Transcatheter Aortic Valve Replacement as a Treatment for Late Apicoaortic Conduit Obstruction in a Patient With Severe Aortic Stenosis

Abstract

A 62-year-old man presented with progressive exertional dyspnea and angina. His past medical history is notable for coronary artery disease, for which he underwent a coronary artery bypass graft surgery 8 years earlier. A few years afterward, he underwent aortic valve (AV) bypass (AVB) surgery for severe aortic stenosis (AS) using an apicoaortic conduit to the descending aorta consisting of a 16-mm connector and an 18-mm valved conduit (Hancock valve; Medtronic, Minneapolis, MN; Figures 1 and 2; onlineonly Data Supplement Movie I). After a period of initial improvement in symptoms, the patient developed progressive dyspnea and angina and was referred for additional cardiac workup.The patient underwent a bicycle ergometer test, which showed a diminished functional capacity and was stopped because of fatigue and a hypotensive response. He underwent a 2-dimensional transthoracic echocardiogram with gradual dobutamine infusion. He was found to have a heavily calcified AV (online-only Data Supplement Movie II) with a rest mean transvalvular gradient of 34 mm Hg and velocity of 3.5 m/s, which increased to 50 mm Hg and 4.8 m/s, respectively, at peak dobutamine dose (Figure 3). This corresponded with a flow increase across the native AV from 1.7 to 4.3 L/min. A minimal mean gradient of 2 mm Hg was detected at the apicoaortic conduit proximal limb at the anastomosis of the left ventricular (LV) apex and conduit, which increased to 3.4 mm Hg at peak dobutamine (Figures 3) and corresponded with a flow increase across the conduit from 2.3 to 4.7 L/min. A left heart and apicoaortic conduit catheterization were performed (Figure 4; online-only Data Supplement Movies III and IV). A mean gradient of 38 mm Hg across the heavily calcified native AV was detected using a double-lumen catheter. On selective catheterization of the distal portion of the apicoaortic conduit (distal to the prosthetic Hancock AV inside the conduit) using an end-hole catheter, a gradient between the LV and distal limb of the apicoaortic conduit of 12 mm Hg was evident. A slow pullback of the end-hole catheter from the distal limb of the apicoaortic conduit into the aorta, with intermittent contrast angiography, showed an 80% narrowing at the conduitaorta anastomosis, and a 40-mm Hg gradient between the distal limb of the apicoaortic conduit and the aorta at the anastomosis site ( Figure 5; online-only Data Supplement Movie V). An ECG-gated contrast-enhanced computed tomography scan showed heavy AV calcification and an aortic annulus area of 489 mm 2 . The apicoaortic conduit was noted from the LV apex to the descending aorta, with severe narrowing at the distal anastomotic site (Figure 6). The patient's calculated STS score put him at 9.4% mortality risk and 38.6% risk of morbidity or mortality for redo AVR. After deliberations by our multidisciplinary heart team, he underwent a successful transfemoral transcatheter AV replacement (TAVR) using an Edwards Sapien 26-mm valve (Edwards Lifesciences LLC, Irvine, CA; online-only Data Supplement Movies VI and V...

Transcatheter Treatment of Apicoaortic Conduit Dysfunction

“…TAVR has supplanted AVB as a treatment for symptomatic severe aortic stenosis in the high or prohibitive surgical risk patient. A case report of AVB conduit obstruction treated with TAVR has been previously reported . In our patient, regurgitation of the valved apicoaortic conduit required treatment of the stenotic native valve by TAVR followed by catheter‐based closure of the conduit.…”

Transcatheter Restoration of the Left Ventricular Outlet in a Patient With an Implanted Apicoaortic Conduit

“…It has been shown that TAVR may improve symptoms in an AVB patient after stenosis at the aortic anastomosis site of the AVB is detected ( 5 ). We were able to demonstrate a similar benefit in our patient, who developed severe regurgitation of the native calcified aortic valve.…”

Transcatheter Valve-in-Valve Replacement Through Apicoaortic Conduit for Aortic Bypass Valve Failure

“…This technology has been used in very few patients with apicoaortic conduit failure by treating the native aortic valve, as in the patient described by Jneid and colleagues [3]. They used the transfemoral route to implant a 26-mm Sapien valve in a patient with severe stenosis of the distal anastomotic site of the apicoaortic conduit as it enters the descending aorta.…”