Division of Neuroimaging and Neurointervention, Department of Radiology, Stanford University School of Medicine, Stanford, California.
Department of Physics, Stanford University School of Humanities and Sciences, Stanford, California.
Clin Anat. 2019 Jul;32(5):618-629. doi: 10.1002/ca.23359. Epub 2019 Mar 12.
A high lumbar puncture (LP) at L2-L3 or above is often necessary to consider on technical grounds, but complications of conus medullaris (CM) damage during high LP are potentially concerning. We hypothesized that a high LP might be safer than previously thought by accounting for movements of the CM upon patient positional changes. We retrospectively reviewed standard normal supine lumbar spine magnetic resonance imaging of 58 patients and used electronic calipers on axial images at the T12-L1, L1-L2, and L2-L3 disc levels to measure the transverse diameter of the CM relative to the size of the dorsal thecal sac space (DTSS) through which a spinal needle could be inserted. On 142 axial images, the means for CM diameters were 8.2, 6.0, and 2.9 mm at the three levels, respectively. We then used known literature mean CM displacement values in the legs flexed and unflexed lateral decubitus position (LDP) to factor in CM shifts to the dependent side. We found that at all three levels, the likely positional shift of the CM would be too small and insufficient to displace the entire CM out of the DTSS. However, if needle placement could be confined to the midsagittal plane, an LP in the unflexed LDP would theoretically be entirely safe at both L1-L2 and L2-L3, and almost so at L2-L3 in the legs flexed LDP. Thus, high LPs at L1-L2 and L2-L3 are in theory likely safer than considered previously, more so in the legs unflexed than in the flexed LDP. Clin. Anat. 32:618-629, 2019. © 2019 Wiley Periodicals, Inc.
高腰椎穿刺（LP）在 L2-L3 或以上通常是必要的，从技术角度考虑，但在高 LP 期间圆锥损伤的并发症是令人担忧的。我们假设，通过考虑患者体位变化时圆锥的运动，高 LP 可能比以前认为的更安全。我们回顾性地研究了 58 例患者的标准正常仰卧位腰椎磁共振成像，并在 T12-L1、L1-L2 和 L2-L3 椎间盘水平的轴位图像上使用电子卡尺，测量圆锥相对于可插入脊柱针的背侧硬脊膜囊（DTSS）的横向直径。在 142 个轴位图像中，三个水平的圆锥直径平均值分别为 8.2、6.0 和 2.9mm。然后，我们使用已知文献中在腿部弯曲和不弯曲侧卧位（LDP）中圆锥的平均位移值来考虑圆锥向依赖侧的移位。我们发现，在所有三个水平，圆锥的可能位置移位都太小且不足以将整个圆锥移出 DTSS。然而，如果将针的位置限制在正中矢状面，那么在不弯曲的 LDP 中，L1-L2 和 L2-L3 的 LP 在理论上是完全安全的，而在腿部弯曲的 LDP 中，L2-L3 几乎也是如此。因此，在理论上，L1-L2 和 L2-L3 的 LP 比以前认为的更安全，在不弯曲的 LDP 中比在弯曲的 LDP 中更安全。临床解剖学 32:618-629，2019。©2019 年 Wiley 期刊，Inc.
