X-ray image guidance workflow development for in-vivo aneurysm treatment using a new retrievable asymmetric flow diverter (RAFD).

The vascular procedures during in-vivo aneurysms treatment with the Retrievable Asymmetric Flow Diverter (RAFD) prototype, require accurate x-ray image guidance and flow diversion assessment using angiography. The new device is made of a high porosity scaffold which supports a low-porosity patch used to divert the blood flow from the aneurysm. Two platinum markers have been added to allow stent placement in the longitudinal and azimuthal direction with regard to the aneurysm ostium. The retrievability of the device allows for multiple re-deployments until the placement is optimal. Eleven elastase aneurysms were created and treated with the new device. Placement was done using high definition x-ray fluoroscopy and optimal blood flow diversion was verified using angiography. Once the flow diversion was confirmed, the devices were deployed using electrolytic detachment. Angiograms pre- and post-stent placement were analyzed using parametric imaging based on dye dilution curves of injected contrast. Average values of the area under the curve (AUC), Meant Transit Time (MTT) and Peak Value (PV) for the aneurysms were measured and normalized to the values recorded in the main vessel. Fluoroscopy time for the device deployment was 15.30 +/- 5.30 minutes. Angiographic analysis indicated that average normalized values for: MTT increased 227%, AUC decreased 51% times while PV decreased 30%. In conclusion, the device was successfully deployed in eleven rabbits. Based on angiogram analysis, significant flow diversion has been observed. Overall this report demonstrates that the imaging workflow we developed for the new device placement was implemented successfully.