Arterial Interventions and Peripheral Arterial Disease (PAD)
Sean Lau, BSc, MSc
University Health Network
Disclosure(s): No financial relationships to disclose
Thoracic endovascular repair (TEVAR) and transcatheter aortic valve implantation (TAVI) have a high risk of post-procedure stroke, which can be caused by air embolism. To address gaseous emboli, carbon dioxide is known to be more soluble in water resulting in less air bubbles and can be used to flush devices prior to standard saline flush. Therefore, this study was aimed to evaluate the safety and efficacy of using carbon dioxide to flush endovascular graft and cardiopulmonary bypass devices in patients undergoing TEVAR or TAVI procedures.
Materials and Methods:
Twenty-three patients (14 TAVI and 9 TEVAR) were randomized into 2 groups: A) carbon dioxide + saline flush B) saline flush only. All participants underwent a baseline brain MRI within 30 days of their procedure. During the procedure, the carbon dioxide flush was performed by connecting the endovascular graft or TAVI device to the gas cylinder with reduction valve. The endovascular graft or TAVI device was held at 40 degrees and the device was flushed for five minutes at 120 kpa. The endovascular graft or TAVI device was flushed with at least 60mL of 0.9% normal saline. The remainder of the pre-procedure, procedure, and post-procedure care were based on the standard of care for TEVAR or TAVI. A follow-up brain MRI was performed 1 to 7 days after their procedure. Cerebral ischemia was quantified by total number of positive lesions on Diffusion Weighted Imaging (DWI).
Within patients treated with TAVI, the mean number of positive lesions in the carbon dioxide + saline flush group was 8 ± 2.58, while the saline group had an average of 9.28 ± 9.14. For patients treated with TEVAR, the mean number of positive lesions in the carbon dioxide + saline flush group was 1 ± 0.56, while the saline group had an average of 1.8 ± 1.92.
Analysis using a two-tailed t test revealed that carbon dioxide and saline, compared to saline alone, in both TEVAR and TAVI procedures was not significantly different with respect to P value > 0.05
The results in this study suggest that using carbon dioxide to flush the endovascular graft and cardiopulmonary bypass devices in patients receiving TEVAR or TAVI procedure does not reduce the number of silent infarctions. Carbon dioxide flushing is not required if device is flushed carefully with saline alone.