The Surgical Form Of The Deep Cervical And Facial Regions And The Relative Position Of The Principal Bloodvessels And Nerves

Sources: Surgical Anatomy

While the human cervix is still extended in surgical position, its

deeper anatomical relations, viewed as a whole, preserve the

quadrilateral form. But as it is necessary to remove the

sterno-cleido-mastoid muscle, in order to expose the entire range of the

greater bloodvessels and nerves, so the diagonal which that muscle

forms, as seen in Plates 3 and 4, disappears, and thus both the cervical

triangles are thrown int one common region. Although, however, the

sterno-mastoid muscle be removed, as seen in Plate 5, still the great

bloodvessels and nerves themselves will be observed to divide the

cervical square diagonally, as they ascend the neck from the

sterno-clavicular articulation to the ear.



The diagonal of every square figure is the junction line of the opposite

triangles which form the square. The cervical square being indicated as

that space which lies within the mastoid process and the top of the

sternum--the symphysis of the lower maxilla and the top of the shoulder,

it will be seen, in Plate 5, that the line which the common carotid and

internal jugular vein occupy in the neck, is the diagonal; and hence the

junction line of the two surgical triangles.



The general course of the common carotid artery and internal jugular

vein is, therefore, obliquely backwards and upwards through the diagonal

of the cervical square, and passing, as it were, from the point of one

angle of the square to that of the opposite--viz., from the

sterno-clavicular junction to the masto-maxillary space; and, taking the

anterior triangle of the cervical square to be that space included

within the points marked H 8 A, Plate 5, it will be seen that the common

carotid artery ranges along the posterior side of this anterior

triangle. Again: taking the points 5 Z Y to mark the posterior triangle

of the cervical square, so will it be seen that the internal jugular

vein and the common carotid artery, with the vagus nerve between them,

range the anterior side of this posterior triangle, while the subclavian

artery, Q, passes through the centre of the inferior side of the

posterior triangle, that is, under the middle of the shaft of the

clavicle.



The main blood vessels (apparently according to original design) will be

found always to occupy the centre of the animal fabric, and to seek

deep-seated protection under cover of the osseous skeleton. The

vertebrae of the neck, like those of the back and loins, support the

principal vessels. Even in the limbs the large bloodvessels range

alongside the protective shafts of the bones. The skeletal points are

therefore the safest guides to the precise localities of the

bloodvessels, and such points are always within the easy recognition of

touch and sight.



Close behind the right sterno-clavicular articulation, but separated

from it by the sternal insertions of the thin ribbon-like muscles named

sterno-hyoid and thyroid, together with the cervical fascia, is situated

the brachio-cephalic or innominate artery, A B, Plates 5 and 6, having

at its outer side the internal jugular division of the brachio-cephalic

vein, W K, Plate 5. Between these vessels lies the vagus nerve, E, Plate

6, N, Plate 5. The common carotid artery, internal jugular vein, and

vagus nerve, hold in respect to each other the same relationship in the

neck, as far upwards as the angle of the jaw. While we view the general

lateral outline of the neck, we find that, in the same measure as the

blood vessels ascend from the thorax to the skull, they recede from the

fore-part of the root of the neck to the angle of the jaw, whereby a

much greater interval occurs between them and the mental symphysis, or

the apex of the thyroid cartilage, than happens between them and the top

of the sternum, as they lie at the root of the neck. This variation as

to the width of the interval between the vessels and fore-part of the

neck, in these two situations, is owing to two causes, 1st, the somewhat

oblique course taken by the vessels from below upwards; 2dly, the

projecting development of the adult lower jaw-bone, and also of the

laryngeal apparatus, which latter organ, as it grows to larger

proportions in the male than in the female, will cause the interval at

this place to be much greater in the one than the other. In the infant,

the larynx is of such small size, as scarcely to stand out beyond the

level of the vessels, viewed laterally.



The internal jugular vein is for almost its entire length covered by the

sterno-mastoid muscle, and by that layer of the cervical aponeurosis

which lies between the vessels and the muscle. The two vessels, K C,

Plate 5, with the vagus nerve, are enclosed in a common sheath of

cellular membrane, which sends processes between them so as to isolate

the structures in some degree from one another.



The trunk of the common carotid artery is in close proximity to the

vagus nerve, this latter lying at the vessel's posterior side. The

internal jugular vein, which sometimes lies upon and covering the

carotid, will be found in general separated from it for a little space.

Opposite the os hyoides, the internal jugular vein lies closer to the

common carotid than it does farther down towards the root of the neck.

Opposite to the sterno-clavicular articulation, the internal jugular

vein will be seen separated from the common carotid for an interval of

an inch and more in width, and at this interval appears the root of the

subclavian artery, B, Plates 5 and 6, giving off its primary branches,

viz., the thyroid axis, D, the vertebral and internal mammary arteries,

at the first part of its course.



