CHAPTER XVI.

THE ANATOMICAL AND LINEAR GUIDES FOR SPECIAL ARTERIES.

=How to Locate and Inject the Carotid Artery.=—The carotid artery, is not used much, by the average embalmer for several reasons. It is usually a hard artery to raise, partly because the average embalmer does not know the anatomy of the neck. In subjects having short and very fleshy necks it is not advisable to use the carotid, however in subjects where the neck is long and not fat it is with some a favorite. It is always essential to know how to raise and inject the carotid for in accident cases, where the arteries of the lower part of the neck and thorax are ruptured it becomes necessary to raise and inject the carotids to get the fluid into the tissues of the face and brain. In cases of suicide where the arteries of the neck have been cut it is necessary to know where the arteries and veins lie so that they may be tied off. Often the body is so badly mutilated that it is impossible to raise any other artery excepting the carotid. Every practitioner should know how to raise and inject this artery, even though some other artery is the one generally used.

_Linear Guide._—By a linear guide is meant that an imaginary line is drawn from a point to a point the same direction the artery runs so that by mentally imagining this line one can be safe to cut on the line and be sure that the desired artery will be reached.

The linear guide for the carotid is represented by a line drawn from the sterno-clavicular junction to a point between the angle of the jaw and the lobe of the ear. (Mastoid process).

As the body lies on the cooling-board place one finger on the sterno-clavicular junction and the other at a point between the angle of the jaw and the lobe of the ear, and by cutting on this imaginary line, the artery will be reached, providing the artery is normal and if the embalmer is thoroughly acquainted with the anatomy about the artery, as is summed up in the anatomical guide.

_Anatomical Guide._—By the anatomical guide is meant the relation which the artery bears to the surrounding tissues.

The anatomical guide for the carotid artery is that the artery lies between the sterno-mastoid muscle to the outside, and the muscles surrounding the trachea (wind pipe) and the esophagus, to the inside. In the middle third or sometimes between the middle and upper third the omohyoid muscle crosses over the artery.

_Perpendicular Incision._—The artery is divided for the sake of description into thirds. By making an incision on the linear guide in any one of the thirds the tissues that must be passed through are the following:—skin, platysma muscle, superficial fascia, deep fascia, common sheath, and the individual sheath.

The platysma muscle is a broad tissue paper like muscle, placed immediately beneath the skin and a part of the superficial fascia, in the cervicle or neck region. It arises by thin fibrous bands from the fascia covering the pectoral and deltoid muscles on the thoracic wall, and passes upward over the clavicle and inserts the lower jaw. This muscle is so delicate and the fibers so finely divided that it is hardly perceptible. When the skin is cut, the platysma muscle will as a rule be cut too, and because of its thinness it will rarely be seen or does it form any hindrance to the raising of the artery. It is only mentioned here because it forms part of one of the questions so often asked by the State Board in their examination: “What tissues would you pass through in raising the carotid artery?”

Having cut through the skin and platysma muscle, the superficial fascia is next seen. In this part of the body it consists of but a single layer and very thin.

The deep fascia lies next and constitutes a complete investment of the neck. When this is torn or cut through the sternomastoid muscle comes into view.

The sternomastoid, is a large, thick muscle, which passes obliquely across the side of the neck, being inclosed between two layers of deep fascia. It has its origin at the sternum and clavicle and attaches to the mastoid process of the temporal bone. By making the perpendicular incision in the lower third, in as much as the muscle slightly covers the artery, it can either be cut or pushed to the outside of the incision. It is best to push the muscle to the outside with the thumb, and with the handle of the scalpel, work down deep through the areolar tissue. The operator will now arrive at the common sheath, or that part of the deep fascia surrounding the artery, vein and nerve. The common sheath will be very tough and a slit must first be cut, then it can be torn the length of the incision.

The artery will now be seen lying next to the wind pipe and the internal jugular vein to the outside. In the lower third the artery will be about one-half inch deep, while in the upper third it will be about one to two inches deep, owing to the amount of fat in this region. In the upper third, the omohyoid muscle crosses over the artery, which must be either pushed aside or cut in two.

