Feasibility and Early and Midterm Outcomes of Midaortic Syndrome: A Retrospective Cohort Study

<b>Background</b>: Midaortic Syndrome (MAS) is a rare vascular condition characterized by segmental narrowing of the thoracic and abdominal aorta, often involving ostial narrowing of the renal or visceral arteries. While open surgical repair has been the standard treatment, it carries significant morbidity, especially in high-risk patients. Endovascular techniques, including the Chimney approach, provide a minimally invasive alternative to preserve and reestablish both aortic and branch vessel perfusion. This study evaluates the feasibility, safety, and early and midterm outcomes of the Chimney technique used in a cohort of patients with MAS. <b>Methods</b>: Between 2019 and 2025, 9 patients with MAS and branch vessel involvement underwent endovascular repair using the Chimney technique at Brüderklinikum Julia Lanz Hospital in the Mannheim Teaching Hospital of Heidelberg University. Pre-procedural planning was based on computed tomography angiography. Technical success, peri-procedural complications, changes in blood pressure, renal function, and target-vessel stent patency were monitored. Patients were followed over a median of 3 years (range, 0.08-6 years). <b>Results</b>: Nine patients (mean age 77.2 ± 8.7 years; 66.6% female) underwent endovascular repair for midaortic syndrome. All patients were unfit for open surgery. Comorbidities included hypertension (100%), coronary artery disease (100%), and chronic kidney disease (77.7%). Technical success and target-vessel patency were 100%, with no intraoperative deaths, impairment of renal function, or 30-day mortality. One patient (11.1%) developed an access-site hematoma, which was managed conservatively. Median hospital stay was 6 days. During a median 3-year follow-up (range 1 month-6 years), all chimney stents remained patent, patients experienced durable symptom relief, blood pressure improvement, and freedom from reintervention. <b>Conclusions</b>: The Chimney technique offers a safe and effective endovascular option for high-risk patients with Midaortic Syndrome, achieving high technical success, preserved branch-vessel patency, and improvement of symptoms. Larger studies with longer follow-up are warranted to confirm durability and optimize patient selection for this technique.