Aortic root motion remodeling after aortic valve replacement--implications for late aortic dissection.

Aortic root motion was previously identified as an additional risk factor for aortic dissection. This study analyzed if the magnitude of aortic root motion changed in patients after aortic valve replacement (AVR) and acute proximal aortic dissection. An institutional database (1984-2005) was used to measure the downward motion of the aortic root (perpendicular to the plane of the sinotubular junction) in contrast injections in 48 patients with aortic insufficiency (AI), aortic stenosis (AS) and proximal aortic dissection pre- and postoperatively, when available. Postoperative aortic root motion was significantly reduced after AVR for AI, while it was significantly increased after AVR for AS. By contrast, aortic root motion was unchanged when functional AI due to paravalvular leak was present post-AVR for AI. In patients with acute aortic dissection, both aortic root motion and aortic diameter were unchanged from pre-dissection. However, in patients who dissected again, aortic root motion was significantly smaller than pre-dissection, and the aortic diameter was significantly less than at first dissection. Removal of aortic stenosis was associated with increased aortic root motion, theoretically heightening the threat of dissection posed to the aortic wall by mechanical stress, although this was not confirmed by our study of dissection patients. Yet, mechanical principles command to include higher magnitude of aortic root motion during follow-up of patients after AVR as an additional risk factor for dissection.