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Updated: Jan 7, 2026
Minimally Invasive Thumb-sized Pterional Craniotomy for Surgical Clip Ligation of Unruptured Anterior Circulation Aneurysms
Published on: August 11, 2015
Exploring the Lamina Terminalis: A Stepwise Anatomical Comparison of Pterional and Orbitozygomatic Craniotomy
Merih C Yilmaz1, Yunus E Durmus2
1Department of Neurosurgery, VM Medical Park Hospital, 55200 Samsun, Turkey.
None:
Background/Objectives: The lamina terminalis is an important anatomical structure located at the anterior wall of the third ventricle and surrounded by critical neurovascular elements. Precise and safe surgical access to this region requires detailed anatomical knowledge and mastery of skull base approaches. This study aims to anatomically illustrate and compare the pterional, one-piece orbitozygomatic, and two-piece orbitozygomatic craniotomies as approaches to the lamina terminalis cistern. The objective is to provide a comprehensive photographic guide to support neurosurgeons and residents in learning these techniques. Methods: Two formalin-fixed, silicone-injected adult cadaveric heads were dissected under an operating microscope. Standard pterional, one-piece orbitozygomatic, and two-piece orbitozygomatic approaches were performed. Key anatomical landmarks and surgical steps were documented photographically. Osteotomies, dural openings, and basal drilling techniques were systematically applied to maximize exposure of the lamina terminalis region while preserving critical neurovascular structures. Results: The results demonstrate that all three approaches effectively expose the lamina terminalis cistern and related vascular structures. By highlighting the trajectory, osteotomies, and neurovascular anatomy, the anatomical dissections provide valuable visual guidance. These findings are intended to support neurosurgical education by illustrating the strengths of each approach in a comparative context. Conclusions: This study offers detailed anatomical visualization of three key approaches to the lamina terminalis. The stepwise dissections and high-resolution images are intended as an educational guide to assist neurosurgeons and residents in mastering these techniques. Such anatomical understanding is vital for safe, effective surgical interventions involving the anterior skull base and vascular pathologies.
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