Manual of Surgery Volume II Part 57

CHAPTER XXIII

THE SALIVARY GLANDS

Surgical Anatomy--Injuries--Salivary fistulae--Salivary calculi--Infective conditions: _Parot.i.tis_; _Inflammation of submaxillary gland_; _Angina Ludovici_; _Inflammation of sublingual gland_; _Tuberculous disease_--Tumours: _Ranula_; _Mixed tumours of parotid_; _Sarcoma_; _Carcinoma_; _Tumours of submaxillary and sublingual glands_.

#Surgical Anatomy.#--_The parotid gland_ lies on the side of the face below and in front of the ear, and extends deeply behind the mandible reaching almost to the side wall of the pharynx. Its deeper part lies in close relation with the internal carotid artery, the internal jugular vein, and the vagus, glosso-pharyngeal, accessory, and hypoglossal nerves. The external carotid artery pa.s.ses through the substance of the parotid, and bifurcates opposite the neck of the condyle into the temporal and internal maxillary arteries. It is accompanied by the venous trunk formed by the junction of the temporal and internal maxillary veins. The facial nerve and its branches traverse the lower third of the gland from behind forwards. The facial portion of the gland lies on the surface of the ma.s.seter muscle, and the _parotid duct (Stenson's duct)_ emerges from its anterior border.

After crossing the ma.s.seter, the duct pierces the buccinator muscle and the mucous membrane obliquely, and opens into the mouth opposite the second upper molar tooth. Its course is indicated by a line pa.s.sing from the upper part of the lobule of the ear to a point midway between the ala of the nose and the margin of the upper lip--that is, at a higher level than the facial nerve. Several lymph glands--pre-auricular--lie inside the capsule of the parotid just in front of the ear.

The _submaxillary gland_ lies under the integument and fascia in the triangle formed by the lower jaw and the two bellies of the digastric muscle. Its anterior part is crossed by the facial vessels, and several lymph glands lie inside its capsule. The _submaxillary duct (Wharton's duct)_ opens into the mouth by the side of the frenum of the tongue.

The _sublingual gland_ lies in the floor of the mouth just beneath the mucous membrane. It has numerous ducts, some of which open directly into the mouth, others into the submaxillary duct.

#Injuries.#--The _parotid_ is frequently injured by accidental wounds and in the course of operations. If the blood vessels traversing the gland are divided, such wounds are liable to bleed freely, and if the facial and auriculo-temporal nerves are damaged, motor and sensory paralysis of the parts supplied by them ensues. Wounds of the parotid heal rapidly and without complications so long as infection is prevented, but if suppuration takes place they are liable to be followed by the escape of saliva, which may go on for weeks; in some cases a salivary fistula is thus established.

_The parotid duct_ may be divided and a salivary fistula result. If the external wound heals rapidly, a salivary cyst may develop in the substance of the cheek, forming a swelling, which fills up at meals, and may be emptied by external pressure, the saliva escaping into the mouth.

In a wound implicating the whole thickness of the cheek the skin should be accurately sutured, care being taken that the st.i.tches do not include the duct, but in order that the saliva may readily reach the mouth, the mucous membrane should not be st.i.tched.

#Salivary Fistulae.#--A salivary fistula may occur in relation to the glandular substance of the parotid or in relation to the duct. Fistula in connection with the glandular substance--_parotid fistula_--seldom results from a wound, made, for example, in the removal of a tumour or in an operation on the ramus of the jaw, so long as it is aseptic; but as a sequel of suppuration in the gland, and particularly of an abscess developing around a concretion, it is not uncommon. The fistulous opening is usually small, and may occur at any point over the gland. The fistula may be dry between meals, or the saliva may escape in small transparent drops, but the quant.i.ty is always greatly increased when food is taken. A parotid fistula, although it may continue to discharge for weeks, or even for months, usually closes spontaneously.

In persistent cases, the edges of the fistula may be pared and brought together with sutures, or the actual cautery may be applied to induce cicatricial contraction.

