title: Ultrasound imaging to estimate risk of esophageal and vascular puncture after conventional stellate ganglion block.
abstract: OBJECTIVE
  The most common techniques to perform stellate ganglion blocks (SGBs) are the blind C6 approach and the fluoroscopic-controlled paratracheal C7 approach, both after manual dislocation of the large vessels. Complications due to vascular or esophageal puncture have been reported. The goal of this ultrasound imaging study was to determine how frequently hazardous structures are located along the needle path of conventional SGB and to determine the influence of the dislocation maneuver on their position.
  
  
  METHODS
  Sixty volunteers were examined on both sides. The presence of the esophagus, vertebral artery, and other arteries located within the needle path of an SGB at the C6 and C7 levels was determined before and during the dislocation maneuver.
  
  
  RESULTS
  On the left side, the esophagus was located along the needle path in 22 and 39 of 60 cases at the C6 and C7 levels, respectively, and remained there in 10 and 22 of 60 cases during dislocation. The esophagus appeared in the needle path during dislocation from a previously safe location in 5 and 8 of these cases at the C6 and C7 locations, respectively. The vertebral artery was located in the needle path in a range of 2 to 8 of 60 cases without impact of dislocation on its position. Other arteries were located in the needle path in the range of 10 to 17 of 60 cases with a slight decrease during dislocation.
  
  
  CONCLUSIONS
  The esophagus and relevant arteries were frequently located in the needle path of conventional SGBs. The dislocation maneuver had a partial impact on moving these structures away from the target and may increase left-sided esophageal puncture risk in certain individuals. Ultrasound (US) imaging is expected to improve the safety of SGB, but it will require clinical trials to confirm this expectation.
authors.affiliation: University Department of Anesthesiology and Pain Therapy, University of Bern, Inselspital, Murtenstrasse, Bern, Switzerland. andisiegenthaler@gmail.com
authors.forename: Andreas
authors.initials: A
authors.lastname: Siegenthaler
authors.forename: Sabine
authors.initials: S
authors.lastname: Mlekusch
authors.forename: Juerg
authors.initials: J
authors.lastname: Schliessbach
authors.forename: Michele
authors.initials: M
authors.lastname: Curatolo
authors.forename: Urs
authors.initials: U
authors.lastname: Eichenberger
mesh_terms: D000328:Adult; D001340:Autonomic Nerve Block / Q000009:adverse effects* / Q000379:methods; D004947:Esophagus / Q000000981:diagnostic imaging* / Q000293:injuries; D005260:Female; D006801:Humans; D008297:Male; D011677:Punctures; D013233:Stellate Ganglion / Q000000981:diagnostic imaging*; D018084:Ultrasonography, Interventional / Q000379:methods*; D014711:Vertebral Artery / Q000000981:diagnostic imaging* / Q000293:injuries; D055815:Young Adult