[Operative neurosurgery: personal view and historical backgrounds (7) reappraisal of approaches]

Selection of an appropriate approach is one of the most important factors for the success in neurosurgery, so the following approaches were reappraised in this session by giving examples from recent cases. Their standard use has already been mentioned elsewhere in the series: 1. Selective extradural anterior clinoidectomy SEAC was once more discussed: 1. the origin of en bloc removal has originated, 2. meaning of an en bloc replacement, if any, and 3. further development of this procedure for low lying upper basilar aneurysms. 2. Trans-sulcus circularis insulae approach TSCIA, which is a part of the selective amygdalohippocampectomy approach SAHEA was applied for removal of a ganglioglioma originating from the head of the hippocampus (cause of intractable temporal lobe epilepsy) of the dominant hemisphere without performing SAHE due to a positive selective Wada test and the full SAHEA for P2 or P2-3 junction aneurysms (Fig. 1, 2, 3). 3. Trans-rostrum corporis callosi-lamina terminalis approach TRCLA revealed to be less invasive and helpful for removal of a small recurrent craniopharyngioma located between the chiasma opticum and the AcomA complex with the use of a small craniotomy, avoiding previous craniotomy routes, both pterional and subfrontal, for fear of structural adhesion (Fig. 4, 5, 6). 4. Within the scope of the trans-lobulus quadrangularis approach TLQA, the paramedian supracerebellar transtentorial approach SCTTA revealed to be useful for removal of a cavernous angioma located at the parahippocampal gyrus corresponding to the head of the hippocampus of the dominant hemisphere, so that the possible impairment of cognitive function could be avoided, because the incision to the temporal stem and to the hippocampus involved in the above mentioned SAHEA could be avoided. Furthermore the approach seems to be more rational in the treatment of P2, P2-P3 junction aneurysms than other approaches especially in the dominant hemisphere (Fig. 7, 8, 9). 5. Trans-vertebralis dural ring approach TVDRA revealed to be useful in the treatment of microvascular decompression for glossopharyngeal neuralgia, because mobilization and displacement of the vertebral artery by circumferential incision from its dural ring plays an important role for the purpose (Fig. 10, 11). Although the sitting position is necessary for the performance of SCTTA and TVDRA, one should know their usefulness and be ready for their performance.