Fistulas of salivary glands and their excretory ducts: causes, symptoms, diagnosis, treatment

Fistulas of the submandibular salivary gland are extremely rare in peacetime.

[ 1 ], [ 2 ], [ 3 ], [ 4 ], [ 5 ], [ 6 ]

What causes submandibular salivary gland fistulas?

Submandibular salivary gland fistulas usually occur as a result of gunshot wounds to the submandibular region.

Fistulas of the parotid glands and their ducts are relatively often observed even in peacetime due to suppuration of the gland, phlegmon of the parotid-masticatory region, cancerous or nomatous process, accidental damage to the gland, including during the opening of abscesses and infiltrates.

Parotid gland fistulas occur especially often when a gunshot wound is complicated by repeatedly recurring phlegmons. The consequence of protracted treatment of such a wound in the gland area is epithelialization of the wound channel, into which the epithelium of the facial skin and the gland itself grows. In this case, a firmly epithelialized fistula tract is formed, associated with the gland or its duct.

Symptoms of salivary gland fistulas

In the presence of a salivary gland fistula, patients complain of more or less intense secretion of saliva from the fistula, especially when eating sour, salty, or bitter foods.

Outside of meals, the secretion of saliva decreases or stops completely.

It especially bothers patients in winter (saliva cools the skin, wets the collar). They are forced to wear a bandage all year round or endlessly wipe away the secreted saliva with a handkerchief. Chronic dermatitis is observed on the skin around the mouth of the fistula.

Objectively, in the area of scarred skin, a pinpoint fistula is found, from which a transparent, slightly sticky liquid is released; sometimes small flakes are mixed with it.

If the inflammatory process in the gland has not yet ended, the saliva has a cloudy tint.

Fistulas are localized on the cheek or in the chewing area, sometimes behind the angle of the lower jaw or in the submandibular area. The length of the fistula tract is 10-18 mm.

There are fistulas of the parotid salivary gland and its excretory duct. Injury to the excretory duct leads to the formation of the most persistent fistulas, which are difficult to treat.

Parotid duct fistulas can be complete or incomplete. A complete fistula is characterized by complete obliteration of the peripheral end of the duct, as a result of which even the thinnest probe or mandrin with an olive on the end cannot be passed through it (from the mouth into the fistula). As a result, all the saliva is drunk out.

If only the wall of the parotid duct is damaged, an incomplete fistula occurs, in which part of the saliva is released outside (onto the skin), and part into the mouth. In this case, it is possible to probe the peripheral end of the duct and bring the end of the probe into the external fistula opening.

To determine the nature of the fistula (glandular part or duct, complete or incomplete), you can use one of the following methods.

1. Examination of the mouth of the parotid duct or submandibular gland duct from the oral cavity: if some saliva flows through it, then the fistula is incomplete, and vice versa.
2. Probing of the fistula tract in the direction of the mouth of the parotid duct or through the mouth in the direction of the fistula using the thinnest eye probe, a polyamide thread (0.2 mm in diameter) or a piece of balalaika string with a tin olive soldered to the end.
3. Contrast sialography of the fistula tract and parotid duct: if the peripheral part of the duct is connected to the fistula, a strip of contrast agent will be visible between them on the image. If the fistula is connected to only one of the lobes of the gland, then the sialogram will show the branched network of ducts of only this lobe.
4. Introduction of a methylene blue solution (1-1.5 ml) into the fistula: if the fistula is incomplete, the dye will appear in the mouth.
5. Bilateral functional study of reflex salivation in response to a food stimulus (dry food) or subcutaneous injection of 1 ml of 1% pilocarpine solution. With an incomplete fistula, the amount of saliva collected in the Krasnogorsky capsule will be greater on the healthy side than on the diseased side. With a complete fistula, saliva on the diseased side will not enter the capsule at all.

Diagnosis of salivary gland fistulas

If the fistula is localized in front of the auricle, it is necessary to differentiate it from the rudimentary external auditory canal, which, as a rule, ends blindly at a depth of 3-5 mm; saliva is not secreted from it.

If the salivary gland fistula is localized in the lower part of the parotid-masticatory region, it is differentiated from the congenital lateral fistula of the gill cleft. Saliva is not secreted from this fistula either.

With the help of contrast radiography, the absence of a connection between the listed congenital anomalies and the salivary gland is revealed.

[ 7 ], [ 8 ], [ 9 ], [ 10 ], [ 11 ], [ 12 ]

Treatment of salivary gland fistulas

Treatment of salivary gland fistulas is a difficult task. The large number of existing (over 60) treatment methods is explained by the diversity of the nature and localization of fistula tracts, as well as the difficulties of performing a number of radical surgical interventions due to the possible danger of damaging the trunk or branches of the facial nerve.

