Midterm Follow-up Geometrical Analysis of Thoracoabdominal Aortic Aneurysms Treated with Multilayer Flow Modulator

Background: Aim of our study is the analysis of clinical results and aneurysmal sac evolution after multilayer flow modulator (MFM) placement, in patients with thoracoabdominal aortic aneurysms (TAAs). Methods: All patients with asymptomatic TAA treated at our institution between 2012 and 2014 with MFM were retrospectively analyzed. Thirty-day evaluated outcomes were mortality and complications. Follow-up evaluated outcomes were mortality, aneurysm collateral branches patency, and reintervention. A geometrical analysis of 2-year follow-up computed tomography scans was carried out to evaluate the total aneurysm volume, the percentage of aneurysm growth, and the evolution of maximum aneurysm diameter. Results: Seven patients (mean age: 71.8 years, range: 63–85 years) were considered in the study. Mean preoperative aneurysm diameter was 6.8 cm (range 6–8.3 cm). No 30-day mortality or complications were observed. Mean follow-up was 29.4 months. During follow-up, 3 deaths (42.8%) were observed, not related to MFM complications. Reintervention rate was 42.8%, occurred in all cases after 2-year follow-up; in 2 cases, the reintervention was necessary due to an excessive increase of the aneurysmal sac. During the follow-up, a mean growth rate of 6 mm/year (4 patients) for the diameter of the aneurysm external wall and a total aneurysm volume increase from 2.45 × 105 mm3 to 3.50 × 105 mm3 (4 patients) was evaluated. Conclusions: Our results have shown no mortality related to aneurysm rupture during the follow-up and high rate of reinterventions after MFM placement. Further geometrical analyses, based on the proposed approach, regarding a larger group of patients with long-term follow-up are required to draw indications about the MFM use.