K.E.M. Radiology

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Department of Radiology 

  Seth G.S. Medical College and K.E.M. Hospital, Mumbai , India

Interventional Case Record

< Case 46 : May 2024 >

 Contributed by : Pranay Gadge

CT guided lumbar sympathectomy


The autonomic nervous system consists of the sympathetic and parasympathetic divisions. As the name implies, the lumbar sympathetic block can be utilized to disrupt the nerve supply from the sympathetic chain to the lower extremities. This is useful in treating sympathetic mediators of pain. Specifically, lumbar sympathetic blocks can be used for the treatment of painful conditions such as complex regional pain syndrome, phantom limb pain, hyperhidrosis, painful vascular insufficiencies, and pain from herpes zoster/shingles.

Erythromelalgia is a rare clinical syndrome characterized by a triad of redness, warmth, and burning pain - most notably affecting the extremities. It usually affects the lower extremities (most commonly feet) or may involve upper extremities (hands) in a few cases. The episodes are typically precipitated by exercise and relieved by cooling the affected parts. Although erythromelalgia is typically bilateral, it can present unilaterally, especially in secondary cases.[1] Atypical cases presenting with lesions and symptoms solely involving the face have been observed; however, they are extremely rare and are often misdiagnosed. Other terms used to describe erythromelalgia are burning feet syndrome, erythermalgia, Gerhardt disease, and Mitchell disease.

Primary erythromelalgia can be particularly resistant to treatment. Medications affecting the voltage-gated sodium channels (lidocaine, mexiletine, and carbamazepine) have shown promise in primary erythromelalgia.[2]. Other agents that may be effective in treating primary and secondary erythromelalgia include gabapentin, pregabalin, venlafaxine, amitriptyline, iloprost, and misoprostol, calcium channel blockers, and beta-blockers. However, these agents are less well studied, and no specific treatment regimen has been proposed.[3]

Alternative therapies used rarely for refractory cases are epidural infusions of bupivacaine/ropivacaine, transcranial magnetic stimulation, subcutaneous injection of botulinum toxin A, and thoracic or lumbar sympathectomy.[4] 

Case Presentation: 

Here we discuss the case of a 22 year old man with erythromelalgia who underwent CT guided lumbar sympathectomy.

The patient came with complaints of intermittent redness, warmth and burning pain of both the legs sine two years. The symptoms were aggravated in warm climate and relieved by cooling the affected area. The patient had no history of fever, recent trauma, joint pain, and malar rash/oral ulcer. Physical examination revealed reddish discoloration of the skin around feet and ankle on both sides.

In view of severe episodes of pain and redness despite multiple medications, CT guided lumbar sympathectomy was advised and followed.

CT-Guided Lumbar Sympathectomy Procedure 

The procedure was performed under local anesthesia. An appropriate site for injection was chosen at the L2–L3 vertebral level, avoiding the vertebral transverse process, ureter, pelvicalyceal system, and major vasculature. The target point was anteromedial to the psoas muscle and dorsolateral to the abdominal aorta (for left-sided CT-guided lumbar sympathectomy) or the Inferior vena cava (for right-sided CT-guided lumbar sympathectomy) because the lumbar sympathetic trunk has the most consistent relation with the medial margin of the psoas muscle at the L2-3 intervertebral disc.

After asepsis of the puncture site was achieved, a local anesthetic agent (2% lignocaine [Lidocaine]) was injected along the expected needle trajectory. Cutaneous temperature is usually monitored before and after the procedure to determine the efficacy of successful sympathetic blockade.[5][6] A 22-gauge Chiba needle was then inserted until the tip was in the fat triangle, bounded by the vertebral body, major vessel (aorta or inferior vena cava), and psoas muscle, that houses the sympathetic ganglion.

A test solution (2 mL) of nonionic contrast medium and 2% lignocaine (1:4 ratio) was injected to check the spread in the appropriate retroperitoneal space. If the spread was within the psoas sheath, the needle was repositioned. Then, a mixture of neurolytic solution (99.9% alcohol) and non-ionic contrast medium in the ratio of 10:1 was injected slowly.[7] A limited scan was obtained after injection of 5 mL of the solution on each side to check the distribution. The amount of solution injected depended on the adequacy of filling of the fatty space on CT. If the scan showed an unopacified potential space, more was injected. However, no more than 10 mL was injected on each side. After injection, needles were removed, and the patient was monitored for 4 hours.

Fig. 1 Non contrast axial CT cut at the level of L2 vertebral body

Fig. 2 Marker grid placement

Fig. 3  Local anaesthesia infiltration

Fig. 4 Chiba needle insertion

Fig. 5 Confirmation of needle position and infiltration of contrast+ absolute alcohol along the sympathetic chain


Lumbar sympathetic blocks for achieving sympathectomy have been described as an effective pain management treatment strategy for several causes of chronic pain since the early 1900s.  The first reports of a lumbar sympathetic block technique, as well as                    sympatholysis, were initially documented in the 1920s.  The conditions for which    thistreatment has been effectively implemented include lower extremity complex regional  pain syndrome (CRPS, formally known as RSD or causalgia) as well as various                    painful conditions resulting in circulatory insufficiency in the lower extremity such as Buerger&#39;s disease, embolic occlusions, frostbite, vasospastic disease, and peripheral arterial disease.  Other possible indications may include phantom limb pain, hyperhidrosis,  and postherpetic neuralgia. Procedural techniques have evolved with the involvement of fluoroscopy, chemical neurolysis approaches, and radiofrequency thermocoagulation approaches. [8]

It is important to distinguish lumbar sympatholysis from a lumbar sympathetic block in that this procedure specifically seeks to accomplish a more long-term or permanent  disruption of the sympathetic chain output to the lower extremity in comparison to the   lumbar sympathetic block which typically utilizes only local anesthetics. However, the lumbar sympathetic block is often useful for diagnostic purposes on a potential candidate before performing more long-term treatment with lumbar sympatholysis.

