Department of Orthopaedic Surgery, Nagoya University Graduate School of Medicine, Nagoya, Japan.
Department of Orthopedic Surgery, Hamamatsu University School of Medicine, Hamamatsu, Japan.
Spine (Phila Pa 1976). 2021 Dec 15;46(24):1738-1747. doi: 10.1097/BRS.0000000000004096.
Prospective multicenter study.
The aim of this study was to evaluate transcranial motor evoked potential (Tc-MEP) waveform monitoring in spinal surgery for patients with severe obesity.
Spine surgeries in obese patients are associated with increased morbidity and mortality. Intraoperative Tc-MEP monitoring can identify neurologic deterioration during surgery, but has not been examined for obese patients.
The subjects were 3560 patients who underwent Tc-MEP monitoring during spine surgery at 16 centers. Tc-MEPs were recorded from multiple muscles via needle or disc electrodes. A decrease in Tc-MEP amplitude of ≥70% from baseline was used as an alarm during surgery. Preoperative muscle weakness with manual muscle test (MMT) grade ≤4 was defined as a motor deficit, and a reduction of one or more MMT grade postoperatively was defined as deterioration.
The 3560 patients (1698 males, 47.7%) had a mean age of 60.0 ± 20.3 years. Patients with body mass index >35 kg/m2 (n = 60, 1.7%) were defined as severely obese. Compared with all other patients (controls), the rates of preoperative motor deficit (41.0% vs. 29.6%, P < 0.05) and undetectable baseline waveforms in all muscles were significantly higher in the severely obese group (20.0% vs. 1.7%, P < 0.01). Postoperative motor deterioration did not differ significantly between the groups. The sensitivity and specificity of the alarm criterion for prediction of postoperative neurologic complications were 75.0% and 83.9% in severely obese patients and 76.4% and 89.6% in controls, with no significant difference between the groups.
Tc-MEPs can be used in spine surgery for severely obese cases to predict postoperative motor deficits, but the rate of undetectable waveforms is significantly higher in such cases. Use of a multichannel waveform approach or multiple modalities may facilitate safe completion of surgery. Waveforms should be carefully evaluated and an appropriate rescue procedure is required if the alarm criterion occurs.Level of Evidence: 3.
前瞻性多中心研究。
本研究旨在评估经颅运动诱发电位（Tc-MEP）波形监测在重度肥胖患者脊柱手术中的应用。
肥胖患者的脊柱手术与发病率和死亡率增加有关。术中 Tc-MEP 监测可识别手术期间的神经功能恶化，但尚未在肥胖患者中进行检查。
本研究共纳入 16 个中心 3560 例行 Tc-MEP 监测的脊柱手术患者。通过针或盘电极记录 Tc-MEPs 来自多个肌肉。术中将 Tc-MEP 振幅较基线下降≥70%定义为报警。术前徒手肌力测试（MMT）分级≤4的肌肉无力定义为运动缺陷，术后 MMT 分级降低一个或多个等级定义为恶化。
3560 例患者（男 1698 例，47.7%）平均年龄为 60.0±20.3 岁。BMI＞35kg/m2（n=60，1.7%）的患者定义为重度肥胖。与所有其他患者（对照组）相比，重度肥胖组术前运动缺陷率（41.0%比 29.6%，P＜0.05）和所有肌肉均无法检测到基线波的比例（20.0%比 1.7%，P＜0.01）显著更高。两组术后运动恶化无显著差异。在重度肥胖患者中，报警标准对预测术后神经并发症的敏感性和特异性分别为 75.0%和 83.9%，在对照组中分别为 76.4%和 89.6%，两组间无显著差异。
Tc-MEP 可用于重度肥胖患者的脊柱手术，以预测术后运动缺陷，但在这种情况下无法检测到波的比例显著更高。使用多通道波形方法或多种模式可能有助于安全完成手术。如果出现报警标准，应仔细评估波形，并需要采取适当的抢救程序。
3 级
