LabLink
Page: Remove the Skin from the Anterior Thoracic Wall
Find these structures:
Check structures as you locate them on the donor.
Nipple
Areola
1.) Prepare for the removal of skin and subcutaneous tissue from 3 areas of the anterior thorax:
Photo 1. Planned thoracic incision lines
Midsagittal Incision
Palpate from the donor’s suprasternal notch to the xiphoid process. Make a midsagittal incision along this line (to the depth of the subcutaneous tissue).
Transverse/Oblique Incisions
Area One
Superior Incision: Begin incision at the suprasternal notch. Continue laterally along the clavicle to the acromioclavicular joint.
Inferior Incision: Begin incision at sternal angle (where rib 2 articulates with the sternum), and extend laterally to the midaxillary line
Note: The 2nd rib is the most superior palpable rib.
Area 2
Inferior Incision: Begin incision at the 5th intercostal space (or more inferiorly to encompass the entirety of the breast), and laterally to the midaxillary line.
Area 3
Inferior Incision: Begin incision at the xiphoid process, following the costal margin inferolaterally to the midaxillary line.
The subcutaneous tissue (hypodermis, superficial fascia) separates the skin from muscles and contains neurovasculature. Depending on the dissection, you may be asked to either remove the skin (“skinning”), or remove both the skin and subcutaneous tissue.
Photo 2. “Skinning”
Photo 3. Removal of both skin and subcutaneous tissue
2.) Dissection of Area One:
Remove the skin and subcutaneous tissue from Area One. Once reflected, the superior portion of pectoralis major m. should be visible. Work from the midline laterally. If necessary, create an incision in the reflected skin and subcutaneous tissue through which a finger or tool can be inserted (‘button hole’) to facilitate removal of superficial tissues.
Photo 4. Area One
Note: Upon removal of the skin and subcutaneous tissue, anterior and lateral cutaneous neurovascular bundles may be seen leaving the muscle and entering the subcutaneous tissue. These nerves are discussed in the learning objectives.
Note: Be careful to not damage the cephalic v. in the deltopectoral triangle, superolateral to pectoralis major m.
Photo 5. Cephalic vein and deltopectoral triangle
3.) Dissection of Area Two:
Make an encircling cut around the nipple and areola down to, but not through pectoralis major m., and leave in situ for future reference. The nipple is typically located at the 4th intercostal space. This landmark can help in orientation for future dissections.
Remove the subcutaneous tissue to further expose the pectoralis major m.
Photo 6. Nipple and areola
4.) Dissection of Area Three:
Remove the skin and subcutaneous tissue in Area Three. The external oblique m. and aponeurosis and the rectus sheath will be anterior. A small portion of the serratus anterior m. will be visible laterally.
Photo 7. Area Three
Page: Clean the pectoralis major and serratus anterior mm., and find the cephalic v.
Find these structures:
Check structures as you find them on the donor.
Pectoralis major m.
Serratus anterior m.
Cephalic v.
Deltopectoral triangle
5.) Remove any remaining subcutaneous tissue and investing fascia from the pectoralis major mm. and the visible portion of the serratus anterior mm.
HOW TO CLEAN MUSCLE: Most muscles are covered with investing fascia that is relatively opaque and firmly attached to the muscle. The thickness of this layer varies in different parts of the body.
Photo 8. Investing fascia
Remove the investing fascia from the muscle via sharp dissection at right angles to the muscle fascicles. This will allow the visualization of basic features of a muscle: fiber directions and attachments (origins and insertions).
Photo 9. Investing fascia and subcutaneous tissue removal
HOW TO REFLECT MUSCLE: Cut a portion of a muscle, and fold it back on itself to reveal deep structures. Reflection may be completed by severing the proximal or distal attachments, or by cutting through the belly of the muscle, as specified. Use blunt dissection methods to further reflect the cut muscle.
