The Role of Endoscopic Assistance in Ambient Cistern Surgery: Analysis of Four Surgical Approaches.
OBJECTIVE
We used microscopy with endoscopic assistance to conduct an objective analysis of 4 surgical approaches commonly used in the surgery of the ambient cistern: infratentorial supracerebellar (SC), occipital interhemispheric (OI), subtemporal (ST), and transchoroideal (TC). In addition, we performed a parahippocampalis gyrus resection in the ST context.


METHODS
Each approach (SC, OI, ST, TC) was performed on 3 cadaveric heads (6 sides). After the microscopic anatomic dissection, the 30-degree endoscope was used to explore the exposure. The parahippocampalis gyrus was resected through an ST approach and the exposure was evaluated. The quantitative analysis was based on linear exposure of the vascular structures (linear exposure), such as the posterior choroidal artery (PChA), the P2 and P3 segments of the posterior cerebral artery (PCA) with their branches, the basal vein of Rosenthal, and the area of exposure of the ambient cistern region (area of exposure) limited by points on its superior, mesial, and anterior walls. In all cases, a P value of less than 0.05 was considered significant.


RESULTS
There was a significant difference (P < 0.05) in linear exposure of the PCA and medial PChA between microsurgery and endoscopic assistance using the ST approach. This approach also improved the medial, superior, and total exposure of the ambient cistern region.


CONCLUSIONS
This study demonstrates that endoscope assistance improved exposure of the ambient cistern region when using the ST approach. Endoscopic assistance provided similar surgical exposure compared with ST associated with parahippocampalis resection.
Department of Neurology, Discipline of Neurosurgery, University of São Paulo Medical School (FMUSP), São Paulo, Brazil. Electronic address: ebgadelha@yahoo.com.
Eberval Gadelha
EG
Figueiredo
Department of Neurology, Discipline of Neurosurgery, University of São Paulo Medical School (FMUSP), São Paulo, Brazil.
André
A
Beer-Furlan
Barrow Neurological Institute, St Josephs Hospital and Medical Center, Phoenix, Arizona, USA.
Peter
P
Nakaji
Barrow Neurological Institute, St Josephs Hospital and Medical Center, Phoenix, Arizona, USA.
Neil
N
Crawford
State University of Ponta Grossa, School of Medicine, Ponta Grossa, Parana, Brazil.
Leonardo C
LC
Welling
Department of Neurology, Discipline of Neurosurgery, University of São Paulo Medical School (FMUSP), São Paulo, Brazil.
Eduardo C
EC
Ribas
Department of Neurology, Discipline of Neurosurgery, University of São Paulo Medical School (FMUSP), São Paulo, Brazil.
Manoel J
MJ
Teixeira
Department of Neurosurgery, University of Florida, Gainsville, Florida, USA.
Albert L
AL
Rhoton
Barrow Neurological Institute, St Josephs Hospital and Medical Center, Phoenix, Arizona, USA.
Robert F
RF
Spetzler
Barrow Neurological Institute, St Josephs Hospital and Medical Center, Phoenix, Arizona, USA.
Mark C
MC
Preul
D001921:Brain / Q000033:anatomy & histology* / Q000601:surgery*; D002102:Cadaver; D002946:Cisterna Magna / Q000033:anatomy & histology* / Q000601:surgery*; D004210:Dissection; D006801:Humans; D008866:Microsurgery; D044583:Neuroendoscopy; D019635:Neurosurgical Procedures / Q000379:methods*
Ambient cistern; Anatomy; Endoscopic assistance; Endoscopy; Microneurosurgery; Microsurgery