Safety and Usefulness of Free Fat Grafts After Microdiscectomy Using an Access Cannula: A Prospective Pilot Study and Literature Review

Placing an interpositional fat graft over the dura has been practiced to prevent sciatica due to nerve tethering from scar. We assessed feasibility, outcomes,
and complications of free fat grafts in patients undergoing lumbar microdiscectomy for herniated discs using an access cannula.

Retrospective review of prospectively collected data on 69 consecutive patients: those who received autologous fat graft (Group I) and those who did not (Group II). Clinical evaluation of leg pain and nerve tension sign was performed in the immediate postoperative period and at 1 month, 6 months, 12 months, and 24 months.

The combined visual analog scale (VAS) scores for leg pain improved from 8.3 preoperatively to 1.3 (P < 0.5). The average VAS score for leg pain was 1.4
(0 to 3) in Group I and 1.3 (0 to 3) in Group II (P > 0.05). Ninety-one percent had resolution of their leg pain immediately postop and 96% at final follow-up.

This study found no increased complications with the use of fat graft, but no clinical benefit, therefore the use of fat graft should be discouraged. The potential complication with the use of fat graft is the “mass effect” on the dura, and therefore, the width of the graft should be <1 cm.