Introduction: Conventional approaches to the atrium of the lateral ventricle can be associated with complications related to direct cortical injury or brain retraction. We describe a novel approach to the medial aspect of the atrium through a retrosigmoid, transtentorial transcollateral sulcus corridor. This approach may be applicable in selected cases.
Methods: Bilateral retrosigmoid craniotomies were performed on latex injected cadaver heads. Visualization was provided by microsurgical dissection (3x - 24x microscope, Global surgical®, St. Louis, MO) and a 2.3 mm diameter, 0° Minop endoscope (Aesculap®, Tuttlingen, Germany). Measurements of the angle of entry to the ventricle, transcortical distance traversed and the total depth of exposure were recorded using a 3 dimensional spatial coordinates tracking system (Trackstar® Ascension Technologies, Vermont).
Results: The retrosigmoid endoscopic approach allowed for clear visualization of the surgical field. Identification of the collateral sulcus permitted easy endoscopic access to the atrium. The optimal angle of entry to the ventricular atrium was found to be approximately 80° to the plane of the tentorium. The mean cortical thickness traversed was 18mm. The intraventricular anatomy was well visualized in this manner.
Conclusions: We have shown that the retrosigmoid transtentorial transcollateral sulcus approach is technically feasible. While this medial approach is unconventional, it provides a minimally invasive trajectory to the atrium that may prove useful in selected cases where conventional approaches may carry a higher than normal risk.
Patient Care: By introducing this novel approach, the atrium may be accessed for pathologies like intraventricular tumors and vascular lesions, especially in situations where conventional approaches are not feasible. The avoidance of cortical injury may translate into lesser complication rates and better patient outcomes.
Learning Objectives: By the conclusion of this session, participants should be able to:
1) Describe the conventional approaches to the atria of the lateral ventricle.
2) Discuss the transcollateral approach as a minimally invasive option to the atrium in certain cases.
3) Identify the utility of this novel approach through a retrosigmoid craniotomy.
References: 1. Izci, Y., Seckin, H., Ates, O., & Baskaya, M. K. (2009). Supracerebellar transtentorial transcollateral sulcus approach to the atrium of the lateral ventricle: microsurgical anatomy and surgical technique in cadaveric dissections. Surg Neurol, 72(5), 509-514; discussion 514. doi: 10.1016/j.surneu.2009.01.025
2. Kawashima, M., Li, X., Rhoton, A. L., Jr., Ulm, A. J., Oka, H., & Fujii, K. (2006). Surgical approaches to the atrium of the lateral ventricle: microsurgical anatomy. Surg Neurol, 65(5), 436-445. doi: 10.1016/j.surneu.2005.09.033
3. Marcus, H. J., Sarkar, H., Mindermann, T., & Reisch, R. (2013). Keyhole supracerebellar transtentorial transcollateral sulcus approach to the lateral ventricle. Neurosurgery, 73(2 Suppl Operative), E295-301; discussion E301. doi: 10.1227/01.neu.0000430294.16175.20
4. Moftakhar, R., Izci, Y., & Baskaya, M. K. (2008). Microsurgical anatomy of the supracerebellar transtentorial approach to the posterior mediobasal temporal region: technical considerations with a case illustration. Neurosurgery, 62(3 Suppl 1), 1-7; discussion 7-8. doi: 10.1227/01.neu.0000317367.61899.65