Endoscope-assisted supraorbital craniotomy for lesions of the interpeduncular fossa

OBJECTIVE: The supraorbital approach is well accepted for lesions in the an terior fossa, the sellar region, and the anterior circle of Willis. However , the usefulness of this approach has not yet been elucidated for lesions i n the interpeduncular fossa. The technique of an endoscope-assisted, ipsi- and contralateral supraorbital approach to lesions within the interpeduncul ar fossa is described, and the initial results are reported. METHODS: A small supraorbital craniotomy, using an eyebrow incision, was pe rformed in each of seven patients who were operated on for different types of lesions in the interpeduncular fossa, including a neuromuscular choristo ma of the oculomotor nerve, a retrosellar epidermoid tumor, and five aneury sms (two of the basilar artery tip, two at the offspring of the superior ce rebellar artery, and one fusiform arterial widening of the basilar artery a pex). The surgical approach, its indications and limitations, and the addit ional Value of an endoscope are outlined. RESULTS: All lesions could be easily reached and well visualized through th is approach by using an endoscope as an adjunct to the operating microscope . The saccular aneurysms all could be clipped successfully, the fusiform wi dening was wrapped, the epidermoid tumor was removed completely, and the ch oristoma was removed only partially because of brain stem invasion. The pat ient with the neuromuscular choristoma had persistent diabetes insipidus po stoperatively, most probably caused by stretching the pituitary stalk with the endoscope. The patient with the epidermoid tumor showed a postoperative transient partial oculomotor nerve paresis at the side of the approach. Th e cosmetic results of the eyebrow incisions for this approach were excellen t in all patients. CONCLUSION: Lesions in the interpeduncular fossa can be effectively treated using a supraorbital approach, which can be ipsi- or contralateral to the side of the lesion, depending on the exact location of the lesion. The use of an endoscope is essential to visualize these lesions that lie in the sha dow of the sellar and parasellar anatomic structures. The major advantage o ver other approaches are a nearly perpendicular surgical route (although th e distance is longer, which is, on the other hand, not a disadvantage), a m inimized amount of dissection and brain retraction by using an endoscope th rough anatomic gateways, and a small surgical incision with excellent cosme tic results.