Classification of methods for treating salivary gland fistulas

Group I - "conservative" methods capable of causing long-term or permanent suppression or cessation of the function of the parotid salivary gland. These include:

1. methods that lead to the destruction of gland tissue or its atrophy (increasing pressure on the gland; injection of sterile oil, sulfuric acid, alcohol into the gland; ligation of the external carotid artery; ligation of the central end of the parotid duct; X-ray irradiation of the gland);
2. methods of permanently stopping the function of the gland (twisting the auriculotemporal nerve; injection of alcohol into the third branch of the trigeminal nerve at the foramen ovale; removal of the superior cervical sympathetic ganglion; a combination of denervation and X-ray irradiation of the gland);
3. methods of removing the gland (complete or partial extirpation);
4. methods of pharmacological suppression of salivation before each meal.

Group II - methods aimed at eliminating the fistula, but not providing for the outflow of saliva into the mouth. These include:

1. methods of mechanical bloodless closure of the fistula opening with a gold plate, adhesive plaster; sealing the fistula with collodion; injection of paraffin into the tissues surrounding the fistula;
2. methods of thermal or chemical action on the fistula canal, leading to the closure of the lumen of the fistula tract (use of hot air in combination with deep massage; cauterization of the fistula with a diathermocoagulator, a hot needle or a thermocauter, monobromoacetic acid, alcohol, lapis crystals; a combination of drug treatment with X-ray therapy, etc.);
3. methods of blind closure of the fistula canal by surgical means:
   • scraping of the fistula followed by application of a skin suture;
   • excision of the fistula with subsequent suturing of the gland, fascia and skin;
   • closure of the duct or gland defect with a piece of fascia with the application of blind sutures over the fascia and onto the skin;
   • excision of the fistula tract, application of a purse-string suture to the damaged area of the gland, closure of it with a fascia flap on a leg with application of a blind suture to the skin;
   • excision of the fistula tract and three-layer closure of the fistula opening with fascia flaps with immersed removable metal sutures;
   • application of an immersion purse-string suture around the fistula and a blind suture on the skin above the fistula (according to K.P. Sapozhkov);
   • ligation of the fistula canal with immersion ligatures:
   • dissection of the fistula and plastic with a flap with a blind suture;
   • excision of the fistula tract using a plate suture and counter triangular skin flaps according to Serre-A. A. Limberg or plastic surgery according to Burov.

Group III - methods of closing fistulas that provide for the preservation of the function of the gland and ensuring the outflow of saliva into the mouth.

Among them, several subgroups can be distinguished:

1. creation of a new path (passage) for the outflow of saliva into the oral cavity:
   • puncture of the cheek with a hot iron or trocar, leaving a rubber tube in the canal;
   • puncture of the cheek with a silk thread left in the canal;
   • double puncture of the cheek with pressing of the bridge (from the soft tissues of the cheek) with a wire loop, silk thread, rubber band;
   • formation of a channel in the thickness of the soft tissues of the cheek to drain saliva from the external fistula towards the mouth and ear;
   • drainage of the canal with multi-row silk drainage, reinforced with a plate suture;
   • drainage of the wound channel from the oral cavity with a metal or thin rubber (nipple) tube (according to A. V. Klementov);
2. restoration of the integrity of the damaged parotid duct:
   • suturing the ends of the duct over a polyethylene catheter;
   • suturing of duct fragments after preliminary expansion of their ends using a string or sticks;
   • suturing the parts of the duct over the silver wire;
   • mobilization of the peripheral part of the duct and suturing it to the central part using a catgut thread;
   • suturing the ends of the duct with a vascular suture;
3. restoration of the peripheral part of the duct by plastic means:
   • replacement of the missing part of the duct with a section of the facial vein;
   • replacement of the missing section of the duct by free skin grafting according to A. S. Yatsenko-Tiersch;
   • restoration of the outflow of saliva into the oral cavity by puncturing the cheek and inserting an elastic rubber tube wrapped in an epidermal transplant into the wound channel, according to Yu. I. Vernadsky;
   • replacement of the missing part of the duct with skin from the cheek;
   • restoration of the missing part of the duct with flaps of various shapes, cut from the mucous membrane of the cheek, according to G. A. Vasiliev;
4. bringing out the central section of the damaged duct to the inner surface of the cheek by suturing it:
   • into the incision on the mucous membrane of the cheek;
   • through the notch in the area of the anterior edge of the masseter muscle itself and in front of the branch of the lower jaw;
   • into the mucous membrane of the cheek between the posterior edge of the masseter muscle itself and the branch of the lower jaw;
   • formation of a blunt passage in the buccal muscle and suturing of the central section of the duct into the gap of this muscle;
   • suturing the proximal end of the duct into the mucous membrane of the cheek with its preliminary splitting into two semilunar flaps;
5. methods of bringing the fistula mouth to the inner surface of the cheek or to the floor of the oral cavity:
   • transplantation of the mobilized fistula opening to the inner surface of the cheek and fixation of it in this position with sutures to the mucous membrane;
   • suturing the fistula opening with the submandibular duct.

