Residency · Residency · Otolaryngology
Sialolithiasis and Obstructive Salivary Disease
Introduction
Sialolithiasis (salivary gland stones) is the most common cause of obstructive salivary gland disease, accounting for approximately 50% of major salivary gland disorders. The condition predominantly affects the submandibular gland due to its anatomic and physiologic characteristics. The advent of sland-preserving techniques, including sialendoscopy, has transformed management away from routine gland excision.
Pathophysiology
Salivary calculi are composed of calcium phosphate and hydroxyapatite in an organic matrix. Stone formation is multifactorial: salivary stasis, altered saliva composition, ductal inflammation, and microliths acting as nidus. Submandibular gland is affected in 80-90% of cases due to: Longer, wider duct with an antigravity course. More alkaline, mucin-rich saliva with higher calcium and phosphate concentrations. Dependent position of the gland. Parotid gland: 10-20% of cases; sublingual and minor glands: rare.
Clinical Presentation
Recurrent, meal-related swelling of the affected gland (postprandial swelling). Pain and tenderness, exacerbated by eating (especially sour/acidic foods). Bimanual palpation may reveal a stone in the floor of mouth (submandibular) or buccal mucosa (parotid). Purulent discharge from the duct orifice if secondary infection (sialadenitis). Chronic obstruction may lead to gland atrophy and fibrosis.
Diagnostic Workup
Imaging
Ultrasound: first-line imaging; sensitivity 70-90% for stones >2 mm; identifies gland enlargement and ductal dilation. CT without contrast: excellent for calcified stones; identifies location within the duct or hilum. Cone beam CT (CBCT): high resolution for stone localization. MR sialography: noninvasive evaluation of the ductal system; identifies strictures and non-calcified stones. Conventional sialography: largely replaced by noninvasive modalities; contraindicated in acute infection. Sialendoscopy: both diagnostic and therapeutic; direct visualization of the ductal lumen.
Classification
By Location
Distal (anterior) duct stones: accessible transorally. Proximal (hilar) stones: near the gland parenchyma; more challenging. Intraglandular stones: within the gland substance.
By Size
Small (<5 mm): amenable to sialendoscopy. Medium (5-10 mm): combined approach (sialendoscopy-assisted transoral). Large (>10 mm): often require gland excision or open duct surgery.
Management
| Approach | Indications | Success Rate | Key Details |
|---|---|---|---|
| Conservative | Small stones, acute episode | Variable (spontaneous passage) | Hydration, sialagogues, massage |
| Transoral removal | Distal submandibular duct stones, palpable | >90% | Intraoral ductotomy |
| Sialendoscopy | Stones <5 mm, strictures | 80-90% | Gland-preserving, diagnostic + therapeutic |
| ESWL | Parotid stones 5-10 mm | 50-70% | Multiple sessions, combined with endoscopy |
| Gland excision | Failed minimally invasive, neoplasm | Definitive | Submandibular excision or parotidectomy |
Conservative Management
Hydration, sialagogues (sour candies, lemon drops), warm compresses, gland massage. Antibiotics if secondary infection (amoxicillin-clavulanate or clindamycin). May be sufficient for small stones that pass spontaneously.
Transoral Stone Removal
For distal submandibular duct stones that are palpable in the floor of mouth. Intraoral incision over the stone, longitudinal ductotomy, stone extraction. Marsupialization of the duct or primary closure.
Sialendoscopy
Minimally invasive endoscopic technique using miniature scopes (0.8-1.6 mm). Diagnostic and therapeutic: direct visualization, stone fragmentation (laser lithotripsy), basket extraction, balloon dilation of strictures. Success rate: 80-90% for stones <5 mm. Gland preservation rate >95%. Can be combined with transoral approach for larger or hilar stones (combined approach).
Extracorporeal Shock Wave Lithotripsy (ESWL)
Fragments stones into smaller pieces that can pass spontaneously or be retrieved endoscopically. Best for parotid stones 5-10 mm, Multiple sessions often required.
Gland Excision
Reserved for failed conservative/minimally invasive management, recurrent sialadenitis with gland destruction, or suspicion of neoplasm. Submandibular gland excision or parotidectomy.
Complications of Untreated Obstruction
Acute suppurative sialadenitis: painful swelling, purulent discharge, fever. Abscess formation: may require I&D. Chronic sialadenitis: gland fibrosis and atrophy. Ranula formation: mucocele from sublingual gland obstruction or ductal injury.
Key Clinical Pearls
Meal-related swelling is the hallmark symptom of salivary duct obstruction. The submandibular gland is affected in 80-90% of sialolithiasis cases due to its anatomy and saliva composition. Sialendoscopy has dramatically reduced the need for gland excision; it is both diagnostic and therapeutic. Always rule out a salivary neoplasm in patients with persistent gland swelling without clear obstruction. The lingual nerve courses in close proximity to Wharton duct and must be protected during transoral duct surgery.
References
- Marchal F, Dulguerov P. Sialolithiasis management: the state of the art. Arch Otolaryngol Head Neck Surg. 2003;129(9):951-956.
- Koch M, Zenk J, Iro H. Algorithms for treatment of salivary gland obstructions. Otolaryngol Clin North Am. 2009;42(6):1173-1192.
- Strychowsky JE, Sommer DD, Guber I, et al. Sialendoscopy for the management of obstructive salivary gland disease: a systematic review and meta-analysis. Arch Otolaryngol Head Neck Surg. 2012;138(6):541-547.
- Walvekar RR, Carrau RL, Schaitkin B. Sialendoscopy: minimally invasive approach to the salivary ductal system. Op Tech Otolaryngol. 2009;20(2):131-137.