MICROANATOMICAL CONSIDERATIONS FOR THE FENESTRATION OF THE SEPTUM PELLUCIDUM

The anatomical foundations for the endoscopic fenestration of the sept um pellucidum have not been presented previously in an isolated fashio n. Using a surgical microscope, the microsurgical anatomy of the septu m pe[lucidum, lateral ventricles, and surrounding structures was exami ned in ten adult brains injected with silicone rubber. The mean antero posterior length of the septum pellucidum was 41 mm (range 40-42). Its mean height was 13.11 mm (range 12-15) at the level of the foramen of Monro; 10 mm (range 9-11) at the frontal horns, and 8 mm (range 7-10) at the ventricular atrium. One to three septal veins delimited 2 or 3 avascular areas in the septum pellucidum. We found an anterior area w hich was consistently avascular and large enough to be fenestrated saf ely. More posterior areas, while avascular, were inconsistent in their size and shape.