The length of the common carotid artery varies, of course, according to

the place where the innominate artery below divides, and also according

to that place whereat the common carotid itself divides into internal

and external carotids. In general, the length of the common carotid is

considerable, and ranges between the sterno-clavicular articulation and

the level of the os hyoides; throughout the whole of this length, it

seldom or never happens that a large arterial branch is given off from

the vessel, and the operation of ligaturing the common carotid is

therefore much more likely to answer the results required of that

proceeding than can be expected from the ligature of any part of the

subclavian artery which gives off large arterial branches from every

part of its course.



The sympathetic nerve, R, Plate 6, is as close to the carotid artery

behind, as the vagus nerve, N, Plate 5, and is as much endangered in

ligaturing this vessel. The branch of the ninth nerve, E, Plate 5,

(descendens noni,) lies upon the common carotid, itself or its sheath,

and is likely to be included in the ligature oftener than we are aware

of.



The trunk of the external carotid, D, Plate 5, is in all cases very

short, and in many bodies can scarcely be said to exist, in consequence

of the thyroid, lingual, facial, temporal, and occipital branches,

springing directly from almost the same point at which the common

carotid gives off the internal carotid artery. The internal carotid is

certainly the continuation of the common arterial trunk, while the

vessel named external carotid is only a series of its branches. If the

greater size of the internal carotid artery, compared to that of the

external carotid, be not sufficient to prove that the former is the

proper continuation of the common carotid, a fact may be drawn from

comparative philosophy which will put the question beyond doubt,

namely--that as the common carotid follows the line of the cervical

vertebrae, just as the aorta follows that of the vertebrae of the trunk,

so does the internal carotid follow the line of the cephalic vertebrae.

I liken, therefore, those branches of the so-called external carotid to

be, as it were, the visceral arteries of the face and neck. It would be

quite possible to demonstrate this point of analogy, were this the place

for analogical reasoning.



The common carotid, or the internal, may be compressed against the

rectus capitis anticus major muscle, 13, Plate 6, as it lies on the

fore-part of the vertebral column. The internal maxillary artery, 16,

Plate 6, and the facial artery, G, Plate 5, are those vessels which

bleed when the lower maxilla is amputated. In this operation, the

temporal artery, 15, Plate 6, will hardly escape being divided also, it

lies in such close proximity to the neck and condyle of the jaw-bone.



The subclavian artery, B Q, Plate 5, traverses the root of the neck, in

an arched direction from the sterno-clavicular articulation to the

middle of the shaft of the clavicle, beneath which it passes, being

destined for the arm. In general, this vessel rises to a level

considerably above the clavicle; and all that portion of the arching

course which it makes at this situation over the first rib has become

the subject of operation. The middle of this arching subclavian artery

is (by as much as the thickness of the scalenus muscle, X, Plate 5)

deeper situated than either extremity of the arch of this vessel, and

deeper also than any part of the common carotid, by the same fact. So

many branches spring from all parts of the arch of the subclavian

artery, that the operation of ligaturing this vessel is less successful

than the same operation exercised on others.



The structures which lie in connexion with the arch of the subclavian

also render the operation of tying the vessel an anxious task. It is

crossed and recrossed at all points by large veins, important nerves,

and by its own principal branches. The vagus nerve, S E, Plate 6,

crosses it at B, its root; external to which place the large internal

jugular vein, K, Plate 5, lies upon it; external to this latter, the

scalenus muscle, X, Plate 5, with the phrenic nerve lying upon the

muscle, binds it fixedly to the first rib; more external still, the

common trunk of the external jugular and shoulder veins, U, Plate 5, lie

upon the vessel, and it is in the immediate vicinity of the great

brachial plexus of nerves, P P, which pass down along its humeral

border, many branches of the same plexus sometimes crossing it

anteriorly.



The depth at which the middle of the subclavian artery lies may be

learned by the space which those structures, beneath which it passes,

necessarily occupy. The clavicle at its sternal end is round and thick,

where it gives attachment to the sterno-cleido-mastoid muscle. The root

of the internal jugular vein, when injected, will be seen to occupy

considerable space behind the clavicle; and the anterior scalenus muscle

is substantial and fleshy. The united spaces occupied by these

structures give the depth of the subclavian artery in the middle part of

its course.



The length of the subclavian artery between its point of branching from

the innominate and that where it gives off its first branches varies in

different bodies, but is seldom so extensive as to assure the operator

of the ultimate success of the process of ligaturing the vessel. Above

and below D, Plate 6, the thyroid axis, come off the vertebral and

internal mammary arteries internal and anterior to the scalenus muscle.

External and posterior to the scalenus, a large vessel, the post

scapular, G, Plate 6, R, Plate 5, arises. If an aneurism attack any part

of this subclavian arch, it must be in close connexion with some one of

these branches. If a ligature is to be applied to any part of the arch,

it will seldom happen that it can be placed farther than half an inch

from some of these principal collateral branches.



When the shoulder is depressed, the clavicle follows it, and the

subclavian artery will be more exposed and more easily reached than if

the shoulder be elevated, as this latter movement raises the clavicle

over the locality of the vessel. Dupuytren alludes practically to the

different depths of the subclavian artery in subjects with short necks

and high shoulders, and those with long necks and pendent shoulders.

