Paul James E, Udovic Lisa A, Oman Kathleen, Kim Thomas, Bernstein Leora, Matteliano Luigi, Singh Nina, Caldwell Alexa, Vanniyasingam Thuva, Thabane Lehana
Department of Anesthesia, McMaster University, Hamilton, Ontario, Canada.
Oakville Trafalgar Hospital, Oakville, Ontario, Canada.
Acta Anaesthesiol Scand. 2025 Mar;69(3):e14580. doi: 10.1111/aas.14580.
Classic teaching is that spinal anesthesia is safe at or below the L2-L3 interspace. To evaluate this, we sought to determine the percentage of individuals with a conus medullaris termination (CMT) level at or below the L1-L2 interspace. Further, the relationship of CMT level to age, sex, body mass index (BMI), and spinal pathology was examined, as was the reliability of using Tuffier's line (TL) as an anatomical landmark.
This retrospective study evaluated magnetic resonance images of 944 adult patients to determine the CMT level. The relationship between age, sex, height, BMI, and spinal pathology and CMT level was explored by logistic regression. The correspondence of the TL line to the L4-L5 interspace and the presence of overlap with the CMT were examined using 720 lumbar x-rays of the same patient cohort.
Of 944 patients (mean age, 57.8 years; 49% male), 18.9% had CMT at or below the L1-L2 interspace, and spinal anesthesia at the L2-L3 interspace was found to carry a 0.7% incidence of neuraxial risk. Only the presence of congenital spinal abnormalities was found to be significantly predictive of having a CMT at or below the L1-L2 interspace. TL was found to correspond to the L4-L5 interspace in 99.8% of patients with lumbar x-rays.
Spinal anesthesia at the L2-L3 interspace, using TL as an anatomical landmark, is safe in >99% of patients. However, caution must be exercised in all patients as demographic variables were found to be limited in predicting a low CMT level.
Unlike previous smaller studies, this retrospective study included MRI data from a total of 944 patients. The present study confirms that spinal anesthesia at the L2-L3 interspace or below can be considered safe. The findings indicate that Tuffier's line can be used as a reliable anatomical landmark.
传统教学认为，在L2 - L3椎间隙及以下进行脊髓麻醉是安全的。为评估这一点，我们试图确定脊髓圆锥终末（CMT）水平在L1 - L2椎间隙及以下的个体百分比。此外，研究了CMT水平与年龄、性别、体重指数（BMI）和脊柱病理状况的关系，以及使用图菲埃线（TL）作为解剖标志的可靠性。
这项回顾性研究评估了944例成年患者的磁共振图像以确定CMT水平。通过逻辑回归探讨年龄、性别、身高、BMI和脊柱病理状况与CMT水平之间的关系。使用同一患者队列的720张腰椎X光片检查TL线与L4 - L5椎间隙的对应关系以及与CMT的重叠情况。
在944例患者（平均年龄57.8岁；49%为男性）中，18.9%的患者CMT在L1 - L2椎间隙及以下，发现在L2 - L3椎间隙进行脊髓麻醉有0.7%的神经轴风险发生率。仅发现先天性脊柱异常是CMT在L1 - L2椎间隙及以下的显著预测因素。在99.8%的腰椎X光片患者中发现TL对应于L4 - L5椎间隙。
以TL作为解剖标志，在L2 - L3椎间隙进行脊髓麻醉在超过99%的患者中是安全的。然而，由于发现人口统计学变量在预测低CMT水平方面有限，所有患者都必须谨慎。
与之前较小规模的研究不同，这项回顾性研究纳入了总共944例患者的MRI数据。本研究证实，在L2 - L3椎间隙或以下进行脊髓麻醉可被认为是安全的。研究结果表明，图菲埃线可作为可靠的解剖标志。
