Is it permissible to implant a heart valve made from pig skin in a patient's body if that is the only option to avoid taking blood thinners for life?

The jurists differed regarding the purity of swine skin after tanning and its utilization thereafter, but they unanimously agreed that the prohibition of pork is definitive. It is permissible to use swine skin for a heart valve if a pure alternative is unavailable, due to extreme necessity, similar to the case of a patient who needs to implant an organ from an impure animal, provided that no pure organ is available and specialized doctors confirm this.