Peripheral Nerves: Ultrasound-Guided Interventional Procedures

Abstract

Specific ultrasound (US)-guided interventional procedures on peripheral nerves are reviewed in this article including regional anesthesia, biopsy of neural lesions, and some injection therapies. For these procedures, US is the best modality to provide a safe imaging guidance because of its excellent spatial resolution and real-time capabilities. With US guidance, the radiologist can visualize the needle tip continuously and ensure that the needle is placed precisely in the desired location, avoiding the risk of inadvertent nerve damage. Practical tips and tricks for US-guided needle placement, biopsy of neural lesions, and US-guided therapy are reviewed in this article. The use of US-guided injections in specific clinical settings, such as the percutaneous treatment of carpal tunnel syndrome, Morton's and saphenous neuromas, painful stump neuromas, piriformis syndrome, and meralgia paresthetica are also illustrated here. US allows the clinician to inject drugs with little or no patient discomfort.

Meralgia paraesthetica: Ultrasound-guided injection at multiple levels with 12-month follow-up

“…As compared to prior reports using a standard dosage of 40 mg/ml methylprednisolone acetate, we used only 10 mg/ml triamcinolone, which represents an equivalent dosage of onequarter [6,7]. In four patients, a complete resolution of symptoms after one injection was achieved, whereas in 16 out of 20 patients more than a single injection was necessary to improve symptoms.…”

“…In the first session the nerve was injected at the level of the inguinal ligament (first level) exactly at the point where the nerve thickening was detected [6]. The needle was inserted from the medial or lateral side depending on best access towards the thickened nerve by using an axial scan plane complemented by a longitudinal scan plane in order to visualize the exact needle positioning and careful observation of the injection procedure.…”

“…Anatomical variability leads to reported failure rates for regional nerve blocks as high as 60 % [5]. Ultrasound (US) has been demonstrated to be useful for visualization of peripheral nerves, especially very small nerves such as the ramus palmaris, the saphenous nerve and the LFCN [6][7][8].…”

Lateral Femoral Cutaneous Nerve Entrapment

“…Moreover, it allows for visual guidance of the needle to the target and confirmation of the deposition of local anesthetic around the nerve [ 28 , 31 , 63 ]. Recent studies also showed that the use of ultrasound reduces patient discomfort [ 68 ]. Ultrasound also reduces the amount of local anesthetic agent required, which can reduce the risk of systemic toxicity, as well as the risk of unintended blockage of the femoral and obturator nerves, or a "3-in-1" block [ 58 ].…”

Update in Musculoskeletal Ultrasound Research

“…8,109 Several studies have demonstrated high sensitivity of US for the diagnosis of nerve pathology (Figure 2), with good correlation to magnetic resonance imaging (MRI) and electromyography (EMG). 102,111 Sonography is now commonly incorporated in the evaluation of carpal tunnel syndrome, 46,71,98 and there are well-described techniques for the US evaluation of peripheral nerve entrapment disorders including cubital tunnel syndrome, meralgia paraesthetica, peroneal neuropathy, and tarsal tunnel syndrome. 71,78,86 US is even useful in the evaluation of posttraumatic brachial plexopathy, where it can be used in the diagnosis of nerve root avulsion, pseudomeningocele, and traction neuroma (Figure 3).…”