Welcome to healthcare magic.
If cosmetically your lip looks good and if you have not developed any allergy
why should you bother removing it ? As the years progress your lip will lose its volume and the effect of filler also diminishes. Surgery to remove filler is very difficult as it would have mixed with your tissue and if removed volume of lip will diminish significantly and cosmetically won't look nice. Stitches will heal in a weeks time and once healed won't affect sensation. But I will recommend you not to remove it. A fuller lip is a sign of beauty.
Hope this helped