tumors: expanding the operative corridor.

Abstract

There are a number of surgical approaches to the third ventricle, each with advantages and disadvantages. Which approach to use depends on the location of the lesion within the ventricle, the goals of the operation, and the surgeon's experience. The authors present their results in children with a modified approach through the expanded foramen of Monro. A retrospective study was conducted to identify and analyze all children who underwent what the authors term the "expanded transforaminal" approach to the third ventricle between 2010 and 2013. Perioperative data included patient demographics, signs and symptoms on presentation, tumor characteristics (type, origin, and size), complications, and clinical and radiographic outcome at final follow-up. Twelve patients were identified (5 female, 7 male) with a mean age of 9 years (range 2-19 years). Two patients underwent gross-total resections, whereas 10 resections were less than total. There were no instances of venous infarction, significant intraoperative bleeding, or short-term memory deficits. Of the 12 patients, 7 suffered a total of 17 complications. Disruption of neuroendocrine function occurred in 4 patients: 2 with transient diabetes insipidus, 2 with permanent panhypopituitarism, and 1 with central hypothroidism (1 patient had 2 complications). The most common group of complications were CSF-related, including 2 patients requiring a new shunt. There was 1 approach-related injury to the fornix, which did not result in any clinical deficits. One child with an aggressive malignancy died of tumor progression 6 months after surgery. Of the remaining 11 patients, none have experienced tumor recurrence or progression to date. The expanded transcallosal transforaminal approach is a safe and relatively easy method of exploiting a natural pathway to the third ventricle, but there remain blind zones in the anterosuperior and posterosuperior regions of the third ventricle.