Muscles of the Chest Wall

Thorac Surg Clin 17 (2007) 463–472

Muscles of the Chest WallJoseph I. Miller, Jr, MD

Section of General Thoracic Surgery, Emory University School of Medicine, 6th Floor,

Medical Office Tower, 550 Peachtree Street NE, Atlanta, GA 30308-2225, USA

Knowledge of the extrathoracic muscles of

the chest wall is an important part of thearmamentarium of the general thoracic surgeon.These muscles are principally important from ananatomic and surgical reconstructive point of

view.The principle muscles that are available for use

in reconstructive and protective areas are (1)

latissimus dorsi, (2) pectoralis major, (3) rectusabdominus, (4) serratus anterior, (5) externaloblique, and (6) trapezius. These are illustrated

in Fig. 1. The specific individual muscle with itsneurovascular supply, its origin, and insertion islisted in Table 1.

Anatomy of extrathoracic and upper

abdomen muscles

Latissimus dorsi

The latissimus dorsi is the most frequently usedmuscle for lateral and anterior chest wall defects(Fig. 2). It is supplied by the thoracodorsal neuro-

vascular bundle, and it receives blood supply fromthe branches supplying the serratus anterior. Ex-cellent musculocutaneous collaterals allow signifi-

cant skin to be taken with the muscle. The largestis the extrathoracic flap (25 � 35 cm) with a skinarea of 30 to 40 cm. It has a large pedicle and

a wide arc of rotation. It arises from T6 to T12,L1 to L4, S1 to S3, the posterior crest, and the

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posterior crest of the ileum. It has its insertion

on the intertubercular groove of the humerus.The latissimus dorsi is used in intrathoracic loca-tions to cover bronchopleural stumps and main-stem stumps and to wrap anastomoses as well as

to fill the thoracic cavity after postpneumonec-tomy empyemas.

Pectoralis major

The second most frequently utilized extra-

thoracic muscle flap in clinical situations is thepectoralis major (Fig. 3). It is appropriate to usefor anterior and midline thoracic wall defects. Itsprimary blood supply is the thoracoacromial neu-

rovascular bundle arising at the midclavicle. Itssecond blood supply is from the internal mam-mary artery, lateral intercostal arteries, and lateral

thoracic perforators. It is the second largest mus-cle (15 � 23 cm) with a potential skin area of 20 to28 cm. Its origin is from the sternum, clavicle, and

the first seven ribs. Its insertion is on the bicipitalgroove of the humerus. It may be used as a pediclegraft based on the primary blood supply or as

a turnover flap if a secondary supply is needed.The possible displacement of the breast and lossof abduction and medial rotation of the armmust be taken into account when harvesting. It

is of excellent reliability and is most frequentlyused in sternal defects after sternal dehiscence orexcision of the sternum as either a turnover or a di-

rect application of a muscle flap. It can also be uti-lized to fill anterior or lateral or midthoracic chestwall defects.

ghts reserved.

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464 MILLER

Pectoralismajor muscle

Serratusanteriormuscle

Rectusabdominismuscle

Trapeziusmuscle

Latissimusdorsimuscle

Externalobliquemuscle

Fig. 1. Overview of chest wall and extrathoracicmuscles (rectus abdominus) that can be used for chest wall reconstruction.

Table 1

Origin, insertion, and neurovascular supply of muscles often used for chest wall reconstruction

Muscle Neurovascular supply Origin Insertion

Latissimus dorsi Thoracodorsal nerve,

artery, vein

Artery to serratus anterior

T6-S3 posterior crest of

ileum

Intratubular groove of the

humerus

Pectoralis major Thoracoabdominal nerve

artery, vein

Internal mammary and

intercostal arteries

Sternum, clavicle, ribs 1–7 Tricipital groove of the

humerus

Rectus abdominus Superior and inferior

epigastric

Pubic crest Rib cartilage 5, 6,7 xiphoid

Serratus anterior Serratus branch of

thoracodorsal artery

Long thoracic artery

Outer surface and superior

border of ribs 8, 9, 10

Intercostal fascia

Scapula tip

External oblique Lower thoracic intercostals

artery, nerve, vein

External surface and inferior

border of ribs 4–12

Iliac crest lower abdominal

process

Trapezius Transverse cervical artery,

nerve, vein

Occipital branches and

intercostal perforators

Occipital bone, C7-T12

spinous processes

Posterior and lateral-third of

clavicle acromion superior

lip of scapular spine

465MUSCLES OF THE CHEST WALL

Muscle flapfreed from origin

Latissimusdorsi muscle

Skin area up to ~ 30-40 cm

Fig. 2. Topographic anatomy of the latissimus dorsi muscle.

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Muscle flapfreed from origin

Pectoralismajor muscle

Skin area up to ~ 20-28 cm

Fig. 3. Topographic anatomy of the pectoralis major muscle.

Rectus abdominus

The third most frequently utilized muscle flap,which is appropriate for use in lower anterior chest

wall repairs, is the rectus abdominus (Fig. 4). Ithas two predominant vascular pedicles: the supe-rior epigastric artery supply and the deep inferior

epigastric artery. If based on the superior epigas-tric, the inferior epigastric must be divided; there-fore, adequate blood flow through the superior

epigastric by way of the internal mammary arterymust be insured. Anterior chest wall radiation maydamage the internal mammary artery; therefore,

angiography is sometimes required. The musclepresents a smaller appearance of 6 � 25 cm with apotential skin area of 21 � 14 cm. Along

the pedicle, the skin flap may be oriented verticallyor horizontally. Vertical orientation preserves

more musculocutaneous perforators and, there-fore, is safer. Its origin is from the pubic crest,and its insertion is on the rib cartilages of 5, 6,

and 7 and the xiphoid. Some atrophy of themuscle may occur because of the loss of in-nervation prerequisite in its harvest. It is most fre-

quently used for anterior and inferior midlinedefects of the sternum and lower parts of thethoracic cage.

