Types and Localization of Salivary Fistulas
Salivary gland fistulas differ in their localization and the nature of the injury.
Depending on the direction of the fistulous tract, the following are distinguished:
- Internal fistulas: open into the oral cavity along the excretory duct (often in the submandibular gland). They do not impair function and require no treatment.
- External fistulas: open onto the skin (most commonly affecting the parotid gland). Patients complain of constant saliva discharge, causing maceration and dermatitis. Blockage of such a fistula leads to swelling of the gland.
According to I.F. Romachyova's classification, fistulas are divided into:
- Complete: occur with a complete rupture of the duct. All saliva flows out through the fistula, and natural outflow is impossible.
- Incomplete: the result of a defect in the duct wall. Part of the saliva drains through the natural orifice, and part outward through the fistula.
Diagnostics of Fistulas and Strictures
Externally, a salivary fistula is characterized by the absence of protruding granulations and pronounced inflammation around it. The main complaint is salivation during meals.
To clarify the diagnosis, the following are used:
- Probing of the fistulous tract and duct.
- Injection of a dye into the duct orifice.
- Sialography (sialographia) — administration of a radiopaque contrast agent.
Differential diagnosis by sialogram: In an incomplete fistula, the contrast medium injected into the orifice flows out through the fistula, and vice versa. In a complete fistula, communication between the orifice and the fistula is completely absent: the contrast does not flow from one opening to another.
Narrowing (stricture) of the duct (usually of a cicatricial nature) is diagnosed by a characteristic pattern: swelling of the gland during meals, which slowly subsides. On the sialogram, the duct before the stricture is unchanged, and beyond it, uniformly dilated.
Duct Obliteration and Traumatic Cysts
Obliteration of the duct occurs after trauma. In the early stages, the gland swells and hurts during meals, and the pain subsides after a few hours. Months later, the gland becomes denser, saliva secretion stops, and eventually its function fades. Sialography shows filling only of the peripheral part of the duct.
Traumatic cyst forms 1–2 weeks after trauma. Patients often indicate a temporary effect from punctures. Objectively, it is a painless, soft mass. Puncture yields transparent saliva. The sialogram reveals a filling defect and displacement of the ducts.
Treatment
Conservative treatment is effective for incomplete fistulas. It includes suppressing salivation (atropine, belladonna tincture), chemical cauterization of the tract with acids or iodine, as well as radiation therapy with electrocoagulation. For incomplete fistulas, a mechanical obstacle to outflow through the fistula is also created, redirecting saliva into the natural duct.
Surgical treatment includes:
- K.P. Sapozhkov's method: excision of the fistula and placement of a purse-string suture.
- A.A. Limberg's method: excision of the tract and plastics with opposing triangular flaps. Used for incomplete fistulas and complete fistulas of small lobules.
- In case of parotid duct injury, its ends are sutured without narrowing the lumen, using a polyethylene catheter for 12 days or bougienage.
- For parenchymal wounds, layered closure, placement of plate sutures, and leaving a drain for 3–4 days are indicated, along with suppression of saliva secretion.
Briefly: answers to topical questions
What anatomical structures are part of the parotid gland and get damaged during injuries?
In the parotid salivary gland, a superficial part (pars superficialis), lying on the masseter muscle, and a deep part (pars profunda), extending into the retromandibular fossa, are distinguished. Structures passing through the thickness of the gland that may be injured during trauma include:
- parotid duct (ductus parotideus);
- external carotid artery (a. carotis externa) and its terminal branches;
- retromandibular vein (v. retromandibularis);
- facial nerve (n. facialis) with its branches forming the parotid plexus (plexus parotideus);
- auriculotemporal nerve (n. auriculotemporalis).
Class and exam questions
What is the difference between complete and incomplete salivary fistulas?
In a complete fistula, the duct is completely ruptured, and all saliva drains through the fistula. In an incomplete one, the wall is partially damaged, and saliva is secreted both through the fistula and through the natural orifice.
What symptoms are characteristic of excretory duct stricture?
The main symptom is swelling and bursting pain in the gland during meals due to the retention of actively secreted saliva. The swelling subsides after eating in early stages but becomes constant in the chronic course.
What will the sialogram show in case of duct obliteration?
Only the peripheral segment of the duct up to the site of complete obstruction will be filled with the contrast agent.
What else to study on this topic
- K.P. Sapozhkov's technique in salivary fistula surgery
- A.A. Limberg's method with transposition of opposing flaps
- Surgical management of gunshot wounds to the face with salivary gland damage
- Mechanisms of salivary duct stricture formation
- Technique of sialography and interpretation of results
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Other topics in the section "Chapter 10. Diseases and injuries of the salivary glands (V.V. Afanasiev)"
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