Autologous Fat Grafting is not Superior to Placebo as Treatment of Postherpetic Neuralgia A Double-Blinded Randomized Clinical Trial

BACKGROUND: Postherpetic neuralgia (PHN) is a chronic pain syndrome occurring after a herpes zoster (HZ) outbreak, also known as shingles. Treatment is complex, and no effective treatment exists today. Autologous fat grafting (AFG) has previously shown promise in treating PHN, but no randomised controlled trial has been performed.This RCT aimed to investigate the effect of autologous fat grafting on postherpetic neuralgia compared to a sham treatment.

METHODS: We included forty-six participants suffering from PHN in our double-blinded, two-armed RCT. Participants were randomly assigned either the intervention group or control group. All participants had liposuction performed under general anaesthesia. The intervention group received AFG to the area of pain, and the control group received a sham treatment of saline injection. The primary outcomes were the average and maximum degree of pain measured on an 11-point numerical rating scale (NRS). Secondary outcomes were quality and degree of neuropathic pain (NPSI) and Quality of Life (SF-36).

RESULTS: Forty-two participants completed follow-up. In the maximal degree of pain, we observed a reduction of -1.1(0.6) and -1.0(0.5) Δ mean(SE) on the NRS in the intervention and control groups, respectively. In the average degree of pain, the reduction was -1.2(0.5) and -1.3(0.4) in the intervention and control groups. We observed stationary or minor improvements in neuropathic pain, with similar changes in both groups. We observed small reductions in QoL in all parameters and in both groups. The exceptions were pain and social functioning, where the control group reported minor improvements. For all the measured outcomes, the differences between the groups were not statistically significant.

CONCLUSIONS: We did not find autologous fat grafting superior to a placebo when treating postherpetic neuralgia of the skin. Based on our results, we cannot recommend the routine use of this method to treat these pains.