_Fistula of the parotid duct_ is more serious. It is usually due to a wound, less frequently to abscess or impacted calculus. From the minute opening, which is most frequently situated over the buccinator muscle, there is an almost continuous flow of clear limpid saliva, which is greatly increased in quant.i.ty while the patient is eating.

These fistulae show little tendency to close spontaneously. Attempts to close the opening by the external application of collodion, by cauterising the edges, or even by paring the edges and introducing sutures, usually fail. It is necessary to establish an opening into the mouth, either by opening up the original duct or by making an internal fistula in place of the external one.

#Salivary Calculi.#--Salivary calculi are most commonly met with _in the submaxillary gland or its duct_. They consist of phosphate and carbonate of lime with a small proportion of organic matter, and result from the chemical action of bacteria on the saliva. In rare cases a foreign body, such as a piece of straw, a fruit-seed, or a fish-bone, forms the nucleus of the concretion. They vary in size from a pea to a walnut, and are hard, of a whitish or grey colour, and rough on the surface. Those that form in the gland itself are usually irregular, while those met with in the duct are rounded or spindle-shaped (Fig. 261).

[Ill.u.s.tration: FIG. 261.--Series of Salivary Calculi.]

A calculus in the duct gives rise to sharp lancinating pain, which is aggravated when the patient takes food. The duct is seldom completely obstructed, but the flow of saliva is usually so much impeded that the gland becomes greatly swollen during meals. The swelling gradually subsides between meals, or can be made to disappear by external pressure. The calculus can usually be felt by means of a probe pa.s.sed along the duct, or by puncturing the swelling with a needle; or, with one finger inside the mouth and another under the jaw, a hard lump can be detected under the mucous membrane of the floor of the mouth. It may be revealed by the X-rays. When the obstruction is complete, a retention cyst forms in which suppuration is liable to occur, causing marked aggravation of the symptoms. In some cases the wall of the duct and the surrounding tissues become thickened and indurated, forming a swelling which is liable to be mistaken for a malignant growth. The treatment consists in making an incision through the mucous membrane over the calculus and extracting it with a scoop or forceps.

INFECTIVE CONDITIONS.--#Parot.i.tis.#--Inflammation of the parotid gland may be non-suppurative or suppurative.

Of the _non-suppurative_ varieties the most common is the epidemic form known as _mumps_. This is an acute infective condition, which usually attacks young children, and implicates both glands, either simultaneously or consecutively. It runs a definite course, which lasts for from one to two weeks, and almost invariably ends in resolution. The parotid gland is swollen and tender, there is pain on attempting to open the mouth, difficulty in swallowing, and dribbling of saliva. The surgical interest of this disease lies in the fact that it is frequently complicated by pain and swelling of the testis, dema of the s.c.r.o.t.u.m, and occasionally by a urethral discharge, and atrophy of the testis has been observed after such an attack. In females there is sometimes pain in the ovary, tenderness and swelling of the mamma, and a v.a.g.i.n.al discharge.

[Ill.u.s.tration: FIG. 262.--Acute Suppurative Parot.i.tis.]

The parotid on one or both sides may suddenly become swollen and tender in patients who are taking large doses of mercury, in gouty subjects, or in patients suffering from infective conditions of the genito-urinary organs, such as orchitis, ovaritis, urethritis, or cyst.i.tis. The condition is usually transient and leads to no complications.

_Recurrent enlargement_ of the parotid and submaxillary glands, as well as of the lachrymal glands, is occasionally met with in adults, and was first described by Mikulicz. It may be a.s.sociated with salivary lithiasis, xerostomia, or organic narrowing of the ducts, but in the majority of cases no such cause can be discovered (D. M.

Greig). When the parotid is affected the condition tends to be bilateral and there is some const.i.tutional disturbance. The submaxillary form is usually unilateral and the symptoms are entirely local. The affected gland rapidly becomes swollen, painful and tender to the touch, and the swelling increases markedly while the patient is eating. Each attack lasts for a few hours to one or two weeks, and then subsides spontaneously. The intervals between attacks vary from a few weeks to a year or more. In the course of a few years there is considerable deformity, and sometimes deficiency in the glandular secretion, but the disease is not attended by other inconvenience.

