Optimizing Surveillance and Re-intervention Strategy Following Elective Endovascular Repair of Abdominal Aortic Aneurysms

Background: EVAR for abdominal aortic aneurysm has an initial survival advantage over OR, but more frequent complications increase costs and long-term aneurysm-related mortality. Randomized controlled trials of EVAR versus OR have shown EVAR is not cost-effective over a patient's lifetime. However, in the EVAR-1 trial, postoperative surveillance may have been sub-optimal, as the importance of sac growth as a predictor of graft failure was overlooked. Methods: Real-world data informed a discrete event simulation model of postoperative outcomes following EVAR. Outcomes observed EVAR-1 were compared with those from 5 alternative postoperative surveillance and reintervention strategies. Key events, quality-adjusted life years and costs were predicted. The impact of using complication and rupture rates from more recent devices, imaging and re-intervention methods was also explored. Results: Compared with observed EVAR-1 outcomes, modeling full adherence to the EVAR-1 scan protocol reduced abdominal aortic aneurysm (AAA) deaths by 3% and increased elective re-interventions by 44%. European Society re-intervention guidelines provided the most clinically effective strategy, with an 8% reduction in AAA deaths, but a 52% increase in elective re-interventions. The cheapest and most cost-effective strategy used lifetime annual ultrasound in primary care with confirmatory computed tomography if necessary, and reduced AAA-related deaths by 5%. Using contemporary rates for complications and rupture did not alter these conclusions. Conclusions: All alternative strategies improved clinical benefits compared with the EVAR-1 trial. Further work is needed regarding the cost and accuracy of primary care ultrasound, and the potential impact of these strategies in the comparison with OR.Peer reviewe

Use of a Steerable Sheath for Retrograde Access to Antegrade Branches in Branched Stent-Graft Repair of Complex Aortic Aneurysms.

PURPOSE To describe how to use a steerable sheath from a femoral access to catheterize antegrade branches in a branched aortic stent-graft. TECHNIQUE Following femoral cutdown, a stent-graft with antegrade branches destined for renovisceral target vessels was deployed in the desired position. A steerable sheath with a tip that rotates up to 180° was introduced from the common femoral artery and navigated to the antegrade branches for consecutive catheterization of the target vessels and deployment of one or more bridging stents per branch. The technique is demonstrated in 4 patients who underwent successful complex abdominal and thoracoabdominal branched endovascular repairs with 1, 2, and 4 antegrade branches. CONCLUSION Retrograde access for complex aortic endografts with antegrade branches using a steerable sheath appears feasible and effective and may serve as an alternative to upper extremity access

Combined Ascending Aortic Stent-Graft and Inner Branched Arch Device for Type A Aortic Dissection.

PURPOSE To report the use of the Zenith Ascend stent-graft in conjunction with the Zenith inner branched arch device to treat type A aortic dissection. CASE REPORT Five patients (mean age 66 years, range 52-78; 4 men) with type A aortic dissection (2 acute) and insufficient distal landing zones were treated with the Zenith Ascend stent-graft and inner branched arch devices to extend the distal landing zone. Left carotid-subclavian bypass was performed in a staged or simultaneous setting depending on the urgency of the condition. Technical success (no type I or III endoleak and successful revascularization of all supra-aortic vessels) was achieved in all patients. Median intensive care unit stay was 5 days (range 4-23) and the median hospital stay was 16 days (range 8-25). The 2 patients with acute dissection died in hospital and at 5 months, respectively. The 3 elective patients were followed for 7, 13, and 19 months, respectively. All had false lumen thrombosis with either a reduced or stable aneurysm diameter. CONCLUSION This limited experience demonstrated the feasibility and safety of the combined use of the Ascend stent-graft and inner branched arch devices. This strategy may sometimes be more beneficial than either stent-graft used alone

Air Embolism During TEVAR: Liquid Perfluorocarbon Absorbs Carbon Dioxide in a Combined Flushing Technique and Decreases the Amount of Gas Released From Thoracic Stent-Grafts During Deployment in an Experimental Setting.

PURPOSE To investigate the influence of flushing thoracic stent-grafts with carbon dioxide and perfluorocarbon on the amount of gas released during stent-graft deployment in thoracic endovascular aortic repair (TEVAR). MATERIALS AND METHODS Ten TX2 ProForm thoracic stent-grafts were deployed into a water-filled container with a curved plastic pipe and flushed sequentially with carbon dioxide, 20 mL of liquid perfluorocarbon (PFC), and 60 mL of saline. Released gas was measured using a calibrated setup. The volume of released gas was compared with the results of an earlier published reference group, in which identical stent-grafts were flushed with 60 mL saline alone as recommended in the instructions for use. RESULTS The average amount of gas released in the test group was 0.076 mL, significantly lower (p<0.001) than the mean 0.79 mL of gas released in the reference group. Big bubbles appearing at the tip of the sheath when deployment was started were seen in all grafts of the reference group but in only 2 of the test group stent-grafts. Small bubbles were less frequent in the test group. CONCLUSION The amount of gas released from thoracic stent-grafts during deployment can be influenced by different flushing techniques. The use of PFC in addition to the carbon dioxide flushing technique reduces the volume of gas released during deployment of tubular thoracic stent-grafts to a few microliters. This significant effect is presumably based on the high solubility of carbon dioxide in perfluorocarbon and could be a potential future approach to lower the risk of cerebral injury and stroke from air embolism during TEVAR