Nerve Hydrodissection

Nerve hydrodissection is the ultrasound-guided injection of fluid around a peripheral nerve to separate it from adjacent tissue thought to be compressing or tethering it.

The idea is that a nerve compressed by, or adherent to, fascia, tendon or scar can be freed by the fluid itself, whatever the injectate. The result is a visible plane of fluid around the nerve.

Carpal tunnel syndrome (CTS) is by far the most studied use, separating the median nerve from the flexor tendons and the flexor retinaculum. It is also used around the ulnar nerve at the elbow, the lateral femoral cutaneous nerve, the sciatic nerve in deep gluteal syndrome and other entrapments. This page covers the technique, the choice of injectate and the evidence.