Benefit has followed the administration of a.r.s.enic and iodides, and the use of radium and X-rays.

The treatment of these non-suppurative forms of parot.i.tis consists in relieving the symptoms.

_Suppurative parot.i.tis_ may be due to direct spread of infection from the mouth along the parotid duct, or to extension of suppurative processes from the temporo-mandibular joint, the jaw, or a lymph gland. It is liable to occur also in the course of any disease in which there is an infection of the blood with pyogenic bacteria, and has been met with in diphtheria, typhoid fever, scarlet fever, measles, and other eruptive fevers.

The _post-operative_ form of parot.i.tis is most frequently met with after laparotomy for such conditions as suppurative appendicitis, perforated gastric ulcer, ovarian cyst, and pyosalpinx.

These secondary forms are probably due to infection from the mouth under conditions in which the secretion of saliva is arrested or its escape from the gland interfered with.

The early symptoms are apt to be overshadowed by those of the general disease from which the patient suffers. At first the gland is swollen, hard, and tender, and the seat of constant, dull, boring pain; later there is redness, dema, and fluctuation. The movements of the jaw are restricted and painful, the patient is unable to open the mouth, and has difficulty in swallowing. The inflammation reaches its height on the third or fourth day, and usually ends in suppuration. The pus is scattered in numerous foci throughout the gland, and sometimes large sloughs form. The dense capsule of the gland prevents the pus reaching the surface and causes it to burrow among the tissues of the neck, giving rise to dyspna and dysphagia. It may find its way downwards towards the mediastinum, inwards towards the pharynx--where it const.i.tutes one form of retro-pharyngeal abscess--or upwards towards the base of the skull. Not infrequently it burrows into the temporo-mandibular joint, or escapes by bursting into the external auditory meatus. Serious haemorrhage may result from erosion of the vessels traversing the gland or of the internal jugular vein, or venous thrombosis may ensue. Persistent paralysis may follow destruction of the facial nerve; and salivary fistulae may form. Death may take place from toxaemia even before pus forms.

_Treatment._--During the first two or three days hyperaemia is induced by means of poultices, hot fomentations, or Klapp's suction bells, and the mouth is frequently washed out with an antiseptic. As soon as there is reason to believe that pus has formed an incision is made behind the angle of the jaw, parallel to the branches of the facial nerve, the abscess opened by Hilton's method, a finger pa.s.sed into the gland, and all septa broken down and drainage secured.

Acute infection of the #submaxillary gland# is met with under the same conditions as that of the parotid. Both glands are occasionally attacked at the same time.

The acute phlegmonous peri-adenitis of the submaxillary gland, known as _angina Ludovici_, is referred to at p. 597.

The _treatment_ consists in making incisions through the deep fascia in order to relieve the tension, or to let out pus if it has formed.

Acute suppurative inflammation of the #sublingual gland# may occur under the same conditions as in the parotid, and is a.s.sociated with the formation of an exceedingly painful and tender swelling under the tongue. The tongue is gradually pushed against the roof of the mouth, so that swallowing is difficult and respiration may be seriously impeded. There is marked const.i.tutional disturbance. An incision into the swelling is immediately followed by relief of the symptoms.

#Tuberculous disease# of the salivary glands is rare. It usually begins in the lymph glands within the capsule of the parotid or submaxillary, and spreads thence to the salivary gland tissue.

TUMOURS.--#Cystic Tumours--Ranula.#--The term ranula is applied to any cystic tumour formed in connection with the glands in the floor of the mouth. Formerly these tumours were believed to be retention cysts due to blocking of the salivary ducts. They are now known to be the result of a cystic degeneration of one or other of the secreting glands in the floor of the mouth. They contain a thick glairy fluid, which differs from saliva in containing a considerable quant.i.ty of mucin and alb.u.min, while it is free from any amylolytic ferment or sulpho-cyanide of pota.s.sium. Numerous degenerated epithelial cells are found in the fluid.

