Successful ventricular transapical thoracic endovascular graft deployment in a pig model

PurposeAortoiliac occlusive disease may preclude retrograde thoracic endovascular aortic repair. This study evaluated the physiologic and anatomic feasibility of introducing an aortic endograft in an antegrade manner into the descending thoracic aorta of a pig through the left ventricular apex.MethodsTwelve adult pigs were to undergo antegrade endograft deployment. Under fluoroscopic guidance, a stiff guidewire was introduced past the aortic valve and into the distal abdominal aorta through the left ventricular apex on a beating heart. An 18F introducer sheath containing a 24 × 36-mm aortic endograft was introduced and deployed in the descending thoracic aorta. The accuracy of graft delivery was determined at necropsy by measuring the distance from the trailing edge of the graft to the downstream margin of the ostium of the left subclavian artery. Aortic valve competency was assessed angiographically and at necropsy. Left ventricular function was assessed angiographically. Five hemodynamic and respiratory variables were recorded at 12 stages during the procedure and assessed for significant changes from baseline.ResultsOne animal died during the sternotomy. All remaining pigs survived the experiment with minimal hemodynamic support. A significant drop in systolic blood pressure (75 ± 2 to 60 ± 4 mm Hg, P = .05) was noted when the aortic valve was crossed with an 18F sheath. The systolic blood pressure returned to baseline on endograft deployment and at the end of the procedure. Bradycardia was noted at several stages of the procedure, requiring treatment in two pigs. Eleven endografts were deployed; seven grafts were delivered within 5 mm and three grafts within 10 to 20 mm of the intended landing point. One graft was deployed 10 mm too proximally, covering the left subclavian artery. No aortic valvular insufficiency or left ventricular dysfunction was noted.ConclusionAn aortic endograft can be delivered in an antegrade manner transapically into the descending thoracic aorta in a pig model with a reasonable degree of accuracy and minimal hemodynamic compromise.

Clinical RelevanceThis study was performed in a pig model to determine the potential feasibility of performing endovascular repair of thoracic aortic pathology in humans through the left apex of the heart. Such an alternative route of endograft delivery might be useful when conventional transarterial access is not available.