Perioperative Argon Inhalation to Improve Neurocognitive Recovery After Carotid Surgery

Summary

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.

Conditions

• Carotid Artery Disease
• Carotid Artery Stenoses

Interventions

DRUG

Аrgon-oxygen breathing mixture

Patients receive a course of inhalations with an argon-oxygen mixture according to the following protocol: 60 minutes on day 1 prior to surgery, 60 minutes one hour before being transferred to the operating room, and 60 minutes on the first postoperative day

DRUG

Nitrogen-oxygen breathing mixture

Patients receive a course of inhalations with an nitrogen-oxygen mixture according to the following protocol: 60 minutes on day 1 prior to surgery, 60 minutes one hour before being transferred to the operating room, and 60 minutes on the first postoperative day

Sponsors & Collaborators

• Negovsky Reanimatology Research Institute

  lead OTHER_GOV

Principal Investigators

• Oleg Grebenchikov, MD, PhD · Negovsky Reanimatology Research Institute

Study Design

Allocation

RANDOMIZED

Purpose

PREVENTION

Masking

TRIPLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2025-09-22

Primary Completion

2026-10-01

Completion

2026-11-01

Countries

• Russia

Study Locations