Boston Scientific Corp. said it is initiating a global, voluntary recall of all unused inventory of the Lotus Edge aortic valve system, blaming complexities associated with the product delivery system. The Marlborough, Mass.-based company emphasized that the valve itself continues to achieve positive and clinically effective performance post-implant. However, because of the time and investment needed to develop and reintroduce a delivery system, the company believes it is necessary to retire the entire Lotus platform immediately.