Posterior interhemispheric transfalx transprecuneus approach to the atrium of the lateral ventricle: a cadaveric study

Abstract

Object The posterior interhemispheric transprecuneus gyrus approach is one of the surgical routes that has been suggested to reach the atrium of the lateral ventricle. It has the advantage of avoiding the disruption of the optic radiations; however, it has a narrow working area that at times makes the execution of this approach rather challenging. The aim of this study was to test a modification of the approach that might create a better surgical angle and a wider corridor by accessing the atrium from the contralateral side after transection of the falx. The authors named this new approach the “posterior interhemispheric transfalx transprecuneus approach.” Methods The posterior interhemispheic transfalx transprecuneus approach was performed bilaterally on 6 fresh adult cadaveric specimens for a total of 12 procedures. Every head was held in the semisitting position and a parasagittal parietooccipital craniotomy on the contralateral side of the targeted ventricle was executed. The dura mater was opened and reflected based on the sagittal sinus. Then the falx was cut in a triangular fashion based on the inferior sagittal sinus. Using the parietooccipital artery and sulcus as landmarks, the contralateral precuneus gyrus was indentified, and a small area of the gyrus was transected to gain access to the atrium. A neuronavigational system was also used to conduct this approach. The working angle of this approach and other distances were measured Results The authors were able to visualize the ventricular atrium, posterior part of the temporal horn, pulvinar, and choroid plexus in all specimens. The temporal horn could be exposed for a length of 20–30 mm from the atrium. The working angle of the approach was better than that of the classic posterior interhemispheric transprecuneus approach with a mean value of 44.5° as opposed to 25.8°. The distance from the middle point of the corticotomy to the splenium ranged from 11 to 16 mm (mean 13.3 mm); the distance to the torcula, from 34 to 53 mm (mean 41.3 mm); and the distance to the atrium, from 22 to 31 mm (mean 25.7 mm). Conclusions Results of this study suggested that the proposed approach can expose the atrium and the posterior part of the temporal horn of the lateral ventricle with a wider surgical angle compared with the conventional homolateral posterior interhemispheric transprecuneus gyrus approach. Moreover, by minimizing the amount of brain retraction homolateral to the target, this approach could make navigation more accurate.

Trigone ventricular meningiomas: surgical approaches

“…This route is indicated for small or medium-size meningiomas with medial projection. The disadvantages are wider brain retraction is necessary, the narrow working angle, narrow surgical corridor and difficult access to the choroidal vessels 3,17,21 . We used this route in our case 6 with excellent evolution.…”

To repeat or to recreate: A contralateral posterior interhemispheric transfalcine transprecuneus approach for recurrent meningiomas at the trigone of the lateral ventricle

“…Occipital lobe retraction may lead to postoperative visual field deficits, and entering the interhemispheric fissure as well as cutting the falx may jeopardise the integrity of the venous structures, including the venous sinuses and bridging veins [9]. By rotating the head so that the retracted hemisphere falls away from the falx, releasing CSF from the cistern of the great cerebral vein, and performing gentle manipulation during surgery, we have avoided postoperative visual field deficits due to occipital lobe retraction.…”

“…Reduced retraction with improved exposure. Based on their anatomical study, Wang et al proved that the CITT approach can expose the trigone with a wider surgical angle compared with the conventional ipsilateral approach [9]. In the CITT approach, the patient is placed in a prone position, and the head is rotated such that the hemisphere harbouring the tumour is at a higher position [4].…”

Parieto-occipital interhemispheric precuneal approach to the lesions of the atrium: experience with 66 patients

“…They suggested that this approach can expose the atrium and the posterior part of the temporal horn of the lateral ventricle with a wider surgical angle compared to the conventional homolateral posterior interhemispheric transprecuneus gyrus approach (36).…”