Salivary Gland Surgical Management Notes

Salivary Gland Structure

  • Three major pairs: parotid, submandibular, sublingual.
  • Surgeon's perspective: understanding anatomical relationships to vital structures (nerves, vasculature).

Parotid Gland

  • Superficial and deep lobes divided by the facial nerve.
  • Facial nerve branches: temporal, zygomatic, buccal, marginal mandibular, cervical.
  • Stenson's duct: Exits anteriorly, associated with the buccal branch of the facial nerve, and opens near the maxillary second molar.
  • Arterial supply: Branch of the external carotid.
  • Venous drainage: Retromandibular vein.
  • Contains lymph nodes.
  • Parasympathetic innervation: Inferior salivatory nucleus via otic ganglion and auriculotemporal nerve.
  • Sympathetic supply: From branches of external carotid.

Submandibular Gland

  • Located in the submandibular triangle.
  • No lymph nodes within the gland itself.
  • Lingual nerve closely associated with the submandibular duct; hypoglossal nerve lies medial to the gland.
  • Marginal mandibular branch of the facial nerve is superficial to the gland.
  • Submandibular duct (Wharton's duct): Curves around the mylohyoid muscle to enter the floor of the mouth.
  • Parasympathetic innervation: Superior salivatory nucleus via cauda tympani and lingual nerve.
  • Sympathetic supply: Branches of the external carotid artery.

Sublingual Glands

  • No capsule; located in the floor of the mouth.
  • Drain directly into the floor of the mouth through multiple small ducts.

Minor Salivary Glands

  • Distributed throughout the oral cavity except for the dorsum of the tongue and attached gingiva.
  • Estimated 500-1000 glands.

Salivary Gland Development

  • Arise from the primitive ectoderm of the stomatodeum.
  • Mature gland may contain mucus, serous, and seromucous acinar secretory cells.
  • Contractile myoepithelial cells aid saliva transport.
  • Secretory fluids enter intercalated ducts and progress to striated ducts and then extra lobular ducts, which converge into the major salivary excretory duct.

Salivary Gland Surgical Sieve

  • Congenital/acquired, neoplastic, iatrogenic, chemical, and radiation.
  • Developmental: aplasia, agenesis, atresia, hypoplasia, congenital fistula, accessory ducts/lobes, heterotopic salivary gland tissue, vascular malformations.
  • Acquired/traumatic: salivary fistula, Frey's syndrome, extravasation cysts, ranula.
  • Inflammatory/infective: Viral (hepatitis C, coxsackie, CMV, EBV), bacterial (acute suppurative sialadenitis), chronic (secondary to obstruction), specific infections (actinomycosis, TB, toxoplasmosis, syphilis).
  • Other acquired: Autoimmune, allergies, radiotherapy, retention/extravasation cysts, psychogenic disorders, drug-related.
  • Neoplasia: Adenomas (pleomorphic, monomorphic), mucoepidermoid tumors, vascular malformations; carcinomas (adenocarcinoma, adenoid cystic, mucoepidermoid, squamous cell), lymphoma.

Reactive Lesions

  • Due to obstruction or trauma.

Mucocele (Mucus Extravasation Lesion)

  • Trauma to minor salivary gland excretory ducts.
  • Retention of saliva in surrounding tissues (false cyst).
  • Mainly occurs in the lower lip.
  • Painless, smooth, round/oval, fluctuant swelling with normal or bluish color.
  • Treatment: Surgical excision with removal of the underlying gland.

Mucus Retention Cyst (True Mucocele/Siala Cyst)

  • Obstruction of salivary gland excretory duct resulting in an epithelial-lined cavity.
  • Less common than extravasation cyst; more common in the upper lip.
  • Treatment: Simple excision.

Ranula

  • Extravasation/retention cyst of the sublingual/submandibular gland.
  • Translucent, soft, fluctuant swelling in the floor of mouth with normal/bluish hue.
  • May cause elevation of the tongue and problems with speech, chewing, swallowing.
  • Plunging ranula: Extends into the neck and may cause airway obstruction.
  • Treatment: Marsupialization, securing of the sublingual gland, or gland removal.

Sialolithiasis

  • Presence of salivary stones in a duct or parenchyma of a salivary gland.
  • 80% occur in the major salivary glands (submandibular > parotid > sublingual).
  • Thought to develop from a nidus of mucin, protein, and epithelial cells.
  • Symptoms: Pain and recurrent swelling, especially at meal times.

Diagnosis

  • History, clinical examination, and imaging (radiographs, ultrasound, sialography).

Treatment

  • Minor salivary gland stones: Surgical excision.
  • Submandibular stones: Manual palpation, surgical cut down, stay suture, duct incision, stone removal, silastic tube, retrograde basket retrieval, lithotripsy.