Tests argon breathing mixture to aid thinking recovery after neck artery surgery
Tests argon breathing mixture in adults having surgery for narrowed neck arteries.
Plain-language title generated from the registry record
Registry title: Perioperative Argon Inhalation to Improve Neurocognitive Recovery After Carotid Surgery
Key facts
- Where
- Moscow, RussiaSee the 2 sites
- Phase
- Phase 3
Where in Russia
- Demikhov Municipal Clinical Hospital 68Moscow, RussiaTaking people
- GBWZ of Moscow city hospital n.a. S.P. BotkinMoscow, RussiaTaking people
Questions to ask the study team
- How often do I need to come in, and for how long each time?
- Are travel costs paid?
- Can I keep my own doctor?
- What happens if I want to stop?
Trial details
- Who runs it
- Negovsky Reanimatology Research Institute
- Trial code
- NCT07200180
- Record updated
- 18 June 2026
- Original description
Currently, over 400,000 reconstructive surgeries on carotid arteries are performed annually worldwide, including carotid endarterectomy (CEA) and carotid stenting. These interventions have proven effective in preventing ischemic stroke in patients with hemodynamically significant carotid artery stenoses. However, even following a technically successful procedure, the risk of perioperative ischemic brain injury persists. According to meta-analyses, one in five patients exhibits covert ("silent") strokes after reconstructive interventions, with their frequency being ten times higher than that of clinically manifest events. Such lesions are associated with cognitive decline and an increased risk of dementia. An additional risk factor is the "no-reflow" phenomenon-an impairment of microcirculatory reperfusion that occurs even after the restoration of macrovascular blood flow, thereby limiting the effectiveness of surgical revascularization.Read full original descriptionShow less
Perioperative Argon Inhalation to Improve Neurocognitive Recovery After Carotid Surgery (PAIRS Trial)
Currently, over 400,000 reconstructive surgeries on carotid arteries are performed annually worldwide, including carotid endarterectomy (CEA) and carotid stenting. These interventions have proven effective in preventing ischemic stroke in patients with hemodynamically significant carotid artery stenoses. However, even following a technically successful procedure, the risk of perioperative ischemic brain injury persists. According to meta-analyses, one in five patients exhibits covert ("silent") strokes after reconstructive interventions, with their frequency being ten times higher than that of clinically manifest events. Such lesions are associated with cognitive decline and an increased risk of dementia. An additional risk factor is the "no-reflow" phenomenon-an impairment of microcirculatory reperfusion that occurs even after the restoration of macrovascular blood flow, thereby limiting the effectiveness of surgical revascularization.
Cognitive disorders and postoperative delirium, observed in 15-30% of patients after CEA, adversely affect rehabilitation and long-term prognosis. To date, there are no reliable pharmacological strategies to prevent these complications.
In this context, inert gases have attracted significant interest as potential neuroprotective agents. Xenon, despite its proven efficacy, is limited by high cost and challenges in industrial production. Argon, in contrast, is accessible, safe, and technologically straightforward to administer. In preclinical models of stroke and ischemia-reperfusion, argon has demonstrated pronounced anti-apoptotic, anti-inflammatory, and antioxidant effects, mediated through the regulation of TLR2/4-, ERK1/2-, Nrf2-, and NF-κB-dependent signaling pathways. Its ability to suppress microglial activation towards the M1 phenotype and inhibit the NLRP3 inflammasome has been noted, which reduces neuroinflammation and decreases the volume of secondary neuronal damage. Short-term argon inhalation in healthy volunteers has shown a favorable safety profile with no adverse effects on cerebral hemodynamics.
Thus, it is highly relevant to clinically test the hypothesis that perioperative inhalation of an argon-containing gas mixture can reduce the incidence of ischemic brain injuries and cognitive impairments in patients undergoing CEA.
Inclusion: age > 18 years; elective carotid artery surgery; general anesthesia; written informed consent.
Exclusion: Previously enrolled in this trial; The presence of any mental disorder according to the International Classification of Diseases 10th Revision which is confirmed by a psychiatrist; The presence of any neuromuscular disease according to the International Classification of Diseases 10th Revision; Heart failure equal 3 or 4 class according to the New York Heart Association Functional Classification; Pregnant or breast-feeding women; Inability to undergo a preoperative assessment for any reason.