When the clavicle is depressed to the fullest extent, if then the

sterno-cleido-mastoid and scalenus muscles be relaxed by inclining the

head and neck towards the artery, I believe it may be possible to arrest

the flow of blood through the artery by compressing it against the first

rib, and this position will also facilitate the operation of ligaturing

the vessel.



The subclavian vein, W, Plate 5, is removed to some distance from the

artery, Q, Plate 5. The width of the scalenus muscle, X, separates the

vein from the artery. An instance is recorded by Blandin in which the

vein passed in company with the artery under the scalenus muscle.





DESCRIPTION OF PLATES 5 & 6.



PLATE 5.



A. Innominate artery at its point of bifurcation.



B. Subclavian artery crossed by the vagus nerve.



C. Common carotid artery with the vagus nerve at its outer side, and

the descendens noni nerve lying on it.



D. External carotid artery.



E. Internal carotid artery with the descendens noni nerve lying on it.



F. Lingual artery passing under the fibres of the hyo-glossus muscle.



G. Tortuous facial artery.



H. Temporo-maxillary artery.



I. Occipital artery crossing the internal carotid artery and jugular

vein.



K. Internal jugular vein crossed by some branches of the cervical

plexus, which join the descendens noni nerve.



L. Spinal accessory nerve, which pierces the sterno-mastoid muscle, to

be distributed to it and the trapezius.



M. Cervical plexus of nerves giving off the phrenic nerve to descend

the neck on the outer side of the internal jugular vein and over the

scalenus muscle.



N. Vagus nerve between the carotid artery and internal jugular vein.



O. Ninth or hypoglossal nerve distributed to the muscles of the tongue.





P P. Branches of the brachial plexus of nerves.



Q. Subclavian artery in connexion with the brachial plexus of nerves.



R R. Post scapular artery passing through the brachial plexus.



S. Transversalis humeri artery.



T. Transversalis colli artery.



U. Union of the post scapular and external jugular veins, which enter

the subclavian vein by a common trunk.



V. Post-half of the omo-hyoid muscle.



W. Part of the subclavian vein seen above the clavicle.



X. Scalenus muscle separating the subclavian artery from vein.



Y. Clavicle.



Z. Trapezius muscle.



1. Sternal origin of sterno-mastoid muscle of left side.



2. Clavicular origin of sterno-mastoid muscle of right side turned

down.



3. Scalenus posticus muscle.



4. Splenius muscle.



5. Mastoid insertion of sterno-mastoid muscle.



6. Internal maxillary artery passing behind the neck of lower jaw-bone.



7. Parotid duct.



8. Genio-hyoid muscle.



9. Mylo-hyoid muscle, cut and turned aside.



10. Superior thyroid artery.



11. Anterior half of omo-hyoid muscle.



12. Sterno-hyoid muscle, cut.



13. Sterno-thyroid muscle, cut.
















PLATE 6.



A. Root of the common carotid artery.



B. Subclavian artery at its origin.



C. Trachea.



D. Thyroid axis of the subclavian artery.



E. Vagus nerve crossing the origin of subclavian artery.



F. Subclavian artery at the third division of its arch.



G. Post scapular branch of the subclavian artery.



H. Transversalis humeri branch of subclavian artery.



I. Transversalis colli branch of subclavian artery.



K. Posterior belly of omo-hyoid muscle, cut.



L. Median nerve branch of brachial plexus.



M. Musculo-spiral branch of same plexus.



N. Anterior scalenus muscle.



O. Cervical plexus giving off the phrenic nerve, which takes tributary

branches from brachial plexus of nerves.



P. Upper part of internal jugular vein.



Q. Upper part of internal carotid artery.



R. Superior cervical ganglion of sympathetic nerve.



S. Vagus nerve lying external to sympathetic nerve, and giving off t

its laryngeal branch.



T. Superior thyroid artery.



U. Lingual artery separated by hyo-glossus muscle from



V. Lingual or ninth cerebral nerve.



W. Sublingual salivary gland.



X. Genio-hyoid muscle.



Y. Mylo-hyoid muscle, cut and turned aside.



Z. Thyroid cartilage.



1. Upper part of sterno-hyoid muscle.



2. Upper part of omo-hyoid muscle.



3. Inferior constrictor of pharynx.



4. Cricoid cartilage.



5. Crico-thyroid muscle.



6. Thyroid body.



7. Inferior thyroid artery of thyroid axis.



8. Sternal tendon of sterno-mastoid muscle, turned down.



9. Clavicular portion of sterno-mastoid muscle, turned down.



10. Clavicle.



11. Trapezius muscle.



12. Scalenus posticus muscle.



13. Rectus capitis anticus major muscle.



14. Stylo-hyoid muscle, turned aside.



15. Temporal artery.



16. Internal maxillary artery.



17. Inferior dental branch of fifth pair of cerebral nerves.



18. Gustatory branch of fifth pair of nerves.



19. External pterygoid muscle.



20. Internal pterygoid muscle.



21. Temporal muscle cut to show the deep temporal branches of fifth pair

of nerves.



22. Zygomatic arch.



23. Buccinator muscle, with buccal nerve and parotid duct.



24. Masseter muscle cut on the lower maxilla.



25. Middle constrictor of pharynx.