Dear expertise:
The rationale I approach is : periapical lesion develops after root canal treatment, (which is rare), redo rct. If periapical lesion does'nt resolve after redo rct, periapical surgery( apicoectomy and retrograde filling), if periapical lesion persists after periapical surgery, root amputation is performed. This approach assumes only one root is involved. If mutiple roots are involved, extraction is indicated.