Neuro Oncology and Brain Tumor

Biography

Biography: Dongwoo John chang

Abstract

THE SUBTEMPORAL APPROACH IN CRANIAL NEUROSURGERY: A ROAD LESS TRAVELED rnINTRODUCTIONrnThe subtemporal approach was popularized by Dr. Charles Drake for the microneurosurgical clipping of aneurysms of the distal basilar artery. The competing approach for such problems was and still is the transsylvian approach to the interpeduncular region. Because an increasing proportion of cerebral aneurysms, particularly those of the basilar artery, are treated by endovascular methods, it is probable that the subtemporal approach is being used less and less in contemporary neurosurgical practice. However, the elegance of this approach lends itself to the neurosurgical treatment of not only vascular lesions, but also for the definitive microsurgical management of tumorous lesions that occur in the deep, central portions of the cranial cavity.rnMETHODSrnRetrospective review of the clinical practice database of a single cerebrovascular/skull base neurosurgeon revealed that the following lesions were treated with the subtemporal approach and its variations: basilar apex aneurysm (small to giant sizes clipped with standard techniques and with hypothermic circulatory standstill), superior cerebellar artery aneurysm, posterior cerebral artery aneurysm, tentorial meningioma, parahippocampal (and other subtemporal) metastatic tumor, large mesencephalic lymphoma, giant pontomesencephalic region pilocytic astrocytoma, and chordoma.rnRESULTSrnThe subtemporal approach can be subdivided into 3 subcategories: (1) anterior subtemporal, (2) mid-subtemporal, and (3) posterior subtemporal. Excellent microsurgical exposure was obtained in all cases approached with each of the 3 variations of the subtemporal approach. Definitive lesionectomy (whether it was aneurysm clipping, lesion biopsy, or tumoral removal) was accomplished in all cases. Technical nuances to avoid surgical complications are discussed in this presentation, ranging from (and including) bony exposure, lumbar drainage, location/method of tentorial incision, and management of cerebral veins to the optimal mechanical trajectories of brain retractors that facilitate final surgical exposure while minimizing iatrogenic brain injury. The specific surgical approach was tailored to the anatomic details of the treated lesion—based on vascular, bony, and lesional anatomy—to arrive at the most applicable surgical approach.rnCONCLUSIONSrnThe subtemporal approaches provide orthogonal anatomic routes that often result in a short, direct route to neurosurgical lesions that occur at the tentorial incisura and in the interpeduncular cistern. The subtemporal approaches are useful for lesions that may originate in different anatomic compartments but have lesional extensions into the traditional “central” cranial compartment (pontomesencephalic, clival, and tentorial incisural regions), for which the classical subtemporal approach has been historically useused. Finally, anatomic insights gained from the use of the subtemporal approaches are particularly useful in the microneurosurgery of the mesial temporal lobe region, and vice versa.rn