Hi and welcome to HCM.
There are complicated procedure which can preserve your spleen
but there is absolutely no need for that. Spleen removal is a routine procedure and it leavs minimal consequences. You shouldnt risk with some other methods which can have doubtful outcome. Spleen shall probably grow more and you ll have to remove it sooner or later. Its immune function can be replaced by vaccinations and this shouldnt worry you. WIsh you good health.