• Satoru Shimizu, Takahiro Mochizuki, Hiroyuki Koizumi, Hiroki Kuroda, Shigeta Miyake, Yasunobu Nakai, and Toshihiro Kumabe.
• Department of Neurosurgery, Yokohama Brain and Spine Center, Yokohama, Japan. Electronic address: Satoru4756@aol.com.
• World Neurosurg. 2022 May 1; 161: 16-20.

BackgroundChronic subdural hematomas (CSDHs) with narrow or multilayered hematomas must be accurately localized for burr hole drainage. We present a simple alternative localization method using conventional computed tomography (CT) scans acquired for the initial diagnosis and a commercially available carpenter's square (CS).MethodsUsing our novel method, we localized 77 narrow or multilayered CSDHs. A single burr hole site on the thickest portion of narrow hematomas or on the site allowing access to both the isolated superficial layer and the deep layer of multilayered hematomas was identified on axial CT images; the image was parallel to the orbitomeatal line (OML). On the target CT slice, the level from the OML and from the surface of the forehead to the intended burr hole (sagittal distance) was measured. The OML and the level of the CT target slice were marked using the CS. Then, the CS was placed at the marked target level; the 2 edges of the CS were situated on the frontal and temporal scalp and parallel to the OML and the sagittal line. The sagittal distance was then marked.ResultsAll burr holes reached the CSDHs. The mean deviation of the burr holes was 4.7 mm inferior and 1.4 mm anterior to the intended site. In 65 instances (84.4%), a deviation within 10 mm was observed in both the superoinferior and the anteroposterior directions.ConclusionsOur simple and inexpensive method can localize narrow or multilayered CSDHs with acceptable accuracy and increases the efficiency of routine clinical work.Copyright © 2022 Elsevier Inc. All rights reserved.

12 keywords...

hide…