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 quantity while the patient is eating. These fistulæ 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]).
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 passed 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.—Parotitis.—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, œdema of the scrotum, 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 vaginal discharge.
Fig. 262.—Acute Suppurative Parotitis.
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 cystitis. The condition is usually transient and leads to no complications.