Original Article   

Journal of Neurosurgical Sciences 2022 Apr 13

DOI: 10.23736/S0390-5616.22.05622-3

Copyright © 2022 EDIZIONI MINERVA MEDICA

language: English

Endoscopic-assisted paramedian supracerebellar infratentorial approach to the posterior portion of the third ventricle. Anatomical study and surgical cases

Lucas SERRANO SPONTON ^{1, 2} ✉, Mohammed ALHOOBI ³, Eleftherios ARCHAVLIS ², Ahmed T. SHAABAN ³, Elias DUMOUR ⁴, Amr NIMER ⁵, Jens CONRAD ², Sven R. KANTELHARDT ², Ali AYYAD ^{3, 6}

¹ Department of Neurosurgery, Sana Klinikum Offenbach, Offenbach am Main, Germany; ² Department of Neurosurgery, Mainz University Medical Center, Mainz, Germany; ³ Department of Neurosurgery, Hamad Medical Corporation, Doha, Qatar; ⁴ Department of Neurosurgery, Bristol Royal Hospital for Children, Bristol, UK; ⁵ Department of Neurosurgery, Charing Cross Hospital, Imperial College Healthcare NHS Trust, London, UK; ⁶ Department of Neurosurgery, Saarland University Medical Center, Homburg, Germany

BACKGROUND: To date, morphometrical data providing a systematic quantification of accessibility and operability parameters to the boundaries of the posterior portion of the third ventricle (PTV) when applying an endoscopic-assisted paramedian supracerebellar infratentorial approach (EPSIA) are lacking. We performed an anatomical study and complemented our findings with surgical cases.
METHODS: Eight EPSIAs towards the PTV were performed in cadaveric specimens. Optimal approach angles (OA), surgical freedom (SF) and operability indexes (Oi) to the PTV boundaries were assessed. Additionally, a 54-year-old man and 33-year-old woman were operated on PTV tumors applying the EPSIA.
RESULTS: Sagittal OA to ventricle’s roof and floor was 36±1.4° and 25.5±3.5° respectively, axial OA to the ipsilateral and contralateral ventricle’s wall were 9.5±1.3° and 28.5±1.6°. SF was maximal on the contralateral wall (121.2±19.3mm2), followed by the roof (112.7±18.8mm2), floor (106.6±19.2mm2) and ipsilateral wall (94.1±15.7mm2). SF was significantly lower along the ipsilateral compared the contralateral wall (p<0.01) and roof (p<0.05). Facilitated surgical maneuvers with multiangled exposure were possible up to 8.5±1.07mm anterior to ventricle’s entrance, whereas surgical maneuvers were possible but difficult up to 15.25±3.7mm. Visualization of more anterior was possible up to a distance of 27±2.9mm, but surgical maneuvers were barely feasible. EPSIA enabled successful resection of both PTV tumors and postoperative course was uneventful.
CONCLUSIONS: EPSIA can be effective for approaching the PTV, enabling surgery along all boundaries, but especially on its roof and contralateral wall. In the not-enlarged ventricle, surgical maneuvers are feasible up to the level of the Monro foramen, becoming more limited anteriorly.

KEY WORDS: Paramedian supracerebellar infratentorial approach; Third ventricle