Perineuromal hydrodissection for acute postamputation pain? An observational study in a time of war

Introduction: This exploratory study investigates the potential of perineuromal hydrodissection as an adjunct to opioid therapy for postamputation pain, specifically focusing on residual limb and phantom limb pain (PLP). Given the correlations between acute pain and the development of chronic pain, the primary aims were to estimate the effect size of early hydrodissection of scar tissue around residual limb neuroma(s) and to identify the best time frame for treatment. Methods: Seventy-four patients with war-related limb amputations and painful neuromas were included in this observational analysis. Thirty-eight Ukrainian patients with war-related limb amputation and a painful neuroma(s) who underwent hydrodissection and opioid therapy within 6 months of amputation were compared with 36 patients who received opioids alone. Co-primary outcome measures were mean reduction from baseline in average residual limb and PLP at 12 weeks. The composite positive outcome was designated as a ≥2-point or 30% reduction in average residual limb and PLP, satisfaction with treatment, and not requiring an increase in analgesics. Results: Hydrodissection as an add-on to opioids resulted in a greater reduction in average residual limb pain at 12 weeks (-4.00±2.00 vs -3.00±1.00; p<0.001) and earlier time periods, but PLP only through 4 weeks. These differences were driven by those with acute (<3-month duration) pain, as differences in those with chronic pain were not significant. At 12 weeks, Hospital Anxiety and Depression Scale anxiety (10.00±2.00 vs 11.00±1.00; p<0.001) but not depression score was lower in the hydrodissection group. Opioid use in the hydrodissection group significantly declined from 41.32±9.63 to 33.42±17.50 morphine equivalents per day (p=0.001) over the study, but not in the opioid-only group (p=0.20). Differences in 12-week satisfaction rates were not significant. Conclusions: This exploratory study suggests perineuromal hydrodissection may improve residual limb pain and to a lesser degree phantom limb pain, particularly when implemented early in the course of postamputation pain. The study provides preliminary effect size estimates and identifies acute pain as a potential characteristic of patients who may respond more favorably to this intervention. Randomized controlled trials are needed to confirm these findings and control for the confounding variables identified.