Safety and Feasibility of In Situ Fenestration in the Aortic Arch: A Prospective Single-Center Observational Cohort...

Background: Thoracic endovascular aortic repair (TEVAR) is an established minimally invasive approach for selected aortic arch pathologies; however, it is associated with risks including stroke and spinal cord ischemia. Revascularization techniques, such as in situ fenestration (ISF), play a critical role in preserving supra-aortic branch perfusion and reducing neurological complications. Methods: This prospective, single-center observational cohort study enrolled 74 consecutive patients undergoing TEVAR with ISF between October 2017 and September 2023. Data collected included demographics, lesion morphology, procedural details, and clinical outcomes. The primary endpoint was procedural technical success; secondary endpoints included 30-day complications, reintervention rate, and all-cause mortality. Results: Technical success was achieved in 100% of cases (74/74; 95% CI: 95.2-100.0%), defined as successful fenestration creation, patent bridging stent graft without kinking or embolization, absence of Type I or III endoleak on completion angiography, and restored antegrade branch flow. Physician-modified fenestration was combined with ISF-thoracic endovascular aortic repair (TEVAR) in 28.4% (21/74) of cases. At 30-day follow-up, 30-day clinical success (freedom from mortality, reintervention, and procedure-related complications) was achieved in 87.8% (65/74) of patients. No mortality was recorded at 30 days. Treatment-related complications included subclavian branch thrombosis (n = 1, 1.4%), transient ischemic attack (n = 1, 1.4%), and endoleaks (n = 7, 9.5%; including Type Ia, Type II, and Type III), with reintervention required in 6 patients (8.1%) during the follow-up period. Beyond 30 days, three late deaths were documented: one aorta-related death (aneurysm rupture at 9 months), one neurological death (ischemic stroke at 13 months), and one cardiovascular death (myocardial infarction at 60 days post-procedure), yielding a late all-cause mortality rate of 4.1% (3/74). Conclusions: ISF-TEVAR demonstrated a high procedural technical success rate and a low 30-day complication and mortality profile in this single-center prospective series of selected patients treated at an experienced center. These early and mid-term results are encouraging; however, given the single-center, non-comparative design and limited standardized follow-up, broader conclusions regarding durability and comparative effectiveness remain premature. Larger multicenter prospective studies with standardized long-term imaging follow-up are warranted.