It is always advisable, to raise this artery in the lower third, as it is less apt to show in that third.

Loosen the artery well from the surrounding tissues with the aneurism hook, raise to the surface and place a bone separator beneath the artery.

Now remove the individual sheath, incise the artery and insert the arterial tube.

If it is desired to raise the internal jugular vein for the withdrawal of blood, it is best not to open up the common sheath, but to raise the artery and the vein both at the same time. Having raised them to the surface they can then be separated by the removal of the common sheath and dropping it back into the incision.

If it is desired only to raise the carotid, the hook should always be inserted between the artery and the vein, and directed toward the trachea. If it is directed around the artery in the other direction there is danger of rupturing the vein, and thus getting a bloody incision.

_The Circular Incision._—In the circular incision as much of the skin as can be, is pushed above the clavical bone from off the chest wall. The cut is then made from one sterno-clavicular junction to the other following the supra-sternal notch. This method was devised for the use of the “Y” shaped tube, where both sides of the face could be injected at the same time. One precaution however should be noted, which is, that care should be taken that not more than the skin, be incised with the first cut. Just below the incision will be noticed a little branch vein which runs into the arch connecting the two external jugular veins. If the first cut is too deep this branch will be cut, and a flow of blood will result. However by cutting carefully this little branch can be noticed, tied off in two places and cut in between, and thus cause no further trouble. Remembering the linear guide, the artery can be reached by going down at either end of the incision. The tissues to go through will be the same as for the perpendicular incision, and the method of raising the artery will be the same, only, in the circular incision usually both carotids are raised, so as to inject both sides of the face at the same time.

The only advantages derived from the circular incision is that one can by the use of the “Y” shaped tube inject both sides of the face at the same time and get an equal distribution of fluid, and that after the injection is over, and the incision sewed up, the skin can be pulled back in place, making the incision appear much below the clavical, and where it is less liable to show than in the perpendicular incision.

For embalming female subjects, if the carotid is chosen as the artery to use, it will be best to use the circular incision. However for ordinary embalming it will perhaps be best to choose some other artery, which will be less apt to show, and not so deep.

We should be so skilled as to never make a mistake, but the best sometimes do make mistakes. If in raising another artery, a mistake should occur, the operator can raise either above or below the original cut, but with the carotid, the only advisable incision to make is in the lower third, and if a mistake is made the last chance is lost. For this reason then a great amount of care should be taken.

In injecting the body from the carotid, the arterial tube should be inserted first toward the heart, and after the body has received a sufficient amount of fluid, if it is noticed that the side of the face from which you are injecting has not received a supply of fluid, then reverse the tube and inject a few bulbs of fluid upward.

_Relation of Artery, Vein and Nerve._—The common carotid artery lies in relation to the internal jugular vein and the pneumogastric nerve. The artery lies to the inside next to the muscles surrounding the trachea (windpipe). The internal jugular artery lies to the outside of the artery. Just back of the common carotid artery and the internal jugular vein and between the two lies the pneumogastric (vagus) nerve. These all as a rule lie in the same common sheath of deep fascia.

=How to Locate and Inject the Axillary Artery.=—The axillary in recent years has come to be a much used artery. It not quite as large as the common carotid, but as a rule large enough to admit the large size arterial tube. It has become a favorite with many because it is quite easy to locate and to raise, and because of its proximity to the axillary vein, a vein which is large enough to admit a drainage tube for the withdrawal of blood. Again the axillary artery is in a secluded place, being as it is in the axillary space (arm pit). The artery does not lie very deep, and is not covered by any muscles as you operate, there being practically nothing to hinder the progress of the operation.

Then after the operation is completed and the arm placed back in normal position, the casual observer is not liable to see the incision, even though the body be only partially dressed.

_Linear Guide._—A line drawn through the center of the axillary space (arm pit), at the anterior border of the hair line.

_The Axillary Space._—When the arm is maintained in a horizontal plane, the axilla has the shape of a three-sided pyramid, the apex of which lies above, below the clavicle, and the base of which corresponds to the lower wall, covered only by skin and fascia.

