Hydrodissection for Carpal Tunnel Syndrome: A Systematic Review

Hydrodissection is an ultrasound-guided technique that has received more attention recently for its role in nerve entrapment syndromes. The purposes of this systematic review were to evaluate the safety and effectiveness of hydrodissection in carpal tunnel syndrome and to investigate the ideal parameters for injectate type, dosage, volume, and frequency; injection approach and technique; as well as operator experience and training required. We searched the Embase, MEDLINE, and PubMed databases with supplemental searches in the CINAHL, Web of Science, and Google Scholar databases for relevant randomized controlled trials. Primary outcome measures were adverse outcomes and clinical effectiveness. Six randomized controlled trials involving 356 wrists were included. All studies used ultrasound guidance in their interventions. No safety-related adverse outcomes were found, although not all studies declared this. Only one study was placebo controlled and revealed symptomatic as well as functional improvements at 6 mos, whereas the rest investigated hydrodissection with different injectate types. We concluded that nerve hydrodissection for carpal tunnel syndrome can be safely performed under ultrasound guidance. However, it is unclear whether the hydrodissection mechanism truly causes improvements in clinical outcomes. We were also unable to draw conclusions regarding the ideal procedure-related parameters. We recommend that future work should not only investigate safety and clinical effectiveness but also attempt to clarify the ideal procedure-related parameters.