[ 13 ], [ 14 ], [ 15 ]

Treatment of chronic incomplete fistula of the duct or a separate lobe of the parotid gland

With this form of fistula, both conservative and surgical treatment can be used.

Conservative methods

Suppression of the gland's secretory function is achieved by introducing a 0.1% solution of atropine sulfate under the skin (0.5 ml 2-3 times a day) or belladonna tincture orally (5-8 drops 30 minutes before meals). At the same time, a gentle diet is prescribed.

Injections of alcohol, 5% alcohol solution of iodine or diathermocoagulation of the fistula into the fistula. As a result, the epithelium of the canal dies, aseptic inflammation develops around the fistula and as a result its walls grow together. Cauterization of the fistula must be combined with the introduction of atropine or belladonna tincture.

Cauterization of the fistula. The end of a thin eye probe, wrapped in cotton wool, is moistened in a 30% solution of silver nitrate and inserted into the fistula canal 2-3 times during one session, repeating them every other day for a week. If the fistula canal is very narrow and it is impossible to insert the probe with cotton wool into it, the end of the probe is heated over an alcohol lamp and immersed in a silver nitrate stick. Then a purse-string suture is applied around the aponeurotic opening of the fistula, passing a silk thread (No. 7 or No. 8) through the notches. Then the red-hot end of the probe, covered with a thin layer of silver, is inserted (once) into the canal. The thin wire electrode of the diathermocoagulator is inserted into the fistula canal as deeply as possible and the electric current is turned on for 2-3 s.

Surgical method of K. P. Sapozhkov

Under infiltration anesthesia with 0.5% novocaine or trimecaine solution, an oval incision is made in the skin around the mouth of the fistula, a thin button probe is inserted into it and, using it as a guide, the fistula tract is isolated to its maximum depth, after which the prepared tissues of the fistula tract are cut off together with the oval rim of skin formed during its dissection at the beginning of the operation.

Stepping back from the edges of the resulting oblong wound up and down by 2-3 cm, make incisions in the skin to the aponeurosis.

Using a sharply curved needle, a circular (purse-string) suture with silk thread (No. 7 or No. 8) is passed through the notches around the aponeurotic opening of the sinus and tightly tied; immersion sutures with catgut are applied to the wound, and blind sutures with a vein (thin fishing line) are applied to the skin. For purse-string and immersion sutures, long-term non-absorbable chromic catgut can be used, since in the case of suppuration of the silk suture, the entire effect of the operation is reduced to zero.

Treatment of fresh incomplete fistula

In case of fresh traumatic incomplete fistulas of the duct or individual lobes of the gland, two methods of A. A. Limberg (1938) or the Serre-A. A. Limberg-Burov method can be recommended:

1. If the fistula is included in a relatively small scar and a small amount of saliva is released from it, the simplest option is used: excision of the scar together with the fistula tract, mobilization of the edges of the wound, application of one plastic suture and ordinary interrupted sutures to the skin; an unsutured area is left in the lower part of the wound for temporary outflow of saliva.
2. If the fistula is located under the earlobe in the area of a wide scar where it is impossible to move the counter triangular flaps without difficulty, the excised scar area with the fistula resembles a triangle in shape. The resulting wound surface is covered with skin mixed using the Burov method; a gap is left in the corner of the wound for the outflow of saliva.
3. When the fistula is localized in the area of an extensive scar, its channel is excised together with the scar tissue, two opposing triangular flaps of skin are formed at an angle of 45°, and a small gap is left in the lower part of the wound for the temporary outflow of saliva.

Thus, with the help of the operation according to the method of A. A. Limberg or Serre-A. A. Limberg, they try to create such biological conditions that would promote favorable wound healing: firstly, ensuring the possibility of temporary outflow of saliva to the outside in the postoperative period, which prevents separation (accumulating saliva) of the wound surfaces; secondly, excision of scar tissue to the full depth with the displacement of surrounding normal tissues, in particular skin, to the area of the damaged part of the gland; thirdly, exclusion in the postoperative period of drugs that suppress salivation.

The described methods are most effective for fresh traumatic fistulas, in the case of a significant outflow of saliva into the mouth and in the absence of acute inflammatory phenomena in the area of the operation.

In case of long-standing fistulas, the operation is completed by applying immersion catgut sutures, and blind sutures with a vein on the skin. In the postoperative period, it is necessary to prescribe drugs that reduce the secretion of saliva.

Treatment of chronic complete parotid duct fistulas

In this type of salivary fistula, especially if they are located in the area of large scars, it is necessary to use the methods of plastic reconstruction of the duct according to G. A. Vasiliev, A. V. Klementov, Yu. I. Vernadsky, S. M. Solomenny et al.