The axilla is filled with blood vessels, lymph vessels, lymph glands, nerves, and masses of fat.

_To Raise the Artery._—Make an incision on the linear guide. After the skin is passed through there is a large quantity of fascia, lymph glands, and lymph vessels, which must be carefully dissected through, and at the same time the axillary vein will be discovered. This vein, for the present, should not be loosened from the surrounding tissues. Dissect down to the upper side of the vein, and the common sheath of fascia surrounding the artery and nerves will be seen. By carefully tearing this the length of the incision, the brachial plexus of nerves now is exposed. Now by gently pushing the nerves apart with the handle of the scalpel, the artery will be seen. With a hook loosen the artery from the surrounding tissues and raise to the surface.

If it is desired to draw blood, now proceed to raise the vein to the surface. Open the vein and insert a drainage tube, which should be long enough to reach through the entire length of the axillary and subclavian veins, because they have valves along their entire course nearly to the bifurcation of the innominate.

Inject a few ounces of fluid toward the hand as the axillary is above the point of collateral circulation. Then reverse the tube and inject toward the heart, until a sufficient amount of fluid has been injected.

_Relation of Artery, Vein and Nerve._—The vein is quite superficial, just below it and to the upper part of the incision is the brachial plexus of nerves, which surrounds the artery.

=How to Locate, Raise, and Inject the Brachial Artery.=—The brachial artery is located in the upper arm and extends from the inferior margin of the muscle pectoralis major, or from the shoulder to the elbow. It is one of the most popular arteries known to the embalmer, and is now used, perhaps, more than all others combined.

The anatomy of this vessel is simple, yet, when we take into consideration all the numerous anomalies or irregularities that surround its use to us as embalmers, we feel the necessity of making the description very thorough and complete, in order to raise it under all the various difficulties that attend its use.

The brachial artery has its several branches, the most prominent of which are the artery profunda brachii (superior profunda artery) and the artery collateralis ulnaris superior (inferior profunda artery) and the artery collateralis inferior (anastomotica magna artery).

For the sake of a more correct description we divide the artery into thirds, viz: the upper, middle and lower thirds. The upper third begins at the extreme upper part of the arm and extends one third of the way to the elbow, the middle and lower thirds occupy the remainder of the artery. In the upper third we have the superior and inferior profunda arteries coming off; their position is not always the same, and in the extreme lower third the anastomotica magna artery. These arteries continue down the outer and inner arm and anastomose with the recurrent radial and ulnar arteries, thus furnishing collateral circulation. Thus if the fluid is injected in the middle third, toward the heart, these branches that come off the brachial in the upper third will convey the fluid down the arm, filling the branches below the point of injection, which supply the forearm and the hand.

The brachial artery is one continuous vessel, the entire length of the upper arm, and varies in size according to the size of the person and the development of the arm. It is accompanied by the venae comites or deep brachial veins, the one to the inner side of the artery about one-third to one-half the size of the artery, the other about one-half its size lies directly underneath. All are encased in the same common sheath of deep fascia that surrounds and holds them together. Great care, then, should be taken to separate the artery from these veins before cutting the artery for injection.

The artery lies along the inner and under border of the large muscle on top of the arm known as the biceps. The biceps is the muscle used when lifting a weight. To those whose occupation is to exercise the muscular tissue of the body liberally, this muscle becomes quite large, and generally the artery is proportionally large.

_Linear Guide._—The course of the brachial artery may be marked out by drawing a line from the middle of the axillary space (arm pit) to the center of the elbow, provided the palm of the hand be turned upward. This line will be immediately over the artery, which will be found by cutting through the skin at any point on the line, and dissecting through the subcutaneous tissue toward the center of the arm.

_The Anatomical Guide._—In the upper third the artery lies between the biceps and coracobrachialis muscles which lie above the artery, and the triceps muscle which lies below the artery. In the upper third the nerve lies close to the muscle, the artery below and to the inner side toward the body, and the vein a little farther to the inside.