Serratus anterior

The serratus anterior has been called theworkhorse of endothoracic surgery (Fig. 5). It


Rectus abdominismuscle

Skin area of 21 x 14 cm

Fig. 4. Topographic anatomy of the rectus abdominus muscle.

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Muscle dividedfrom origin


Fig. 5. Topographic anatomy of the serratus anterior muscle.

is less frequently used for extrathoracic recon-struction. It is located between the latissimus

and pectoralis major and the midaxillary line. Itis a small muscle best suited as an intrathoracicflap, but it may be used in combination with thelatissimus or pectoralis to supplement blood sup-

ply of the cutaneous segments of these larger flaps.The primary blood supply is the serratus branchof the thoracodorsal pedicle. Its secondary blood

supply is the long thoracic artery. It arises fromthe outer surface and superior borders of theeighth, ninth, and tenth ribs and from intercostal

fascia. Its insertion is into the tip of the scapula.The blood supply is reliable, but the bulk of themuscle is small, therefore, limiting its usefulness

as an extrathoracic muscle flap. It is most fre-quently used to cover a lobar or mainstem bron-

chial stump, to wrap an anastomosis, or to useas a buffer between the esophagus and tracheain tracheoesophageal fistula.

External oblique

The external oblique is infrequently used butmay be used for upper abdomen and lowerthoracic defects as far as the inframammary

fold. Its primary blood supply is from the lowerthoracic intercostal vessels. It arises from theexternal surface and inferior border of the lower


Axillaryartery

Latissimusdorsi muscle

Thoracodorsalartery

Fig. 6. Predominant blood supply of latissimus dorsi muscle.

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Axillaryartery

Pectoral branch ofthoracoacromialartery

Pectoralismajormuscle

Fig. 7. Predominant blood supply of pectoralis major muscle.

eight ribs, and its insertion is into the iliac crest

and abdominal fascia.

Trapezius

The trapezius muscle is infrequently used inextrathoracic muscle wall surgery. It is occasion-

ally used for upper chest and neck defects. It ismost useful for the base of the neck and thoracicoutlet defects. Its major pedicle is the transverse

cervical artery by way of the thyrocervical trunk.Its secondary blood supply includes occipitalbranches and intercostal perforators. It is of

moderate size and bulk (34 � 18 cm) with a po-tential skin island of 20 to 80 cm, making ita good muscle for use in the upper thoracic

area. It arises from the occipital bone and the

seventh cervical and all thoracic vertebralspinous processes. Its insertion is in the posteriorand lateral third of the clavicle, the acromion

process, and the superior lip of the spine of thescapula.

The predominant blood supplies for the lat-issimus dorsi, serratus anterior, pectoralis major,

and rectus abdominus are illustrated in Figs. 6–9,respectively.

Summary

The extrathoracic muscle flaps can be used ina number of different situations such as in sternalreconstruction, for filling many types of defects,


Inferiorepigastricartery

Superiorepigastricartery

Rectusabdominismuscle

Externaliliacartery

Fig. 8. Predominant blood supply of rectus abdominus muscle.

and in chest wall reconstruction. The extrathora-

cic flaps can be utilized in the treatment ofpostpneumonectomy empyema and bronchopleu-ral fistula after lobectomy. Another use for these

flaps is in tracheal resection as coverage of ananastomotic area and in the gastrointestinal tract

as wrapping for an anastomoses. After repair of

certain defects in the heart and great vessels, theymay be used to wrap the heart or the great vessels;they may also be used in total sternal reconstruc-

tion and in the treatment of postoperative openheart mediastinitis. A thorough knowledge of the

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Axillaryartery


Thoracodorsalartery

Lateralthoracicartery

Fig. 9. Predominant blood supply of serratus anterior muscle.

extrathoracic muscle flaps is a prerequisite in the

training of any cardiothoracic surgeon.

Suggested readings

Netter FM. The Ciba Collection ofMedical Illustrations.

vol. 7. Respiratory System Ciba; 1979.

Graeber GM. Embryology, anatomy and physiology

of the chest wall. In: Seyfer AK, Graeber GM,

Wind GC, editors. Atlas of chest wall recon-

struction. Rockville (MD): Aspen Publishers; 1986.

p. 11–30.

Miller JI. Muscle flaps and thoracic problems: applicabil-

ity and utilization for various conditions. In: Current

controversies in thoracic surgery. Philadelphia:W.B.

Saunders; 1986. p. 235–40.

Shahani R. Anatomy of the thorax, chapter 1. In:

Sabiston D, Spencer F, editors. Surgery of the chest.

7th edition. Philadelphia: Elsevier Sanders; 2005. p.

1–16.

Graeber GM, SzwerlcMF. Anatomy& physiology of the

chest wall and sternum. chapter 48. In: Pearson GF,

Copper JD, Deslauriers J, et al, editors. Thoracic

surgery. 2nd edition. Philadelphia: Churchill Living-

ston; 2001. p. 1325–35.

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Muscles of the Chest Wall