Ultrasound-Guided Minimal Invasive Carpal Tunnel Release: An Optimized Algorithm.

Purpose: To present a safety-optimized ultrasound-guided minimal invasive carpal tunnel release (CTR) procedure.

Materials And Methods: 104 patients (67 female, 37 male; mean age 60.6 ± 14.3 years, 95% CI 57.9 to 63.4 years) with clinical and electrophysiological verified typical carpal tunnel syndrome were referred for a high-resolution ultrasound of the median nerve and were then consecutively assigned for an ultrasound-guided CTR after exclusion of possible secondary causes of carpal tunnel syndrome such as tumors, tendovaginitis, ganglia and possible contraindications (e.g., crossing collateral vessels, nerve variations). Applying a newly adapted and optimized algorithm, basing on the work proposed by Petrover et al. CTR was performed using a button tip cannula which has several safety advantages: On the one hand, the button tip cannula acts as a blunt and atraumatic guiding splint for the subsequent insertion of the hook-knife, and on the other hands, it serves as a "hydro-inflation"-tool, i.e., a fluid-based expansion of the working-space is warranted during the whole procedure whenever needed.

Results: In all patients, successful releases were confirmed by the depiction of a completely transected transverse carpal ligament during and in the postoperative ultrasound-controls two weeks after intervention. All patients reported markedly reduction of symptoms promptly after this safety-optimized ultrasound-guided minimal invasive CTR and at the follow-up examination. No complications were evident.

Conclusion: The here proposed optimized algorithm assures a reliable and safe ultrasound-guided CTR and thus should be taken into account for this minimal invasive interventional procedure.