A pitfall in the interhemispheric translamina terminalis approach for the removal of a craniopharyngioma. Significance of preserving draining veins. Part II. Experimental study.

The authors have reported a case of a craniopharyngioma removed by the interhemispheric translamina terminalis approach, and the postoperative development of a subcortical hematoma. We suspected that the cause of the subcortical hematoma was dividing the bridging veins and applying a retractor over them. In this paper, we report our experimental study, using dogs and monkeys, to evaluate the effect of cutting the vein and applying a retractor over it. The incidence of a subcortical hematoma was highest (60%) when the veins were cut and the retraction was applied. Vein occlusion only did not cause hematoma to develop, and the retraction alone caused 13% of the hematomas. This clearly indicated that the clinical case reported in Part I developed the subcortical hematoma postoperatively because the frontal bridging vein was cut and a retractor was applied for 60 minutes over the cut vein.