Luís Duarte-Gamas1, António Pereira-Neves2, Joel Sousa3, Bernardo Sousa-Pinto4, João Rocha-Neves2. 1. Department of Angiology and Vascular Surgery, Centro Hospitalar Universitário de São João, Porto, Portugal; Department of Surgery and Physiology, Faculdade de Medicina da Universidade do Porto, Porto, Portugal. Electronic address: afonso_gamas@hotmail.com. 2. Department of Angiology and Vascular Surgery, Centro Hospitalar Universitário de São João, Porto, Portugal; Department of Surgery and Physiology, Faculdade de Medicina da Universidade do Porto, Porto, Portugal; Department of Biomedicine - Unity of Anatomy, Faculdade de Medicina da Universidade do Porto, Porto, Portugal. 3. Department of Angiology and Vascular Surgery, Centro Hospitalar Universitário de São João, Porto, Portugal; Department of Surgery and Physiology, Faculdade de Medicina da Universidade do Porto, Porto, Portugal. 4. Centre for Health Technology and Services Research (CINTESIS), Porto, Portugal; MEDCIDS - Department of Community Medicine, Information and Health Decision Sciences, Faculty of Medicine, University of Porto, Porto, Portugal.
Abstract
OBJECTIVE: Intra-operative near infrared spectroscopy (NIRS) is a non-invasive tool used to monitor regional cerebral oxygen saturation during carotid endarterectomy (CEA), for which accuracy remains unclear. Therefore, this systematic review and meta-analysis aimed to determine the diagnostic accuracy of NIRS in patients undergoing CEA under regional anaesthesia (RA). DATA SOURCES: MEDLINE, Scopus, and Web of Science were searched for studies that compared NIRS with the "awake test" in patients undergoing CEA under RA. REVIEW METHODS: Bivariable random effects meta-analysis was performed to determine the diagnostic accuracy of NIRS to detect cerebral ischaemia. Meta-regression was performed to explore causes of heterogeneity. Meta-analysis of proportions was also performed to determine the accuracy of NIRS in predicting 30 day stroke. Study quality was evaluated using the QUADAS-2 criteria. RESULTS: Eleven primary studies were included, assessing 1 237 participants. The meta-analysis obtained a partial area under the summary receiver operating characteristic curve for diagnosing brain ischaemia of 0.646, with a summary sensitivity of 72.0% (95% confidence interval [CI] 58.1 - 82.7; I2 = 48.6%) and a specificity of 84.1% (95% CI 78.5-88.4; I2 = 48.6%). In meta-regression analysis, the frequency of hypertension (p = .011) and patients with symptomatic carotid stenosis (p = .031) were significant effect modifiers. Higher frequency of arterial hypertension (z score = -2.15; p = .032) and diabetes (z score = -2.12; p = .034) were associated with lower summary sensitivity, while a higher frequency of symptomatic carotid stenosis (z score = 2.11; p = .035) was associated with higher summary sensitivity. Point estimate sensitivity and specificity for predicting 30 day stroke occurrence were 41% (95% CI 19.5 - 66.6; I2 = 0%) and 81.4% (95% CI 74.4 - 86.9, I2 = 65.6%), respectively. CONCLUSION: The results of this study suggest that NIRS as a cerebral monitoring technique does not have sufficiently high sensitivity or specificity to be used alone in the neurological monitoring of patients undergoing CEA under RA.
OBJECTIVE: Intra-operative near infrared spectroscopy (NIRS) is a non-invasive tool used to monitor regional cerebral oxygen saturation during carotid endarterectomy (CEA), for which accuracy remains unclear. Therefore, this systematic review and meta-analysis aimed to determine the diagnostic accuracy of NIRS in patients undergoing CEA under regional anaesthesia (RA). DATA SOURCES: MEDLINE, Scopus, and Web of Science were searched for studies that compared NIRS with the "awake test" in patients undergoing CEA under RA. REVIEW METHODS: Bivariable random effects meta-analysis was performed to determine the diagnostic accuracy of NIRS to detect cerebral ischaemia. Meta-regression was performed to explore causes of heterogeneity. Meta-analysis of proportions was also performed to determine the accuracy of NIRS in predicting 30 day stroke. Study quality was evaluated using the QUADAS-2 criteria. RESULTS: Eleven primary studies were included, assessing 1 237 participants. The meta-analysis obtained a partial area under the summary receiver operating characteristic curve for diagnosing brain ischaemia of 0.646, with a summary sensitivity of 72.0% (95% confidence interval [CI] 58.1 - 82.7; I2 = 48.6%) and a specificity of 84.1% (95% CI 78.5-88.4; I2 = 48.6%). In meta-regression analysis, the frequency of hypertension (p = .011) and patients with symptomatic carotid stenosis (p = .031) were significant effect modifiers. Higher frequency of arterial hypertension (z score = -2.15; p = .032) and diabetes (z score = -2.12; p = .034) were associated with lower summary sensitivity, while a higher frequency of symptomatic carotid stenosis (z score = 2.11; p = .035) was associated with higher summary sensitivity. Point estimate sensitivity and specificity for predicting 30 day stroke occurrence were 41% (95% CI 19.5 - 66.6; I2 = 0%) and 81.4% (95% CI 74.4 - 86.9, I2 = 65.6%), respectively. CONCLUSION: The results of this study suggest that NIRS as a cerebral monitoring technique does not have sufficiently high sensitivity or specificity to be used alone in the neurological monitoring of patients undergoing CEA under RA.