title: Block of the superior cervical ganglion, description of a novel ultrasound-guided technique in human cadavers.
abstract: OBJECTIVE
  Injection of opioids to the superior cervical ganglion (SCG) has been reported to provide pain relief in patients suffering from different kinds of neuropathic facial pain conditions, such as trigeminal neuralgia, postherpetic neuralgia, and atypical facial pain. The classic approach to the SCG is a transoral technique using a so-called "stopper" to prevent accidental carotid artery puncture. The main disadvantage of this technique is that the needle tip is positioned distant from the actual target, possibly impeding successful block of the SCG. A further limitation is that injection of local anesthetics due to potential carotid artery puncture is contraindicated. We hypothesized that the SCG can be identified and blocked using ultrasound imaging, potentially increasing precision of this technique.
  
  
  METHODS
  In this pilot study, 20 US-guided simulated blocks of the SCG were performed in 10 human cadavers in order to determine the accuracy of this novel block technique. After injection of 0.1 mL of dye, the cadavers were dissected to evaluate the needle position and coloring of the SCG.
  
  
  RESULTS
  Nineteen of the 20 needle tips were located in or next to the SCG. This corresponded to a simulated block success rate of 95% (95% confidence interval 85-100%). In 17 cases, the SCG was completely colored, and in two cases, the caudal half of the SCG was colored with dye.
  
  
  CONCLUSIONS
  The anatomical dissections confirmed that our ultrasound-guided approach to the SCG is accurate. Ultrasound could become an attractive alternative to the "blind" transoral technique of SCG blocks.
authors: Pain Center, Department of Anesthesiology, University Hospital Center and University of Lausanne, Lausanne, Switzerland. andisiegenthaler@gmail.com
authors: Andreas
authors: A
authors: Siegenthaler
authors: Matthias
authors: M
authors: Haug
authors: Urs
authors: U
authors: Eichenberger
authors: Marc Rene
authors: MR
authors: Suter
authors: Bernhard
authors: B
authors: Moriggl
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000779:Anesthetics, Local / Q000008:administration & dosage*; D002102:Cadaver; D005260:Female; D006801:Humans; D008297:Male; D009407:Nerve Block / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D017783:Superior Cervical Ganglion / Q000000981:diagnostic imaging* / Q000187:drug effects*; D018084:Ultrasonography, Interventional / Q000379:methods*
chemical_list: D000779:Anesthetics, Local