Stellate ganglion block
The stellate ganglion (or cervicothoracic ganglion) is a sympathetic ganglion formed by fusion of inferior cervical ganglion and the first thoracic ganglion. It is located at the level of C7 (7th cervical vertebra), anterior to the transverse process of C7, superior to the neck of the first rib, just above the subclavian artery.
The stellate ganglion is only supplied by efferent sympathetic fibres from the ipsilateral sympathetic chain (which lies inferiorly), along with the first and second thoracic segmental anterior rami.
The stellate ganglion lies in front of the neck of the first rib. The vertebral artery lies anterior to the ganglion as it has just originated from the subclavian artery. After passing over the ganglion, it enters the vertebral foramen and lies posterior to the anterior tubercle of C6 (Chassaignac’s Tubercle).
Anatomy of stellate ganglion-
The anatomic relations are:
o Subcutaneous tissue
o Sternocleidomastoid muscle
o Subclavian artery
o Carotid sheath
o Anterior scalene muscle
o Sheath of brachial plexus
o Neck of first rib
o Transverse process of C7
o Vertebral artery
o Longus colli muscle
o Superior intercostals vein
o Superior intercostals artery
o Ventral ramus of first thoracic nerve
o Prevertebral fascia
o Vertebral body of C7
o Thoracic duct
o Pleural dome over the lung apex
• Chronic pain syndromes
o CRPS (complex regional pain syndrome) 1 and 2
o Herpes zoster affecting the face and neck
o Refractory chest pain or angina
o Phantom limb pain
• Vascular disorders of the upper limbs
o Raynaud’s phenomenon
o Obliterative vascular disease
o Embolic phenomenon
o Frost bites
• Recent myocardial infarction
• Anti coagulated patients or those with coagulopathy
• Pre existing contralateral phrenic nerve palsy (may precipitate respiratory distress)
Techniques used for stellate ganglion block
- Landmark technique
• Patient in supine position with slight extension o the neck
• The head is turned to the opposite side
• The needle is introduced between the trachea and the carotid sheath at the level of cricoids cartilage and Chassaignac’s tubercle (C6) to avoid any injury to the pleura
• The sternocledomastoid muscle and carotid artery are pushed laterally while simultaneously palpating the
- Chassaignac;s tubercle
• The skin and subcutaneous tissue are pressed firmly onto the tubercle, the needle is directed medially and inferiorly towards the body of C6 to hit it and then withdrawn by 1-2 mm to rest outside the longus colli muscle
• 10 mls of 0.25% L-Bupivacaine is injected aftera small test dose of 0.5 mls and repeated negative aspiration for blood is done to rule out intravascular placement of the needle
• Pain specialists usually use Bupivacaine (0.125-0.5%) or Ropivacaine 0.2% in a volume ranging from 5-15 mls
Patient position in stellate ganglion block:
Stellate ganglion block using landmark technique
- Fluoroscopy assisted
• The anatomic landmarks are used to guide the approach and direction of the needle and then fluoroscopy is used to confirm the position.
• Radioopaque contrast is injected and the spread is visualized using anteroposterior and lateral views.
• Injection into longus colli muscle is indicated by the inability of the contrast medium to spread in between the tissue planes while instantaneous disappearance indicates the presence of needle in the vessel
- CT guided
• The patient in supine with chin turned away from the injection site
• The head of the first rib, adjacent vertebral artery and vein are identified and 25-gauge spinal needle is directed onto the head of the first rib, as close to the vertebral artery as possible
- Ultrasound guided
• The patient is in a supine position with slight extension of the neck
• After cleaning and draping the site, the transducer s placed on the neck at the level of C6 to enable cross sectional visualization of the anatomical structures
• At this level, the carotid artery, internal jugular vein, thyroid gland, trachea, longus colli muscle, root of C6 and transverse process of C6 are identified.
• To retract the carotid artery laterally and to position the transducer close to the longus colli, the transducer is then gently pressed between the carotid artery and the trachea
• Using an in plane approach, a 1.0 inch, 25 gauge long bevel needle is inserted paratracheally toward the middle toward the middle of the longus colli.
• The end point for the injection is the ultrasound image demonstrating the tip of the needle penetrating the prevertebral fascia in the longus colli.
• Following a negative aspiration test for blood or CSF, local anesthetic is injected and visualized spreading in real time.
- Horners syndrome: is caused by sympathetic blockade and produces the following features on the ipsilateral side of the face:
• Drooping of eyelid (ptosis)
• Constriction of the pupil (meiosis)
• Decreased sweating of the face on the same side (anhydrosis)
• Redness of the conjunctiva of the eye
• Impression of an apparently sunken eyeball (enophthalmos)
This may lead to increased amplitude of accommodation, paradoxical contralateral eyelid retraction, transient decrease in intraocular pressure and changes in tear viscosity.
Although it is a complication, the presence of Horner’s syndrome is a confirmatory sign of successful stellate ganglion blockade.
- Misplaced needle puncturing important adjacent structures
• Vascular (may lead to local hematoma or hemothorax)
o Carotid artery puncture
o Internal jugular vein puncture
o Inferior thyroid artery puncture during ultrasound guided approach
o Vagus nerve injury
o Brachial plexus root injury
o Pulmonary injury, pneumothorax
o Chylothorax (thoracic duct injury)
o Esophageal perforation
- Inadvertent spread of local anesthetic
• Intravascular injection into carotid artery, vertebral artery, internal jugular vein or inferior thyroid artery
• Neuraxial/ brachial plexus spread
• Localized spread
• Hoarseness due to recurrent laryngeal nerve injury
• Elevated hemodiaphragm from phrenic nerve blockade
- Local anesthetic toxicity
• Soft tissue abscess