Parotid Gland Surgery

Parotid Gland Surgeries.

1. Extracapsular dissection (ECD)
2. Superficial parotidectomy
3. Total conservative parotidectomy.
4. Radical parotidectomy

 

1. Extracapsular dissection (ECD)

It is indicated for mobile lesions in the parotid tail and small, superficial tumours within the superficial lobe. It is not suitable for inflammatory lesions, large tumours, those extending into the deep lobe, or cases where malignancy is suspected. The procedure involves similar incision and skin flap elevation as in standard parotidectomy. The tumour is removed by developing a plane between its capsule and normal parotid tissue, without identifying the facial nerve. A nerve stimulator is used during dissection. If facial nerve position is unclear, partial parotidectomy with formal nerve identification is recommended.

 

2. Superficial Parotidectomy: The principle of surgery is to expose the facial nerve and then remove the superficial lobe of parotid gland and tumour around the facial nerve. Depending upon the extent of parotidectomy, it can be further divided into total superficial parotidectomy and partial superficial parotidectomy (the tumour and a cuff of normal tissue). Partial superficial parotidectomy is practised in the UK more commonly.

Steps of Superficial Parotidectomy:

1. Patient Positioning: Place the patient in the reverse Trendelenberg (head-up) position.
2. Incision: A Modified Blair incision in the preauricular crease extends inferiorly to the ear lobe, and then a circum-lobular incision is made around the ear lobule up to the mastoid tip. Then gently curving downwards from the mastoid tip along the sternocleidomastoid muscle and turning anteriorly into a natural neck crease, approximately two fingerbreadths below the angle of the mandible (at the hyoid bone level).
   
3. Haemostasis: Infiltrate the area with adrenaline (1:100,000) to reduce bleeding.
4. Raise Skin Flaps: Elevate skin flaps superficial to the parotid fascia, including the SMAS (superficial musculoaponeurotic system) layer. This thick flap reduces the risk of Frey’s syndrome in the postoperative period.
5. Mobilize Parotid Gland: Dissect the parotid gland from the tragal cartilage, sternocleidomastoid, and posterior belly of digastric muscles. At this time section the greater auricular nerve if necessary, preserving the posterior branch (provides sensory supply to ear lobule) when possible. Judicious use of traction will aid in the identification of the facial nerve. Avoid excessive traction to prevent capsule rupture and tumour spillage. If spillage occurs, it should be contained and excise the deeper tissues to reduce the risk of tumour seeding.
   
6. Facial Nerve Trunk Identification: Identify the facial nerve using anatomical landmarks:
   • Cartilaginous pointer (tragal pointer). The facial nerve lies 1 cm deep and slightly anterior and inferior to the pointer. Cartilaginous pointer is a sharp triangular piece of cartilage of the pinna and “points” to the nerve. The tragal pointer is slightly mobile when retracted so care must be taken when using this as a landmark.
   • Tympanomastoid suture. The nerve lies 6–8 mm deep to this suture. The facial nerve lies 6–8 mm deep to this suture. This groove is very easy to feel, and this is an extremely reliable landmark. The surgeon can get a ‘feel’ for where the nerve is expected to be.
   • Styloid process. The nerve crosses laterally to the styloid process. Whilst easy to palpate it lies deep to the exit of the nerve from the stylomastoid foramen so dissection onto the styloid may increase the risk of facial nerve damage
   • Anterior border of the posterior belly of the digastric muscle. If the posterior belly of digastric muscle is traced backwards along its upper border to its attachment to the digastric groove, the nerve is found to lie between it and the styloid process. The facial nerve leaves the stylomastoid foramen immediately anterior to the attachment of the muscle to the digastric groove.
     
7. Tumour Removal: Dissect the superficial lobe or relevant part of the parotid gland and tumour from the branches of facial nerve branches.
8. Haemostasis & Wound Closure: Achieve haemostasis and place a drain before closing the wound.

• 

Surgery For Recurrent, Soft or Large tumours. Identification of the facial nerve main trunk is difficult in such cases, it is better to locate a major branch of the facial nerve and do retrograde dissection.

• • Zygomatic and Temporal Branches: These cross the zygomatic arch anterior to, and within 1–2 cm of, the superficial temporal artery.
  • Marginal Mandibular Branch: It can be located at the angle of the mandible, superficial to the facial vessels.
  • Cervical Branch: It is located where it pierces the deep fascia below the body of the mandible.

 

3. Total conservative parotidectomy.

It is indicated for deep lobe tumours, malignant tumours, vascular malformations, or large tumours where involvement of the tumour between superficial and deep lobes is doubtful. It may also be necessary when tumour spillage occurs during superficial parotidectomy. Typically, the procedure begins with superficial parotidectomy, followed by mobilizing the facial nerve and developing a plane deep to the main nerve trunk. The tumour and any remaining parotid tissue are removed, often through extracapsular dissection. All facial nerve branches are carefully identified and preserved during the procedure. Haemostasis is achieved and drain is placed before closing the wound.

