Can Ultrasound-Guided Hydrodissection be a Viable Alternative for Carpal Tunnel Syndrome?

A randomized controlled trial shows that the minimally invasive treatment provided long-term relief of carpal tunnel syndrome.

Ultrasound-guided hydrodissection of the median nerve with normal saline provided complete relief for patients with carpal tunnel syndrome (CTS), a condition that affects about 3 percent of the population in the United States. The minimally invasive treatment may provide a promising treatment alternative to corticosteroids, according to a study presented at the Radiological Society of North America (RSNA) 2022 Annual Meeting.

“Previously, the studies that have been done on ultrasound-guided hydrodissection for carpal tunnel syndrome have used corticosteroids either alone or as a part of the injection, making it difficult to assess whether hydrodissection alone was beneficial, or if it was due to the effect of the steroids,” explained lead author Anindita Bose, M.B.B.S., M.D., a senior resident at the University College of Medical Sciences and Guru Teg Bahadur Hospital in Delhi, India.

The procedure uses ultrasound-guided fluid injection to separate nerves from the surrounding structures, aiming to release soft tissue adhesions that cause nerve entrapment while restoring nerve function. Dr. Bose said the procedure takes only 10 to 15 minutes and is very cost-effective as it does not require any high-end equipment.

The randomized controlled trial included 63 patients with refractory CTS. There were three treatment groups with group one having ultrasound-guided hydrodissection with normal saline alone, group two having ultrasound-guided hydrodissection with a mixture of normal saline and corticosteroid, and group three receiving guided perineural corticosteroid injection without hydrodissection.

To evaluate patient pain and symptoms before and after the procedure, the researchers utilized the Boston Carpal Tunnel Questionnaire (BCTQ; symptom and functional) and the visual analog scale (VAS), and reviewed findings from the cross-sectional area of the median nerve on ultrasound. Follow-up was completed at four weeks, 12 weeks, and six months.

At four weeks, significant improvement was seen in the mean BCTQ score (symptom and functional) and VAS score in groups one, two and three at 61.9 percent, 85.7 percent, and 100 percent respectively. At week 12 and six months, both hydrodissection groups had further improvement at 95.2 percent for group one and 96 percent for group two, while 14.7 percent of group three reported a recurrence of symptoms with an increase in BCTQ and VAS scores.

Researchers also found significant reductions of median nerve cross-sectional area on ultrasound in both hydrodissection groups, noting a 43 percent reduction for group one and a 46 percent reduction for group two in comparison to an 11 percent reduction for group three. No significant adverse effects were reported.

The authors concluded that ultrasound-guided hydrodissection of the median nerve with normal saline alone provided a significant and persistent clinical and morphological improvement for patients with CTS. They added that as the addition of corticosteroid to the saline did not offer any significant benefit as “the therapeutic effect was primarily due to hydrodissection.”

“It came as a pleasant surprise when this simple procedure of ultrasound-guided hydrodissection provided patients with long-term relief,” said co-author Anupama Tandon, M.B.B.S, M.D., a professor at the University College of Medical Sciences and Guru Teg Bahadur Hospital. “The patients were highly satisfied as the cost was low, no anesthesia or hospitalization was needed, and they could go back in an hour’s time and resume their routine work.”