Submandibular Gland Excision
The submandibular glands are salivary glands located at the inferior border of the mandible with outflow ducts draining into the floor of mouth. They provide the majority of saliva production in the oral cavity at rest. Excision is performed via a cervical approach.
Indications for Surgery:
- Recurrent sialadenitis (infection of the submandibular gland)
- Obstruction of the submandibular duct due to salivary stones
- Sialorrhea (drooling)
- As part of a neck dissection, where the submandibular gland is often removed as part of level I in order to access the perifacial lymph nodes
- Submandibular gland tumors, which may include a neck dissection in some malignancies
Contraindications to Surgery:
- Medical comorbidities that would preclude surgical or anesthesia risk
- Ultrasound or computed tomography (CT) without contrast is useful in identifying salivary duct stones. Sialography is an alternative imaging modality for assessment of duct obstruction.
- Fine needle aspiration biopsy is performed for a discrete submandibular mass, as it has a 70% sensitivity rate for identifying salivary gland malignancy.
- Magnetic resonance imaging (MRI) gives the most information regarding the extent of submandibular tumors.
- The patient is placed supine on the operating table and general anesthesia is induced via endotracheal intubation.
- The head is rotated away from the side of the gland to be operated on.
- A transverse incision is marked in an existing skin crease at least 2 finger breadths inferior to the inferior border of the mandible. This is done to ensure that the marginal mandibular nerve is not injured by the incision. The incision begins near the midline and extends laterally to the anterior (medial) border of the sternocleidomastoid.
- A subplatysmal flap is elevated, exposing the sternocleidomastoid. This is raised directly onto the platysma in order to avoid damage to the marginal mandibular nerve.
- The submandibular gland is identified superior to the digastric muscle.
- The superficial layer of the deep cervical fascia, which overlies the gland, is incised near the inferior border of the gland, bringing the facial vein into view. If submandibular gland excision is performed for an inflammatory or benign process, the "Hayes-Martin" maneuver is performed, where the facial vein is ligated at the inferior border of the gland and retracted superiorly. Further dissection is performed deep to the vein in order to protect the marginal mandibular nerve, which lies superficial to the facial vein. If the gland is removed for a malignancy, or as part of a level I neck dissection, the nerve can be preserved by elevating the superficial layer of the deep cervical fascia superiorly from the submandibular gland, carrying the nerve with it in the process.
- Once the marginal mandibular nerve has been safely elevated away from the submandibular gland, the gland is fully exposed and retracted inferiorly with a clamp. The facial artery is ligated as it passes over the submandibular gland and the inferior border of the mandible.
- The anterior portion of the gland is mobilized, exposing the mylohyoid muscle. The posterior border of the mylohyoid is retracted anteriorly to expose the lingual nerve.The hypoglossal nerve may be seen inferiorly, deep to the digastric.
- The submandibular gland is separated from the lingual nerve by dividing the submandibular ganglion.
- The submandibular duct is traced anteriorly and transected. The facial artery is ligated again at the posterior aspect of the gland, completing the excision.
- The wound bed is irrigated and a drain is placed. The incision is then closed in layers.
- Care of the patient is returned to the anesthesiologist for extubation and recovery.
- The patient is admitted postoperatively.
- Diet may be started at clear liquids and advanced as tolerated, as long as the floor of mouth has not been entered.
- Drain output is monitored, and drains are removed when output has decreased sufficiently.
- The patient may be discharged after all drains have been removed. Alternatively, the patient may be discharged with the drain in place if taught drain care.
- Antibiotic ointment may be applied to the incision three times daily.
- Sutures or staples may be removed on postoperative day 5-7.
- Bleeding, hematoma, or seroma
- Wound infection
- Wound dehiscence or flap necrosis
- Injury to marginal mandibular nerve, resulting in weakness or paralysis of lower lip depressor
- Injury to lingual nerve, resulting in loss of tongue sensation and taste to one half of the tongue
- Injury to hypoglossal nerve resulting in paralysis of one half of the tongue