O-103 - CARBON DIOXIDE STENT FLUSHING TO PREVENT CEREBRAL AIR MICROEMBOLISM DURING CAROTID ARTERY STENTING: PROTOCOL FOR A RANDOMIZED STUDY.

TOPIC:
New vascular techniques and devices
AUTHORS:
Mansour W. (Sapienza University of Rome ~ Rome ~ Italy) , Capoccia L. (Sapienza University of Rome ~ Rome ~ Italy) , Sirignano P. (Sapienza University of Rome ~ Rome ~ Italy) , Di Girolamo A. (Sapienza University of Rome ~ Rome ~ Italy) , Molinari A. (Sapienza University of Rome ~ Rome ~ Italy) , Bozzao A. (Sapienza University of Rome ~ Rome ~ Italy) , Taurino M. (Sapienza University of Rome ~ Rome ~ Italy) , Di Marzo L. (Sapienza University of Rome ~ Rome ~ Italy)
Introduction:
Carotid artery stenting (CAS) has been shown to protect patients from future stroke with long-term efficacy like CEA. However, differences between CAS and CEA still exist and they consist primarily of a higher rate of neurologic events occurring in the peri-procedural period after CAS, caused by embolization from aortic arch manipulation, plaque debris and probably air embolism, the latter reported in literature after TEVAR, due to air trap in the thoracic endograft flushed only by saline solution. We suppose that the same mechanism could be responsible for air microembolization during CAS and microembolization has been documented as a cause of neurocognitive decline. New generations of dual-layer mesh-covered carotid stent systems increase plaque coverage with a reduction of debris, but their design also increase the risk of more air trapped into the stent shaft because of multiple components, thus increasing the risk of air brain embolism. We present a protocol of a study assessing effectiveness of a new technique for reducing air microembolism during CAS. Aim: after an in-vitro pipeline test of a c-guard stent saline solution washing and deployment demonstrating little bubble air release, we will investigate the effectiveness of CO2 flushing of stent to prevent air microembolism after CAS using the c-guard stent, and we will analyze diagnostic and clinical outcomes.
Methods:
In two university referral teaching hospitals, consecutive patients (divided in 2 groups) affected by asymptomatic carotid stenosis ≥70% and enrolled for CAS will be submitted to preoperative DW-MRI scan, to exclude the presence of preoperative silent cerebral lesions. Patients will be randomized to CAS using C-Guard stent with or without CO2 flushing using a computer-generated random allocation sequence with a blocked randomization by an allocation ratio 1:1. A transfemoral approach through an 8 fr. arterial sheath will be established, and an initial intravenous heparin bolus will be administered, followed by a continuous intra-arterial infusion of heparinized saline solution through the guiding catheter/reinforced sheath in a closed flushing system in order to avoid external air bubble introduction. A distal cerebral protection by filter wire will be used in all patients. The c-guard stent flushing will be done as recommended by IFU with saline solution for the control group, preceded by medical carbon dioxide CO2 flushing for the study group. DWMRI will be performed within 24 hours after intervention. Moreover, pre and postoperative Mini-Mental-State-Examination Test (MMSE) test will be conducted, as well as serum S100β neurobiomarkers assessment.
Results:
The primary endpoint of the study will be the evaluation of technical and clinical success of CAS with or without CO2 stent flushing peri-operatively, at 24 hours, 30 days, and at one and two years. The following secondary endpoints will also be assessed: operative time, radiation exposure and contrast medium use, postoperative DW-MR new lesions, neurobiomarkers and MMSE variation within 24 hours. After that at 30 days, one and two years an MMSE test will be evaluated. Sample size estimation is 80 patients (40 patients per each group). The study will start in June 2022 and the final patient is expected to be treated by June 2023. The estimated study completion date should be June 2025.
Conclusion:
This study will provide to show in a real-world practice the effectiveness of CO2 stent flushing to prevent cerebral embolism during CAS, and its effectiveness in neurocognitive decline prevention.
References:
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