In the middle third the artery lies between the biceps which lies above the artery, and the triceps muscle which lies below the artery. In the middle third the artery will lie beneath the nerve.

In the lower third the artery lies between the biceps which lies above the artery, and the triceps which lies below the artery. In the lower third the artery lies next to the muscle and the nerve to the inner side next to the body, and the vein still farther to the inner side.

_How to Raise the Artery._—First trace the inner border of the biceps muscle, feel for the median nerve, which will always be present. The artery in the middle and lower thirds will follow the border of the muscle. The palm of the hand should always be turned upward, and the linear guide, as stated above, will indicate the exact position of the artery. Make an incision through the skin, on the linear guide, pushing the fatty subcutaneous tissue to one side, if there be any, and with the handle of the scalpel, work through the superficial fascia. Reverse the blade, and at each end of the incision, cut forward and upward to make it clean. Now with the scalpel cautiously cut through the deep fascia, and remove this from the vessels below. This will expose to view the median nerve, and with the handle of the scalpel, separate the tissue between the artery and the muscle, and between the artery and the nerve. Having thus freed the artery, use the hook end of the aneurism needle and pass it under the artery toward the muscle, and raise the artery to the surface. Pass the bone separator or the forceps with the closed end, underneath, remove the sheath surrounding the artery and the deep brachial veins. The natural position will be, the artery on top, the larger deep brachial vein to the inner side and the smaller one underneath. It is very necessary to remove these deep brachial veins, for the reason that if they are not, in cutting the artery for injection, they will be cut also, resulting in a flow of venous blood into the incision.

=How to Locate, Raise and Inject the Radial Artery.=—The radial artery is one of the branches of the brachial artery, and extends from about one half inch below the bend of the elbow, along the valley of the forearm, to the thumb part of the hand. It is divided into thirds, viz: the upper, middle and lower thirds. It is accompanied in close relation by the radial veins, but in no way do they interfere with the operation of raising the vessel. The value of this artery is in the embalming of ladies, where the body has been dressed and the sleeve cannot be removed to use the brachial artery without material inconvenience and annoyance. It is especially desirable to those who are just beginning to use the arteries. The radial artery is somewhat smaller than the ulnar, but, on account of the depth of the latter and inconvenience of raising, the radial artery is the one artery in the forearm which is generally used. It is an excellent vessel to employ in cases where the friends are opposed to embalming because of the mutilation of the body, as they choose to call it. Some object to the use of this artery on account of the fact that the mutilation is not easily hidden. The wound can be easily covered by simply pulling the sleeve down to its normal place. The incision necessary to be made is so small and it can be closed so neatly, that no objection on the part of the relatives need be apprehended.

Before the advent of formaldehyde fluids the radial artery offered more advantages to the embalmer than any other artery used for injecting. But at the present time almost all embalming fluids contain large quantities of formaldehyde, and when injected into this artery, which is very small, it is liable to constrict the vessel to such an extent as to sometimes make it difficult to inject the fluid.

Moreover, since both the radial and the ulnar arteries have many branches, a large quantity of fluid is liable to accumulate in the forearm, hardening it more than is necessary and giving the hand an undesirable color.

The radial artery is very superficially located, and can be secured without the possibility of error and with very little mutilation. The expert will, of course, choose that vessel which he believes will at the time and under the circumstances best serve his purpose.

_The Linear Guide._—Is a line drawn from the center of the bend of the elbow to the center of the ball of the thumb.

_The anatomical guide_ for the radial artery (in the wrist, where it should be raised) is the brachio-radialis muscle on the outside of the artery and the flexor carpi radialis muscle on the inside of the artery.

When about to raise this vessel, the embalmer should hold the arm at right angles with the body, with the palm up, and holding the hand of the body, with the hand, draw the arm tight. In most bodies this will show plainly the tendons of the muscles between which the vessel lies, thus affording an excellent guide for the incision. The arm should never be grasped and the tissues drawn out of their normal position, as that is very misleading. The vessel should be raised at a point about three inches above the wrist joint (the space where you would feel the pulse beat in life). The operator making an incision through the skin, superficial fascia, and fat, about one-half inch in length, will plainly see the artery lying in its sheath between the two tendons of the muscles. The cut should now be opened carefully, by placing the fingers on either side of it, and the fascia dissected from the artery, when it can easily be raised with the aneurism hook. There is no other vessel at this point that can be mistaken for the radial artery. Its two venae comites, or accompanying veins, are usually attached to the artery and need not be removed, as they are very small and can give the embalmer no trouble.