 

4. Radical parotidectomy

It is indicated when preoperative facial paralysis is already present in the patient or when a malignant tumour circumferentially involves the nerve. The procedure involves the removal of the entire parotid gland, including the facial nerve. In such cases, simultaneous nerve grafting or other facial reanimation procedures are typically employed to address the resulting facial nerve deficit.

 

Complications of Parotid Surgery

Before undergoing superficial or total conservative parotidectomy, patients should be informed and written consent should be taken about the following potential complications:

1. Facial Weakness: Temporary or permanent facial weakness may occur. Neuropraxia typically recovers in 4-6 weeks, while more severe injuries may take 6-12 months or may not fully recover.
2. Sensory Loss: Sensory loss around the mandible and ear lobule (due to greater auricular nerve damage) is common but often improves after 12 months. Preservation of the nerve’s posterior branch can help reduce this effect.
3. Cosmetic Defects: Incisions rarely cause major cosmetic concerns, but loss of bulk behind the mandible may be visible, especially in thin patients. Fat transfer can help mitigate this.
4. Frey’s Syndrome (Gustatory sweating or flushing): There is abnormal innervation of the sweat glands present in the skin by parasympathetic secretomotor fibres that were originally supplying the parotid gland to produce saliva. After parotid surgery, these fibres mistakenly stimulate sweating instead of causing salivary secretion from the parotid during meals. It usually manifests several months after the parotid surgery. It is characterized by sweating and flushing of the preauricular skin area during mastication causing social embarrassment to the person.
   Treatment options.

• • Tympanic neurectomy to intercept the parasympathetic fibres at the level of middle ear.
  • Placement of fascia lata between the skin and the underlying fat to prevent innervation of sweat glands.
  • Anti-perspirants application can be used.
  • Subcutaneous injections of botulinum toxin (repeated at 6–12 monthly intervals).
  • The risk of Frey’s syndrome can be reduced by elevation of skin flaps superficial to the parotid fascia, including the SMAS (superficial musculoaponeurotic system) layer during the surgery. This thick flap prevent secretomotor fibres reaching the sweat glands and reduces the risk of Frey’s syndrome in the postoperative period.
  • Use of interpositional flaps (e.g. sternomastoid) .
  • In many cases, simple reassurance is sufficient for treatment.

5. Sialocoele or Salivary Fistula: Except when we remove the complete gland in total conservative or radical parotidectomy, saliva leaks from the cut surface of the gland. It can also result from duct damage. The saliva can form a collection (sialocoele) or leak through the site of incision (fistula), typically within a few days post-surgery. Sialocoele can be quite tense and painful, especially during eating and may require repeated aspiration. Fistula need compressive dressing and strict wound hygiene. Antibiotics should be considered to prevent secondary infection. Both conditions usually resolve within 1–2 weeks. Hyoscine patches can reduce saliva production, and if conservative measures fail, ultrasound guided botulinum toxin can be injected into the main/residual parotid gland, which stops saliva production and reverses within 2–3 months.
6. Stump Neuroma: Painful neuromas may form after greater auricular nerve injury. It presents as a tender nodule just anterior to the sternomastoid muscle. Local excision of nodule and then burying the fresh nerve end in the muscle can prevent recurrence. Preservation of posterior branch of the greater auricular nerve may also reduce the risk of stump neuroma.
7. First Bite Syndrome: Intense pain in the parotid gland may occur before eating and subsides quickly after beginning to eat. It occurs as a result of sympathetic denervation of remaining parotid tissue. Treatment includes botulinum toxin injections into the parotid gland or medications like gabapentin or Pregabalin.
8. Trismus: Mild, transient inflammation of the masseter muscle is possible.

——– End of the chapter ——–

Learning resources.

• Scott-Brown, Textbook of Otorhinolaryngology-Head and Neck Surgery.
• Susan Standring, Gray’s Anatomy.
• Stell and Maran’s, Textbook of Head and Neck Surgery and Oncology
• Frank H. Netter, Atlas of Human Anatomy.
• B.D. Chaurasiya, Human Anatomy.
• P L Dhingra, Textbook of Diseases of Ear, Nose and Throat.
   

  Author:

Dr. Rahul Bagla
MBBS (MAMC, Delhi) MS ENT (UCMS, Delhi)
Fellow Rhinoplasty & Facial Plastic Surgery.
Renowned Teaching Faculty
Mail: msrahulbagla@gmail.com
India

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