Comprehensive Guide to Submandibular Gland Excision for Surgeons

Introduction to Submandibular Gland Excision

Submandibular gland excision, also known as submandibular sialadenectomy, is a surgical procedure performed to remove the submandibular gland, one of the major salivary glands located beneath the lower jaw. This gland plays a critical role in the production of saliva, which is essential for digestion and oral hygiene. However, certain pathological conditions may necessitate its removal. This article provides an in-depth exploration of the procedure, covering indications, preoperative evaluation, contraindications, surgical techniques, postoperative care, complications, prognosis, and recent advances.

Indications for Submandibular Gland Excision

Submandibular gland excision is indicated in several clinical scenarios, including:

1. Chronic Sialadenitis: Persistent inflammation of the submandibular gland, often due to recurrent infections or obstruction by sialoliths (salivary stones), can lead to fibrosis and loss of gland function, necessitating removal.
2. Sialolithiasis: The presence of calculi within the salivary duct or gland can cause obstruction, leading to pain, swelling, and infection. When conservative treatments fail, excision of the gland may be required.
3. Neoplasms: Both benign and malignant tumors can develop in the submandibular gland. Pleomorphic adenoma is the most common benign tumor, while adenoid cystic carcinoma and mucoepidermoid carcinoma are the more common malignancies. Surgical excision is the definitive treatment for most tumors.
4. Mucocele or Ranula: These cystic lesions, caused by the rupture of the salivary gland duct, can become large and symptomatic. When involving the submandibular gland, excision may be necessary.
5. Autoimmune Diseases: Conditions like Sjögren's syndrome can lead to chronic inflammation and dysfunction of the submandibular gland, occasionally necessitating its removal.

Preoperative Evaluation

A thorough preoperative evaluation is crucial for planning a submandibular gland excision. This includes:

1. Patient History and Physical Examination: Detailed history taking is essential, focusing on symptoms such as pain, swelling, and recurrent infections. Physical examination should include palpation of the gland and surrounding structures.
2. Imaging Studies:
   • Ultrasound: Often the first imaging modality used, it helps in evaluating the size, structure, and presence of any masses or calculi.
   • CT Scan or MRI: These provide detailed images of the gland and surrounding tissues, particularly useful in assessing the extent of tumors or deep-seated stones.
   • Sialography: An imaging technique where contrast is injected into the salivary duct, useful in visualizing ductal structures and identifying obstructions.
3. Fine-Needle Aspiration Biopsy (FNAB): If a mass is detected, FNAB can help determine the nature of the lesion, distinguishing between benign and malignant tumors.
4. Laboratory Tests: Blood tests, including complete blood count and serum markers, may be ordered to assess the patient’s general health and readiness for surgery.
5. Preoperative Counseling: Patients should be informed about the procedure, potential risks, benefits, and expected outcomes. This includes discussing possible complications such as nerve injury or scarring.

Contraindications

While submandibular gland excision is a generally safe procedure, there are certain contraindications, including:

1. Uncontrolled Coagulopathies: Patients with bleeding disorders that cannot be corrected preoperatively are at high risk of intraoperative bleeding.
2. Severe Comorbidities: Patients with significant cardiac, pulmonary, or other systemic diseases may not tolerate anesthesia or surgery well.
3. Infection: Acute infections in the area may require deferral of surgery until the infection is resolved.
4. Patient Refusal: A patient who declines the surgery after understanding the risks and benefits cannot be compelled to undergo the procedure.

Surgical Techniques and Steps

The technique for submandibular gland excision involves several meticulous steps:

1. Anesthesia: General anesthesia is commonly used, although local anesthesia with sedation may be considered in select cases.
2. Patient Positioning: The patient is placed in a supine position with the neck slightly extended to expose the submandibular region.
3. Incision: A horizontal incision is made approximately 2-3 cm below the mandible in a natural skin crease to minimize visible scarring. The incision is usually 4-6 cm long, depending on the size of the gland.
4. Dissection:
   • Skin Flap Elevation: The skin and subcutaneous tissue are carefully elevated to expose the platysma muscle, which is then incised to reveal the submandibular gland.
   • Identification of Marginal Mandibular Nerve: This nerve, which controls the muscles of the lower lip, must be carefully preserved during the dissection. It is typically located superior to the gland.
   • Gland Exposure: The gland is dissected free from surrounding tissues, taking care to preserve the facial artery and vein.
5. Division of Duct and Vessels:
   • The Wharton’s duct is identified, ligated, and divided. The gland is then mobilized and its blood supply, primarily from the facial artery, is ligated.
   • The gland is removed in toto, with careful attention to any surrounding structures, including the hypoglossal and lingual nerves, which must be preserved.
6. Wound Closure: Hemostasis is achieved, and a drain may be placed to prevent hematoma formation. The platysma and skin are then closed in layers with absorbable sutures.