=How to Locate, Raise and Inject the Ulnar Artery.=—The ulnar is the larger branch of the brachial artery. It crosses obliquely the inner side of the forearm, to the beginning of its lower half, it then runs along the ulnar border to the wrist, crosses the annular ligament on the radial side of the pisiform bone (wrist bone), and immediately beyond this bone into two branches, the superficial and deep palmar arch. In its upper half it is deeply seated, being covered by all the surface muscles. It is crossed by the median nerve, which lies to the inner side for about an inch. In the lower half of the forearm the artery runs more superficially, and is covered only by the skin and superficial and deep fascia, but at that, the ulnar lies a little deeper in the wrist than the radial. The ulnar nerve lies to the inner side in the lower half and the ulnar artery is accompanied by two ulnar veins, one on either side, called the venae comites.

_The Linear Guide._—Is a line drawn from the center of the bend of the elbow, to the inside of the pisiform bone in the wrist.

_The Anatomical Guide._—The artery lies in a groove in the wrist, made by the flexor carpi ulnaris muscle on the outside, and the flexor digitorum sublimis on the inside.

To raise the ulnar artery, locate the valley in the lower third about one to two inches above the pisiform bone. Make an incision about an inch in length, cutting first the skin, superficial fascia, layer of fat, which will vary in thickness. The deep fascia is now reached, which should be split by means of the fascia needle and bistoury. Then separate with the handle of the knife or bone separator, the artery from its connective tissue on either side. Then with the hook raise it to the surface, and place the bone separator beneath, remove the hook, and tear off the individual sheath.

The two ulnar veins will be separated from the artery by taking away the individual sheath, which should be allowed to drop back into the incision. Proceed now to open and inject the artery the same as you would the radial or the brachial. While this artery may seem just a little more difficult to raise, still at times it has its place in arterial embalming.

=How to Locate, Raise and Inject the Femoral Artery.=—The femoral artery is usually objected to, because, situated as it is, it requires an undue exposure of the limb, especially in ladies. For this reason, then, the femoral artery should never be raised in the female, excepting in accidental case when it is impossible to raise any other artery. In the male, however, the femoral with many is a favorite. The artery should be raised either in the upper or the middle thirds, but preferably in the former, as by raising at this point the artery is not very deep in the tissues as it will be further down, and at the same time one is able to get collateral circulation to the lower leg and foot by means of the deep femoral and the recurrent anterior and posterior tibials.

It is believed quite commonly, that by the injection of the femoral artery, there is a great danger of flushing the face. This belief is erroneous. Flushing of the face will result from the injection of any artery if it is full of blood and if it is found that the femoral artery contains blood, and likewise any other artery, this blood should be removed before injection takes place, and what little then remains, will not discolor the face, since it will be greatly diluted.

The internal long saphenous vein is mistaken frequently for the femoral artery. It is a superficial vein and is usually found empty after death. It lies a short distance to the inner side of the femoral artery in Scarpa's triangle. This vein is taken up frequently, not only by the younger members of the profession, but by the older as well, when the guides are not followed closely, and when this mistake does occur, and fluid is injected through it, flushing of the face results.

Next to the common carotid artery the femoral artery is the largest branch artery used in embalming. The femoral artery commences immediately behind Poupart's ligament and is a continuation of the external iliac artery.

It passes down the forepart and inner side of the thigh, terminates at the opening in the adductor magnus, at the junction of the middle with the lower third of the thigh, where it becomes the popliteal artery. In the upper third the artery is contained in a triangular space called _Scarpa's triangle_ and in the middle third of the thigh it is contained in an aponeurotic canal called _Hunter's canal_.

