Initial and midterm results of the Bolton Relay Thoracic Aortic Endovascular Pivotal Trial.

OBJECTIVE: To report the initial and midterm results of the Bolton Relay Thoracic Stent Graft for the endovascular treatment of thoracic aortic lesions [thoracic endovascular aortic repair (TEVAR)].

METHODS: The Bolton Relay Thoracic Aortic Endovascular Pivotal Trial was a prospective, nonrandomized, multicenter, U.S. Investigational Device Exemption study conducted at 27 U.S. investigational sites. One hundred twenty TEVAR subjects were treated with the Relay device between January 2007 and May 2010, with 13 patients enrolled during the continued access phase through September 2012. TEVAR outcomes were compared with a prospectively and retrospectively enrolled surgical cohort consisting of 60 patients enrolled under similar inclusion/exclusion criteria. Follow-up examinations were prescribed at 1 month, 6 months, and yearly thereafter for 5 years. Major adverse events (MAEs) included stroke, paralysis/paraplegia, myocardial infarction, procedural bleeding, respiratory failure, renal failure, wound healing complications, and aneurysm-related mortality.

RESULTS: Stent grafts were successfully delivered and deployed in 129 of 133 patients (97.0%). At 30 days, a lower rate of mortality was observed in the TEVAR arm (5.3% vs 10.0%; P = .230), and TEVAR was associated with a significantly lower rate of MAEs (20.3% vs 48.3%; P < .001), primarily driven by a lower frequency of respiratory failure in the cohort (5.5% vs 21.6%; P = .007) and procedural bleeding. Freedom from aneurysm-related mortality through 5 years was similar at 91.3% for the TEVAR cohort and 89.4% for the surgical cohort (P = .406); with 5-year freedom from all-cause mortality at 57.1% and 50.2% (P = .289), respectively. Freedom from MAEs through 5 years was significantly higher in the TEVAR cohort (65.7% vs 44.7%; P = .001). Six TEVAR patients (4.5%) experienced core laboratory-reported type I or III endoleaks, and secondary procedures were performed in 10 patients (7.5%), with seven procedures to correct endoleak and one surgical conversion. Endograft migration occurred in three patients (2.3%) and wireform fractures were assessed in two patients (1.5%). Aneurysm sac size decreased or remained stable in 113 patients (85.0%) over 5-year follow-up. There were no instances of rupture or endograft occlusion. A 38-subject subset treated with the newer Relay Plus Delivery System had a significantly reduced MAE rate (15.8% vs 35.8%; P = .035), and fewer perioperative strokes (2.6% vs 12.6%; P = .108).

CONCLUSIONS: Data from the Relay TEVAR clinical trial demonstrate safety and effectiveness of the Relay device compared with surgical controls, indicating continued device durability with a low rate of device-related complications through 5 years.