Park Jaechan, Son Wonsoo, Park Ki-Su, Kim Min Young, Lee Joomi
Department of Neurosurgery.
Research Center for Neurosurgical Robotic Systems, and.
J Neurosurg. 2016 May;124(5):1429-33. doi: 10.3171/2015.5.JNS15226. Epub 2015 Nov 6.
OBJECT The Ghajar Guide technique is used to direct a ventricular catheter at a 90° angle to the skull surface at Kocher's point. However, the human calvaria is not completely spherical. Lateral to the sagittal midline, the calvaria slopes downward with individual variation and thereby affects the accuracy of ventricular catheter placement. Accordingly, the authors investigated the accuracy of the orthogonal catheter trajectory using radiographic simulation and examined the effect of the calvarial slope on this accuracy. METHODS A catheter trajectory orthogonal to the skull surface at Kocher's point and the ideal catheter trajectory to the foramen of Monro were drawn bilaterally on coronal head images of 52 patients with hydrocephalus. The correction angle, the difference between the 2 catheter trajectories, was then measured. Meanwhile, the calvarial slope was measured around Kocher's point by using a coronal head image. The correlation between the correction angle and factors such as the calvarial slope and bicaudate index was then assessed using a Pearson correlation analysis. RESULTS The ventricular catheter trajectory orthogonal to the skull at Kocher's point in the patients with hydrocephalus led to a catheter trajectory into the ipsilateral (70.2%) or contralateral (29.8%) lateral ventricles. The correction angles ranged from -3.3° to 16.4° (mean ± SD 5.7° ± 3.7°). In 87 (83.7%) head sides, lateral deviation from the orthogonal trajectory was required to approximate the ideal trajectory, and the correction angle ranged from 2.0° to 16.4° (mean 6.7° ± 2.9°). The calvarial slope in the 104 head sides ranged from 15.6° to 32.5° (mean 24.2° ± 3.1°). Pearson correlation analysis revealed a strong positive correlation (r = 0.733) between the calvarial slope and the correction angle. CONCLUSIONS The accuracy of ventricular catheter placement using the Ghajar Guide technique is affected primarily by the calvarial slope around Kocher's point. A radiographic analysis of a preoperative coronal head image can be used to estimate the accuracy of ventricular catheter placement and enable adjustment to approximate the ideal catheter trajectory.
加贾尔引导技术用于在科赫尔点将脑室导管以90°角指向颅骨表面。然而，人类颅骨并非完全球形。在矢状中线外侧，颅骨向下倾斜且存在个体差异，从而影响脑室导管置入的准确性。因此，作者通过影像学模拟研究了正交导管轨迹的准确性，并考察了颅骨倾斜度对该准确性的影响。方法：在52例脑积水患者的冠状位头部图像上，双侧绘制在科赫尔点与颅骨表面正交的导管轨迹以及至孟氏孔的理想导管轨迹。然后测量校正角度，即两条导管轨迹之间的差值。同时，通过冠状位头部图像测量科赫尔点周围的颅骨倾斜度。随后采用Pearson相关分析评估校正角度与颅骨倾斜度、双尾状核指数等因素之间的相关性。结果：脑积水患者在科赫尔点与颅骨正交的脑室导管轨迹导致导管进入同侧（70.2%）或对侧（29.8%）侧脑室。校正角度范围为-3.3°至16.4°（平均±标准差5.7°±3.7°）。在87个（83.7%）头部侧别中，需要偏离正交轨迹以接近理想轨迹，校正角度范围为2.0°至16.4°（平均6.7°±2.9°）。104个头部侧别的颅骨倾斜度范围为15.6°至32.5°（平均24.2°±3.1°）。Pearson相关分析显示颅骨倾斜度与校正角度之间存在强正相关（r = 0.733）。结论：使用加贾尔引导技术进行脑室导管置入的准确性主要受科赫尔点周围颅骨倾斜度的影响。术前冠状位头部图像的影像学分析可用于估计脑室导管置入的准确性，并进行调整以接近理想的导管轨迹。
