Patent No. EP2257243 (titled "Stent For The Positioning And Anchoring Of A Valvular Prosthesis In An Implantation Site In The Heart Of A Patient") was filed by Jenavalve Technology on Feb 25, 2009. The application was issued on May 7, 2014.

Patent oppositions filed by competitors challenge the validity of a granted patent. These oppositions are typically based on claims of prior art, lack of novelty, or non-obviousness. They are a key part of the process for determining a patent's strength and enforceability.
The dossier documents provide a comprehensive record of the patent's prosecution history - including filings, correspondence, and decisions made by patent offices - and are crucial for understanding the patent's legal journey and any challenges it may have faced during examination.