Generally, there should be no major harm.
The spinal cord terminates at the first lumbar segment (aka L1). 90% of disc herniations that produce sciatic pain are located a few handbreadths below the spinal cord at L5/S1, L4/5, or L3/4. It is important to ensure there is no lapse of strength and associated nerve injury with sciatica.
Additionally, it is critical that there are no bladder or fecal control issues that can be associated with a condition called cauda equina syndrome. Provided there are no weakness or bowel/bladder difficulties, it is acceptable to manage sciatica surgically.
If the sciatic pain continues for more than nine to 12 months, however, there is greater risk of permanent nerve irritation and persistent pain. This condition is called radiculitis. Microdiscectomy for a ruptured disc herniation and associated sciatica is usually performed either for severe sciatic pain or the presence of weakness.