Deltopectoral approach

Introduction

Advantages

• Potential for exposure
• Wide exposure
• Minimal bleeding (between muscles plane)
• Internervous plane

Disadvantages

• Difficulty exposing the glenoid
• Access to greater tuberosity and cuff

Indications

• Reconstruction of recurrent dislocations
• Drainage of sepsis
• Biopsy and excision of tumors
• Repair or stabilization of the tendon of the long head of the biceps
• Open reduction, internal fixation of proximal humerus fractures
• Shoulder arthroplasties

Position of patient

• The patient is in the beach chair position. The waist is flexed approximately 45 degrees and the knees are placed in 30 degrees of flexion.
• A rolled up towel under the medial border of the scapula may help with exposure of the shoulder region.

Landmarks and incision

Landmarks

The landmarks of the shoulder are carefully palpated and marked with a marking pen, including the posterior spine of the scapula, lateral border of the acromion, anteriorborder of the acromion, anterior portion of the clavicle, and the coracoid (Figure 1).

• Coracoid Process: At the deepest point in the clavicular concavity, the surgeon should drop his or her fingers distally about 1 inch from the anterior edge of the clavicle and press laterally and posteriorly in an oblique line until the coracoid process is felt. The process faces anterolaterally; because it lies deep under the cover of the pectoralis major, it can be felt only by firm palpation.

• Deltopectoral Groove: The deltopectoral groove is easier to see than to feel.

Incisions

• Make a 10- to 15-cm straight incision, following the line of the deltopectoral groove.
• The incision should begin just above the coracoid process.

Internervous plane

• Deltoid (axillary nerve).
• Pectoralis major (medial and lateral pectoral nerves).

Superficial dissection

• Find the deltopectoral groove, with its cephalic vein.
• Retract the pectoralis major medially and the deltoid laterally.
• Splitting the two muscles apart.
• The vein may be retracted either medially or laterally.

Deep dissection

• The short head of the biceps (which is supplied by the musculocutaneous nerve) and the coracobrachialis (which is supplied by the musculocutaneous nerve) displaced medially.
• Apply external rotation to the arm to stretch the subscapularis as it lies beneath the conjoined tendons and forms the only remaining anterior covering of the shoulder joint capsule (Figure 3).
• The most easily identified landmarks on the inferior border of the subscapularis are a series of small vessels that run transversely and often require ligation or cauterization.
• The superior border of the subscapularis muscle is indistinct and blends in with the fibers of the supraspinatus muscle.
• Pass a blunt instrument between the capsule and the subscapularis, moving upward.
• Rotate the shoulder internally and identify the insertion of the tendon of the subscapularis onto the humerus.
• Tag the muscle belly with stay sutures to prevent it from disappearing medially when it is cut and to allow easy reattachment of the muscle to its new insertion onto the humerus.
• Divide the subscapularis 1 inch from its insertion onto the lesser tuberosity of the humerus (Figure 4).
• Incise the capsule longitudinally to enter the joint.

Dangers

Nerves

• The musculocutaneous nerve enters the body of the coracobrachialis about 5 to 8 cm distal to the muscle's origin at the coracoid process. Because the nerve enters the muscle from its medial side, all dissection must remain on the lateral side of the muscle. Great care should be taken not to retract the muscle inferiorly, to avoid stretching the nerve and causing paralysis of the elbow flexors.

Vessels

• The cephalic vein should be preserved, if possible, although ligation leads to few problems. A traumatized cephalic vein should be ligated to prevent the slight danger of thromboembolism.

How to enlarge the approach

Proximal Extension
To expose the brachial plexus and axillary artery, and to gain control of arterial bleeding from the axillary artery.

• Extend the skin incision superomedially, crossing the middle third of the clavicle.
• Dissect the middle third of the clavicle subperiosteally and perform osteotomy of the bone, removing the middle third.
• Cut the subclavius muscle, which runs transversely under the clavicle.
• Retract the trapezius superiorly and the pectoralis major and pectoralis minor inferiorly to reveal the underlying axillary artery and the surrounding brachial plexus
• Take care not to damage the musculocutaneous nerve, which is the most superficial nerve in the brachial plexus.

Distal Extension
The approach can be extended into an anterolateral approach to the humerus.

• Extend the skin incision down the deltopectoral groove.
• Curve it inferiorly, following the lateral border of the biceps.
• Deep dissection consists of moving the biceps brachii medially to reveal the underlying brachialis, which then can be split along the line of its fibers to provide access to the humerus.

Figures