Controversies and Complications in the Perioperative Management of Transcatheter Aortic Valve Replacement

Transcatheter aortic valve replacement (TAVR) is performed with increasing frequency in the United States since Food and Drug Administration approval in 2011. The procedure involves the replacement of a severely stenosed native or bioprosthetic aortic valve with a specially constructed valvular prosthesis that is mounted onto a stent, without the use of cardiopulmonary bypass and the complications of a major open surgical procedure. TAVR has been performed mostly in elderly patients with multiple comorbidities or who have undergone previous cardiac surgery. The most commonly used access routes are the femoral artery (transfemoral) or the cardiac apex (transapical), but the transaortic and transubclavian approaches are also used with varying frequency. Conscious sedation may be used in patients undergoing transfemoral TAVR, but the use of general anesthesia has not been shown to carry greater risk and permits the use of transesophageal echocardiography to assist in valve positioning and diagnose complications. Cardiovascular instability during TAVR is relatively common, necessitating invasive monitoring and frequent use of vasoactive medications. Complications of the procedure are still relatively common and the most frequent is vascular injury to the access sites or the aorta. Cardiovascular collapse may be the result of major hemorrhage pericardial effusion with tamponade or coronary occlusion due to incorrect valve placement. Persistent hypotension, myocardial stunning, or injury requiring open surgical intervention may necessitate the use of cardiopulmonary bypass, the facilities for which should always be immediately available. Ongoing and planned trials comparing conventional surgery with TAVR in lower risk and younger patients should determine the place of TAVR in the medium-to long-term future.