Photo 10: How to Reflect a Muscle
6.) Observe attachments of pectoralis major mm. and serratus anterior mm.:
Photo 11. Pectoralis major muscle and serratus anterior muscle
7.) Find the cephalic v. in the deltopectoral triangle. Keep this vein intact during reflection of the pectoralis major m. We will examine the cephalic v. in subsequent dissections.
Note: The deltopectoral triangle is bounded superolaterally by the deltoid m., superomedially by the clavicle, and inferiorly by the pectoralis major m.
Photo 12. Cephalic vein and deltopectoral triangle
Page: Reflect pectoralis major mm., and identify pectoralis minor mm. and associated neurovasculature.
Check structures as you find them on your donor:
Pectoralis minor m.
Lateral pectoral n.
Medial pectoral n.
Thoracoacromial a. (pectoral brs.)
8.) Reflect the pectoralis major mm. from their proximal attachments (clavicle and sternum/costal cartilages).
Photo 13. Pectoralis major muscle incision
Photo 14. Pectoralis major muscle, reflected
Note: Neurovasculature lies immediately deep to the clavicular head of pectoralis major m. Use blunt dissection to reflect the muscle laterally to protect the deep neurovasculature.
9.) Identify and clean the pectoralis minor mm., lateral pectoral nn., medial pectoral nn., and branches of the thoracoacromial aa.
Note: The medial pectoral n. innervates both the pectoralis major and minor mm. It typically pierces the pectoralis minor m., which can be helpful for differentiating between the 2 nerves. The medial pectoral n. may emerge as two branches (either through or inferolateral to pectoralis minor m.).
*Note: The lateral pectoral n. only innervates the pectoralis major m. and is typically located superomedial to the medial pectoral n.
Photo 15. Medial and lateral pectoral nn.
Note: There are numerous branches of the thoracoacromial a.: acromial, clavicular, deltoid, and pectoral branches. The pectoral branches are found deep to pectoralis major and minor mm.
Photo 16. Thoracoacromial a. and v., pectoral branches and lateral pectoral n.
Page: Reflect pectoralis minor mm. to identify neurovasculature
Check structures as you find them on your donor:
Medial pectoral n.
Thoracoacromial a. (pectoral brs.)
10.) Reflect the pectoralis minor mm. from their proximal attachments (3rd-5th ribs). Reflect the muscles superolateral (toward the coracoid process of the scapula).
11.) Observe pectoral branches of the thoracoacromial a. and the medial pectoral n.
Photo 17. Pectoralis minor muscle, reflected
Page: Place donor into a prone position
12.) The donor will need to be moved into a prone (face downward) position to dissect the superficial back.
Note: To help prevent mold issues, be mindful of the plastic shroud and muslin on the table. Do NOT allow these to fall on the ground. If these elements contact the ground, throw them away, and ask for replacements.
Page: Remove skin from the back
13.) Make a midsagittal incision, beginning at the external occipital protuberance of the occipital bone and continuing inferiorly to the tip of the coccyx.
Note: The skin of the back of the neck is difficult to remove, because of its curvature and thickness of skin. Place a wooden block under the sternum to flex the neck.
Photo 18. Midsagittal incision on the back
14.) Create paired transverse incisions perpendicular to the length of the midsagittal incision. This should create “skin flaps” with subcutaneous tissue that are approximately 3-4 inches wide and extend laterally to either the posterior axillary, or the midaxillary lines.
Photo 19. Transverse incisions of the back
The most superior incision extends from the external occipital protuberance of the occipital bone to the mastoid process of the temporal bone. Continue this incision inferiorly to the base of the neck.
A second incision should extend laterally to the acromioclavicular joint.
All other incisions should extend laterally to either the posterior axillary, or the midaxillary lines.
Photo 20. Superior longitudinal and transverse incisions
15.) Using toothed forceps or hemostats, lift the edge of skin at the corner of two incisions. Remove skin flaps and subcutaneous tissue to reveal the underlying muscle and thoracolumbar aponeurosis.