At a point about one and one-half to two inches below Poupart's ligament, the femoral artery gives off a branch to the outer and under side, known as the deep femoral artery, or the profunda femoris, which courses the thigh downward, and connects with branches coming off the popliteal and the anterior tibial arteries, thus forming the collateral circulation to the lower leg and foot.

As the femoral artery leaves the body, it is accompanied by the femoral vein, which for two inches down, lies along side the femoral artery to the inner and under side. At about this juncture, however, it passes underneath the artery and continues its course in that position until it passes below where we have occasion to use the artery.

The femoral artery can be used all the way from where it leaves the body at Poupart's ligament until it reaches Hunter's canal. At Poupart's ligament the artery is very superficial, being covered only by the skin, superficial fascia and superficial lymphatic glands, but it gets deeper further down, being covered not only by the above named tissues, but also by muscles, making it very difficult to raise in the middle and lower thirds of the thigh. About five to seven inches below Poupart's ligament the artery passes under the adductor magnus muscle, and enters what is known as Hunter's canal. Because this artery does get deeper as it courses down the thigh, it is generally raised in the upper third.

A knowledge of the anatomy of the vessels of the thigh and leg will be of value in treating accidents when this member is injured.

_Scarpa's triangle_ is a triangular space, the apex of which is directed downward, and the sides formed externally by the sartorius muscle, internally by the inner border of the adductor longus muscle, and above by Poupart's ligament. The floor of the space is formed from without inward by the ilio-psoas pectineus and the adductor longus muscles. The space is divided into two nearly equal divisions by the femoral vessels, which extend from the middle of its base to its apex, the artery giving off in this situation the superficial and profunda branches, and the vein receiving the deep femoral and the internal saphenous veins. Besides the vessels and nerves this space contains some fat and lymphatics.

_Hunter's canal_ is the aponeurotic space in the middle third of the thigh, extending from the apex of Scarpa's triangle to the femoral opening in the adductor magnus muscle. Hunter's canal contains the femoral artery and vein inclosed in their own sheath of areolar tissue, the vein being behind and on the outer side of the artery, and the long saphenous nerve lying at first on the outer side and then in front of the vessels.

_Linear Guide._—The guide for the femoral artery is represented by a line drawn from the center of Poupart's ligament to the inner side of the knee joint.

Poupart's ligament extends from the crest of the ileum bone to the top of the pubic bone. To determine the center of Poupart's ligament for the right leg, get on the right side of the body and with the left hand, place the second finger on the top of the pubic bone and the thumb on the crest of the ileum bone, then let the index finger drop down between the two which will represent the commencement of the femoral artery.

_Anatomical Guide._—The artery runs through the center of Scarpa's triangle from the center of its base to its apex. In the middle third of the thigh the artery passes beneath the vastus medialis muscle and enters Hunter's canal.

_Relation of the Artery, Vein and Nerve._—The femoral vein at Poupart's ligament lies close to the inner side of the artery, separated from it by a thin fibrous partition; but two inches down the vein runs behind the artery and then to its outer side.

There is no nerve in relation to the artery in the upper third, the anterior crural nerve lies about half an inch to the outer side of the femoral artery, being separated from the artery by the ilio-psoas muscle. In the middle third of the thigh the internal saphenous nerve is situated on the outer side of the artery, but not usually in the same sheath with the artery.

_To raise the femoral artery_ in its proper place, is to measure down from Poupart's ligament from one and one-half to two inches in the linear guide, and there begin the incision, making it two inches or less in length. This will bring the incision below the point where the collateral branches are given off. Cut through the skin, then the fat, which will vary in thickness with the subject. Underneath the fat are several layers of deep fascia, which must be split the length of the incision.

The femoral artery will then be seen, and underneath it will be the femoral vein. Both will be in the same common sheath of fascia, which may be removed with a hook by gently tearing the sheath loose over the artery. When the artery has been loosened the length of the incision, raise it to the surface, placing a bone separator underneath for a bridge.

If it is desired to remove the blood, the femoral vein should then be raised.