Microsurgical resection of tumors of the lateral and third ventricles: operative corridors for difficult-to-reach lesions

Abstract

Tumors of the lateral and third ventricles are cradled on all sides by vital vascular and eloquent neural structures. Microsurgical resection, which always requires attentive planning, plays a critical role in the contemporary management of these lesions. This article provides an overview of the open microsurgical approaches to the region highlighting key clinical perspectives.

Keywords: Brain tumor surgery; Lateral ventricle; Microneurosurgery; Surgical approach; Third ventricle.

Fig. 1

The surgical approaches to the lateral ventricle (LV) are shown on a lateral view of a cadaveric dissection of the brain. LV and third ventricle (TV) are shown in blue. Anatomical portions of the LV are depicted with gray ellipses. Red arrows show the direction of the approaches and the parts of the LV that can be reached by that individual approach

Fig. 2

a–f Cadaveric dissection demonstrating the steps of interhemispheric transcallosal approach. a A C-shaped incision for the interhemispheric approach. b After craniotomy, the superior sagittal sinus (SSS) is seen at the midline. c After elevation of the dura, vasculature of the region, including cortical veins draining into the SSS, is seen more clearly. d The corpus callosum (CC), cingulate gyrus (CG), and the pericallosal arteries are seen in the interhemispheric fissure. e Dissection demonstrating the anatomical relationships of the LVs. Corpus callosum (CC), column of fornix (cf), foramen of Monro (FM), thalamus (T), genu of CC (G), body of fornix (bf), choroid plexus (chp). f Superior view of the LV over the FM (arrow) demonstrating the close relationship of the third ventricle with the optic nerve and the lamina terminalis. Optic nerve (II), septum pellucidum (sp), choroid plexus (chp), thalamus (T), thalamostriate vein (tsv), lamina terminalis (LT), column of the fornix (CF)

Fig. 3

Preoperative and postoperative MR images of the cases which are presented in the complementary videos of the article. Case 1 Sagittal and axial MRI with contrast show non-enhancing right LV tumor. Post-operative sagittal flair imaging shows the minimal callosotomy and axial post-contrast T1 imaging confirms gross total resection through interhemispheric transcallosal approach. [Please see the video 1]. Case 2 Sagittal flair MRI and axial post-contrast T1 MRI shows a heterogeneously enhancing cystic tumor in the posterior TV. Post-operative sagittal cube MRI and post-contrast axial T1 MRI confirms gross total removal through this approach. [Please see the video 2]. Case 3 Sagittal and axial flair MRI show a tumor occupying the frontal horn, body and atrium of the LV. Post-operative sagittal flair MRI show the extent of the callosotomy and axial T1 MRI confirms the gross total removal. [Please see the video 3]. Case 4 The extent of heterogeneously enhancing tumor originating from the thalamus and the peripheral edema due to mass effect are shown in the contrasted sagittal and axial MRI. Postoperative sagittal flair MRI and post-contrast axial MRI confirm the gross total resection via posterior interhemispheric approach. [Please see the video 4]

Fig. 4

The surgical approaches to the third ventricle are shown on the lateral view of a cadaveric dissection of the brain. LV and TV are shown in blue. Parts of the TV are depicted with gray circles. Red arrows show the direction of the approaches and the parts of the TV that can be reached by that individual approach

Fig. 5

a The posterior part of the corpus callosum (CC) is removed, along with the posterior and superior walls of the LV, exposing the TV. The thalamus (T) forms the lateral walls of the posterior TV (III). The anatomical relation with the pineal gland (pi), superior colliculus (sc) and inferior colliculus (ic) can be seen. The red arrow shows the route leading to the FM and the TV through the CC. b An intra-operative picture demonstrating the anatomy of the choroidal fissure after entering to the LV. c Dissection between the fornix and the choroid plexus exposes the anterior septal vein. d The anterior septal vein and thalamostriate vein merge and form the internal cerebral vein. e Intraoperative picture revealing the velum interpositum (the roof of the TV) after retracting the venous structures and the choroid plexus