Supracerebellar transtentorial transcollateral sulcus approach to the atrium of the lateral ventricle: microsurgical anatomy and surgical technique in cadaveric dissections

Background: Access to lesions located in the atrium of the lateral ventricle without causing neurologic deficit can be challenging. Here, we demonstrate the supracerebellar transtentorial transcollateral sulcus (STTS) approach as an alternative route to the atrium of the lateral ventricle using anatomical dissections in cadavers. Methods: Suboccipital craniotomy with extension above the transverse sinus was performed in 5 arterial and venous latex-injected cadaveric heads (10 hemispheres). After the dural opening, arachnoidal dissection of the supracerebellar space was performed, and the tentorium cerebelli was cut from lateral to medial. This revealed the parahippocampal and fusiform gyri and collateral sulcus (CS). The distance from the CS to the atrium was measured. Results: The atrium of the lateral ventricle was entered through the CS in each specimen. The cerebral hemispheres were removed from each cadaveric specimen, and dissections were performed. The distance from the CS to the atrium was 1.30 cm on the right side and 1.31 cm on the left. The CS was bifurcated in 62% of the hemispheres, whereas it was single in 38%. Through this approach, only the "u" fibers of the CS were damaged, and the fibers of the optic radiation in the inferolateral wall of the atrium were preserved. Conclusion: The STTS approach may be an effective alternative approach to lesions located in the medioposterior aspect of the atrium of the lateral ventricle in selected cases. Further clinical studies to evaluate the safety and efficacy of this approach are needed. (C) 2009 Elsevier Inc. All rights reserved.