Transtentorial transcollateral sulcus approach to the ventricular atrium: an endoscope-assisted anatomical study

Abstract

OBJECTIVE Conventional approaches to the atrium of the lateral ventricle may be associated with complications related to direct cortical injury or brain retraction. The authors describe a novel approach to the atrium through a retrosigmoid transtentorial transcollateral sulcus corridor. METHODS Bilateral retrosigmoid craniotomies were performed on 4 formalin-fixed, colored latex-injected human cadaver heads (a total of 8 approaches). Microsurgical dissections were performed under 3× to 24× magnification, and endoscopic visualization was provided by 0° and 30° rigid endoscope lens systems. Image guidance was provided by coupling an electromagnetic tracking system with an open source software platform. Objective measurements on cortical thickness traversed and total depth of exposure were recorded. Additionally, the basal occipitotemporal surfaces of 10 separate cerebral hemisphere specimens were examined to define the surface topography of sulci and gyri, with attention to the appearance and anatomical patterns and variations of the collateral sulcus and the surrounding gyri. RESULTS The retrosigmoid approach allowed for clear visualization of the basal occipitotemporal surface. The collateral sulcus was identified and permitted easy endoscopic access to the ventricular atrium. The conical corridor thus obtained provided an average base working area of 3.9 cm at an average depth of 4.5 cm. The mean cortical thickness traversed to enter the ventricle was 1.4 cm. The intraventricular anatomy of the ipsilateral ventricle was defined clearly in all 8 exposures in this manner. The anatomy of the basal occipitotemporal surface, observed in a total of 18 hemispheres, showed a consistent pattern, with the collateral sulcus abutted by the parahippocampal gyrus medially, and the fusiform and lingual gyrus laterally. The collateral sulcus was found to be caudally bifurcated in 14 of the 18 specimens. CONCLUSIONS The retrosigmoid supracerebellar transtentorial transcollateral sulcus approach is technically feasible. This approach has the potential advantage of providing a short and direct path to the atrium, hence avoiding violation of deep neurovascular structures and preserving eloquent areas. Although this approach appears unconventional, it may provide a minimally invasive option for the surgical management of selected lesions within the atrium of the lateral ventricle.

Resection of the tumor in the trigone of the lateral ventricle via the contralateral posterior interhemispheric transfalcine transprecuneus approach with multi-modern neurosurgery technology: a case report

“…In generally, the ideal approach should enable comprehensive microsurgical resection while concurrently mitigating risks to the adjacent structures ( 20 ). Kawashima outlined three primary surgical routes: the anterior transsylvian, posterior transcortical/transcallosal, and lateral trans- or subtemporal ( 21 ).…”

Defining the relationship of the optic radiation to the roof and floor of the ventricular atrium: a focused microanatomical study

“…Although previous laboratory studies have explored the microsurgical anatomy of the visual pathways and investigated their possible implications in the most commonly used approaches to the ventricular compartmen ts, 5,8,9,12,13,15,19,27,29,33,36,37,[42][43][44] evidence regarding the specific relationship of the optic radiations to the floor and roof of the ventricular trigone is ambiguous. Although some authors topographically related the atrial roof and floor to the fibers of the posterior and/or central optic bundle and anterior optic bundle, respectively, others did not define the precise anatomical correlation.…”

“…During our study, particular emphasis was placed on the correlative topography of the intraparietal and collateral sulci to the roof and floor of the ventricular atrium, respectively, because these sulci have been used as surgical corridors for treating atrial lesions because of their short and direct access to the ventricle. 1,9,10,12,13,15,[17][18][19]29,41,50 In this context, the intraparietal sulcus, when it has the appropriate morphological characteristics (i.e., a straight, continuous sulcal segment of at least 3 cm for microsurgical dissection), offers a safe and effective trajectory to the atrium that avoids injury to the optic pathway. 12,15,[17][18][19]21,41 However, there is a tight relation between the plane of subcortical dissection achieved and the location of the SLF, particularly at the most anterior part of the sulcus.…”

“…Some authors have argued that part of the roof and floor of the ventricular trigone is covered by optic fibers, 34,36,37,42 whereas others have claimed exactly the opposite. 12,13,15 As a consequence, ambiguity remains as to whether surgical access to the atrial roof and floor through the most common superiorly or inferiorly directed transcortical or transsulcal transventricular variants, such as the superior parietal lobule, intraparietal sulcus, transcollateral sulcus, or subtemporal approach, confers risk of injury to the visual pathways.…”

Inferior is Superior—Transtentorial Transcollateral Sulcus Approach to the Ventricular Atrium: 2-Dimensional Operative Video

“…[1][2][3] This approach to the ventricular atrium through the collateral sulcus has been investigated in cadaveric studies and reported in 2 clinical cases. [4][5][6][7] The collateral sulcus is a consistently identifiable landmark and relatively shallow, providing a reliable and short route to the atrium. 8,9 Navigation is extremely helpful in determining the entry and trajectory.…”