Anatomy and Physiology

The sympathetic chain (also referred to as the sympathetic trunk) consists of a bilaterally paired set of paravertebral nerves extending from the neck to the coccyx. These nerves play an essential role in the autonomic nervous system and subdivide into cervical, thoracic, lumbar, and sacral sections.

The majority of the sympathetic output to the lower extremity is in the upper lumbar region. The presynaptic efferent nerve roots emerge from the anteromedial spinal cord, via white rami of the ventral roots of the spinal nerves, which then synapse at the appropriate lumbar sympathetic ganglion. These ganglia provide the sympathetic output to the lower extremity. The postganglionic neurons continue to innervate their target sites. 

The lumbar sympathetic chain of ganglia innervating the lower extremity is located anterolaterally along the lumbar spine, usually at the levels of L2 through L4, lying at the medial margin of the psoas muscle. The aorta is anterior and medial to the left lumbar sympathetic chain, while the inferior vena cava is located closely anteriorly to the right lumbar sympathetic chain. Significant variation has been reported in the specifics of the location, size, and quantity of ganglia. The number of ganglia varies between 2 and 5, with an average of 3. The ganglia may appear as up to six individual ganglia or fused into a single mass of tissue. Frequently there are no ganglia corresponding to the L1 level.[9]

Neurolysis can be performed to disrupt the sympathetic ganglia at the levels of L2-L4, leading to decreased vasomotor tone and decreased afferent pain signals. This phenomenon explains the symptomatic relief patients experience as well as findings of hyperemia of the foot that often occur following successful lumbar sympathetic neurolysis, due to increased vasodilation and arteriovenous shunting of cutaneous capillary beds.


Numerous disorders affecting the lower extremities are treatable with lumbar sympathetic neurolysis, such as complex regional pain syndrome (CRPS), postherpetic neuralgia, and phantom limb pain. From a vascular standpoint, lumbar sympathetic neurolysis has also been useful for patients with severe ischemic rest pain and peripheral arterial disease that is considered non-reconstructable. Patients considered for this procedure often demonstrate significant interruption in quality of life as a result of their symptoms and likely have failed medical management as well as other modalities of treatment.

Cases of chronic visceral pain (e.g., inoperable malignancy) associated with the descending colon and upper portion of the sigmoid colon, kidney, and parts of bladder and ovaries may also benefit from this procedure; more specifically, the hypogastric plexus and ganglion impar are usually the targets.[10] Lumbar sympathetic neurolysis has also seen use in the treatment of plantar hyperhidrosis.[11]


Strong contraindication is an infection at the procedure site. Relative contraindications include coagulation abnormalities, bleeding dyscrasias such as various platelet dysfunctions, malignancy near the treatment site, systemic infection, bacteremia, and severe cardiac and/or pulmonary disease.[12].

Lumbar sympatholysis can be an effective treatment option for patients suffering from chronic, intractable pain in the lower extremity as a result of various causes such as complex regional pain syndrome, post-herpetic neuralgia, inoperable peripheral arterial disease, phantom limb pain, erythromelalgia, or hyperhidrosis.  The relief and symptom improvement resulting from the destruction of the lumbar sympathetic chain can last up to several years at a time and can be performed by chemical neurolysis, radiofrequency thermocoagulation, and surgical sympathectomy approaches.  In order to help provide effective and safe care for patients suffering with these often debilitating conditions, it is important for healthcare providers to have an understanding of these techniques as well as having an understanding of the indications for, contraindications for, potential side effects of, and potential complications of lumbar sympatholysis.

Genitofemoral neuralgia is the most common complication, with an incidence of 5 to 7% following chemical lumbar sympathectomy. The groin dysesthesia symptoms of genitofemoral neuralgia are usually transient and often resolve within 4 to 6 weeks.[13][14] The risk of genitofemoral neuralgia is reducible by avoiding injection of medications into the psoas muscle, especially at levels L3 and L4, where the intramuscular injection is more common.[15]

Variations in lumbar vessel anatomy, such as the artery of Adamkiewicz, may also be a factor in inadvertent intravascular injection, resulting in direct toxic or ischemic injury to the spinal cord.[16] These risks highlight the importance of aspiration before injection to avoid accidental intravascular injection of medication.

Lumbar sympatholysis is an invasive procedure and can be associated with serious complications such as paralysis or even death.[17][18] Thus it is critical to determine if a patient would be an ideal candidate. Interdisciplinary communication between different medical specialties is often needed to evaluate the patient properly pre- procedure. It is also imperative for the performing provider to understand the anatomy, physiology, and various approaches of the technique to produce improved outcomes and minimize complications, and that these ideas are clearly explained tothe patient as well.


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