Here are the steps to follow:

  • Skin incision above clavicle (collar bone), 8-10 cm length
  • Subplatysmal mobilization upwards / downwards
  • Sternocledomastoid muscle. It is not necessary to divide the external gaster although it is acceptable. However, if you want to keep it intact, you need to fully mobilize it upwards and downwards
  • Division of the homohyoid muscle
  • Fat pad: can be mobilized externally (laterally)
  • Anterior scalene muscle (ASM): Full mobilization upwards (close to the transverse processes of the vertebra) and downwards (close to the first rib). The muscle must be fully resected after the phrenic nerve is identified
  • Subclavian artery is recognized after the ASM has been divided. The artery should be dissected free especially where it gets close to the first rib
  • Brachial plexus (BP). All three trunks must be recognized (Image 1). They need to be mobilized so as to be protected when the first rib is resected. Be careful as the inferior trunk of the plexus is medially to the previous two and is usually covered by muscles
  • Middle scalene muscle (MSM): It should be divided very carefully (piece meal), after recognizing and protecting the Bell’s nerve (3 branches). The posterior division of the MSM reveals the posterior part of the first rib.
  • Accessory spinal rib: it is usually inside or close to the MSM. It is a common find to be cohesive to the first rib on a T-shape configuration. In this situation both the accessory rib and the first rib should be excised
  • The posterior part of the rib is divided with a bone cutter (Kerrison Rongeur)
  • For complete removal of the first rib a paraclavicular approach should be used. This can be done with a second infraclavicular incision on top of the junction of the first rib to the sternum, about 2 cm below the clavicle. The anterior part of the rib is recognized after the division on the subclavian muscle and the costoclavicular ligament.

The three trunks of the brachial plexus: the superior / upper (C5-C6), the middle (C7), and the inferior / lower (C8-T1)



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