A Canadian study has found that vascular and bleeding complications following percutaneous aortic valve replacement (PAVR) appear to be markedly reduced with careful patient selection, advanced interventional techniques, and a fully percutaneous procedure. Vascular complications following PAVR occurred most often if:

The external sheath diameter was larger than the minimal artery diameter.
Moderate or severe calcification existed.
Patients had peripheral vascular disease.

Abstract: Journal of the American College of Cardiology, January 10, 2012.