Pure Endoscopic Contralateral Transfalcine Transparieto-Occipital Fissure Approach to the Atrium of the Lateral Ventricle: Anatomic Study

BACKGROUND AND OBJECTIVES: The atrium is one of the most complex regions to approach in the brain because of its deep location and the complexity of the surrounding white matter fiber anatomy. The ipsilateral posterior interhemispheric transprecuneus approach was first described, and subsequently, the contralateral posterior interhemispheric transprecuneus approach gained popularity. Each surgical route presents some disadvantages such as the difficulty of exposing the lateral portion of the lesion, the presence of bridging veins, brain retraction, and the risk of memory impairment. We present an alternative approach to lesions of the atrium using a natural pathway through the parieto-occipital fissure. The aim of this anatomic study is to evaluate the surgical feasibility of the contralateral transfalcine transparieto-occipital fissure approach (CTTFa) and the usefulness of the endoscope as the sole visualization source. METHODS: Four formalin-fixed cadaver heads were used for this study and investigated to perform 8 surgical CTTFa procedures. Surgical measurements were obtained, evaluating skin incision, craniotomy area, working area and distance from the craniotomy to the splenium, the parieto-occipital fissure, and the atrium. Moreover, 2 human cerebral hemispheres treated using the Klingler technique were used to investigate the relative white matter anatomy. RESULTS: The craniotomy area measurements averaged 8.2, 4.2, and 3.1 cm2 for the ipsilateral posterior interhemispheric transprecuneus approach, CTTFa without endoscopy, and CTTFa with the use of an endoscope, respectively. In addition, the endoscopic CTTFa showed an optimal working angle and distance from craniotomy to parieto-occipital fissure, splenium, and atrium. CONCLUSION: The pure endoscopic CTTFa allows adequate visualization of the atrium while minimizing brain retraction, avoiding damage to white matter tracts, and reducing both the size of the craniotomy and the skin incision. This is achieved without exposing the superior sagittal sinus or damaging the precuneus area.