A brief report on a technical description of ultrasound-guided lumbar sympathetic block

The pros and cons of ultrasound-guided procedures in pain medicine

The application of ultrasound (US) in pain medicine has been a rapidly growing field since the 2000s. Musculoskeletal injections, peripheral nerve blocks, and neuraxial injections under US guidance have been acknowledged for managing chronic pain. Although many studies on US-guided pain procedures have been published, there needs to be a classification system to evaluate which image device, the US or fluoroscopy, is clinically and technically better in various pain interventions. Therefore, this narrative review introduces the classification system for the US-guided pain procedures according to their clinical and technical outcomes and designates US-guided pain procedures into one of the four categories by reviewing previous prospective randomized comparative trials.

Efficacy of the lumbar sympathetic ganglion block in lower limb pain and its application prospects during the perioperative period

The sympathetic nervous system is involved in the physiological pathogenesis of many different types of chronic pain. Sympathetic blocks can interrupt the reflex control system by intercepting the noxious afferent fibers accompanying autonomic nerves, resulting in changes in peripheral or central sensory processing. A lumbar sympathetic ganglion block (LSGB), as a treatment method, refers to the injection of nerve blockers into the corresponding lumbar sympathetic nerve segments, usually requiring imaging assistance (CT, X-ray, ultrasound) to guide. At present, LSGB has been widely used in the clinical treatment of lower limb pain, such as neuropathic pain, lower limb ischemic pain, and so on. Its mechanism of action may be through inhibiting sympathetic nerve activity and dilating blood vessels, thereby alleviating pain and inhibiting stress response. However, there are few reports of LSGB during the perioperative period, especially in postoperative pain and gastrointestinal function. Therefore, by studying the literature about LSGB-related studies, this article reviews the anatomy of the lumbar sympathetic nerve (LSN), with its clinical application and possible mechanism. We reviewed the analgesic effect of LSGB in patients with lower limb pain and postoperative pain and the potential application prospects in the recovery of gastrointestinal function, finally providing a reference for its clinical application.

To Assess Technical Feasibility of Ultrasound Lumbar Sympathetic Block with Electrical Stimulation Needle in Out of Plane Needle Orientation: A Prospective Interventional Study

OBJECTIVE

We describe technical feasibility of a new technique of ultrasound lumbar sympathectomy (ULS) validated by fluoroscopy.

DESIGN

Prospective interventional study.

SETTING

Pain block area.

SUBJECTS

Thirty patients of peripheral arterial disease (PAD) with rest pain numerical rating score (NRS) ≥ 3 were recruited.

METHODS

In lateral position, curved probe (FUJIFILM SonoSite Edge, 2-5 MHz) was placed transversely at iliac crest. An electrical stimulation needle was inserted out-plane, below lower pole of kidneys directed anterior to the vertebral body below. When needle tip was not visualized, current of 2.0 A was applied. Patients quadriceps contractions, ultrasound psoas contractions and bone contact guided needle placement and confirmed on fluoroscopy. Other parameters noted were: number of needle insertions, vertebral level, Pain NRS at baseline and at 4 hrs, 24 hrs, one week and two weeks post block, temperature rise and any other complications.

RESULTS

In all patients, needle tip was correctly placed in one to three attempts. In 73% patients, needle tip was at L3. Baseline Pain NRS was 8 (IQR 7-8) which decreased to 2 (IQR 2-3) at one week post-procedure and maintained at this range till 2 weeks later. Temperature rise of > 20C was noted in all patients.

CONCLUSION

ULS can safely be performed in patients of PAD by out-plane approach in lateral patient position with electrical stimulation needle. Before injection of drug, aspiration of blood should be ruled out in view of possibility of aortocaval injection.

Ultrasound-Assisted Versus Fluoroscopic-Guided Lumbar Sympathetic Ganglion Block: A Prospective and Randomized Study

BACKGROUND

Fluoroscopy (FL)-guided lumbar sympathetic ganglion block (LSGB) is widely performed to diagnose and manage various diseases associated with sympathetically maintained pain. Recently, numerous ultrasound (US)-assisted procedures in pain medicine have been attempted, showing an advantage of low radiation exposure. This randomized, prospective trial compared the procedural outcomes and complications between FL-guided and US-assisted LSGBs.

METHODS

Fifty LSGBs were randomly divided into 2 groups: FL-guided (FL group) or US-assisted (US group) LSGB group. Both groups received FL-guided or US-assisted LSGB with 10 mL of 0.25% levobupivacaine. The primary end point was the total procedure time. Secondary outcomes were success rate, imaging time, onset time (based on temperature rise), dosage of radiation exposure, other procedure-related outcomes, and complications.

RESULTS

Total procedure time and success rate were not statistically different between the 2 groups, whereas imaging time of the US group was longer than that of the FL group (P = .012). The onset time was faster in the US group (P = .019), and bone touching during the procedure was less frequent in the US group (P = .001). Moreover, radiation exposure was significantly lower in the US group than in the FL group (P < .001). No serious complications were reported in all patients.

CONCLUSIONS

US-assisted LSGB appears to be a feasible method with the added benefit of lower radiation exposure. In our study, we did not find an advantage of US-assisted LSGB over FL-guided LSGB in terms of performance time.

Ganglion blocks as a treatment of pain: current perspectives

The inputs from sympathetic ganglia have been known to be involved in the pathophysiology of various painful conditions such as complex regional pain syndrome, cancer pain of different origin, and coccygodynia. Sympathetic ganglia blocks are used to relieve patients who suffer from these conditions for over a century. Many numbers of local anesthetics such as bupivacaine or neurolytic agents such as alcohol can be chosen for a successful block. The agent is selected according to its duration of effect and the purpose of the injection. Most commonly used sympathetic blocks are stellate ganglion block, lumbar sympathetic block, celiac plexus block, superior hypogastric block, and ganglion Impar block. In this review, indications, methods, effectiveness, and complications of these blocks are discussed based on the data from the current literature.