Replacement bileaflet mechanical heart valves 를 위한 안전성 경고 / 현장 안전성 서한

Data from the United Kingdom is current through April 2019. All of the data comes from the Medicines and Healthcare products Regulatory Agency, except for the categories Manufacturer Parent Company and Product Classification.
The Parent Company and the Product Classification were added by ICIJ.
The parent company information is based on 2017 public records. The device classification information comes from FDA’s Product Classification by Review Panel, based on matches of recall data from the U.S. and the United Kingdom.

MHRA is aware of 5 incidents worldwide over the last 15 years where mechanical bi-leaflet prosthetic valves of different models are believed to have been implanted inverted because they were put on their holder upside-down. The actual figure is likely to be higher as there is under-reporting of these events.Details of the 5 incidents:2 cases (one known to be fatal) in 2003 and 2004, resulting from a manufacturing quality control release mistake where valves were loaded inverted at the factory
1 in 2006 resulting from separation of the valve from the holder (due to suture breakage) during transportation and subsequent remounting prior to surgery
1 in 2006 where evidence indicates that the valve was remounted during the valve surgery
1 UK incident (2015) involving inverted remounting of a valve in theatre leading to subsequent patient death.The probability of this error remains very low relative to the millions of valves implanted during this time, but the harm that can result is extreme, sometimes fatal.Despite warnings in the manufacturers’ IFU not to remount a valve on its holder, this has not entirely prevented this practice, with tragic consequences. Although the risk of inverted valve implantation cannot be completely eliminated, the holder itself can be designed to be unidirectional, preventing inverted mounting. One manufacturer’s (St. Jude Medical, now Abbott) holder design is currently unidirectional, thereby also eliminating the risk of inversion on the holder during valve assembly.As a consequence of the recent UK incident (coupled with cases cited above), MHRA has acquired agreement from the other 3 manufacturers of mechanical heart valves (Liva Nova, Medtronic, On-X Life Technologies) to redesign their holders to be unidirectional.These undertakings involve long-term design projects, including thorough risk/benefit assessment and regulatory approval. As a result, valves mounted on unidirectional holders are unlikely to become available in the UK for up to a year or more, depending on the manufacturer.Until all manufacturers have made these changes, it is important that all clinical personnel handling mechanical heart valves are aware of the serious risk associated with inversion of the valve on its holder.