title: Refining the ultrasound-guided interscalene brachial plexus block: the superior trunk approach.
abstract: OBJECTIVE
  The conventional ultrasound-guided interscalene block targets the C5 and C6 nerve roots at approximately the level of the cricoid cartilage where they lie in the groove between the anterior and middle scalene muscles. This technique, although effective at providing regional anesthesia of the shoulder, is associated with risks of phrenic nerve palsy, injury to the dorsal scapular and long thoracic nerves, and long-term postoperative neurologic symptoms. In this case report, we describe the ultrasound-guided superior trunk block. This procedure targets the C5 and C6 components of the brachial plexus more distally after they unite into the superior trunk but before the suprascapular nerve branches off.
  
  
  METHODS
  We performed an ultrasound-guided superior trunk block to provide perioperative analgesia for ambulatory arthroscopic shoulder repair in a patient with moderate chronic obstructive pulmonary disease. The technique, relevant sonoanatomy of the brachial plexus, and the potential advantages of the superior trunk block are discussed.
  
  
  CONCLUSIONS
  The enhanced anatomical knowledge provided by ultrasound-guidance has allowed anesthesiologists to devise new block techniques and refine existing ones. The superior trunk block is an example of this refinement and is intended as an alternative to the conventional interscalene block for anesthesia of the shoulder. Further research is planned to confirm the efficacy and safety of the technique.
authors.affiliation: Department of Anesthesia, Toronto Western Hospital, University of Toronto, 399 Bathurst St., Toronto, ON, M5T 2S8, Canada.
authors.forename: David
authors.initials: D
authors.lastname: Burckett-St Laurent
authors.forename: Vincent
authors.initials: V
authors.lastname: Chan
authors.forename: Ki Jinn
authors.initials: KJ
authors.lastname: Chin
mesh_terms: D001182:Arthroscopy; D001917:Brachial Plexus / Q000000981:diagnostic imaging; D065527:Brachial Plexus Block / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012782:Shoulder / Q000601:surgery*; D018084:Ultrasonography, Interventional