Quantitative Anatomical Study of Tailored Far-Lateral Approach for the VA-PICA Regions

Abstract

Objective The extent of the far-lateral approach (FLA) has not yet been quantified for the region of the vertebral and posterior inferior cerebellar arteries (VA-PICA). We quantitatively analyzed six main sequential steps of the FLA. Methods A modified small FLA (msFLA) and a classic large FLA (clFLA) were performed sequentially on both sides of five cadaveric heads. A frameless navigational system was used to quantify the angle of attack for the origin (T1) and lateral medullary segment (T2) of the PICA and the surgical area of exposure above and below the vagus nerve (cranial nerve [CN] X). Results The total area of exposure above CN X increased significantly (p < 0.05) from the msFLA to the clFLA. However, the surgical exposure area below CN X did not change (p > 0.05). C1 hemilaminectomy increased (p < 0.05) the vertical angle of attack, and drilling the posteromedial third of the occipital condyle increased (p < 0.05) the horizontal angle of attack to the origin of the PICA. Conclusions For the VA-PICA region, the msFLA offered a similar practical surgical working area and similar angles of attack when compared with the clFLA. The FLA should be tailored based on the location, size, and pathology of lesions and on the exposure required for effective surgical treatment.

Is less always better? Keyhole and standard subtemporal approaches: evaluation of temporal lobe retraction and surgical volume with and without zygomatic osteotomy in a cadaveric model

“…5,14,19,31 Keyhole and endoscopic subtemporal ap- proaches, as well as zygomatic arch osteotomy, have been proposed to reduce these complications. 3,15,17,18 The term "keyhole surgery" does not refer to a specific technique or approach but rather to a philosophy that emphasizes using the smallest opening necessary to achieve the anatomical goals of surgery. 9,21,25 Ideally, the aim of any neurosurgical procedure used to access deep brain lesions should be minimal brain retraction.…”

Microsurgical Treatment Strategy of Vertebral Artery Fusiform Aneurysm—From the Standpoint of Hemodynamic Integrity and Perforator Preservation

“…Principles in Direct Surgery for VAFA D'Ambrosio et al reported that for approaching the VA-PICA region while minimizing the risk of LCN palsy, a trajectory from the caudo-dorsal side of the vulnerable LCNs should be used, and that the next most useful corridor is the space between the LCNs and 7-8th nerve complex (35)(36)(37). To use these two corridors from a more caudo-dorsal direction, we utilize the suboccipital far lateral approach.…”

Descrição técnica e avaliação anatômica da minicraniotomia suboccipital extrema lateral

“…São eles o acesso transfacetário, o retrocondilar, o transcondilar parcial, o transcondilar total, o acesso transjugular extremo lateral e o acesso transtubercular 13 . Importante salientar que, atualmente, a condilectomia não é passo obrigatório do acesso extremo lateral, devendo a craniotomia ser centrada na fossa subcondilar 10,[37][38][39][40] .…”

“…A necessidade e o benefício da condilectomia do terço posterior do côndilo variam de acordo com o tamanho do côndilo occipital, com a forma e o tamanho do forame magno, com a distância entre a porção rostral/ventral do tronco cerebral em relação ao clivus, com a quantidade de drenagem liquórica da cisterna magna e o grau de relaxamento cerebral, com o tamanho do desvio do tronco cerebral e dos nervos cranianos pela afecção específica da transição occipitocervical, com o trajeto da artéria vertebral através da dura-máter, com a altura da confluência das artérias vertebrais para a formação da artéria basilar, com as variações anatômicas da artéria cerebelar posteroinferior e com o tamanho do tubérculo jugular [37][38][39][40] .…”

“…não ser necessária para o ganho de exposição angular para a maioria das afecções cirúrgicas abordadas por esse acesso 10,[37][38][39][40] ; -drilagem do côndilo, além do seu terço distal e da articulação atlantoaxial, ser, na atualidade, sabidamente associada à instabilidade occipitocervical, com necessidade de fusão occipitocervical 46,47,48 , sendo esse o principal objetivo com a transposição da artéria vertebral; -haver riscos de lesão vascular pela manipulação.…”