Method of G. A. Vasiliev

Under infiltration anesthesia, arc-shaped incisions are made in a horizontal direction, framing the opening of the fistula canal in accordance with the course of the parotid duct, so that the anterior pole of the surgical wound is located 1 cm in front of the anterior edge of the masseter muscle itself. It is best to dissect the tissues by inserting thin eye probes into the fistula tract and the parotid duct.

The central section of the duct is dissected from the surrounding tissues, and the adjacent section of skin with the fistula tract passing through it is cut off.

From the oral cavity, a tongue-shaped flap of about 1 cm in width is formed from the mucous membrane of the cheek by an arcuate incision. The base of this flap should be at the level of the anterior edge of the masticatory muscle itself, above the line of occlusion of the teeth. The length of the flap depends on the location of the fistula.

An incision (puncture) is made between the anterior edge of the masseter muscle itself and the fatty lump of the cheek, and through it the cut flap is brought out into the wound on the cheek.

The central end of the prepared duct is dissected lengthwise for 35 mm and a flap of mucous membrane (P) is sutured to it (with thin catgut). Along the epithelialized surface of this flap, a narrow rubber strip (from a glove) is left, which is sutured with catgut to the mucous membrane of the cheek.

The defect on the mucous membrane of the cheek (at the site where the flap is cut out of it) is closed by bringing the edges of the wound together and applying catgut sutures in such a way that the inverted flap is not too tightly pulled together at the base (where the rubber strip lies).

The external wound is sutured tightly in layers, and a solution of antibiotics to which the microflora of the oral cavity of the operated patient is sensitive is introduced into the surrounding tissues (sensitivity is determined in the preoperative period).

In order to increase the secretory function of the salivary gland after surgery, it is recommended to prescribe 8-10 drops of 1% pilocarpine solution orally 3 times a day, and before meals during the first 3 days, perform a light massage of the parotid gland to free it from secretion.

The rubber strip is removed after 12-14 days, when an epithelial tract has already formed around it.

Method of A. V. Klementov

The fistula tract with adjacent scar tissue is excised with oval incisions. A puncture is made into the oral cavity in the depth of the wound with a narrow (ocular) scalpel. A drainage rubber tube (nipple) is inserted into the perforation.

The external wound is closed by moving opposing triangular flaps of skin.

The rubber tube is fixed in the oral cavity to the edges of the mucous membrane incision with two silk sutures and left in the wound for 2 weeks. During this time, the artificial internal fistula epithelializes, after which the tube is removed.

During the first days after the operation, saliva may accumulate under the displaced skin flaps during meals. To prevent this, it is recommended to apply a pressure bandage after the operation and prescribe 8-10 drops of belladonna tincture or 0.1% atropine sulfate solution orally 15-20 minutes before meals. If saliva does accumulate, a light massage is performed over a napkin placed on the operated area.

The method of Y. I. Vernadsky

The method of Y. I. Vernadsky is similar to the method of A. V. Klementov. The difference is, firstly, that a thin epidermal flap taken from the patient's abdomen or arm is glued (with glue) to a rubber drainage tube. In this case, the outer (epithelial) surface of the flap faces the rubber. Secondly, for this purpose, not a thin nipple tube is used, but a thicker and more rigid tube, the internal lumen of which is 4-5 mm. This ensures unimpeded passage of saliva into the mouth and tight adhesion of the wound surface of the skin flap glued to the tube to the wound channel-puncture. Thirdly, in order to observe the passage of saliva from the gland, the end of the tube is brought out of the oral cavity. To prevent saliva from getting on the neck and chest, a cotton-gauze pad can be attached to the end of the tube, into which the saliva is absorbed and from which it gradually evaporates.

After 14-16 days, the tube is removed. During this time, the newly created duct epitheliizes and will freely allow saliva to pass through.

After such an operation, there is no need to prescribe drugs that stimulate the secretion of saliva or, on the contrary, suppress it. Preventive administration of antibiotics (intramuscularly) is mandatory.

Method of S. M. Solomennyi and co-authors

It differs from the method of Yu. I. Vernadsky in that instead of an epidermal autograft, a venous autograft is used to restore the duct, which is sutured end-to-end with the stump of the proximal end of the excretory duct of the gland (using non-absorbable suture material and an atraumatic needle).

Treatment of fresh cut wounds of the parotid duct

In case of cut wounds of the parotid duct, its ends can be sutured using the Kazanjan-Converse method. To do this, after stopping the bleeding from the wound, a thin (No. 24) polyethylene catheter is inserted through the mouth of the parotid duct. The end of the catheter that appears in the wound is inserted into the proximal fragment of the excretory duct, the fragments of the duct are brought together and sutured using thin silk on an atraumatic needle. After this, the wound on the face is sutured layer by layer.