The accessory nerve (CN XI) is superficial in the neck region. In the superior-most sections of this dissection, use sharp dissection to remove skin only. Blunt dissection should be used to clean and investigate areas deep to the skin.
Photo 21. Trapezius muscle, latissimus dorsi muscle, and thoracolumbar aponeurosis
Page: Identify and reflect the trapezius m. Identify the neurovasculature associated with this muscle.
Check structures as you find them on your donor:
Ligamentum nuchae
Thoracolumbar aponeurosis
Trapezius m.
Accessory n. (CN XI)
Transverse cervical a.
Transverse cervical v.
16.) Clean and define the proximal and distal attachments, and borders of the trapezius m.
a.) Locate the thoracolumbar aponeurosis.
17.) Reflect the trapezius m. (unless otherwise noted, when reflecting, use blunt dissection techniques to separate the muscle from deeper structures):
a.) Incise along proximal attachments of the trapezius m. (spinous processes of the vertebrae and the ligamentum nuchae). Lift the trapezius m. off of the deep neck muscles.
b.) Sever the scapular distal attachments of the trapezius m. (spine of the scapula and acromion); maintain the distal attachment to clavicle.
c.) Reflect the trapezius m. toward the clavicle.
Photo 22. Trapezius Muscle Incisions
Photo 23: Trapezius Reflected
18.) Locate and clean the neurovasculature associated with the trapezius m.
Note: The accessory nerve (CN XI) and branches of the transverse cervical a. and v. are located deep to the trapezius m. This neurovasculature runs between the tip of the shoulder (acromion of the scapula) and the levator scapulae m.
Note: In close proximity to the accessory n. are branches of the ventral primary rami of cervical nn. 3 & 4 (C3 & C4) that provides sensory innervation to the trapezius m. This complex of nerves is often referred to as the subtrapezial plexus of nerves.
Photo 24. Transverse cervical a. and v. and subtrapezial plexus
Page: Identify and reflect the latissimus dorsi mm. Locate neurovasculature associated with this muscle.
Check structures as you find them on your donor:
Latissimus dorsi m.
Thoracodorsal n.
Thoracodorsal a.
Thoracodorsal v.
19.) Clean and define the proximal attachments and borders of the latissimus dorsi mm.
20.) On each side, reflect the latissimus dorsi mm. The incision of the latissimus dorsi mm. should separate the muscle fibers at the thoracolumbar aponeurosis, and reflect the belly of the muscle toward the axilla.
Photo 25. Latissimus dorsi incision
Note: Use blunt dissection techniques to reflect this muscle, and be careful to not reflect or damage the deeper musculature: serratus anterior mm. and serratus posterior inferior mm. Pay special attention to the direction of muscle fibers.
21.) Identify thoracodorsal neurovasculature deep to the latissimus dorsi mm.
*Note: The thoracodorsal neurovascular bundle is visible near the axilla and deep to the latissimus dorsi m.
Photo 26. Latissimus dorsi and thoracodorsal neurovasculature
Page: Identify and reflect muscles deep to the trapezius m.
Check structures as you find them on your donor:
Levator scapulae m.
Rhomboid minor m.
Rhomboid major m.
Dorsal scapular n.
Dorsal scapular a.
Dorsal scapular v.
22.) On each side, locate levator scapulae m., rhomboid minor m., and rhomboid major m. This musculature has distal attachments along the medial border of the scapula, sequentially from superior to inferior.
Photo 27. Levator scapulae muscle, rhomboid minor and minor muscle
Note: the rhomboid mm. are often difficult to distinguish from one another or may be fused.
Rhomboid minor m. attaches on the medial border of the scapula at the scapular spine.
Rhomboid major m. attaches on the medial border of the scapula inferior to the scapular spine.
23.) Cut the rhomboid mm. from the spines of the vertebrae (C7-T5), and reflect the muscles towards the scapulae.
24.) Locate the dorsal scapular neurovascular bundle. This will be located along the medial border of the scapula.
Photo 28. Dorsal scapular neurovascular bundle
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