You are in: eMedicine Specialties > Radiology > BRAIN/SPINE Image-guided Stellate Ganglion BlocksArticle Last Updated: May 1, 2008AUTHOR AND EDITOR INFORMATIONAuthor: Andrew L Wagner, MD, Assistant Professor of Radiology, Instructional Faculty, University of Virginia School of Medicine; Director of Neuroradiology, Department of Radiology, Rockingham Memorial Hospital Andrew L Wagner is a member of the following medical societies: American College of Radiology, American Roentgen Ray Society, American Society of Neuroradiology, and Radiological Society of North America Editors: David S Levey, MD, PhD, Orthopedic/Spine MRI TeleRadiologist, Radsource, LLC; Bernard D Coombs, MB, ChB, PhD, Consulting Staff, Department of Specialist Rehabilitation Services, Hutt Valley District Health Board, New Zealand; C Douglas Phillips, MD, Professor, Departments of Radiology, Neurosurgery, and Otolaryngology, University of Virginia Health Sciences Center; Robert M Krasny, MD, Consulting Staff, Department of Radiology, The Angeles Clinic and Research Institute; Lawrence M Davis, MD, Assistant Professor of Diagnostic Imaging (Clinical), Department of Diagnostic Imaging, Warren Alpert Medical School at Brown University Author and Editor Disclosure Synonyms and related keywords: injection procedure for reflex sympathetic dystrophy, ganglia, ganglion, inferior cervical ganglion, first thoracic ganglion, Horner syndrome, paravertebral sympathetic chain, reflex sympathetic dystrophy, bupivacaine, Omnipaque INTRODUCTIONThe stellate ganglion is part of the sympathetic network and is formed by the inferior cervical and first thoracic ganglia.1, 2 Located just anterior to the head of the first rib, the ganglion receives input from the paravertebral sympathetic chain and provides sympathetic efferents to the upper extremities, head, neck, and heart. The infiltration of local anesthetic around the 1-cm ganglion has been used to treat a variety of disorders, but it is primarily performed in the setting of reflex sympathetic dystrophy. Although most often performed by pain management physicians, fluoroscopic, and computed tomography (CT)-guided, techniques have been described in the radiology literature. Stellate ganglion blocks have been traditionally performed blindly by palpating the transverse process of C6 and infiltrating a large volume (as much as 20 mL) of local anesthetic. This technique is dependent on enough volume reaching the stellate ganglion to result in an effective block.3, 4 The method has a relatively high rate of inadequate block and adverse effects. Image-guided stellate ganglion blocks have the advantages of increased safety and accuracy compared with blind injections because the needle can be accurately placed close to the ganglion itself. Because of the close proximity of the needle to the ganglion, a smaller amount of local anesthetic can be used, resulting in a decrease in adverse effects. Indications for stellate ganglion blocks include reflex sympathetic dystrophy of the upper extremities, Raynaud syndrome of the upper extremities, herpes zoster of the face or neck, hyperhidrosis of the neck of an upper extremity, and upper extremity pain due to arterial insufficiency. Pain due to arterial insufficiency can be treated with a stellate ganglion block, but this would have no effect on someone with venous insufficiency. ANATOMYThe stellate ganglion is a long, flat structure approximately 1 cm in length. It lies just anterior to the head of the first rib, directly adjacent to the vertebral artery and lateral to the longus colli muscle. It is also closely related to the apex of the lung and the phrenic nerve. FLUOROSCOPIC TECHNIQUEWith the patient in the supine position, the C7 vertebral body is identified under fluoroscopy. After the administration of local anesthesia, a 25-gauge spinal needle is directed in the anteroposterior (AP) plane toward the junction of the vertebral body and the ipsilateral transverse process (see Image 1). When bone is reached, the needle is aspirated, and a small amount of iodinated contrast material (eg, Omnipaque 180) is injected to rule out an intravascular or intraspinal needle tip placement. Once the needle has been positioned, as much as 10 mL of 0.25% bupivacaine is slowly injected, and the patient is monitored for signs of a sympathetic block. An increase in temperature in the affected extremity of at least 3°F from the baseline is the most specific means of detecting a successful block. Temperatures are typically measured by use of hand thermistors placed on the patient's middle digits. Horner syndrome (ipsilateral miosis, ptosis, and sinonasal congestion) is frequently seen. However, this finding is not diagnostic of a stellate block because this can be seen when only the cervical plexus is anesthetized. Hoarseness may develop if the recurrent laryngeal nerve is included in the anesthetized region, and a partial brachial plexus blockade with arm numbness and weakness is not unusual. Use of the smallest possible volume of anesthetic minimizes the adverse effects. After the procedure, the patient should be allowed to recover in the department for approximately 1 hour. CT-GUIDED TECHNIQUEThe patient is placed supine with his or her chin turned away slightly from the injection site. By using CT scanning or CT fluoroscopy, the head of the first rib is identified, as well as the adjacent vertebral artery and vein. Under sterile conditions, the skin and needle track are anesthetized, and a 25-gauge spinal needle is maneuvered onto the head of the first rib, as close to the vertebral body as possible.1, 2, 5, 6 The physician should take care to avoid the vertebral vessels (see Image 2). The needle tip should be placed on the cortex to minimize the likelihood of intravascular placement, and a small amount of Omnipaque 180 is injected to confirm an extravascular location of the needle tip (see Image 3). Once the needle is in place, a small amount of 0.25% bupivacaine is injected, and additional amounts are slowly added until a sympathetic block is elicited. If the needle is optimally placed, only 1-2 mL of local anesthetic is necessary. The needle is withdrawn, and pressure is held for 5-10 minutes. The patient should remain in the department for at least 1 hour. CONTRAINDICATIONSContraindications to the use of image-guided stellate ganglion blocks include current coagulopathy, recent myocardial infarction, pathologic bradycardia, and glaucoma. COMPLICATIONSComplications of image-guided stellate ganglion blocks may include the following: pneumothorax, bleeding, infection, allergic reaction, intravascular injection and its consequences, phrenic nerve or recurrent laryngeal nerve paralysis, hypotension, injury to adjacent vascular structures (particularly the vertebral artery), and bradycardia. Pneumothorax can occur when the stellate ganglion is close to the lung apex, although this condition does not occur as often with CT guidance. Because the heart accelerator nerves are included in the stellate ganglion, anesthetizing these nerves can result in profound bradycardia or heart block. MULTIMEDIA
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Image-guided Stellate Ganglion Blocks excerpt Article Last Updated: May 1, 2008 | ||||||||||||||||||||||||||