Postoperative Care

Postoperative management is critical to ensure successful outcomes and minimize complications:

1. Monitoring: Patients should be closely monitored in the recovery room for any signs of airway compromise or bleeding.
2. Pain Management: Analgesics are administered to manage postoperative pain. NSAIDs and acetaminophen are commonly used, with opioids reserved for more severe pain.
3. Drain Management: If a drain is placed, it is usually removed within 24-48 hours, depending on the amount of drainage.
4. Wound Care: The surgical site should be kept clean and dry. Stitches are typically removed within 7-10 days if non-absorbable sutures are used.
5. Diet: Patients are encouraged to start with a soft diet, gradually advancing as tolerated. Adequate hydration is essential.
6. Follow-Up: Regular follow-up is necessary to monitor for complications, ensure wound healing, and assess the patient’s overall recovery.

Possible Complications

As with any surgical procedure, submandibular gland excision carries risks. Potential complications include:

1. Nerve Injury: The marginal mandibular nerve is at risk during dissection, and injury can lead to temporary or permanent lower lip weakness. The lingual and hypoglossal nerves are also at risk, potentially resulting in tongue numbness or weakness.
2. Hemorrhage: Bleeding can occur intraoperatively or postoperatively, particularly from the facial artery or vein.
3. Infection: Wound infections are possible, though uncommon. They are usually managed with antibiotics.
4. Salivary Fistula: Leakage of saliva from the wound can occur if the Wharton’s duct is not properly ligated. This usually resolves with conservative management.
5. Hematoma: Accumulation of blood under the skin flap may necessitate drainage to prevent wound complications.
6. Scarring: While efforts are made to minimize scarring, some patients may develop hypertrophic or keloid scars.

Different Techniques

While the standard approach to submandibular gland excision has been described, variations exist:

1. Transoral Approach: In select cases, particularly when the gland is small or the patient desires minimal external scarring, a transoral approach may be used. This technique is more technically demanding and carries a higher risk of nerve injury.
2. Endoscopic-Assisted Approach: Endoscopic techniques have been explored to minimize scarring and improve visualization. However, this approach is not widely adopted and is generally reserved for specialized centers.
3. Robotic Surgery: Robotic-assisted submandibular gland excision is an emerging technique that allows for precision in dissection and potentially reduces nerve injury. However, it requires specialized equipment and training.

Prognosis and Outcome

The prognosis following submandibular gland excision is generally excellent, especially when performed for benign conditions. Most patients experience significant relief from symptoms, such as pain and swelling, with minimal long-term complications. In cases of malignancy, the outcome depends on the tumor type, stage, and completeness of excision. Adjuvant therapy, such as radiation, may be required in some cases.

Alternative Options

In some cases, alternatives to submandibular gland excision may be considered:

1. Conservative Management: For mild sialadenitis or small sialoliths, conservative measures such as hydration, massage, sialogogues, and antibiotics may suffice.
2. Sialendoscopy: This minimally invasive technique allows for the retrieval of stones or dilation of strictures within the duct, potentially avoiding the need for gland excision.
3. Radiotherapy: In inoperable malignant cases, radiotherapy may be considered as a palliative measure.
4. Botulinum Toxin Injection: For patients with sialorrhea (excessive salivation) or recurrent sialadenitis, Botox injections into the gland can reduce saliva production and alleviate symptoms.

Average Cost

The cost of submandibular gland excision varies depending on the region, the complexity of the case, and the healthcare facility. In the United States, the cost can range from $5,000 to $15,000, including surgeon’s fees, anesthesia, and hospital charges. Costs may be lower in other countries or higher in specialized centers offering advanced techniques like robotic surgery.

Recent Advances

Recent advances in submandibular gland surgery focus on minimizing complications and improving cosmetic outcomes:

1. Robotic Surgery: As mentioned, robotic techniques are being refined to offer better precision and nerve preservation.
2. Sialendoscopy: Advances in sialendoscopic equipment and techniques are allowing for less invasive management of submandibular gland disorders, potentially reducing the need for excision.
3. Molecular Targeting: In cases of malignancy, molecular targeting and personalized medicine are being explored to improve outcomes in conjunction with surgical excision.

Conclusion

Submandibular gland excision remains a vital surgical procedure in the management of various salivary gland disorders. With proper patient selection, meticulous surgical technique, and vigilant postoperative care, the outcomes are generally favorable. Surgeons must stay abreast of the latest advancements and alternative techniques to provide the best care for their patients.