Abstracts

Rationale: Hemispheric epileptogenic lesion such as hemimegalencephaly often presents intractable epilepsy in early infantile age. Hemispherotomy is a treatment of choice in controlling intractable hemispheric epilepsy. Less invasive procedure is desirable when performing surgery on infantile patients with low body weight. In this study, our experience on interhemispheric vertical hemispherotomy was presented, and its advantage was discussed. Methods: The study included 13 consecutive pediatric patients who underwent hemispherotomy for treatment of intractable epilepsy in our institution between the year 2001 and 2012. The age at surgery was 16.7 months in average ranged between 3 and 48. The etiology of epilepsy included hemimegalencephaly in 7 patients and cortical dysplasia in 3. Peri-insular hemispherotomy (PIH) was performed on the first 5 patients and interhemispheric vertical hemispherotomy (IVH) was performed on the last 8 patients. In the latter procedure, complete section of the corpus callosum was first performed via interhemispheric approach, the lateral ventricle was entered, and the dorsal aspect of the thalamus was fully visualized by removing a part of cingulate gyrus. Section of descending fibers was performed antero-laterally to the thalamus according to the Delalande s method. Clinical characteristics, duration of operation, and the amount of blood transfusion were compared between PIH and IVH groups.Results: There was no difference in age at surgery, body weight, and age of epilepsy onset between two groups. No surgery-related die was observed. No patients required shunt operation. In one patient who underwent IVH, re-operation was required for incomplete disconnection. The amount of intra-operative blood transfusion was smaller (174 80ml vs 44 28ml) and the total duration of operation was shorter (555 51min vs 373 68min) in IVH group than in PIH group. Conclusions: Using interhemispheric approach, amount of cortical resection is minimized and disconnection of descending fibers is efficiently performed under the common operative space to callosal section. Interhemispheric vertical hemispherotomy is advantageous especially when performing on infants with low body weight in viewpoint of operation duration and blood loss.