Centre for Neuroscience Studies, Queen's University, Kingston, ON, Canada; School of Medicine, Queen's University, Kingston, ON, Canada. Electronic address: https://twitter.com/jasmine_m_khan.
School of Medicine, Queen's University, Kingston, ON, Canada.
Eur J Vasc Endovasc Surg. 2021 Nov;62(5):695-704. doi: 10.1016/j.ejvs.2021.08.022. Epub 2021 Oct 6.
Carotid endarterectomy is recommended for the prevention of ischaemic stroke due to carotid stenosis. However, the risk of stroke after carotid endarterectomy has been estimated at 2% - 5%. Monitoring intra-operative cerebral oxygenation with near infrared spectroscopy (NIRS) has been assessed as a strategy to reduce intra- and post-operative complications. The aim was to summarise the diagnostic accuracy of NIRS to detect intra-operative ischaemic events, the values associated with ischaemic events, and the relative contribution of external carotid contamination to the NIRS signal in adults undergoing carotid endarterectomy.
EMBASE, MEDLINE, Cochrane Centre Register of Controlled Trials, and reference lists through May 2019 were searched.
Non-randomised and randomised studies assessing NIRS as an intra-operative monitoring tool in carotid endarterectomy were included. Studies using NIRS as the reference were excluded. Risk of bias was assessed using the Newcastle Ottawa Scale, RoB-2, and QUADAS-2.
Seventy-six studies were included (n = 8 480), under local (n = 1 864) or general (n = 6 582) anaesthesia. Seven studies were eligible for meta-analysis (n = 524). As a tool for identifying intra-operative ischaemia, specificity increased with more stringent NIRS thresholds, while there was unpredictable variation in sensitivity across studies. A Δ20% threshold under local anaesthesia resulted in pooled estimates for sensitivity and specificity of 70.5% (95% confidence interval, CI, 54.1 - 82.9) and 92.4% (95% CI 85.5 - 96.1) compared with awake neurological monitoring. These studies had low or unclear risk of bias. NIRS signal consistently dropped across clamping and recovered to pre-clamp values upon de-clamp in most studies, and larger decreases were observed in patients with ischaemic events. The contribution of extracranial signal to change in signal across clamp varied from 3% to 50%.
NIRS has low sensitivity and high specificity to identify intra-operative ischaemia compared with awake monitoring. Extracranial signal contribution was highly variable. Ultimately, data from high quality studies are desperately needed to determine the utility of NIRS.
颈动脉内膜切除术被推荐用于预防颈动脉狭窄引起的缺血性中风。然而，颈动脉内膜切除术后中风的风险估计为 2%-5%。近红外光谱（NIRS）监测术中脑氧合已被评估为降低术中及术后并发症的策略。目的是总结 NIRS 检测术中缺血事件的诊断准确性、与缺血事件相关的值，以及颈内动脉内膜切除术患者中颈外信号对 NIRS 信号的相对贡献。
通过 2019 年 5 月的 EMBASE、MEDLINE、Cochrane 中心对照试验登记处和参考文献列表进行检索。
纳入评估 NIRS 作为颈动脉内膜切除术术中监测工具的非随机和随机研究。使用 NIRS 作为参考的研究被排除在外。使用纽卡斯尔-渥太华量表、RoB-2 和 QUADAS-2 评估偏倚风险。
共纳入 76 项研究（n=8480），局部麻醉下（n=1864）或全身麻醉下（n=6582）。7 项研究符合荟萃分析条件（n=524）。作为术中缺血的一种检测工具，特异性随更严格的 NIRS 阈值而增加，而敏感性在研究之间存在不可预测的变化。局部麻醉下的 Δ20%阈值得出的敏感性和特异性的汇总估计值分别为 70.5%（95%置信区间，54.1-82.9）和 92.4%（95%置信区间 85.5-96.1），与清醒神经监测相比。这些研究的偏倚风险较低或不明确。在大多数研究中，NIRS 信号在夹闭期间持续下降，并在夹闭解除后恢复到夹闭前的值，在发生缺血事件的患者中观察到更大的下降。在夹闭期间，信号的变化中外周信号的贡献从 3%到 50%不等。
与清醒监测相比，NIRS 对术中缺血的敏感性低，特异性高。外周信号的贡献差异很大。最终，非常需要高质量研究的数据来确定 NIRS 的实用性。