The _sublingual ranula_ is the most common variety. It appears as a painless, smooth, tense, globular swelling of a bluish colour. It usually lies on one side of the frenum, and over it the mucous membrane moves freely. As it increases in size it gradually pushes the tongue towards the roof of the mouth, and so causes interference with speech, mastication, and swallowing. It is to be differentiated from a retention cyst of the submaxillary gland by the fact that a probe can usually be pa.s.sed down the submaxillary duct alongside of the swelling, and from sublingual dermoid (p. 539).

The _treatment_ consists in making an incision through the mucous membrane over the swelling, dissecting away the whole of the cyst wall if possible, and, if any portion cannot be removed, swabbing it with a solution of chloride of zinc (40 grains to the ounce), after which the cavity is stuffed with bis.m.u.th gauze and allowed to close by granulation. It is sometimes found more satisfactory to dissect out the cyst through an incision below the jaw, and in the event of recurrence this should be undertaken.

Cystic tumours, similar to the sublingual ranula, form in the other glands in the floor of the mouth--for example, the incisive gland, which lies just behind the symphysis menti, as well as in the apical gland on the under aspect of the tip of the tongue. The latter is distinguished by the fact that it moves with the tongue. In rare cases children are born with a cystic swelling in the floor of the mouth--the so-called _congenital ranula_. It is usually due to an imperfect development of the duct of the submaxillary or sublingual gland.

#Solid Tumours--Mixed Tumours of the Parotid.#--The most important of the solid tumours met with in the salivary glands is the so-called "mixed tumour of the parotid." This was formerly believed to be an endothelioma derived from a proliferation of the endothelial cells lining the lymph s.p.a.ces and blood vessels of the gland. A more probable view is that it develops from rests derived from the first branchial arch an not from the parotid. The matrix of the tumour is made up of cartilaginous, myxomatous, sarcomatous, or angiomatous tissue, the proportion of these different elements varying in individual specimens, and it may include some portions that are adenomatous. A gelatinous substance forms in the intercellular s.p.a.ces of the tumour, and may acc.u.mulate in sufficient quant.i.ty to give rise to cysts of various sizes. There is reason to believe that the tumours of the parotid previously described as adenoma, chondroma, angioma, myxoma, and many of the cases of sarcoma, were really mixed tumours in which one or other of these tissues predominated.

The tumour usually develops in the vicinity of the parotid, and presses on the salivary tissue, thinning it out and causing it to undergo atrophy.

_Clinical Features._--The mixed tumour is usually first observed between the ages of twenty and thirty. It is of slow growth and painless, and forms a rounded, nodular swelling, the consistence of which varies with its structure. The skin over the swelling is normal in appearance and is not attached to the tumour (Figs. 263, 264). Only in rare cases does paralysis result from pressure on the facial nerve.

[Ill.u.s.tration: FIG. 263.--Mixed Tumour of Parotid.]

[Ill.u.s.tration: FIG. 264.--Mixed Tumour of the Parotid of over twenty years' duration.]

Although usually benign, these tumours may, after lasting for years, take on malignant characters, growing rapidly, implicating adjacent lymph glands, and showing a marked tendency to recur after removal.

The _treatment_ consists in sh.e.l.ling out the tumour, care being taken to avoid injuring the facial nerve or the parotid duct by making the incision and the subsequent cuts in the dissection run parallel to them. If the tumour is removed early and completely, recurrence is the exception.

#Sarcoma and carcinoma# are rare. They are very malignant, grow rapidly, infiltrate surrounding parts, including the skin, and infect the adjacent lymph glands. There is severe neuralgic pain, and paralysis from involvement of the facial nerve is an early symptom.

The _treatment_ consists in excising the whole of the parotid gland with the tumour, no attempt being made to conserve the facial nerve or other structures traversing it. Recourse should be had to the use of radium both before and after operation, otherwise recurrence is all but inevitable.

The _submaxillary and sublingual glands_ may be the seat of the same varieties of tumour as the parotid. These glands are particularly liable to become invaded along with the adjacent lymph glands in epithelioma of the tongue and floor of the mouth.

CHAPTER XXIV